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linux/arch/tile/include/gxio/mpipe.h

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/*
* Copyright 2012 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#ifndef _GXIO_MPIPE_H_
#define _GXIO_MPIPE_H_
/*
*
* An API for allocating, configuring, and manipulating mPIPE hardware
* resources.
*/
#include <gxio/common.h>
#include <gxio/dma_queue.h>
#include <linux/time.h>
#include <arch/mpipe_def.h>
#include <arch/mpipe_shm.h>
#include <hv/drv_mpipe_intf.h>
#include <hv/iorpc.h>
/*
*
* The TILE-Gx mPIPE&tm; shim provides Ethernet connectivity, packet
* classification, and packet load balancing services. The
* gxio_mpipe_ API, declared in <gxio/mpipe.h>, allows applications to
* allocate mPIPE IO channels, configure packet distribution
* parameters, and send and receive Ethernet packets. The API is
* designed to be a minimal wrapper around the mPIPE hardware, making
* system calls only where necessary to preserve inter-process
* protection guarantees.
*
* The APIs described below allow the programmer to allocate and
* configure mPIPE resources. As described below, the mPIPE is a
* single shared hardware device that provides partitionable resources
* that are shared between all applications in the system. The
* gxio_mpipe_ API allows userspace code to make resource request
* calls to the hypervisor, which in turns keeps track of the
* resources in use by all applications, maintains protection
* guarantees, and resets resources upon application shutdown.
*
* We strongly recommend reading the mPIPE section of the IO Device
* Guide (UG404) before working with this API. Most functions in the
* gxio_mpipe_ API are directly analogous to hardware interfaces and
* the documentation assumes that the reader understands those
* hardware interfaces.
*
* @section mpipe__ingress mPIPE Ingress Hardware Resources
*
* The mPIPE ingress hardware provides extensive hardware offload for
* tasks like packet header parsing, load balancing, and memory
* management. This section provides a brief introduction to the
* hardware components and the gxio_mpipe_ calls used to manage them;
* see the IO Device Guide for a much more detailed description of the
* mPIPE's capabilities.
*
* When a packet arrives at one of the mPIPE's Ethernet MACs, it is
* assigned a channel number indicating which MAC received it. It
* then proceeds through the following hardware pipeline:
*
* @subsection mpipe__classification Classification
*
* A set of classification processors run header parsing code on each
* incoming packet, extracting information including the destination
* MAC address, VLAN, Ethernet type, and five-tuple hash. Some of
* this information is then used to choose which buffer stack will be
* used to hold the packet, and which bucket will be used by the load
* balancer to determine which application will receive the packet.
*
* The rules by which the buffer stack and bucket are chosen can be
* configured via the @ref gxio_mpipe_classifier API. A given app can
* specify multiple rules, each one specifying a bucket range, and a
* set of buffer stacks, to be used for packets matching the rule.
* Each rule can optionally specify a restricted set of channels,
* VLANs, and/or dMACs, in which it is interested. By default, a
* given rule starts out matching all channels associated with the
* mPIPE context's set of open links; all VLANs; and all dMACs.
* Subsequent restrictions can then be added.
*
* @subsection mpipe__load_balancing Load Balancing
*
* The mPIPE load balancer is responsible for choosing the NotifRing
* to which the packet will be delivered. This decision is based on
* the bucket number indicated by the classification program. In
* general, the bucket number is based on some number of low bits of
* the packet's flow hash (applications that aren't interested in flow
* hashing use a single bucket). Each load balancer bucket keeps a
* record of the NotifRing to which packets directed to that bucket
* are currently being delivered. Based on the bucket's load
* balancing mode (@ref gxio_mpipe_bucket_mode_t), the load balancer
* either forwards the packet to the previously assigned NotifRing or
* decides to choose a new NotifRing. If a new NotifRing is required,
* the load balancer chooses the least loaded ring in the NotifGroup
* associated with the bucket.
*
* The load balancer is a shared resource. Each application needs to
* explicitly allocate NotifRings, NotifGroups, and buckets, using
* gxio_mpipe_alloc_notif_rings(), gxio_mpipe_alloc_notif_groups(),
* and gxio_mpipe_alloc_buckets(). Then the application needs to
* configure them using gxio_mpipe_init_notif_ring() and
* gxio_mpipe_init_notif_group_and_buckets().
*
* @subsection mpipe__buffers Buffer Selection and Packet Delivery
*
* Once the load balancer has chosen the destination NotifRing, the
* mPIPE DMA engine pops at least one buffer off of the 'buffer stack'
* chosen by the classification program and DMAs the packet data into
* that buffer. Each buffer stack provides a hardware-accelerated
* stack of data buffers with the same size. If the packet data is
* larger than the buffers provided by the chosen buffer stack, the
* mPIPE hardware pops off multiple buffers and chains the packet data
* through a multi-buffer linked list. Once the packet data is
* delivered to the buffer(s), the mPIPE hardware writes the
* ::gxio_mpipe_idesc_t metadata object (calculated by the classifier)
* into the NotifRing and increments the number of packets delivered
* to that ring.
*
* Applications can push buffers onto a buffer stack by calling
* gxio_mpipe_push_buffer() or by egressing a packet with the
* ::gxio_mpipe_edesc_t::hwb bit set, indicating that the egressed
* buffers should be returned to the stack.
*
* Applications can allocate and initialize buffer stacks with the
* gxio_mpipe_alloc_buffer_stacks() and gxio_mpipe_init_buffer_stack()
* APIs.
*
* The application must also register the memory pages that will hold
* packets. This requires calling gxio_mpipe_register_page() for each
* memory page that will hold packets allocated by the application for
* a given buffer stack. Since each buffer stack is limited to 16
* registered pages, it may be necessary to use huge pages, or even
* extremely huge pages, to hold all the buffers.
*
* @subsection mpipe__iqueue NotifRings
*
* Each NotifRing is a region of shared memory, allocated by the
* application, to which the mPIPE delivers packet descriptors
* (::gxio_mpipe_idesc_t). The application can allocate them via
* gxio_mpipe_alloc_notif_rings(). The application can then either
* explicitly initialize them with gxio_mpipe_init_notif_ring() and
* then read from them manually, or can make use of the convenience
* wrappers provided by @ref gxio_mpipe_wrappers.
*
* @section mpipe__egress mPIPE Egress Hardware
*
* Applications use eDMA rings to queue packets for egress. The
* application can allocate them via gxio_mpipe_alloc_edma_rings().
* The application can then either explicitly initialize them with
* gxio_mpipe_init_edma_ring() and then write to them manually, or
* can make use of the convenience wrappers provided by
* @ref gxio_mpipe_wrappers.
*
* @section gxio__shortcomings Plans for Future API Revisions
*
* The API defined here is only an initial version of the mPIPE API.
* Future plans include:
*
* - Higher level wrapper functions to provide common initialization
* patterns. This should help users start writing mPIPE programs
* without having to learn the details of the hardware.
*
* - Support for reset and deallocation of resources, including
* cleanup upon application shutdown.
*
* - Support for calling these APIs in the BME.
*
* - Support for IO interrupts.
*
* - Clearer definitions of thread safety guarantees.
*
* @section gxio__mpipe_examples Examples
*
* See the following mPIPE example programs for more information about
* allocating mPIPE resources and using them in real applications:
*
* - @ref mpipe/ingress/app.c : Receiving packets.
*
* - @ref mpipe/forward/app.c : Forwarding packets.
*
* Note that there are several more examples.
*/
/* Flags that can be passed to resource allocation functions. */
enum gxio_mpipe_alloc_flags_e {
/* Require an allocation to start at a specified resource index. */
GXIO_MPIPE_ALLOC_FIXED = HV_MPIPE_ALLOC_FIXED,
};
/* Flags that can be passed to memory registration functions. */
enum gxio_mpipe_mem_flags_e {
/* Do not fill L3 when writing, and invalidate lines upon egress. */
GXIO_MPIPE_MEM_FLAG_NT_HINT = IORPC_MEM_BUFFER_FLAG_NT_HINT,
/* L3 cache fills should only populate IO cache ways. */
GXIO_MPIPE_MEM_FLAG_IO_PIN = IORPC_MEM_BUFFER_FLAG_IO_PIN,
};
/* An ingress packet descriptor. When a packet arrives, the mPIPE
* hardware generates this structure and writes it into a NotifRing.
*/
typedef MPIPE_PDESC_t gxio_mpipe_idesc_t;
/* An egress command descriptor. Applications write this structure
* into eDMA rings and the hardware performs the indicated operation
* (normally involving egressing some bytes). Note that egressing a
* single packet may involve multiple egress command descriptors.
*/
typedef MPIPE_EDMA_DESC_t gxio_mpipe_edesc_t;
/*
* Max # of mpipe instances. 2 currently.
*/
#define GXIO_MPIPE_INSTANCE_MAX HV_MPIPE_INSTANCE_MAX
#define NR_MPIPE_MAX GXIO_MPIPE_INSTANCE_MAX
/* Get the "va" field from an "idesc".
*
* This is the address at which the ingress hardware copied the first
* byte of the packet.
*
* If the classifier detected a custom header, then this will point to
* the custom header, and gxio_mpipe_idesc_get_l2_start() will point
* to the actual L2 header.
*
* Note that this value may be misleading if "idesc->be" is set.
*
* @param idesc An ingress packet descriptor.
*/
static inline unsigned char *gxio_mpipe_idesc_get_va(gxio_mpipe_idesc_t *idesc)
{
return (unsigned char *)(long)idesc->va;
}
/* Get the "xfer_size" from an "idesc".
*
* This is the actual number of packet bytes transferred into memory
* by the hardware.
*
* Note that this value may be misleading if "idesc->be" is set.
*
* @param idesc An ingress packet descriptor.
*
* ISSUE: Is this the best name for this?
* FIXME: Add more docs about chaining, clipping, etc.
*/
static inline unsigned int gxio_mpipe_idesc_get_xfer_size(gxio_mpipe_idesc_t
*idesc)
{
return idesc->l2_size;
}
/* Get the "l2_offset" from an "idesc".
*
* Extremely customized classifiers might not support this function.
*
* This is the number of bytes between the "va" and the L2 header.
*
* The L2 header consists of a destination mac address, a source mac
* address, and an initial ethertype. Various initial ethertypes
* allow encoding extra information in the L2 header, often including
* a vlan, and/or a new ethertype.
*
* Note that the "l2_offset" will be non-zero if (and only if) the
* classifier processed a custom header for the packet.
*
* @param idesc An ingress packet descriptor.
*/
static inline uint8_t gxio_mpipe_idesc_get_l2_offset(gxio_mpipe_idesc_t *idesc)
{
return (idesc->custom1 >> 32) & 0xFF;
}
/* Get the "l2_start" from an "idesc".
*
* This is simply gxio_mpipe_idesc_get_va() plus
* gxio_mpipe_idesc_get_l2_offset().
*
* @param idesc An ingress packet descriptor.
*/
static inline unsigned char *gxio_mpipe_idesc_get_l2_start(gxio_mpipe_idesc_t
*idesc)
{
unsigned char *va = gxio_mpipe_idesc_get_va(idesc);
return va + gxio_mpipe_idesc_get_l2_offset(idesc);
}
/* Get the "l2_length" from an "idesc".
*
* This is simply gxio_mpipe_idesc_get_xfer_size() minus
* gxio_mpipe_idesc_get_l2_offset().
*
* @param idesc An ingress packet descriptor.
*/
static inline unsigned int gxio_mpipe_idesc_get_l2_length(gxio_mpipe_idesc_t
*idesc)
{
unsigned int xfer_size = idesc->l2_size;
return xfer_size - gxio_mpipe_idesc_get_l2_offset(idesc);
}
/* A context object used to manage mPIPE hardware resources. */
typedef struct {
/* File descriptor for calling up to Linux (and thus the HV). */
int fd;
/* Corresponding mpipe instance #. */
int instance;
/* The VA at which configuration registers are mapped. */
char *mmio_cfg_base;
/* The VA at which IDMA, EDMA, and buffer manager are mapped. */
char *mmio_fast_base;
/* The "initialized" buffer stacks. */
gxio_mpipe_rules_stacks_t __stacks;
} gxio_mpipe_context_t;
/* This is only used internally, but it's most easily made visible here. */
typedef gxio_mpipe_context_t gxio_mpipe_info_context_t;
/* Initialize an mPIPE context.
*
* This function allocates an mPIPE "service domain" and maps the MMIO
* registers into the caller's VA space.
*
* @param context Context object to be initialized.
* @param mpipe_instance Instance number of mPIPE shim to be controlled via
* context.
*/
extern int gxio_mpipe_init(gxio_mpipe_context_t *context,
unsigned int mpipe_instance);
/* Destroy an mPIPE context.
*
* This function frees the mPIPE "service domain" and unmaps the MMIO
* registers from the caller's VA space.
*
* If a user process exits without calling this routine, the kernel
* will destroy the mPIPE context as part of process teardown.
*
* @param context Context object to be destroyed.
*/
extern int gxio_mpipe_destroy(gxio_mpipe_context_t *context);
/*****************************************************************
* Buffer Stacks *
******************************************************************/
/* Allocate a set of buffer stacks.
*
* The return value is NOT interesting if count is zero.
*
* @param context An initialized mPIPE context.
* @param count Number of stacks required.
* @param first Index of first stack if ::GXIO_MPIPE_ALLOC_FIXED flag is set,
* otherwise ignored.
* @param flags Flag bits from ::gxio_mpipe_alloc_flags_e.
* @return Index of first allocated buffer stack, or
* ::GXIO_MPIPE_ERR_NO_BUFFER_STACK if allocation failed.
*/
extern int gxio_mpipe_alloc_buffer_stacks(gxio_mpipe_context_t *context,
unsigned int count,
unsigned int first,
unsigned int flags);
/* Enum codes for buffer sizes supported by mPIPE. */
typedef enum {
/* 128 byte packet data buffer. */
GXIO_MPIPE_BUFFER_SIZE_128 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_128,
/* 256 byte packet data buffer. */
GXIO_MPIPE_BUFFER_SIZE_256 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_256,
/* 512 byte packet data buffer. */
GXIO_MPIPE_BUFFER_SIZE_512 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_512,
/* 1024 byte packet data buffer. */
GXIO_MPIPE_BUFFER_SIZE_1024 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_1024,
/* 1664 byte packet data buffer. */
GXIO_MPIPE_BUFFER_SIZE_1664 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_1664,
/* 4096 byte packet data buffer. */
GXIO_MPIPE_BUFFER_SIZE_4096 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_4096,
/* 10368 byte packet data buffer. */
GXIO_MPIPE_BUFFER_SIZE_10368 =
MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_10368,
/* 16384 byte packet data buffer. */
GXIO_MPIPE_BUFFER_SIZE_16384 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_16384
} gxio_mpipe_buffer_size_enum_t;
/* Convert a buffer size in bytes into a buffer size enum. */
extern gxio_mpipe_buffer_size_enum_t
gxio_mpipe_buffer_size_to_buffer_size_enum(size_t size);
/* Convert a buffer size enum into a buffer size in bytes. */
extern size_t
gxio_mpipe_buffer_size_enum_to_buffer_size(gxio_mpipe_buffer_size_enum_t
buffer_size_enum);
/* Calculate the number of bytes required to store a given number of
* buffers in the memory registered with a buffer stack via
* gxio_mpipe_init_buffer_stack().
*/
extern size_t gxio_mpipe_calc_buffer_stack_bytes(unsigned long buffers);
/* Initialize a buffer stack. This function binds a region of memory
* to be used by the hardware for storing buffer addresses pushed via
* gxio_mpipe_push_buffer() or as the result of sending a buffer out
* the egress with the 'push to stack when done' bit set. Once this
* function returns, the memory region's contents may be arbitrarily
* modified by the hardware at any time and software should not access
* the memory region again.
*
* @param context An initialized mPIPE context.
* @param stack The buffer stack index.
* @param buffer_size_enum The size of each buffer in the buffer stack,
* as an enum.
* @param mem The address of the buffer stack. This memory must be
* physically contiguous and aligned to a 64kB boundary.
* @param mem_size The size of the buffer stack, in bytes.
* @param mem_flags ::gxio_mpipe_mem_flags_e memory flags.
* @return Zero on success, ::GXIO_MPIPE_ERR_INVAL_BUFFER_SIZE if
* buffer_size_enum is invalid, ::GXIO_MPIPE_ERR_BAD_BUFFER_STACK if
* stack has not been allocated.
*/
extern int gxio_mpipe_init_buffer_stack(gxio_mpipe_context_t *context,
unsigned int stack,
gxio_mpipe_buffer_size_enum_t
buffer_size_enum, void *mem,
size_t mem_size,
unsigned int mem_flags);
/* Push a buffer onto a previously initialized buffer stack.
*
* The size of the buffer being pushed must match the size that was
* registered with gxio_mpipe_init_buffer_stack(). All packet buffer
* addresses are 128-byte aligned; the low 7 bits of the specified
* buffer address will be ignored.
*
* @param context An initialized mPIPE context.
* @param stack The buffer stack index.
* @param buffer The buffer (the low seven bits are ignored).
*/
static inline void gxio_mpipe_push_buffer(gxio_mpipe_context_t *context,
unsigned int stack, void *buffer)
{
MPIPE_BSM_REGION_ADDR_t offset = { {0} };
MPIPE_BSM_REGION_VAL_t val = { {0} };
/*
* The mmio_fast_base region starts at the IDMA region, so subtract
* off that initial offset.
*/
offset.region =
MPIPE_MMIO_ADDR__REGION_VAL_BSM -
MPIPE_MMIO_ADDR__REGION_VAL_IDMA;
offset.stack = stack;
#if __SIZEOF_POINTER__ == 4
val.va = ((ulong) buffer) >> MPIPE_BSM_REGION_VAL__VA_SHIFT;
#else
val.va = ((long)buffer) >> MPIPE_BSM_REGION_VAL__VA_SHIFT;
#endif
__gxio_mmio_write(context->mmio_fast_base + offset.word, val.word);
}
/* Pop a buffer off of a previously initialized buffer stack.
*
* @param context An initialized mPIPE context.
* @param stack The buffer stack index.
* @return The buffer, or NULL if the stack is empty.
*/
static inline void *gxio_mpipe_pop_buffer(gxio_mpipe_context_t *context,
unsigned int stack)
{
MPIPE_BSM_REGION_ADDR_t offset = { {0} };
/*
* The mmio_fast_base region starts at the IDMA region, so subtract
* off that initial offset.
*/
offset.region =
MPIPE_MMIO_ADDR__REGION_VAL_BSM -
MPIPE_MMIO_ADDR__REGION_VAL_IDMA;
offset.stack = stack;
while (1) {
/*
* Case 1: val.c == ..._UNCHAINED, va is non-zero.
* Case 2: val.c == ..._INVALID, va is zero.
* Case 3: val.c == ..._NOT_RDY, va is zero.
*/
MPIPE_BSM_REGION_VAL_t val;
val.word =
__gxio_mmio_read(context->mmio_fast_base +
offset.word);
/*
* Handle case 1 and 2 by returning the buffer (or NULL).
* Handle case 3 by waiting for the prefetch buffer to refill.
*/
if (val.c != MPIPE_EDMA_DESC_WORD1__C_VAL_NOT_RDY)
return (void *)((unsigned long)val.
va << MPIPE_BSM_REGION_VAL__VA_SHIFT);
}
}
/*****************************************************************
* NotifRings *
******************************************************************/
/* Allocate a set of NotifRings.
*
* The return value is NOT interesting if count is zero.
*
* Note that NotifRings are allocated in chunks, so allocating one at
* a time is much less efficient than allocating several at once.
*
* @param context An initialized mPIPE context.
* @param count Number of NotifRings required.
* @param first Index of first NotifRing if ::GXIO_MPIPE_ALLOC_FIXED flag
* is set, otherwise ignored.
* @param flags Flag bits from ::gxio_mpipe_alloc_flags_e.
* @return Index of first allocated buffer NotifRing, or
* ::GXIO_MPIPE_ERR_NO_NOTIF_RING if allocation failed.
*/
extern int gxio_mpipe_alloc_notif_rings(gxio_mpipe_context_t *context,
unsigned int count, unsigned int first,
unsigned int flags);
/* Initialize a NotifRing, using the given memory and size.
*
* @param context An initialized mPIPE context.
* @param ring The NotifRing index.
* @param mem A physically contiguous region of memory to be filled
* with a ring of ::gxio_mpipe_idesc_t structures.
* @param mem_size Number of bytes in the ring. Must be 128, 512,
* 2048, or 65536 * sizeof(gxio_mpipe_idesc_t).
* @param mem_flags ::gxio_mpipe_mem_flags_e memory flags.
*
* @return 0 on success, ::GXIO_MPIPE_ERR_BAD_NOTIF_RING or
* ::GXIO_ERR_INVAL_MEMORY_SIZE on failure.
*/
extern int gxio_mpipe_init_notif_ring(gxio_mpipe_context_t *context,
unsigned int ring,
void *mem, size_t mem_size,
unsigned int mem_flags);
/* Configure an interrupt to be sent to a tile on incoming NotifRing
* traffic. Once an interrupt is sent for a particular ring, no more
* will be sent until gxio_mica_enable_notif_ring_interrupt() is called.
*
* @param context An initialized mPIPE context.
* @param x X coordinate of interrupt target tile.
* @param y Y coordinate of interrupt target tile.
* @param i Index of the IPI register which will receive the interrupt.
* @param e Specific event which will be set in the target IPI register when
* the interrupt occurs.
* @param ring The NotifRing index.
* @return Zero on success, GXIO_ERR_INVAL if params are out of range.
*/
extern int gxio_mpipe_request_notif_ring_interrupt(gxio_mpipe_context_t
*context, int x, int y,
int i, int e,
unsigned int ring);
/* Enable an interrupt on incoming NotifRing traffic.
*
* @param context An initialized mPIPE context.
* @param ring The NotifRing index.
* @return Zero on success, GXIO_ERR_INVAL if params are out of range.
*/
extern int gxio_mpipe_enable_notif_ring_interrupt(gxio_mpipe_context_t
*context, unsigned int ring);
/* Map all of a client's memory via the given IOTLB.
* @param context An initialized mPIPE context.
* @param iotlb IOTLB index.
* @param pte Page table entry.
* @param flags Flags.
* @return Zero on success, or a negative error code.
*/
extern int gxio_mpipe_register_client_memory(gxio_mpipe_context_t *context,
unsigned int iotlb, HV_PTE pte,
unsigned int flags);
/*****************************************************************
* Notif Groups *
******************************************************************/
/* Allocate a set of NotifGroups.
*
* The return value is NOT interesting if count is zero.
*
* @param context An initialized mPIPE context.
* @param count Number of NotifGroups required.
* @param first Index of first NotifGroup if ::GXIO_MPIPE_ALLOC_FIXED flag
* is set, otherwise ignored.
* @param flags Flag bits from ::gxio_mpipe_alloc_flags_e.
* @return Index of first allocated buffer NotifGroup, or
* ::GXIO_MPIPE_ERR_NO_NOTIF_GROUP if allocation failed.
*/
extern int gxio_mpipe_alloc_notif_groups(gxio_mpipe_context_t *context,
unsigned int count,
unsigned int first,
unsigned int flags);
/* Add a NotifRing to a NotifGroup. This only sets a bit in the
* application's 'group' object; the hardware NotifGroup can be
* initialized by passing 'group' to gxio_mpipe_init_notif_group() or
* gxio_mpipe_init_notif_group_and_buckets().
*/
static inline void
gxio_mpipe_notif_group_add_ring(gxio_mpipe_notif_group_bits_t *bits, int ring)
{
bits->ring_mask[ring / 64] |= (1ull << (ring % 64));
}
/* Set a particular NotifGroup bitmask. Since the load balancer
* makes decisions based on both bucket and NotifGroup state, most
* applications should use gxio_mpipe_init_notif_group_and_buckets()
* rather than using this function to configure just a NotifGroup.
*/
extern int gxio_mpipe_init_notif_group(gxio_mpipe_context_t *context,
unsigned int group,
gxio_mpipe_notif_group_bits_t bits);
/*****************************************************************
* Load Balancer *
******************************************************************/
/* Allocate a set of load balancer buckets.
*
* The return value is NOT interesting if count is zero.
*
* Note that buckets are allocated in chunks, so allocating one at
* a time is much less efficient than allocating several at once.
*
* Note that the buckets are actually divided into two sub-ranges, of
* different sizes, and different chunk sizes, and the range you get
* by default is determined by the size of the request. Allocations
* cannot span the two sub-ranges.
*
* @param context An initialized mPIPE context.
* @param count Number of buckets required.
* @param first Index of first bucket if ::GXIO_MPIPE_ALLOC_FIXED flag is set,
* otherwise ignored.
* @param flags Flag bits from ::gxio_mpipe_alloc_flags_e.
* @return Index of first allocated buffer bucket, or
* ::GXIO_MPIPE_ERR_NO_BUCKET if allocation failed.
*/
extern int gxio_mpipe_alloc_buckets(gxio_mpipe_context_t *context,
unsigned int count, unsigned int first,
unsigned int flags);
/* The legal modes for gxio_mpipe_bucket_info_t and
* gxio_mpipe_init_notif_group_and_buckets().
*
* All modes except ::GXIO_MPIPE_BUCKET_ROUND_ROBIN expect that the user
* will allocate a power-of-two number of buckets and initialize them
* to the same mode. The classifier program then uses the appropriate
* number of low bits from the incoming packet's flow hash to choose a
* load balancer bucket. Based on that bucket's load balancing mode,
* reference count, and currently active NotifRing, the load balancer
* chooses the NotifRing to which the packet will be delivered.
*/
typedef enum {
/* All packets for a bucket go to the same NotifRing unless the
* NotifRing gets full, in which case packets will be dropped. If
* the bucket reference count ever reaches zero, a new NotifRing may
* be chosen.
*/
GXIO_MPIPE_BUCKET_DYNAMIC_FLOW_AFFINITY =
MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_DFA,
/* All packets for a bucket always go to the same NotifRing.
*/
GXIO_MPIPE_BUCKET_STATIC_FLOW_AFFINITY =
MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_FIXED,
/* All packets for a bucket go to the least full NotifRing in the
* group, providing load balancing round robin behavior.
*/
GXIO_MPIPE_BUCKET_ROUND_ROBIN =
MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_ALWAYS_PICK,
/* All packets for a bucket go to the same NotifRing unless the
* NotifRing gets full, at which point the bucket starts using the
* least full NotifRing in the group. If all NotifRings in the
* group are full, packets will be dropped.
*/
GXIO_MPIPE_BUCKET_STICKY_FLOW_LOCALITY =
MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_STICKY,
/* All packets for a bucket go to the same NotifRing unless the
* NotifRing gets full, or a random timer fires, at which point the
* bucket starts using the least full NotifRing in the group. If
* all NotifRings in the group are full, packets will be dropped.
* WARNING: This mode is BROKEN on chips with fewer than 64 tiles.
*/
GXIO_MPIPE_BUCKET_PREFER_FLOW_LOCALITY =
MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_STICKY_RAND,
} gxio_mpipe_bucket_mode_t;
/* Copy a set of bucket initialization values into the mPIPE
* hardware. Since the load balancer makes decisions based on both
* bucket and NotifGroup state, most applications should use
* gxio_mpipe_init_notif_group_and_buckets() rather than using this
* function to configure a single bucket.
*
* @param context An initialized mPIPE context.
* @param bucket Bucket index to be initialized.
* @param bucket_info Initial reference count, NotifRing index, and mode.
* @return 0 on success, ::GXIO_MPIPE_ERR_BAD_BUCKET on failure.
*/
extern int gxio_mpipe_init_bucket(gxio_mpipe_context_t *context,
unsigned int bucket,
gxio_mpipe_bucket_info_t bucket_info);
/* Initializes a group and range of buckets and range of rings such
* that the load balancer runs a particular load balancing function.
*
* First, the group is initialized with the given rings.
*
* Second, each bucket is initialized with the mode and group, and a
* ring chosen round-robin from the given rings.
*
* Normally, the classifier picks a bucket, and then the load balancer
* picks a ring, based on the bucket's mode, group, and current ring,
* possibly updating the bucket's ring.
*
* @param context An initialized mPIPE context.
* @param group The group.
* @param ring The first ring.
* @param num_rings The number of rings.
* @param bucket The first bucket.
* @param num_buckets The number of buckets.
* @param mode The load balancing mode.
*
* @return 0 on success, ::GXIO_MPIPE_ERR_BAD_BUCKET,
* ::GXIO_MPIPE_ERR_BAD_NOTIF_GROUP, or
* ::GXIO_MPIPE_ERR_BAD_NOTIF_RING on failure.
*/
extern int gxio_mpipe_init_notif_group_and_buckets(gxio_mpipe_context_t
*context,
unsigned int group,
unsigned int ring,
unsigned int num_rings,
unsigned int bucket,
unsigned int num_buckets,
gxio_mpipe_bucket_mode_t
mode);
/* Return credits to a NotifRing and/or bucket.
*
* @param context An initialized mPIPE context.
* @param ring The NotifRing index, or -1.
* @param bucket The bucket, or -1.
* @param count The number of credits to return.
*/
static inline void gxio_mpipe_credit(gxio_mpipe_context_t *context,
int ring, int bucket, unsigned int count)
{
/* NOTE: Fancy struct initialization would break "C89" header test. */
MPIPE_IDMA_RELEASE_REGION_ADDR_t offset = { {0} };
MPIPE_IDMA_RELEASE_REGION_VAL_t val = { {0} };
/*
* The mmio_fast_base region starts at the IDMA region, so subtract
* off that initial offset.
*/
offset.region =
MPIPE_MMIO_ADDR__REGION_VAL_IDMA -
MPIPE_MMIO_ADDR__REGION_VAL_IDMA;
offset.ring = ring;
offset.bucket = bucket;
offset.ring_enable = (ring >= 0);
offset.bucket_enable = (bucket >= 0);
val.count = count;
__gxio_mmio_write(context->mmio_fast_base + offset.word, val.word);
}
/*****************************************************************
* Egress Rings *
******************************************************************/
/* Allocate a set of eDMA rings.
*
* The return value is NOT interesting if count is zero.
*
* @param context An initialized mPIPE context.
* @param count Number of eDMA rings required.
* @param first Index of first eDMA ring if ::GXIO_MPIPE_ALLOC_FIXED flag
* is set, otherwise ignored.
* @param flags Flag bits from ::gxio_mpipe_alloc_flags_e.
* @return Index of first allocated buffer eDMA ring, or
* ::GXIO_MPIPE_ERR_NO_EDMA_RING if allocation failed.
*/
extern int gxio_mpipe_alloc_edma_rings(gxio_mpipe_context_t *context,
unsigned int count, unsigned int first,
unsigned int flags);
/* Initialize an eDMA ring, using the given memory and size.
*
* @param context An initialized mPIPE context.
* @param ering The eDMA ring index.
* @param channel The channel to use. This must be one of the channels
* associated with the context's set of open links.
* @param mem A physically contiguous region of memory to be filled
* with a ring of ::gxio_mpipe_edesc_t structures.
* @param mem_size Number of bytes in the ring. Must be 512, 2048,
* 8192 or 65536, times 16 (i.e. sizeof(gxio_mpipe_edesc_t)).
* @param mem_flags ::gxio_mpipe_mem_flags_e memory flags.
*
* @return 0 on success, ::GXIO_MPIPE_ERR_BAD_EDMA_RING or
* ::GXIO_ERR_INVAL_MEMORY_SIZE on failure.
*/
extern int gxio_mpipe_init_edma_ring(gxio_mpipe_context_t *context,
unsigned int ering, unsigned int channel,
void *mem, size_t mem_size,
unsigned int mem_flags);
/* Set the "max_blks", "min_snf_blks", and "db" fields of
* ::MPIPE_EDMA_RG_INIT_DAT_THRESH_t for a given edma ring.
*
* The global pool of dynamic blocks will be automatically adjusted.
*
* This function should not be called after any egress has been done
* on the edma ring.
*
* Most applications should just use gxio_mpipe_equeue_set_snf_size().
*
* @param context An initialized mPIPE context.
* @param ering The eDMA ring index.
* @param max_blks The number of blocks to dedicate to the ring
* (normally min_snf_blks + 1). Must be greater than min_snf_blocks.
* @param min_snf_blks The number of blocks which must be stored
* prior to starting to send the packet (normally 12).
* @param db Whether to allow use of dynamic blocks by the ring
* (normally 1).
*
* @return 0 on success, negative on error.
*/
extern int gxio_mpipe_config_edma_ring_blks(gxio_mpipe_context_t *context,
unsigned int ering,
unsigned int max_blks,
unsigned int min_snf_blks,
unsigned int db);
/*****************************************************************
* Classifier Program *
******************************************************************/
/*
*
* Functions for loading or configuring the mPIPE classifier program.
*
* The mPIPE classification processors all run a special "classifier"
* program which, for each incoming packet, parses the packet headers,
* encodes some packet metadata in the "idesc", and either drops the
* packet, or picks a notif ring to handle the packet, and a buffer
* stack to contain the packet, usually based on the channel, VLAN,
* dMAC, flow hash, and packet size, under the guidance of the "rules"
* API described below.
*
* @section gxio_mpipe_classifier_default Default Classifier
*
* The MDE provides a simple "default" classifier program. It is
* shipped as source in "$TILERA_ROOT/src/sys/mpipe/classifier.c",
* which serves as its official documentation. It is shipped as a
* binary program in "$TILERA_ROOT/tile/boot/classifier", which is
* automatically included in bootroms created by "tile-monitor", and
* is automatically loaded by the hypervisor at boot time.
*
* The L2 analysis handles LLC packets, SNAP packets, and "VLAN
* wrappers" (keeping the outer VLAN).
*
* The L3 analysis handles IPv4 and IPv6, dropping packets with bad
* IPv4 header checksums, requesting computation of a TCP/UDP checksum
* if appropriate, and hashing the dest and src IP addresses, plus the
* ports for TCP/UDP packets, into the flow hash. No special analysis
* is done for "fragmented" packets or "tunneling" protocols. Thus,
* the first fragment of a fragmented TCP/UDP packet is hashed using
* src/dest IP address and ports and all subsequent fragments are only
* hashed according to src/dest IP address.
*
* The L3 analysis handles other packets too, hashing the dMAC
* smac into a flow hash.
*
* The channel, VLAN, and dMAC used to pick a "rule" (see the
* "rules" APIs below), which in turn is used to pick a buffer stack
* (based on the packet size) and a bucket (based on the flow hash).
*
* To receive traffic matching a particular (channel/VLAN/dMAC
* pattern, an application should allocate its own buffer stacks and
* load balancer buckets, and map traffic to those stacks and buckets,
* as decribed by the "rules" API below.
*
* Various packet metadata is encoded in the idesc. The flow hash is
* four bytes at 0x0C. The VLAN is two bytes at 0x10. The ethtype is
* two bytes at 0x12. The l3 start is one byte at 0x14. The l4 start
* is one byte at 0x15 for IPv4 and IPv6 packets, and otherwise zero.
* The protocol is one byte at 0x16 for IPv4 and IPv6 packets, and
* otherwise zero.
*
* @section gxio_mpipe_classifier_custom Custom Classifiers.
*
* A custom classifier may be created using "tile-mpipe-cc" with a
* customized version of the default classifier sources.
*
* The custom classifier may be included in bootroms using the
* "--classifier" option to "tile-monitor", or loaded dynamically
* using gxio_mpipe_classifier_load_from_file().
*
* Be aware that "extreme" customizations may break the assumptions of
* the "rules" APIs described below, but simple customizations, such
* as adding new packet metadata, should be fine.
*/
/* A set of classifier rules, plus a context. */
typedef struct {
/* The context. */
gxio_mpipe_context_t *context;
/* The actual rules. */
gxio_mpipe_rules_list_t list;
} gxio_mpipe_rules_t;
/* Initialize a classifier program rules list.
*
* This function can be called on a previously initialized rules list
* to discard any previously added rules.
*
* @param rules Rules list to initialize.
* @param context An initialized mPIPE context.
*/
extern void gxio_mpipe_rules_init(gxio_mpipe_rules_t *rules,
gxio_mpipe_context_t *context);
/* Begin a new rule on the indicated rules list.
*
* Note that an empty rule matches all packets, but an empty rule list
* matches no packets.
*
* @param rules Rules list to which new rule is appended.
* @param bucket First load balancer bucket to which packets will be
* delivered.
* @param num_buckets Number of buckets (must be a power of two) across
* which packets will be distributed based on the "flow hash".
* @param stacks Either NULL, to assign each packet to the smallest
* initialized buffer stack which does not induce chaining (and to
* drop packets which exceed the largest initialized buffer stack
* buffer size), or an array, with each entry indicating which buffer
* stack should be used for packets up to that size (with 255
* indicating that those packets should be dropped).
* @return 0 on success, or a negative error code on failure.
*/
extern int gxio_mpipe_rules_begin(gxio_mpipe_rules_t *rules,
unsigned int bucket,
unsigned int num_buckets,
gxio_mpipe_rules_stacks_t *stacks);
/* Set the headroom of the current rule.
*
* @param rules Rules list whose current rule will be modified.
* @param headroom The headroom.
* @return 0 on success, or a negative error code on failure.
*/
extern int gxio_mpipe_rules_set_headroom(gxio_mpipe_rules_t *rules,
uint8_t headroom);
/* Indicate that packets from a particular channel can be delivered
* to the buckets and buffer stacks associated with the current rule.
*
* Channels added must be associated with links opened by the mPIPE context
* used in gxio_mpipe_rules_init(). A rule with no channels is equivalent
* to a rule naming all such associated channels.
*
* @param rules Rules list whose current rule will be modified.
* @param channel The channel to add.
* @return 0 on success, or a negative error code on failure.
*/
extern int gxio_mpipe_rules_add_channel(gxio_mpipe_rules_t *rules,
unsigned int channel);
/* Commit rules.
*
* The rules are sent to the hypervisor, where they are combined with
* the rules from other apps, and used to program the hardware classifier.
*
* Note that if this function returns an error, then the rules will NOT
* have been committed, even if the error is due to interactions with
* rules from another app.
*
* @param rules Rules list to commit.
* @return 0 on success, or a negative error code on failure.
*/
extern int gxio_mpipe_rules_commit(gxio_mpipe_rules_t *rules);
/*****************************************************************
* Ingress Queue Wrapper *
******************************************************************/
/*
*
* Convenience functions for receiving packets from a NotifRing and
* sending packets via an eDMA ring.
*
* The mpipe ingress and egress hardware uses shared memory packet
* descriptors to describe packets that have arrived on ingress or
* are destined for egress. These descriptors are stored in shared
* memory ring buffers and written or read by hardware as necessary.
* The gxio library provides wrapper functions that manage the head and
* tail pointers for these rings, allowing the user to easily read or
* write packet descriptors.
*
* The initialization interface for ingress and egress rings is quite
* similar. For example, to create an ingress queue, the user passes
* a ::gxio_mpipe_iqueue_t state object, a ring number from
* gxio_mpipe_alloc_notif_rings(), and the address of memory to hold a
* ring buffer to the gxio_mpipe_iqueue_init() function. The function
* returns success when the state object has been initialized and the
* hardware configured to deliver packets to the specified ring
* buffer. Similarly, gxio_mpipe_equeue_init() takes a
* ::gxio_mpipe_equeue_t state object, a ring number from
* gxio_mpipe_alloc_edma_rings(), and a shared memory buffer.
*
* @section gxio_mpipe_iqueue Working with Ingress Queues
*
* Once initialized, the gxio_mpipe_iqueue_t API provides two flows
* for getting the ::gxio_mpipe_idesc_t packet descriptor associated
* with incoming packets. The simplest is to call
* gxio_mpipe_iqueue_get() or gxio_mpipe_iqueue_try_get(). These
* functions copy the oldest packet descriptor out of the NotifRing and
* into a descriptor provided by the caller. They also immediately
* inform the hardware that a descriptor has been processed.
*
* For applications with stringent performance requirements, higher
* efficiency can be achieved by avoiding the packet descriptor copy
* and processing multiple descriptors at once. The
* gxio_mpipe_iqueue_peek() and gxio_mpipe_iqueue_try_peek() functions
* allow such optimizations. These functions provide a pointer to the
* next valid ingress descriptor in the NotifRing's shared memory ring
* buffer, and a count of how many contiguous descriptors are ready to
* be processed. The application can then process any number of those
* descriptors in place, calling gxio_mpipe_iqueue_consume() to inform
* the hardware after each one has been processed.
*
* @section gxio_mpipe_equeue Working with Egress Queues
*
* Similarly, the egress queue API provides a high-performance
* interface plus a simple wrapper for use in posting
* ::gxio_mpipe_edesc_t egress packet descriptors. The simple
* version, gxio_mpipe_equeue_put(), allows the programmer to wait for
* an eDMA ring slot to become available and write a single descriptor
* into the ring.
*
* Alternatively, you can reserve slots in the eDMA ring using
* gxio_mpipe_equeue_reserve() or gxio_mpipe_equeue_try_reserve(), and
* then fill in each slot using gxio_mpipe_equeue_put_at(). This
* capability can be used to amortize the cost of reserving slots
* across several packets. It also allows gather operations to be
* performed on a shared equeue, by ensuring that the edescs for all
* the fragments are all contiguous in the eDMA ring.
*
* The gxio_mpipe_equeue_reserve() and gxio_mpipe_equeue_try_reserve()
* functions return a 63-bit "completion slot", which is actually a
* sequence number, the low bits of which indicate the ring buffer
* index and the high bits the number of times the application has
* gone around the egress ring buffer. The extra bits allow an
* application to check for egress completion by calling
* gxio_mpipe_equeue_is_complete() to see whether a particular 'slot'
* number has finished. Given the maximum packet rates of the Gx
* processor, the 63-bit slot number will never wrap.
*
* In practice, most applications use the ::gxio_mpipe_edesc_t::hwb
* bit to indicate that the buffers containing egress packet data
* should be pushed onto a buffer stack when egress is complete. Such
* applications generally do not need to know when an egress operation
* completes (since there is no need to free a buffer post-egress),
* and thus can use the optimized gxio_mpipe_equeue_reserve_fast() or
* gxio_mpipe_equeue_try_reserve_fast() functions, which return a 24
* bit "slot", instead of a 63-bit "completion slot".
*
* Once a slot has been "reserved", it MUST be filled. If the
* application reserves a slot and then decides that it does not
* actually need it, it can set the ::gxio_mpipe_edesc_t::ns (no send)
* bit on the descriptor passed to gxio_mpipe_equeue_put_at() to
* indicate that no data should be sent. This technique can also be
* used to drop an incoming packet, instead of forwarding it, since
* any buffer will still be pushed onto the buffer stack when the
* egress descriptor is processed.
*/
/* A convenient interface to a NotifRing, for use by a single thread.
*/
typedef struct {
/* The context. */
gxio_mpipe_context_t *context;
/* The actual NotifRing. */
gxio_mpipe_idesc_t *idescs;
/* The number of entries. */
unsigned long num_entries;
/* The number of entries minus one. */
unsigned long mask_num_entries;
/* The log2() of the number of entries. */
unsigned long log2_num_entries;
/* The next entry. */
unsigned int head;
/* The NotifRing id. */
unsigned int ring;
#ifdef __BIG_ENDIAN__
/* The number of byteswapped entries. */
unsigned int swapped;
#endif
} gxio_mpipe_iqueue_t;
/* Initialize an "iqueue".
*
* Takes the iqueue plus the same args as gxio_mpipe_init_notif_ring().
*/
extern int gxio_mpipe_iqueue_init(gxio_mpipe_iqueue_t *iqueue,
gxio_mpipe_context_t *context,
unsigned int ring,
void *mem, size_t mem_size,
unsigned int mem_flags);
/* Advance over some old entries in an iqueue.
*
* Please see the documentation for gxio_mpipe_iqueue_consume().
*
* @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init().
* @param count The number of entries to advance over.
*/
static inline void gxio_mpipe_iqueue_advance(gxio_mpipe_iqueue_t *iqueue,
int count)
{
/* Advance with proper wrap. */
int head = iqueue->head + count;
iqueue->head =
(head & iqueue->mask_num_entries) +
(head >> iqueue->log2_num_entries);
#ifdef __BIG_ENDIAN__
/* HACK: Track swapped entries. */
iqueue->swapped -= count;
#endif
}
/* Release the ring and bucket for an old entry in an iqueue.
*
* Releasing the ring allows more packets to be delivered to the ring.
*
* Releasing the bucket allows flows using the bucket to be moved to a
* new ring when using GXIO_MPIPE_BUCKET_DYNAMIC_FLOW_AFFINITY.
*
* This function is shorthand for "gxio_mpipe_credit(iqueue->context,
* iqueue->ring, idesc->bucket_id, 1)", and it may be more convenient
* to make that underlying call, using those values, instead of
* tracking the entire "idesc".
*
* If packet processing is deferred, optimal performance requires that
* the releasing be deferred as well.
*
* Please see the documentation for gxio_mpipe_iqueue_consume().
*
* @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init().
* @param idesc The descriptor which was processed.
*/
static inline void gxio_mpipe_iqueue_release(gxio_mpipe_iqueue_t *iqueue,
gxio_mpipe_idesc_t *idesc)
{
gxio_mpipe_credit(iqueue->context, iqueue->ring, idesc->bucket_id, 1);
}
/* Consume a packet from an "iqueue".
*
* After processing packets peeked at via gxio_mpipe_iqueue_peek()
* or gxio_mpipe_iqueue_try_peek(), you must call this function, or
* gxio_mpipe_iqueue_advance() plus gxio_mpipe_iqueue_release(), to
* advance over those entries, and release their rings and buckets.
*
* You may call this function as each packet is processed, or you can
* wait until several packets have been processed.
*
* Note that if you are using a single bucket, and you are handling
* batches of N packets, then you can replace several calls to this
* function with calls to "gxio_mpipe_iqueue_advance(iqueue, N)" and
* "gxio_mpipe_credit(iqueue->context, iqueue->ring, bucket, N)".
*
* Note that if your classifier sets "idesc->nr", then you should
* explicitly call "gxio_mpipe_iqueue_advance(iqueue, idesc)" plus
* "gxio_mpipe_credit(iqueue->context, iqueue->ring, -1, 1)", to
* avoid incorrectly crediting the (unused) bucket.
*
* @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init().
* @param idesc The descriptor which was processed.
*/
static inline void gxio_mpipe_iqueue_consume(gxio_mpipe_iqueue_t *iqueue,
gxio_mpipe_idesc_t *idesc)
{
gxio_mpipe_iqueue_advance(iqueue, 1);
gxio_mpipe_iqueue_release(iqueue, idesc);
}
/* Peek at the next packet(s) in an "iqueue", without waiting.
*
* If no packets are available, fills idesc_ref with NULL, and then
* returns ::GXIO_MPIPE_ERR_IQUEUE_EMPTY. Otherwise, fills idesc_ref
* with the address of the next valid packet descriptor, and returns
* the maximum number of valid descriptors which can be processed.
* You may process fewer descriptors if desired.
*
* Call gxio_mpipe_iqueue_consume() on each packet once it has been
* processed (or dropped), to allow more packets to be delivered.
*
* @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init().
* @param idesc_ref A pointer to a packet descriptor pointer.
* @return The (positive) number of packets which can be processed,
* or ::GXIO_MPIPE_ERR_IQUEUE_EMPTY if no packets are available.
*/
static inline int gxio_mpipe_iqueue_try_peek(gxio_mpipe_iqueue_t *iqueue,
gxio_mpipe_idesc_t **idesc_ref)
{
gxio_mpipe_idesc_t *next;
uint64_t head = iqueue->head;
uint64_t tail = __gxio_mmio_read(iqueue->idescs);
/* Available entries. */
uint64_t avail =
(tail >= head) ? (tail - head) : (iqueue->num_entries - head);
if (avail == 0) {
*idesc_ref = NULL;
return GXIO_MPIPE_ERR_IQUEUE_EMPTY;
}
next = &iqueue->idescs[head];
/* ISSUE: Is this helpful? */
__insn_prefetch(next);
#ifdef __BIG_ENDIAN__
/* HACK: Swap new entries directly in memory. */
{
int i, j;
for (i = iqueue->swapped; i < avail; i++) {
for (j = 0; j < 8; j++)
next[i].words[j] =
__builtin_bswap64(next[i].words[j]);
}
iqueue->swapped = avail;
}
#endif
*idesc_ref = next;
return avail;
}
/* Drop a packet by pushing its buffer (if appropriate).
*
* NOTE: The caller must still call gxio_mpipe_iqueue_consume() if idesc
* came from gxio_mpipe_iqueue_try_peek() or gxio_mpipe_iqueue_peek().
*
* @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init().
* @param idesc A packet descriptor.
*/
static inline void gxio_mpipe_iqueue_drop(gxio_mpipe_iqueue_t *iqueue,
gxio_mpipe_idesc_t *idesc)
{
/* FIXME: Handle "chaining" properly. */
if (!idesc->be) {
unsigned char *va = gxio_mpipe_idesc_get_va(idesc);
gxio_mpipe_push_buffer(iqueue->context, idesc->stack_idx, va);
}
}
/*****************************************************************
* Egress Queue Wrapper *
******************************************************************/
/* A convenient, thread-safe interface to an eDMA ring. */
typedef struct {
/* State object for tracking head and tail pointers. */
__gxio_dma_queue_t dma_queue;
/* The ring entries. */
gxio_mpipe_edesc_t *edescs;
/* The number of entries minus one. */
unsigned long mask_num_entries;
/* The log2() of the number of entries. */
unsigned long log2_num_entries;
/* The context. */
gxio_mpipe_context_t *context;
/* The ering. */
unsigned int ering;
/* The channel. */
unsigned int channel;
} gxio_mpipe_equeue_t;
/* Initialize an "equeue".
*
* This function uses gxio_mpipe_init_edma_ring() to initialize the
* underlying edma_ring using the provided arguments.
*
* @param equeue An egress queue to be initialized.
* @param context An initialized mPIPE context.
* @param ering The eDMA ring index.
* @param channel The channel to use. This must be one of the channels
* associated with the context's set of open links.
* @param mem A physically contiguous region of memory to be filled
* with a ring of ::gxio_mpipe_edesc_t structures.
* @param mem_size Number of bytes in the ring. Must be 512, 2048,
* 8192 or 65536, times 16 (i.e. sizeof(gxio_mpipe_edesc_t)).
* @param mem_flags ::gxio_mpipe_mem_flags_e memory flags.
*
* @return 0 on success, ::GXIO_MPIPE_ERR_BAD_EDMA_RING or
* ::GXIO_ERR_INVAL_MEMORY_SIZE on failure.
*/
extern int gxio_mpipe_equeue_init(gxio_mpipe_equeue_t *equeue,
gxio_mpipe_context_t *context,
unsigned int ering,
unsigned int channel,
void *mem, unsigned int mem_size,
unsigned int mem_flags);
/* Reserve completion slots for edescs.
*
* Use gxio_mpipe_equeue_put_at() to actually populate the slots.
*
* This function is slower than gxio_mpipe_equeue_reserve_fast(), but
* returns a full 64 bit completion slot, which can be used with
* gxio_mpipe_equeue_is_complete().
*
* @param equeue An egress queue initialized via gxio_mpipe_equeue_init().
* @param num Number of slots to reserve (must be non-zero).
* @return The first reserved completion slot, or a negative error code.
*/
static inline int64_t gxio_mpipe_equeue_reserve(gxio_mpipe_equeue_t *equeue,
unsigned int num)
{
return __gxio_dma_queue_reserve_aux(&equeue->dma_queue, num, true);
}
/* Reserve completion slots for edescs, if possible.
*
* Use gxio_mpipe_equeue_put_at() to actually populate the slots.
*
* This function is slower than gxio_mpipe_equeue_try_reserve_fast(),
* but returns a full 64 bit completion slot, which can be used with
* gxio_mpipe_equeue_is_complete().
*
* @param equeue An egress queue initialized via gxio_mpipe_equeue_init().
* @param num Number of slots to reserve (must be non-zero).
* @return The first reserved completion slot, or a negative error code.
*/
static inline int64_t gxio_mpipe_equeue_try_reserve(gxio_mpipe_equeue_t
*equeue, unsigned int num)
{
return __gxio_dma_queue_reserve_aux(&equeue->dma_queue, num, false);
}
/* Reserve slots for edescs.
*
* Use gxio_mpipe_equeue_put_at() to actually populate the slots.
*
* This function is faster than gxio_mpipe_equeue_reserve(), but
* returns a 24 bit slot (instead of a 64 bit completion slot), which
* thus cannot be used with gxio_mpipe_equeue_is_complete().
*
* @param equeue An egress queue initialized via gxio_mpipe_equeue_init().
* @param num Number of slots to reserve (should be non-zero).
* @return The first reserved slot, or a negative error code.
*/
static inline int64_t gxio_mpipe_equeue_reserve_fast(gxio_mpipe_equeue_t
*equeue, unsigned int num)
{
return __gxio_dma_queue_reserve(&equeue->dma_queue, num, true, false);
}
/* Reserve slots for edescs, if possible.
*
* Use gxio_mpipe_equeue_put_at() to actually populate the slots.
*
* This function is faster than gxio_mpipe_equeue_try_reserve(), but
* returns a 24 bit slot (instead of a 64 bit completion slot), which
* thus cannot be used with gxio_mpipe_equeue_is_complete().
*
* @param equeue An egress queue initialized via gxio_mpipe_equeue_init().
* @param num Number of slots to reserve (should be non-zero).
* @return The first reserved slot, or a negative error code.
*/
static inline int64_t gxio_mpipe_equeue_try_reserve_fast(gxio_mpipe_equeue_t
*equeue,
unsigned int num)
{
return __gxio_dma_queue_reserve(&equeue->dma_queue, num, false, false);
}
/*
* HACK: This helper function tricks gcc 4.6 into avoiding saving
* a copy of "edesc->words[0]" on the stack for no obvious reason.
*/
static inline void gxio_mpipe_equeue_put_at_aux(gxio_mpipe_equeue_t *equeue,
uint_reg_t ew[2],
unsigned long slot)
{
unsigned long edma_slot = slot & equeue->mask_num_entries;
gxio_mpipe_edesc_t *edesc_p = &equeue->edescs[edma_slot];
/*
* ISSUE: Could set eDMA ring to be on generation 1 at start, which
* would avoid the negation here, perhaps allowing "__insn_bfins()".
*/
ew[0] |= !((slot >> equeue->log2_num_entries) & 1);
/*
* NOTE: We use "__gxio_mpipe_write()", plus the fact that the eDMA
* queue alignment restrictions ensure that these two words are on
* the same cacheline, to force proper ordering between the stores.
*/
__gxio_mmio_write64(&edesc_p->words[1], ew[1]);
__gxio_mmio_write64(&edesc_p->words[0], ew[0]);
}
/* Post an edesc to a given slot in an equeue.
*
* This function copies the supplied edesc into entry "slot mod N" in
* the underlying ring, setting the "gen" bit to the appropriate value
* based on "(slot mod N*2)", where "N" is the size of the ring. Note
* that the higher bits of slot are unused, and thus, this function
* can handle "slots" as well as "completion slots".
*
* Normally this function is used to fill in slots reserved by
* gxio_mpipe_equeue_try_reserve(), gxio_mpipe_equeue_reserve(),
* gxio_mpipe_equeue_try_reserve_fast(), or
* gxio_mpipe_equeue_reserve_fast(),
*
* This function can also be used without "reserving" slots, if the
* application KNOWS that the ring can never overflow, for example, by
* pushing fewer buffers into the buffer stacks than there are total
* slots in the equeue, but this is NOT recommended.
*
* @param equeue An egress queue initialized via gxio_mpipe_equeue_init().
* @param edesc The egress descriptor to be posted.
* @param slot An egress slot (only the low bits are actually used).
*/
static inline void gxio_mpipe_equeue_put_at(gxio_mpipe_equeue_t *equeue,
gxio_mpipe_edesc_t edesc,
unsigned long slot)
{
gxio_mpipe_equeue_put_at_aux(equeue, edesc.words, slot);
}
/* Post an edesc to the next slot in an equeue.
*
* This is a convenience wrapper around
* gxio_mpipe_equeue_reserve_fast() and gxio_mpipe_equeue_put_at().
*
* @param equeue An egress queue initialized via gxio_mpipe_equeue_init().
* @param edesc The egress descriptor to be posted.
* @return 0 on success.
*/
static inline int gxio_mpipe_equeue_put(gxio_mpipe_equeue_t *equeue,
gxio_mpipe_edesc_t edesc)
{
int64_t slot = gxio_mpipe_equeue_reserve_fast(equeue, 1);
if (slot < 0)
return (int)slot;
gxio_mpipe_equeue_put_at(equeue, edesc, slot);
return 0;
}
/* Ask the mPIPE hardware to egress outstanding packets immediately.
*
* This call is not necessary, but may slightly reduce overall latency.
*
* Technically, you should flush all gxio_mpipe_equeue_put_at() writes
* to memory before calling this function, to ensure the descriptors
* are visible in memory before the mPIPE hardware actually looks for
* them. But this should be very rare, and the only side effect would
* be increased latency, so it is up to the caller to decide whether
* or not to flush memory.
*
* @param equeue An egress queue initialized via gxio_mpipe_equeue_init().
*/
static inline void gxio_mpipe_equeue_flush(gxio_mpipe_equeue_t *equeue)
{
/* Use "ring_idx = 0" and "count = 0" to "wake up" the eDMA ring. */
MPIPE_EDMA_POST_REGION_VAL_t val = { {0} };
/* Flush the write buffers. */
__insn_flushwb();
__gxio_mmio_write(equeue->dma_queue.post_region_addr, val.word);
}
/* Determine if a given edesc has been completed.
*
* Note that this function requires a "completion slot", and thus may
* NOT be used with a "slot" from gxio_mpipe_equeue_reserve_fast() or
* gxio_mpipe_equeue_try_reserve_fast().
*
* @param equeue An egress queue initialized via gxio_mpipe_equeue_init().
* @param completion_slot The completion slot used by the edesc.
* @param update If true, and the desc does not appear to have completed
* yet, then update any software cache of the hardware completion counter,
* and check again. This should normally be true.
* @return True iff the given edesc has been completed.
*/
static inline int gxio_mpipe_equeue_is_complete(gxio_mpipe_equeue_t *equeue,
int64_t completion_slot,
int update)
{
return __gxio_dma_queue_is_complete(&equeue->dma_queue,
completion_slot, update);
}
/* Set the snf (store and forward) size for an equeue.
*
* The snf size for an equeue defaults to 1536, and encodes the size
* of the largest packet for which egress is guaranteed to avoid
* transmission underruns and/or corrupt checksums under heavy load.
*
* The snf size affects a global resource pool which cannot support,
* for example, all 24 equeues each requesting an snf size of 8K.
*
* To ensure that jumbo packets can be egressed properly, the snf size
* should be set to the size of the largest possible packet, which
* will usually be limited by the size of the app's largest buffer.
*
* This is a convenience wrapper around
* gxio_mpipe_config_edma_ring_blks().
*
* This function should not be called after any egress has been done
* on the equeue.
*
* @param equeue An egress queue initialized via gxio_mpipe_equeue_init().
* @param size The snf size, in bytes.
* @return Zero on success, negative error otherwise.
*/
static inline int gxio_mpipe_equeue_set_snf_size(gxio_mpipe_equeue_t *equeue,
size_t size)
{
int blks = (size + 127) / 128;
return gxio_mpipe_config_edma_ring_blks(equeue->context, equeue->ering,
blks + 1, blks, 1);
}
/*****************************************************************
* Link Management *
******************************************************************/
/*
*
* Functions for manipulating and sensing the state and configuration
* of physical network links.
*
* @section gxio_mpipe_link_perm Link Permissions
*
* Opening a link (with gxio_mpipe_link_open()) requests a set of link
* permissions, which control what may be done with the link, and potentially
* what permissions may be granted to other processes.
*
* Data permission allows the process to receive packets from the link by
* specifying the link's channel number in mPIPE packet distribution rules,
* and to send packets to the link by using the link's channel number as
* the target for an eDMA ring.
*
* Stats permission allows the process to retrieve link attributes (such as
* the speeds it is capable of running at, or whether it is currently up), and
* to read and write certain statistics-related registers in the link's MAC.
*
* Control permission allows the process to retrieve and modify link attributes
* (so that it may, for example, bring the link up and take it down), and
* read and write many registers in the link's MAC and PHY.
*
* Any permission may be requested as shared, which allows other processes
* to also request shared permission, or exclusive, which prevents other
* processes from requesting it. In keeping with GXIO's typical usage in
* an embedded environment, the defaults for all permissions are shared.
*
* Permissions are granted on a first-come, first-served basis, so if two
* applications request an exclusive permission on the same link, the one
* to run first will win. Note, however, that some system components, like
* the kernel Ethernet driver, may get an opportunity to open links before
* any applications run.
*
* @section gxio_mpipe_link_names Link Names
*
* Link names are of the form gbe<em>number</em> (for Gigabit Ethernet),
* xgbe<em>number</em> (for 10 Gigabit Ethernet), loop<em>number</em> (for
* internal mPIPE loopback), or ilk<em>number</em>/<em>channel</em>
* (for Interlaken links); for instance, gbe0, xgbe1, loop3, and
* ilk0/12 are all possible link names. The correspondence between
* the link name and an mPIPE instance number or mPIPE channel number is
* system-dependent; all links will not exist on all systems, and the set
* of numbers used for a particular link type may not start at zero and may
* not be contiguous. Use gxio_mpipe_link_enumerate() to retrieve the set of
* links which exist on a system, and always use gxio_mpipe_link_instance()
* to determine which mPIPE controls a particular link.
*
* Note that in some cases, links may share hardware, such as PHYs, or
* internal mPIPE buffers; in these cases, only one of the links may be
* opened at a time. This is especially common with xgbe and gbe ports,
* since each xgbe port uses 4 SERDES lanes, each of which may also be
* configured as one gbe port.
*
* @section gxio_mpipe_link_states Link States
*
* The mPIPE link management model revolves around three different states,
* which are maintained for each link:
*
* 1. The <em>current</em> link state: is the link up now, and if so, at
* what speed?
*
* 2. The <em>desired</em> link state: what do we want the link state to be?
* The system is always working to make this state the current state;
* thus, if the desired state is up, and the link is down, we'll be
* constantly trying to bring it up, automatically.
*
* 3. The <em>possible</em> link state: what speeds are valid for this
* particular link? Or, in other words, what are the capabilities of
* the link hardware?
*
* These link states are not, strictly speaking, related to application
* state; they may be manipulated at any time, whether or not the link
* is currently being used for data transfer. However, for convenience,
* gxio_mpipe_link_open() and gxio_mpipe_link_close() (or application exit)
* can affect the link state. These implicit link management operations
* may be modified or disabled by the use of link open flags.
*
* From an application, you can use gxio_mpipe_link_get_attr()
* and gxio_mpipe_link_set_attr() to manipulate the link states.
* gxio_mpipe_link_get_attr() with ::GXIO_MPIPE_LINK_POSSIBLE_STATE
* gets you the possible link state. gxio_mpipe_link_get_attr() with
* ::GXIO_MPIPE_LINK_CURRENT_STATE gets you the current link state.
* Finally, gxio_mpipe_link_set_attr() and gxio_mpipe_link_get_attr()
* with ::GXIO_MPIPE_LINK_DESIRED_STATE allow you to modify or retrieve
* the desired link state.
*
* If you want to manage a link from a part of your application which isn't
* involved in packet processing, you can use the ::GXIO_MPIPE_LINK_NO_DATA
* flags on a gxio_mpipe_link_open() call. This opens the link, but does
* not request data permission, so it does not conflict with any exclusive
* permissions which may be held by other processes. You can then can use
* gxio_mpipe_link_get_attr() and gxio_mpipe_link_set_attr() on this link
* object to bring up or take down the link.
*
* Some links support link state bits which support various loopback
* modes. ::GXIO_MPIPE_LINK_LOOP_MAC tests datapaths within the Tile
* Processor itself; ::GXIO_MPIPE_LINK_LOOP_PHY tests the datapath between
* the Tile Processor and the external physical layer interface chip; and
* ::GXIO_MPIPE_LINK_LOOP_EXT tests the entire network datapath with the
* aid of an external loopback connector. In addition to enabling hardware
* testing, such configuration can be useful for software testing, as well.
*
* When LOOP_MAC or LOOP_PHY is enabled, packets transmitted on a channel
* will be received by that channel, instead of being emitted on the
* physical link, and packets received on the physical link will be ignored.
* Other than that, all standard GXIO operations work as you might expect.
* Note that loopback operation requires that the link be brought up using
* one or more of the GXIO_MPIPE_LINK_SPEED_xxx link state bits.
*
* Those familiar with previous versions of the MDE on TILEPro hardware
* will notice significant similarities between the NetIO link management
* model and the mPIPE link management model. However, the NetIO model
* was developed in stages, and some of its features -- for instance,
* the default setting of certain flags -- were shaped by the need to be
* compatible with previous versions of NetIO. Since the features provided
* by the mPIPE hardware and the mPIPE GXIO library are significantly
* different than those provided by NetIO, in some cases, we have made
* different choices in the mPIPE link management API. Thus, please read
* this documentation carefully before assuming that mPIPE link management
* operations are exactly equivalent to their NetIO counterparts.
*/
/* An object used to manage mPIPE link state and resources. */
typedef struct {
/* The overall mPIPE context. */
gxio_mpipe_context_t *context;
/* The channel number used by this link. */
uint8_t channel;
/* The MAC index used by this link. */
uint8_t mac;
} gxio_mpipe_link_t;
/* Translate a link name to the instance number of the mPIPE shim which is
* connected to that link. This call does not verify whether the link is
* currently available, and does not reserve any link resources;
* gxio_mpipe_link_open() must be called to perform those functions.
*
* Typically applications will call this function to translate a link name
* to an mPIPE instance number; call gxio_mpipe_init(), passing it that
* instance number, to initialize the mPIPE shim; and then call
* gxio_mpipe_link_open(), passing it the same link name plus the mPIPE
* context, to configure the link.
*
* @param link_name Name of the link; see @ref gxio_mpipe_link_names.
* @return The mPIPE instance number which is associated with the named
* link, or a negative error code (::GXIO_ERR_NO_DEVICE) if the link does
* not exist.
*/
extern int gxio_mpipe_link_instance(const char *link_name);
/* Retrieve one of this system's legal link names, and its MAC address.
*
* @param index Link name index. If a system supports N legal link names,
* then indices between 0 and N - 1, inclusive, each correspond to one of
* those names. Thus, to retrieve all of a system's legal link names,
* call this function in a loop, starting with an index of zero, and
* incrementing it once per iteration until -1 is returned.
* @param link_name Pointer to the buffer which will receive the retrieved
* link name. The buffer should contain space for at least
* ::GXIO_MPIPE_LINK_NAME_LEN bytes; the returned name, including the
* terminating null byte, will be no longer than that.
* @param link_name Pointer to the buffer which will receive the retrieved
* MAC address. The buffer should contain space for at least 6 bytes.
* @return Zero if a link name was successfully retrieved; -1 if one was
* not.
*/
extern int gxio_mpipe_link_enumerate_mac(int index, char *link_name,
uint8_t *mac_addr);
/* Open an mPIPE link.
*
* A link must be opened before it may be used to send or receive packets,
* and before its state may be examined or changed. Depending up on the
* link's intended use, one or more link permissions may be requested via
* the flags parameter; see @ref gxio_mpipe_link_perm. In addition, flags
* may request that the link's state be modified at open time. See @ref
* gxio_mpipe_link_states and @ref gxio_mpipe_link_open_flags for more detail.
*
* @param link A link state object, which will be initialized if this
* function completes successfully.
* @param context An initialized mPIPE context.
* @param link_name Name of the link.
* @param flags Zero or more @ref gxio_mpipe_link_open_flags, ORed together.
* @return 0 if the link was successfully opened, or a negative error code.
*
*/
extern int gxio_mpipe_link_open(gxio_mpipe_link_t *link,
gxio_mpipe_context_t *context,
const char *link_name, unsigned int flags);
/* Close an mPIPE link.
*
* Closing a link makes it available for use by other processes. Once
* a link has been closed, packets may no longer be sent on or received
* from the link, and its state may not be examined or changed.
*
* @param link A link state object, which will no longer be initialized
* if this function completes successfully.
* @return 0 if the link was successfully closed, or a negative error code.
*
*/
extern int gxio_mpipe_link_close(gxio_mpipe_link_t *link);
/* Return a link's channel number.
*
* @param link A properly initialized link state object.
* @return The channel number for the link.
*/
static inline int gxio_mpipe_link_channel(gxio_mpipe_link_t *link)
{
return link->channel;
}
/* Set a link attribute.
*
* @param link A properly initialized link state object.
* @param attr An attribute from the set of @ref gxio_mpipe_link_attrs.
* @param val New value of the attribute.
* @return 0 if the attribute was successfully set, or a negative error
* code.
*/
extern int gxio_mpipe_link_set_attr(gxio_mpipe_link_t *link, uint32_t attr,
int64_t val);
///////////////////////////////////////////////////////////////////
// Timestamp //
///////////////////////////////////////////////////////////////////
/* Get the timestamp of mPIPE when this routine is called.
*
* @param context An initialized mPIPE context.
* @param ts A timespec structure to store the current clock.
* @return If the call was successful, zero; otherwise, a negative error
* code.
*/
extern int gxio_mpipe_get_timestamp(gxio_mpipe_context_t *context,
struct timespec *ts);
/* Set the timestamp of mPIPE.
*
* @param context An initialized mPIPE context.
* @param ts A timespec structure to store the requested clock.
* @return If the call was successful, zero; otherwise, a negative error
* code.
*/
extern int gxio_mpipe_set_timestamp(gxio_mpipe_context_t *context,
const struct timespec *ts);
/* Adjust the timestamp of mPIPE.
*
* @param context An initialized mPIPE context.
* @param delta A signed time offset to adjust, in nanoseconds.
* The absolute value of this parameter must be less than or
* equal to 1000000000.
* @return If the call was successful, zero; otherwise, a negative error
* code.
*/
extern int gxio_mpipe_adjust_timestamp(gxio_mpipe_context_t *context,
int64_t delta);
/** Adjust the mPIPE timestamp clock frequency.
*
* @param context An initialized mPIPE context.
* @param ppb A 32-bit signed PPB (Parts Per Billion) value to adjust.
* The absolute value of ppb must be less than or equal to 1000000000.
* Values less than about 30000 will generally cause a GXIO_ERR_INVAL
* return due to the granularity of the hardware that converts reference
* clock cycles into seconds and nanoseconds.
* @return If the call was successful, zero; otherwise, a negative error
* code.
*/
extern int gxio_mpipe_adjust_timestamp_freq(gxio_mpipe_context_t* context,
int32_t ppb);
#endif /* !_GXIO_MPIPE_H_ */
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