mirror of https://gitee.com/openkylin/linux.git
powerpc/perf: Add support for the hv 24x7 interface
This provides a basic interface between hv_24x7 and perf. Similar to the one provided for gpci, it lacks transaction support and does not list any events. Example usage via perf tool: perf stat -e 'hv_24x7/domain=2,offset=8,starting_index=0,lpar=0xffffffff/' -r 0 -C 0 -x ' ' sleep 0.1 Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Cody P Schafer
Benjamin Herrenschmidt
parent
220a0c609a
commit
0e93a6edd9
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@ -0,0 +1,510 @@
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/*
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* Hypervisor supplied "24x7" performance counter support
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*
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* Author: Cody P Schafer <cody@linux.vnet.ibm.com>
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* Copyright 2014 IBM Corporation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#define pr_fmt(fmt) "hv-24x7: " fmt
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#include <linux/perf_event.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <asm/firmware.h>
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#include <asm/hvcall.h>
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#include <asm/io.h>
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#include "hv-24x7.h"
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#include "hv-24x7-catalog.h"
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#include "hv-common.h"
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/*
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* TODO: Merging events:
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* - Think of the hcall as an interface to a 4d array of counters:
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* - x = domains
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* - y = indexes in the domain (core, chip, vcpu, node, etc)
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* - z = offset into the counter space
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* - w = lpars (guest vms, "logical partitions")
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* - A single request is: x,y,y_last,z,z_last,w,w_last
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* - this means we can retrieve a rectangle of counters in y,z for a single x.
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*
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* - Things to consider (ignoring w):
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* - input cost_per_request = 16
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* - output cost_per_result(ys,zs) = 8 + 8 * ys + ys * zs
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* - limited number of requests per hcall (must fit into 4K bytes)
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* - 4k = 16 [buffer header] - 16 [request size] * request_count
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* - 255 requests per hcall
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* - sometimes it will be more efficient to read extra data and discard
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*/
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/*
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* Example usage:
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* perf stat -e 'hv_24x7/domain=2,offset=8,starting_index=0,lpar=0xffffffff/'
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*/
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/* u3 0-6, one of HV_24X7_PERF_DOMAIN */
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EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3);
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/* u16 */
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EVENT_DEFINE_RANGE_FORMAT(starting_index, config, 16, 31);
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/* u32, see "data_offset" */
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EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63);
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/* u16 */
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EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15);
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EVENT_DEFINE_RANGE(reserved1, config, 4, 15);
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EVENT_DEFINE_RANGE(reserved2, config1, 16, 63);
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EVENT_DEFINE_RANGE(reserved3, config2, 0, 63);
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static struct attribute *format_attrs[] = {
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&format_attr_domain.attr,
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&format_attr_offset.attr,
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&format_attr_starting_index.attr,
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&format_attr_lpar.attr,
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NULL,
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};
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static struct attribute_group format_group = {
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.name = "format",
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.attrs = format_attrs,
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};
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static struct kmem_cache *hv_page_cache;
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/*
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* read_offset_data - copy data from one buffer to another while treating the
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* source buffer as a small view on the total avaliable
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* source data.
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*
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* @dest: buffer to copy into
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* @dest_len: length of @dest in bytes
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* @requested_offset: the offset within the source data we want. Must be > 0
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* @src: buffer to copy data from
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* @src_len: length of @src in bytes
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* @source_offset: the offset in the sorce data that (src,src_len) refers to.
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* Must be > 0
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*
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* returns the number of bytes copied.
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*
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* The following ascii art shows the various buffer possitioning we need to
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* handle, assigns some arbitrary varibles to points on the buffer, and then
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* shows how we fiddle with those values to get things we care about (copy
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* start in src and copy len)
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*
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* s = @src buffer
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* d = @dest buffer
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* '.' areas in d are written to.
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*
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* u
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* x w v z
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* d |.........|
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* s |----------------------|
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*
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* u
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* x w z v
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* d |........------|
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* s |------------------|
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*
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* x w u,z,v
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* d |........|
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* s |------------------|
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*
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* x,w u,v,z
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* d |..................|
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* s |------------------|
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*
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* x u
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* w v z
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* d |........|
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* s |------------------|
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*
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* x z w v
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* d |------|
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* s |------|
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*
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* x = source_offset
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* w = requested_offset
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* z = source_offset + src_len
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* v = requested_offset + dest_len
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*
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* w_offset_in_s = w - x = requested_offset - source_offset
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* z_offset_in_s = z - x = src_len
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* v_offset_in_s = v - x = request_offset + dest_len - src_len
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*/
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static ssize_t read_offset_data(void *dest, size_t dest_len,
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loff_t requested_offset, void *src,
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size_t src_len, loff_t source_offset)
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{
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size_t w_offset_in_s = requested_offset - source_offset;
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size_t z_offset_in_s = src_len;
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size_t v_offset_in_s = requested_offset + dest_len - src_len;
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size_t u_offset_in_s = min(z_offset_in_s, v_offset_in_s);
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size_t copy_len = u_offset_in_s - w_offset_in_s;
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if (requested_offset < 0 || source_offset < 0)
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return -EINVAL;
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if (z_offset_in_s <= w_offset_in_s)
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return 0;
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memcpy(dest, src + w_offset_in_s, copy_len);
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return copy_len;
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}
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static unsigned long h_get_24x7_catalog_page(char page[static 4096],
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u32 version, u32 index)
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{
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WARN_ON(!IS_ALIGNED((unsigned long)page, 4096));
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return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE,
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virt_to_phys(page),
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version,
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index);
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}
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static ssize_t catalog_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr, char *buf,
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loff_t offset, size_t count)
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{
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unsigned long hret;
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ssize_t ret = 0;
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size_t catalog_len = 0, catalog_page_len = 0, page_count = 0;
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loff_t page_offset = 0;
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uint32_t catalog_version_num = 0;
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void *page = kmem_cache_alloc(hv_page_cache, GFP_USER);
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struct hv_24x7_catalog_page_0 *page_0 = page;
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if (!page)
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return -ENOMEM;
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hret = h_get_24x7_catalog_page(page, 0, 0);
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if (hret) {
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ret = -EIO;
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goto e_free;
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}
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catalog_version_num = be32_to_cpu(page_0->version);
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catalog_page_len = be32_to_cpu(page_0->length);
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catalog_len = catalog_page_len * 4096;
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page_offset = offset / 4096;
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page_count = count / 4096;
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if (page_offset >= catalog_page_len)
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goto e_free;
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if (page_offset != 0) {
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hret = h_get_24x7_catalog_page(page, catalog_version_num,
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page_offset);
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if (hret) {
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ret = -EIO;
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goto e_free;
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}
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}
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ret = read_offset_data(buf, count, offset,
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page, 4096, page_offset * 4096);
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e_free:
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if (hret)
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pr_err("h_get_24x7_catalog_page(ver=%d, page=%lld) failed: rc=%ld\n",
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catalog_version_num, page_offset, hret);
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kfree(page);
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pr_devel("catalog_read: offset=%lld(%lld) count=%zu(%zu) catalog_len=%zu(%zu) => %zd\n",
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offset, page_offset, count, page_count, catalog_len,
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catalog_page_len, ret);
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return ret;
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}
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#define PAGE_0_ATTR(_name, _fmt, _expr) \
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static ssize_t _name##_show(struct device *dev, \
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struct device_attribute *dev_attr, \
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char *buf) \
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{ \
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unsigned long hret; \
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ssize_t ret = 0; \
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void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \
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struct hv_24x7_catalog_page_0 *page_0 = page; \
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if (!page) \
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return -ENOMEM; \
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hret = h_get_24x7_catalog_page(page, 0, 0); \
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if (hret) { \
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ret = -EIO; \
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goto e_free; \
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} \
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ret = sprintf(buf, _fmt, _expr); \
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e_free: \
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kfree(page); \
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return ret; \
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} \
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static DEVICE_ATTR_RO(_name)
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PAGE_0_ATTR(catalog_version, "%lld\n",
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(unsigned long long)be32_to_cpu(page_0->version));
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PAGE_0_ATTR(catalog_len, "%lld\n",
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(unsigned long long)be32_to_cpu(page_0->length) * 4096);
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static BIN_ATTR_RO(catalog, 0/* real length varies */);
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static struct bin_attribute *if_bin_attrs[] = {
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&bin_attr_catalog,
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NULL,
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};
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static struct attribute *if_attrs[] = {
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&dev_attr_catalog_len.attr,
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&dev_attr_catalog_version.attr,
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NULL,
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};
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static struct attribute_group if_group = {
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.name = "interface",
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.bin_attrs = if_bin_attrs,
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.attrs = if_attrs,
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};
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static const struct attribute_group *attr_groups[] = {
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&format_group,
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&if_group,
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NULL,
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};
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static bool is_physical_domain(int domain)
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{
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return domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CHIP ||
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domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CORE;
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}
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static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix,
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u16 lpar, u64 *res,
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bool success_expected)
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{
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unsigned long ret;
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/*
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* request_buffer and result_buffer are not required to be 4k aligned,
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* but are not allowed to cross any 4k boundary. Aligning them to 4k is
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* the simplest way to ensure that.
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*/
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struct reqb {
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struct hv_24x7_request_buffer buf;
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struct hv_24x7_request req;
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} __packed __aligned(4096) request_buffer = {
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.buf = {
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.interface_version = HV_24X7_IF_VERSION_CURRENT,
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.num_requests = 1,
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},
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.req = {
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.performance_domain = domain,
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.data_size = cpu_to_be16(8),
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.data_offset = cpu_to_be32(offset),
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.starting_lpar_ix = cpu_to_be16(lpar),
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.max_num_lpars = cpu_to_be16(1),
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.starting_ix = cpu_to_be16(ix),
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.max_ix = cpu_to_be16(1),
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}
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};
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struct resb {
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struct hv_24x7_data_result_buffer buf;
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struct hv_24x7_result res;
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struct hv_24x7_result_element elem;
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__be64 result;
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} __packed __aligned(4096) result_buffer = {};
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ret = plpar_hcall_norets(H_GET_24X7_DATA,
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virt_to_phys(&request_buffer), sizeof(request_buffer),
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virt_to_phys(&result_buffer), sizeof(result_buffer));
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if (ret) {
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if (success_expected)
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pr_err_ratelimited("hcall failed: %d %#x %#x %d => 0x%lx (%ld) detail=0x%x failing ix=%x\n",
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domain, offset, ix, lpar,
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ret, ret,
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result_buffer.buf.detailed_rc,
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result_buffer.buf.failing_request_ix);
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return ret;
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}
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*res = be64_to_cpu(result_buffer.result);
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return ret;
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}
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static unsigned long event_24x7_request(struct perf_event *event, u64 *res,
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bool success_expected)
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{
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return single_24x7_request(event_get_domain(event),
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event_get_offset(event),
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event_get_starting_index(event),
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event_get_lpar(event),
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res,
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success_expected);
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}
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static int h_24x7_event_init(struct perf_event *event)
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{
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struct hv_perf_caps caps;
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unsigned domain;
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unsigned long hret;
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u64 ct;
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/* Not our event */
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if (event->attr.type != event->pmu->type)
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return -ENOENT;
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/* Unused areas must be 0 */
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if (event_get_reserved1(event) ||
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event_get_reserved2(event) ||
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event_get_reserved3(event)) {
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pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n",
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event->attr.config,
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event_get_reserved1(event),
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event->attr.config1,
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event_get_reserved2(event),
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event->attr.config2,
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event_get_reserved3(event));
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return -EINVAL;
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}
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/* unsupported modes and filters */
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if (event->attr.exclude_user ||
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event->attr.exclude_kernel ||
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event->attr.exclude_hv ||
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event->attr.exclude_idle ||
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event->attr.exclude_host ||
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event->attr.exclude_guest ||
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is_sampling_event(event)) /* no sampling */
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return -EINVAL;
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/* no branch sampling */
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if (has_branch_stack(event))
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return -EOPNOTSUPP;
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/* offset must be 8 byte aligned */
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if (event_get_offset(event) % 8) {
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pr_devel("bad alignment\n");
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return -EINVAL;
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}
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/* Domains above 6 are invalid */
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domain = event_get_domain(event);
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if (domain > 6) {
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pr_devel("invalid domain %d\n", domain);
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return -EINVAL;
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}
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hret = hv_perf_caps_get(&caps);
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if (hret) {
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pr_devel("could not get capabilities: rc=%ld\n", hret);
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return -EIO;
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}
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/* PHYSICAL domains & other lpars require extra capabilities */
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if (!caps.collect_privileged && (is_physical_domain(domain) ||
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(event_get_lpar(event) != event_get_lpar_max()))) {
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pr_devel("hv permisions disallow: is_physical_domain:%d, lpar=0x%llx\n",
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is_physical_domain(domain),
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event_get_lpar(event));
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return -EACCES;
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}
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/* see if the event complains */
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if (event_24x7_request(event, &ct, false)) {
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pr_devel("test hcall failed\n");
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return -EIO;
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}
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return 0;
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}
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static u64 h_24x7_get_value(struct perf_event *event)
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{
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unsigned long ret;
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u64 ct;
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ret = event_24x7_request(event, &ct, true);
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if (ret)
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/* We checked this in event init, shouldn't fail here... */
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return 0;
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return ct;
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}
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static void h_24x7_event_update(struct perf_event *event)
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{
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s64 prev;
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u64 now;
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now = h_24x7_get_value(event);
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prev = local64_xchg(&event->hw.prev_count, now);
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local64_add(now - prev, &event->count);
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}
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static void h_24x7_event_start(struct perf_event *event, int flags)
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{
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if (flags & PERF_EF_RELOAD)
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local64_set(&event->hw.prev_count, h_24x7_get_value(event));
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}
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static void h_24x7_event_stop(struct perf_event *event, int flags)
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{
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h_24x7_event_update(event);
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}
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static int h_24x7_event_add(struct perf_event *event, int flags)
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{
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if (flags & PERF_EF_START)
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h_24x7_event_start(event, flags);
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return 0;
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}
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static int h_24x7_event_idx(struct perf_event *event)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct pmu h_24x7_pmu = {
|
||||
.task_ctx_nr = perf_invalid_context,
|
||||
|
||||
.name = "hv_24x7",
|
||||
.attr_groups = attr_groups,
|
||||
.event_init = h_24x7_event_init,
|
||||
.add = h_24x7_event_add,
|
||||
.del = h_24x7_event_stop,
|
||||
.start = h_24x7_event_start,
|
||||
.stop = h_24x7_event_stop,
|
||||
.read = h_24x7_event_update,
|
||||
.event_idx = h_24x7_event_idx,
|
||||
};
|
||||
|
||||
static int hv_24x7_init(void)
|
||||
{
|
||||
int r;
|
||||
unsigned long hret;
|
||||
struct hv_perf_caps caps;
|
||||
|
||||
if (!firmware_has_feature(FW_FEATURE_LPAR)) {
|
||||
pr_info("not a virtualized system, not enabling\n");
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
hret = hv_perf_caps_get(&caps);
|
||||
if (hret) {
|
||||
pr_info("could not obtain capabilities, error 0x%80lx, not enabling\n",
|
||||
hret);
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL);
|
||||
if (!hv_page_cache)
|
||||
return -ENOMEM;
|
||||
|
||||
r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
|
||||
if (r)
|
||||
return r;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
device_initcall(hv_24x7_init);
|
||||
Loading…
Reference in New Issue