linux/arch/tile/gxio/kiorpc.c

62 lines
1.7 KiB
C

/*
* 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.
*
* TILE-Gx IORPC support for kernel I/O drivers.
*/
#include <linux/mmzone.h>
#include <linux/module.h>
#include <linux/io.h>
#include <gxio/iorpc_globals.h>
#include <gxio/kiorpc.h>
#ifdef DEBUG_IORPC
#define TRACE(FMT, ...) pr_info(SIMPLE_MSG_LINE FMT, ## __VA_ARGS__)
#else
#define TRACE(...)
#endif
/* Create kernel-VA-space MMIO mapping for an on-chip IO device. */
void __iomem *iorpc_ioremap(int hv_fd, resource_size_t offset,
unsigned long size)
{
pgprot_t mmio_base, prot = { 0 };
unsigned long pfn;
int err;
/* Look up the shim's lotar and base PA. */
err = __iorpc_get_mmio_base(hv_fd, &mmio_base);
if (err) {
TRACE("get_mmio_base() failure: %d\n", err);
return NULL;
}
/* Make sure the HV driver approves of our offset and size. */
err = __iorpc_check_mmio_offset(hv_fd, offset, size);
if (err) {
TRACE("check_mmio_offset() failure: %d\n", err);
return NULL;
}
/*
* mmio_base contains a base pfn and homing coordinates. Turn
* it into an MMIO pgprot and offset pfn.
*/
prot = hv_pte_set_lotar(prot, hv_pte_get_lotar(mmio_base));
pfn = pte_pfn(mmio_base) + PFN_DOWN(offset);
return ioremap_prot(PFN_PHYS(pfn), size, prot);
}
EXPORT_SYMBOL(iorpc_ioremap);