362 lines
8.2 KiB
C
362 lines
8.2 KiB
C
/*
|
|
* atomicio.c - ACPI IO memory pre-mapping/post-unmapping, then
|
|
* accessing in atomic context.
|
|
*
|
|
* This is used for NMI handler to access IO memory area, because
|
|
* ioremap/iounmap can not be used in NMI handler. The IO memory area
|
|
* is pre-mapped in process context and accessed in NMI handler.
|
|
*
|
|
* Copyright (C) 2009-2010, Intel Corp.
|
|
* Author: Huang Ying <ying.huang@intel.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License version
|
|
* 2 as published by the Free Software Foundation.
|
|
*
|
|
* 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. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/acpi.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kref.h>
|
|
#include <linux/rculist.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/slab.h>
|
|
#include <acpi/atomicio.h>
|
|
|
|
#define ACPI_PFX "ACPI: "
|
|
|
|
static LIST_HEAD(acpi_iomaps);
|
|
/*
|
|
* Used for mutual exclusion between writers of acpi_iomaps list, for
|
|
* synchronization between readers and writer, RCU is used.
|
|
*/
|
|
static DEFINE_SPINLOCK(acpi_iomaps_lock);
|
|
|
|
struct acpi_iomap {
|
|
struct list_head list;
|
|
void __iomem *vaddr;
|
|
unsigned long size;
|
|
phys_addr_t paddr;
|
|
struct kref ref;
|
|
};
|
|
|
|
/* acpi_iomaps_lock or RCU read lock must be held before calling */
|
|
static struct acpi_iomap *__acpi_find_iomap(phys_addr_t paddr,
|
|
unsigned long size)
|
|
{
|
|
struct acpi_iomap *map;
|
|
|
|
list_for_each_entry_rcu(map, &acpi_iomaps, list) {
|
|
if (map->paddr + map->size >= paddr + size &&
|
|
map->paddr <= paddr)
|
|
return map;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Atomic "ioremap" used by NMI handler, if the specified IO memory
|
|
* area is not pre-mapped, NULL will be returned.
|
|
*
|
|
* acpi_iomaps_lock or RCU read lock must be held before calling
|
|
*/
|
|
static void __iomem *__acpi_ioremap_fast(phys_addr_t paddr,
|
|
unsigned long size)
|
|
{
|
|
struct acpi_iomap *map;
|
|
|
|
map = __acpi_find_iomap(paddr, size);
|
|
if (map)
|
|
return map->vaddr + (paddr - map->paddr);
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
/* acpi_iomaps_lock must be held before calling */
|
|
static void __iomem *__acpi_try_ioremap(phys_addr_t paddr,
|
|
unsigned long size)
|
|
{
|
|
struct acpi_iomap *map;
|
|
|
|
map = __acpi_find_iomap(paddr, size);
|
|
if (map) {
|
|
kref_get(&map->ref);
|
|
return map->vaddr + (paddr - map->paddr);
|
|
} else
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Used to pre-map the specified IO memory area. First try to find
|
|
* whether the area is already pre-mapped, if it is, increase the
|
|
* reference count (in __acpi_try_ioremap) and return; otherwise, do
|
|
* the real ioremap, and add the mapping into acpi_iomaps list.
|
|
*/
|
|
static void __iomem *acpi_pre_map(phys_addr_t paddr,
|
|
unsigned long size)
|
|
{
|
|
void __iomem *vaddr;
|
|
struct acpi_iomap *map;
|
|
unsigned long pg_sz, flags;
|
|
phys_addr_t pg_off;
|
|
|
|
spin_lock_irqsave(&acpi_iomaps_lock, flags);
|
|
vaddr = __acpi_try_ioremap(paddr, size);
|
|
spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
|
|
if (vaddr)
|
|
return vaddr;
|
|
|
|
pg_off = paddr & PAGE_MASK;
|
|
pg_sz = ((paddr + size + PAGE_SIZE - 1) & PAGE_MASK) - pg_off;
|
|
vaddr = ioremap(pg_off, pg_sz);
|
|
if (!vaddr)
|
|
return NULL;
|
|
map = kmalloc(sizeof(*map), GFP_KERNEL);
|
|
if (!map)
|
|
goto err_unmap;
|
|
INIT_LIST_HEAD(&map->list);
|
|
map->paddr = pg_off;
|
|
map->size = pg_sz;
|
|
map->vaddr = vaddr;
|
|
kref_init(&map->ref);
|
|
|
|
spin_lock_irqsave(&acpi_iomaps_lock, flags);
|
|
vaddr = __acpi_try_ioremap(paddr, size);
|
|
if (vaddr) {
|
|
spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
|
|
iounmap(map->vaddr);
|
|
kfree(map);
|
|
return vaddr;
|
|
}
|
|
list_add_tail_rcu(&map->list, &acpi_iomaps);
|
|
spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
|
|
|
|
return vaddr + (paddr - pg_off);
|
|
err_unmap:
|
|
iounmap(vaddr);
|
|
return NULL;
|
|
}
|
|
|
|
/* acpi_iomaps_lock must be held before calling */
|
|
static void __acpi_kref_del_iomap(struct kref *ref)
|
|
{
|
|
struct acpi_iomap *map;
|
|
|
|
map = container_of(ref, struct acpi_iomap, ref);
|
|
list_del_rcu(&map->list);
|
|
}
|
|
|
|
/*
|
|
* Used to post-unmap the specified IO memory area. The iounmap is
|
|
* done only if the reference count goes zero.
|
|
*/
|
|
static void acpi_post_unmap(phys_addr_t paddr, unsigned long size)
|
|
{
|
|
struct acpi_iomap *map;
|
|
unsigned long flags;
|
|
int del;
|
|
|
|
spin_lock_irqsave(&acpi_iomaps_lock, flags);
|
|
map = __acpi_find_iomap(paddr, size);
|
|
BUG_ON(!map);
|
|
del = kref_put(&map->ref, __acpi_kref_del_iomap);
|
|
spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
|
|
|
|
if (!del)
|
|
return;
|
|
|
|
synchronize_rcu();
|
|
iounmap(map->vaddr);
|
|
kfree(map);
|
|
}
|
|
|
|
/* In NMI handler, should set silent = 1 */
|
|
static int acpi_check_gar(struct acpi_generic_address *reg,
|
|
u64 *paddr, int silent)
|
|
{
|
|
u32 width, space_id;
|
|
|
|
width = reg->bit_width;
|
|
space_id = reg->space_id;
|
|
/* Handle possible alignment issues */
|
|
memcpy(paddr, ®->address, sizeof(*paddr));
|
|
if (!*paddr) {
|
|
if (!silent)
|
|
pr_warning(FW_BUG ACPI_PFX
|
|
"Invalid physical address in GAR [0x%llx/%u/%u]\n",
|
|
*paddr, width, space_id);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if ((width != 8) && (width != 16) && (width != 32) && (width != 64)) {
|
|
if (!silent)
|
|
pr_warning(FW_BUG ACPI_PFX
|
|
"Invalid bit width in GAR [0x%llx/%u/%u]\n",
|
|
*paddr, width, space_id);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY &&
|
|
space_id != ACPI_ADR_SPACE_SYSTEM_IO) {
|
|
if (!silent)
|
|
pr_warning(FW_BUG ACPI_PFX
|
|
"Invalid address space type in GAR [0x%llx/%u/%u]\n",
|
|
*paddr, width, space_id);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Pre-map, working on GAR */
|
|
int acpi_pre_map_gar(struct acpi_generic_address *reg)
|
|
{
|
|
u64 paddr;
|
|
void __iomem *vaddr;
|
|
int rc;
|
|
|
|
if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
|
|
return 0;
|
|
|
|
rc = acpi_check_gar(reg, &paddr, 0);
|
|
if (rc)
|
|
return rc;
|
|
|
|
vaddr = acpi_pre_map(paddr, reg->bit_width / 8);
|
|
if (!vaddr)
|
|
return -EIO;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(acpi_pre_map_gar);
|
|
|
|
/* Post-unmap, working on GAR */
|
|
int acpi_post_unmap_gar(struct acpi_generic_address *reg)
|
|
{
|
|
u64 paddr;
|
|
int rc;
|
|
|
|
if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
|
|
return 0;
|
|
|
|
rc = acpi_check_gar(reg, &paddr, 0);
|
|
if (rc)
|
|
return rc;
|
|
|
|
acpi_post_unmap(paddr, reg->bit_width / 8);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(acpi_post_unmap_gar);
|
|
|
|
/*
|
|
* Can be used in atomic (including NMI) or process context. RCU read
|
|
* lock can only be released after the IO memory area accessing.
|
|
*/
|
|
static int acpi_atomic_read_mem(u64 paddr, u64 *val, u32 width)
|
|
{
|
|
void __iomem *addr;
|
|
|
|
rcu_read_lock();
|
|
addr = __acpi_ioremap_fast(paddr, width);
|
|
switch (width) {
|
|
case 8:
|
|
*val = readb(addr);
|
|
break;
|
|
case 16:
|
|
*val = readw(addr);
|
|
break;
|
|
case 32:
|
|
*val = readl(addr);
|
|
break;
|
|
case 64:
|
|
*val = readq(addr);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int acpi_atomic_write_mem(u64 paddr, u64 val, u32 width)
|
|
{
|
|
void __iomem *addr;
|
|
|
|
rcu_read_lock();
|
|
addr = __acpi_ioremap_fast(paddr, width);
|
|
switch (width) {
|
|
case 8:
|
|
writeb(val, addr);
|
|
break;
|
|
case 16:
|
|
writew(val, addr);
|
|
break;
|
|
case 32:
|
|
writel(val, addr);
|
|
break;
|
|
case 64:
|
|
writeq(val, addr);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* GAR accessing in atomic (including NMI) or process context */
|
|
int acpi_atomic_read(u64 *val, struct acpi_generic_address *reg)
|
|
{
|
|
u64 paddr;
|
|
int rc;
|
|
|
|
rc = acpi_check_gar(reg, &paddr, 1);
|
|
if (rc)
|
|
return rc;
|
|
|
|
*val = 0;
|
|
switch (reg->space_id) {
|
|
case ACPI_ADR_SPACE_SYSTEM_MEMORY:
|
|
return acpi_atomic_read_mem(paddr, val, reg->bit_width);
|
|
case ACPI_ADR_SPACE_SYSTEM_IO:
|
|
return acpi_os_read_port(paddr, (u32 *)val, reg->bit_width);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(acpi_atomic_read);
|
|
|
|
int acpi_atomic_write(u64 val, struct acpi_generic_address *reg)
|
|
{
|
|
u64 paddr;
|
|
int rc;
|
|
|
|
rc = acpi_check_gar(reg, &paddr, 1);
|
|
if (rc)
|
|
return rc;
|
|
|
|
switch (reg->space_id) {
|
|
case ACPI_ADR_SPACE_SYSTEM_MEMORY:
|
|
return acpi_atomic_write_mem(paddr, val, reg->bit_width);
|
|
case ACPI_ADR_SPACE_SYSTEM_IO:
|
|
return acpi_os_write_port(paddr, val, reg->bit_width);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(acpi_atomic_write);
|