+++ /dev/null
-/*
- * 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/export.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 <linux/mm.h>
-#include <linux/highmem.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/8);
- 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;
-}
-
-#ifndef CONFIG_IA64
-#define should_use_kmap(pfn) page_is_ram(pfn)
-#else
-/* ioremap will take care of cache attributes */
-#define should_use_kmap(pfn) 0
-#endif
-
-static void __iomem *acpi_map(phys_addr_t pg_off, unsigned long pg_sz)
-{
- unsigned long pfn;
-
- pfn = pg_off >> PAGE_SHIFT;
- if (should_use_kmap(pfn)) {
- if (pg_sz > PAGE_SIZE)
- return NULL;
- return (void __iomem __force *)kmap(pfn_to_page(pfn));
- } else
- return ioremap(pg_off, pg_sz);
-}
-
-static void acpi_unmap(phys_addr_t pg_off, void __iomem *vaddr)
-{
- unsigned long pfn;
-
- pfn = pg_off >> PAGE_SHIFT;
- if (page_is_ram(pfn))
- kunmap(pfn_to_page(pfn));
- else
- iounmap(vaddr);
-}
-
-/*
- * 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 = acpi_map(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);
- acpi_unmap(pg_off, map->vaddr);
- kfree(map);
- return vaddr;
- }
- list_add_tail_rcu(&map->list, &acpi_iomaps);
- spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
-
- return map->vaddr + (paddr - map->paddr);
-err_unmap:
- acpi_unmap(pg_off, 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();
- acpi_unmap(map->paddr, 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);
-
-#ifdef readq
-static inline u64 read64(const volatile void __iomem *addr)
-{
- return readq(addr);
-}
-#else
-static inline u64 read64(const volatile void __iomem *addr)
-{
- u64 l, h;
- l = readl(addr);
- h = readl(addr+4);
- return l | (h << 32);
-}
-#endif
-
-/*
- * 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 = read64(addr);
- break;
- default:
- return -EINVAL;
- }
- rcu_read_unlock();
-
- return 0;
-}
-
-#ifdef writeq
-static inline void write64(u64 val, volatile void __iomem *addr)
-{
- writeq(val, addr);
-}
-#else
-static inline void write64(u64 val, volatile void __iomem *addr)
-{
- writel(val, addr);
- writel(val>>32, addr+4);
-}
-#endif
-
-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:
- write64(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);
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff