On Thursday, September 29, 2011, Myron Stowe wrote: > From: Myron Stowe <mstowe@xxxxxxxxxx> > > APEI needs memory access in interrupt context. The obvious choice is > acpi_read(), but originally it couldn't be used in interrupt context > because it makes temporary mappings with ioremap(). Therefore, we added > drivers/acpi/atomicio.c, which provides: > acpi_pre_map_gar() <-- ioremap in process context > acpi_atomic_read() <-- memory access in interrupt context > acpi_post_unmap_gar() <-- iounmap > > Later we added acpi_os_map_generic_address() (2971852) and enhanced > acpi_read() so it works in interrupt context as long as the address has > been previously mapped (620242a). Now this sequence: > acpi_os_map_generic_address() <-- ioremap in process context > acpi_read() <-- now OK in interrupt context > acpi_os_unmap_generic_address() > is equivalent to what atomicio.c provides. > > > This patch converts APEI to use the existing calls within osl.c and the > CA, based on the re-factoring that was done in an earlier patch series - > http://marc.info/?l=linux-acpi&m=128769263327206&w=2 > acpi_pre_map_gar() --> acpi_os_map_generic_address() > acpi_post_unmap_gar() --> acpi_os_unmap_generic_address() > acpi_atomic_read() --> acpi_read() > acpi_atomic_write() --> acpi_write() > and removes atomicio.[ch]. > > Signed-off-by: Myron Stowe <myron.stowe@xxxxxxxxxx> Makes sense to me. Reviewed-by: Rafael J. Wysocki <rjw@xxxxxxx> > --- > > drivers/acpi/Makefile | 1 > drivers/acpi/apei/apei-base.c | 12 + > drivers/acpi/apei/ghes.c | 10 + > drivers/acpi/atomicio.c | 365 ----------------------------------------- > include/acpi/atomicio.h | 10 - > 5 files changed, 11 insertions(+), 387 deletions(-) > delete mode 100644 drivers/acpi/atomicio.c > delete mode 100644 include/acpi/atomicio.h > > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index ecb26b4..e7c1d0f 100644 > --- a/drivers/acpi/Makefile > +++ b/drivers/acpi/Makefile > @@ -19,7 +19,6 @@ obj-y += acpi.o \ > > # All the builtin files are in the "acpi." module_param namespace. > acpi-y += osl.o utils.o reboot.o > -acpi-y += atomicio.o > > # sleep related files > acpi-y += wakeup.o > diff --git a/drivers/acpi/apei/apei-base.c b/drivers/acpi/apei/apei-base.c > index 6154036..2ea95ec 100644 > --- a/drivers/acpi/apei/apei-base.c > +++ b/drivers/acpi/apei/apei-base.c > @@ -34,13 +34,13 @@ > #include <linux/module.h> > #include <linux/init.h> > #include <linux/acpi.h> > +#include <linux/acpi_io.h> > #include <linux/slab.h> > #include <linux/io.h> > #include <linux/kref.h> > #include <linux/rculist.h> > #include <linux/interrupt.h> > #include <linux/debugfs.h> > -#include <acpi/atomicio.h> > > #include "apei-internal.h" > > @@ -70,7 +70,7 @@ int __apei_exec_read_register(struct acpi_whea_header *entry, u64 *val) > { > int rc; > > - rc = acpi_atomic_read(val, &entry->register_region); > + rc = acpi_read(val, &entry->register_region); > if (rc) > return rc; > *val >>= entry->register_region.bit_offset; > @@ -116,13 +116,13 @@ int __apei_exec_write_register(struct acpi_whea_header *entry, u64 val) > val <<= entry->register_region.bit_offset; > if (entry->flags & APEI_EXEC_PRESERVE_REGISTER) { > u64 valr = 0; > - rc = acpi_atomic_read(&valr, &entry->register_region); > + rc = acpi_read(&valr, &entry->register_region); > if (rc) > return rc; > valr &= ~(entry->mask << entry->register_region.bit_offset); > val |= valr; > } > - rc = acpi_atomic_write(val, &entry->register_region); > + rc = acpi_write(val, &entry->register_region); > > return rc; > } > @@ -243,7 +243,7 @@ static int pre_map_gar_callback(struct apei_exec_context *ctx, > u8 ins = entry->instruction; > > if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER) > - return acpi_pre_map_gar(&entry->register_region); > + return acpi_os_map_generic_address(&entry->register_region); > > return 0; > } > @@ -276,7 +276,7 @@ static int post_unmap_gar_callback(struct apei_exec_context *ctx, > u8 ins = entry->instruction; > > if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER) > - acpi_post_unmap_gar(&entry->register_region); > + acpi_os_unmap_generic_address(&entry->register_region); > > return 0; > } > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index 0784f99..9814e05 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -33,6 +33,7 @@ > #include <linux/module.h> > #include <linux/init.h> > #include <linux/acpi.h> > +#include <linux/acpi_io.h> > #include <linux/io.h> > #include <linux/interrupt.h> > #include <linux/timer.h> > @@ -46,7 +47,6 @@ > #include <linux/llist.h> > #include <linux/genalloc.h> > #include <acpi/apei.h> > -#include <acpi/atomicio.h> > #include <acpi/hed.h> > #include <asm/mce.h> > #include <asm/tlbflush.h> > @@ -298,7 +298,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic) > if (!ghes) > return ERR_PTR(-ENOMEM); > ghes->generic = generic; > - rc = acpi_pre_map_gar(&generic->error_status_address); > + rc = acpi_os_map_generic_address(&generic->error_status_address); > if (rc) > goto err_free; > error_block_length = generic->error_block_length; > @@ -318,7 +318,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic) > return ghes; > > err_unmap: > - acpi_post_unmap_gar(&generic->error_status_address); > + acpi_os_unmap_generic_address(&generic->error_status_address); > err_free: > kfree(ghes); > return ERR_PTR(rc); > @@ -327,7 +327,7 @@ err_free: > static void ghes_fini(struct ghes *ghes) > { > kfree(ghes->estatus); > - acpi_post_unmap_gar(&ghes->generic->error_status_address); > + acpi_os_unmap_generic_address(&ghes->generic->error_status_address); > } > > enum { > @@ -398,7 +398,7 @@ static int ghes_read_estatus(struct ghes *ghes, int silent) > u32 len; > int rc; > > - rc = acpi_atomic_read(&buf_paddr, &g->error_status_address); > + rc = acpi_read(&buf_paddr, &g->error_status_address); > if (rc) { > if (!silent && printk_ratelimit()) > pr_warning(FW_WARN GHES_PFX > diff --git a/drivers/acpi/atomicio.c b/drivers/acpi/atomicio.c > deleted file mode 100644 > index 7489b89..0000000 > --- a/drivers/acpi/atomicio.c > +++ /dev/null > @@ -1,365 +0,0 @@ > -/* > - * 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@xxxxxxxxx> > - * > - * 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 map->vaddr + (paddr - map->paddr); > -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; > -#ifdef readq > - case 64: > - *val = readq(addr); > - break; > -#endif > - 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; > -#ifdef writeq > - case 64: > - writeq(val, addr); > - break; > -#endif > - 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); > diff --git a/include/acpi/atomicio.h b/include/acpi/atomicio.h > deleted file mode 100644 > index 8b9fb4b..0000000 > --- a/include/acpi/atomicio.h > +++ /dev/null > @@ -1,10 +0,0 @@ > -#ifndef ACPI_ATOMIC_IO_H > -#define ACPI_ATOMIC_IO_H > - > -int acpi_pre_map_gar(struct acpi_generic_address *reg); > -int acpi_post_unmap_gar(struct acpi_generic_address *reg); > - > -int acpi_atomic_read(u64 *val, struct acpi_generic_address *reg); > -int acpi_atomic_write(u64 val, struct acpi_generic_address *reg); > - > -#endif > > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
