[1/2] ACPI: Introduce acpi_os_ioremap()

Rafael J. Wysocki
2011-01-19T21:29:19Z

From: Rafael J. Wysocki <rjw@sisk.pl>

Commit ca9b600 (ACPI / PM: Make suspend_nvs_save() use
acpi_os_map_memory()) attempted to prevent the code in osl.c and
nvs.c from using different ioremap() variants by making the latter
use acpi_os_map_memory() for mapping the NVS pages. However, that
also requires acpi_os_unmap_memory() to be used for unmapping them,
which causes synchronize_rcu() to be executed many times in a row
unnecessarily and introduces substantial delays during resume on
some systems.

Instead of using acpi_os_map_memory() for mapping the NVS pages in
nvs.c introduce acpi_os_ioremap() calling ioremap_cache() and make
the code in both osl.c and nvs.c use it.

Reported-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/acpi/nvs.c | 7 ++++---
drivers/acpi/osl.c | 12 +++++++-----
include/linux/acpi.h | 3 ---
include/linux/acpi_io.h | 16 ++++++++++++++++
4 files changed, 27 insertions(+), 11 deletions(-)

Index: linux-2.6/drivers/acpi/osl.c
===================================================================
--- linux-2.6.orig/drivers/acpi/osl.c
+++ linux-2.6/drivers/acpi/osl.c
@@ -38,6 +38,7 @@
#include <linux/workqueue.h>
#include <linux/nmi.h>
#include <linux/acpi.h>
+#include <linux/acpi_io.h>
#include <linux/efi.h>
#include <linux/ioport.h>
#include <linux/list.h>
@@ -302,9 +303,10 @@ void __iomem *__init_refok
acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
{
struct acpi_ioremap *map, *tmp_map;
- unsigned long flags, pg_sz;
+ unsigned long flags;
void __iomem *virt;
- phys_addr_t pg_off;
+ acpi_physical_address pg_off;
+ acpi_size pg_sz;

if (phys > ULONG_MAX) {
printk(KERN_ERR PREFIX "Cannot map memory that high\n");
@@ -320,7 +322,7 @@ acpi_os_map_memory(acpi_physical_address

pg_off = round_down(phys, PAGE_SIZE);
pg_sz = round_up(phys + size, PAGE_SIZE) - pg_off;
- virt = ioremap_cache(pg_off, pg_sz);
+ virt = acpi_os_ioremap(pg_off, pg_sz);
if (!virt) {
kfree(map);
return NULL;
@@ -642,7 +644,7 @@ acpi_os_read_memory(acpi_physical_addres
virt_addr = acpi_map_vaddr_lookup(phys_addr, size);
rcu_read_unlock();
if (!virt_addr) {
- virt_addr = ioremap_cache(phys_addr, size);
+ virt_addr = acpi_os_ioremap(phys_addr, size);
unmap = 1;
}
if (!value)
@@ -678,7 +680,7 @@ acpi_os_write_memory(acpi_physical_addre
virt_addr = acpi_map_vaddr_lookup(phys_addr, size);
rcu_read_unlock();
if (!virt_addr) {
- virt_addr = ioremap_cache(phys_addr, size);
+ virt_addr = acpi_os_ioremap(phys_addr, size);
unmap = 1;
}

Index: linux-2.6/drivers/acpi/nvs.c
===================================================================
--- linux-2.6.orig/drivers/acpi/nvs.c
+++ linux-2.6/drivers/acpi/nvs.c
@@ -12,6 +12,7 @@
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/acpi.h>
+#include <linux/acpi_io.h>
#include <acpi/acpiosxf.h>

/*
@@ -80,7 +81,7 @@ void suspend_nvs_free(void)
free_page((unsigned long)entry->data);
entry->data = NULL;
if (entry->kaddr) {
- acpi_os_unmap_memory(entry->kaddr, entry->size);
+ iounmap(entry->kaddr);
entry->kaddr = NULL;
}
}
@@ -114,8 +115,8 @@ int suspend_nvs_save(void)

list_for_each_entry(entry, &nvs_list, node)
if (entry->data) {
- entry->kaddr = acpi_os_map_memory(entry->phys_start,
- entry->size);
+ entry->kaddr = acpi_os_ioremap(entry->phys_start,
+ entry->size);
if (!entry->kaddr) {
suspend_nvs_free();
return -ENOMEM;
Index: linux-2.6/include/linux/acpi.h
===================================================================
--- linux-2.6.orig/include/linux/acpi.h
+++ linux-2.6/include/linux/acpi.h
@@ -306,9 +306,6 @@ extern acpi_status acpi_pci_osc_control_
u32 *mask, u32 req);
extern void acpi_early_init(void);

-int acpi_os_map_generic_address(struct acpi_generic_address *addr);
-void acpi_os_unmap_generic_address(struct acpi_generic_address *addr);
-
#else /* !CONFIG_ACPI */

#define acpi_disabled 1
Index: linux-2.6/include/linux/acpi_io.h
===================================================================
--- /dev/null
+++ linux-2.6/include/linux/acpi_io.h
@@ -0,0 +1,16 @@
+#ifndef _ACPI_IO_H_
+#define _ACPI_IO_H_
+
+#include <linux/io.h>
+#include <acpi/acpi.h>
+
+static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
+ acpi_size size)
+{
+ return ioremap_cache(phys, size);
+}
+
+int acpi_os_map_generic_address(struct acpi_generic_address *addr);
+void acpi_os_unmap_generic_address(struct acpi_generic_address *addr);
+
+#endif