ACPI: Introduce acpi_os_ioremap()
Commit ca9b600be38c ("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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/acpi/nvs.c b/drivers/acpi/nvs.c
index 54b6ab8..fa5a1df 100644
--- a/drivers/acpi/nvs.c
+++ b/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 @@
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 @@
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;