ACPI: Introduce acpi_os_ioremap()

Commit ca9b600be3 ("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>
This commit is contained in:
Rafael J. Wysocki 2011-01-19 22:27:14 +01:00 committed by Linus Torvalds
parent 8d99641f6c
commit 2d6d9fd3a5
4 changed files with 27 additions and 11 deletions

View file

@ -306,9 +306,6 @@ extern acpi_status acpi_pci_osc_control_set(acpi_handle handle,
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