Modify the NVS save/restore code to use acpi_os_get_iomem() and
acpi_os_unmap_memory() to acquire and release references to ACPI
iomaps, respectively. If there's no ACPI iomap corresponding to the
given NVS page, acpi_os_ioremap() is used to map that page and
iounmap() is used to unmap it during resume. [If the page is not
present in the ACPI iomaps already, it doesn't make sense to add its
mapping to the list of ACPI iomaps, because it's going to be thrown
away during the subsequent resume anyway.]
Testing on my HP nx6325 shows that approx. 90% of the NVS pages
have already been mapped by ACPI before suspend and are present in
the ACPI iomaps, so this change appears to be the right thing to do
in general.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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>
It turns out that the NVS memory region that suspend_nvs_save()
attempts to map has been already mapped by acpi_os_map_memory(), so
suspend_nvs_save() should better use acpi_os_map_memory() for mapping
memory to avoid conflicts.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
The file information and the list of include in drivers/acpi/nvs.c
are outdated, so update them.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
The saving of the ACPI NVS area during hibernation and suspend and
restoring it during the subsequent resume is entirely specific to
ACPI, so move it to drivers/acpi and drop the CONFIG_SUSPEND_NVS
configuration option which is redundant.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Rafael J. Wysocki