[PATCH v6 5/6] ACPI: do not map/unmap memory regions for FADT entries in reduced HW mode
From: Rafael J. Wysocki <hidden>
Date: 2014-01-10 23:32:18
Also in:
linux-acpi
On Friday, January 10, 2014 03:52:19 PM al.stone at linaro.org wrote:
From: Al Stone <redacted> Several of the FADT fields are normally kept in specific memory regions. Since these fields are to be ignored in hardware reduced ACPI mode, do not map those addresses when in that mode, and of course do not release the mappings that have not been made. The function acpi_os_initialize() could become a stub in the header file but is left here in case it can be of further use.
Why exactly is this change necessary? Will things work incorrectly on HW-reduced ACPI systems if we don't make it?
quoted hunk ↗ jump to hunk
Signed-off-by: Al Stone <redacted> --- drivers/acpi/osl.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index c946a3a..7822821 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c@@ -1778,10 +1778,12 @@ __setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup); acpi_status __init acpi_os_initialize(void) { - acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1a_event_block); - acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1b_event_block); - acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe0_block); - acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe1_block); + if (!acpi_gbl_reduced_hardware) { + acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1a_event_block); + acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1b_event_block); + acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe0_block); + acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe1_block); + } return AE_OK; }@@ -1806,10 +1808,12 @@ acpi_status acpi_os_terminate(void) acpi_irq_handler); } - acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe1_block); - acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe0_block); - acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1b_event_block); - acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1a_event_block); + if (!acpi_gbl_reduced_hardware) { + acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe1_block); + acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe0_block); + acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1b_event_block); + acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1a_event_block); + } destroy_workqueue(kacpid_wq); destroy_workqueue(kacpi_notify_wq);
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.