ACPI: PM: s2idle: Enable Low-Power S0 Idle MSFT UUID for non-AMD systems

Systems based on Intel platforms that use the MSFT UUID for Low-Power S0
Idle (LPS0) have started to ship, so allow the kernel to use the MSFT
UUID in the non-AMD case too, but in that case make it avoid evaluating
the same _DSM function for two different UUIDs and prioritize the MSFT
one.

While at it, combine two MSFT _DSM function mask checks in
acpi_s2idle_restore_early() so as to make it reflect the
acpi_s2idle_prepare_late() flow more closely and adjust the
Modern Standby entry and exit comments slightly.

Non-AMD systems that do not support MSFT UUID for Low-power S0 Idle are
not expected to be affected by this change in any way.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>

diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
index 7d64e655f1b86c875856af23a2a1d2c5bcc680dc..cd84af23f7eac8fad793c6393bcd8130596077ce 100644 (file)
--- a/drivers/acpi/x86/s2idle.c
+++ b/drivers/acpi/x86/s2idle.c
@@ -488,7 +488,21 @@ static int lps0_device_attach(struct acpi_device *adev,
                rev_id = 1;
                lps0_dsm_func_mask = validate_dsm(adev->handle,
                                        ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid);
-               lps0_dsm_func_mask_microsoft = -EINVAL;
+               if (lps0_dsm_func_mask > 0 && lps0_dsm_func_mask_microsoft > 0) {
+                       unsigned int func_mask;
+
+                       /*
+                        * Avoid evaluating the same _DSM function for two
+                        * different UUIDs and prioritize the MSFT one.
+                        */
+                       func_mask = lps0_dsm_func_mask & lps0_dsm_func_mask_microsoft;
+                       if (func_mask) {
+                               acpi_handle_info(adev->handle,
+                                                "Duplicate LPS0 _DSM functions (mask: 0x%x)\n",
+                                                func_mask);
+                               lps0_dsm_func_mask &= ~func_mask;
+                       }
+               }
        }
 
        if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0)
@@ -549,19 +563,22 @@ int acpi_s2idle_prepare_late(void)
                                lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
 
        /* LPS0 entry */
-       if (lps0_dsm_func_mask > 0)
-               acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
-                                       ACPI_LPS0_ENTRY_AMD :
-                                       ACPI_LPS0_ENTRY,
+       if (lps0_dsm_func_mask > 0 && acpi_s2idle_vendor_amd())
+               acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY_AMD,
                                        lps0_dsm_func_mask, lps0_dsm_guid);
+
        if (lps0_dsm_func_mask_microsoft > 0) {
-               /* modern standby entry */
+               /* Modern Standby entry */
                acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY,
                                lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
                acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
                                lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
        }
 
+       if (lps0_dsm_func_mask > 0 && !acpi_s2idle_vendor_amd())
+               acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
+                                       lps0_dsm_func_mask, lps0_dsm_guid);
+
        list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
                if (handler->prepare)
                        handler->prepare();
@@ -600,14 +617,14 @@ void acpi_s2idle_restore_early(void)
                                        ACPI_LPS0_EXIT_AMD :
                                        ACPI_LPS0_EXIT,
                                        lps0_dsm_func_mask, lps0_dsm_guid);
-       if (lps0_dsm_func_mask_microsoft > 0)
+
+       if (lps0_dsm_func_mask_microsoft > 0) {
                acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT,
                                lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
-
-       /* Modern standby exit */
-       if (lps0_dsm_func_mask_microsoft > 0)
+               /* Modern Standby exit */
                acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT,
                                lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
+       }
 
        /* Screen on */
        if (lps0_dsm_func_mask_microsoft > 0)