ACPICA: Hardware: Do not flush CPU cache when entering S4 and S5

[ Upstream commit 1d4e0b3abb168b2ee1eca99c527cffa1b80b6161 ]

ACPICA commit 3dd7e1f3996456ef81bfe14cba29860e8d42949e

According to ACPI 6.4, Section 16.2, the CPU cache flushing is
required on entering to S1, S2, and S3, but the ACPICA code
flushes the CPU cache regardless of the sleep state.

Blind cache flush on entering S5 causes problems for TDX.

Flushing happens with WBINVD that is not supported in the TDX
environment.

TDX only supports S5 and adjusting ACPICA code to conform to the
spec more strictly fixes the issue.

Link: https://github.com/acpica/acpica/commit/3dd7e1f3
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/acpi/acpica/hwesleep.c b/drivers/acpi/acpica/hwesleep.c
index 7f8c57177819f0ea510b16dda53f7da8fe668eab..45b392fa366579c8dd8a73f859dbfd3c0a036539 100644 (file)
--- a/drivers/acpi/acpica/hwesleep.c
+++ b/drivers/acpi/acpica/hwesleep.c
@@ -138,7 +138,9 @@ acpi_status acpi_hw_extended_sleep(u8 sleep_state)
 
        /* Flush caches, as per ACPI specification */
 
-       ACPI_FLUSH_CPU_CACHE();
+       if (sleep_state < ACPI_STATE_S4) {
+               ACPI_FLUSH_CPU_CACHE();
+       }
 
        status = acpi_os_enter_sleep(sleep_state, sleep_control, 0);
        if (status == AE_CTRL_TERMINATE) {

diff --git a/drivers/acpi/acpica/hwsleep.c b/drivers/acpi/acpica/hwsleep.c
index 2c54d08b20ca6b98cb8e2668e86476a2bcebc6a8..9e50529bb3cc9c7d6e5da3b7b96bfddc4a08040c 100644 (file)
--- a/drivers/acpi/acpica/hwsleep.c
+++ b/drivers/acpi/acpica/hwsleep.c
@@ -149,7 +149,9 @@ acpi_status acpi_hw_legacy_sleep(u8 sleep_state)
 
        /* Flush caches, as per ACPI specification */
 
-       ACPI_FLUSH_CPU_CACHE();
+       if (sleep_state < ACPI_STATE_S4) {
+               ACPI_FLUSH_CPU_CACHE();
+       }
 
        status = acpi_os_enter_sleep(sleep_state, pm1a_control, pm1b_control);
        if (status == AE_CTRL_TERMINATE) {

diff --git a/drivers/acpi/acpica/hwxfsleep.c b/drivers/acpi/acpica/hwxfsleep.c
index 827c3242225d9725df485956f22e3f4241707a45..b3c7736611908708b7512e65a11f87766f28c0d4 100644 (file)
--- a/drivers/acpi/acpica/hwxfsleep.c
+++ b/drivers/acpi/acpica/hwxfsleep.c
@@ -223,8 +223,6 @@ acpi_status acpi_enter_sleep_state_s4bios(void)
                return_ACPI_STATUS(status);
        }
 
-       ACPI_FLUSH_CPU_CACHE();
-
        status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
                                    (u32)acpi_gbl_FADT.s4_bios_request, 8);