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 4836a4b8b38b87709091009efe209d29fd400d03..142a755be68811445ebef9b90660c5ac8924c421 100644 (file)
--- a/drivers/acpi/acpica/hwesleep.c
+++ b/drivers/acpi/acpica/hwesleep.c
@@ -104,7 +104,9 @@ 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 fcc84d196238a90c6c4a6e6d46895f7a8d157114..6a20bb5059c1d815a33ab83149dca348065e5a44 100644 (file)
--- a/drivers/acpi/acpica/hwsleep.c
+++ b/drivers/acpi/acpica/hwsleep.c
@@ -110,7 +110,9 @@ 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 f1645d87864c3dcd6dc32ca3f35e6c6e69b4fbb1..3948c34d85830e0e671ff4fd2008431d21ffe5e0 100644 (file)
--- a/drivers/acpi/acpica/hwxfsleep.c
+++ b/drivers/acpi/acpica/hwxfsleep.c
@@ -162,8 +162,6 @@ 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);
        if (ACPI_FAILURE(status)) {