This is a note to let you know that I've just added the patch titled
ACPICA: Hardware: Do not flush CPU cache when entering S4 and S5
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
acpica-hardware-do-not-flush-cpu-cache-when-entering.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d144261187d92e9160ea89c9ddcfea0d4bc0e9a9
Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Date: Wed Dec 22 17:33:51 2021 +0100
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@xxxxxxxxxxxxxxx>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/acpi/acpica/hwesleep.c b/drivers/acpi/acpica/hwesleep.c
index 4836a4b8b38b8..142a755be6881 100644
--- 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 fcc84d196238a..6a20bb5059c1d 100644
--- 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 f1645d87864c3..3948c34d85830 100644
--- 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)) {
