This is a note to let you know that I've just added the patch titled
ACPI: CPPC: Check _OSC for flexible address space
to the 5.18-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:
acpi-cppc-check-_osc-for-flexible-address-space.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 569af7365c3c7d4c9917cb54e5605737ff6a97a6
Author: Pierre Gondois <pierre.gondois@xxxxxxx>
Date: Wed May 18 11:08:57 2022 +0200
ACPI: CPPC: Check _OSC for flexible address space
[ Upstream commit 0651ab90e4ade17f1d4f4367b70f6120480410f3 ]
ACPI 6.2 Section 6.2.11.2 'Platform-Wide OSPM Capabilities':
Starting with ACPI Specification 6.2, all _CPC registers can be in
PCC, System Memory, System IO, or Functional Fixed Hardware address
spaces. OSPM support for this more flexible register space scheme is
indicated by the “Flexible Address Space for CPPC Registers” _OSC bit
Otherwise (cf ACPI 6.1, s8.4.7.1.1.X), _CPC registers must be in:
- PCC or Functional Fixed Hardware address space if defined
- SystemMemory address space (NULL register) if not defined
Add the corresponding _OSC bit and check it when parsing _CPC objects.
Signed-off-by: Pierre Gondois <pierre.gondois@xxxxxxx>
Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 3e58b613a2c4..9eca43d1d941 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -278,6 +278,20 @@ bool osc_sb_apei_support_acked;
bool osc_pc_lpi_support_confirmed;
EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed);
+/*
+ * ACPI 6.2 Section 6.2.11.2 'Platform-Wide OSPM Capabilities':
+ * Starting with ACPI Specification 6.2, all _CPC registers can be in
+ * PCC, System Memory, System IO, or Functional Fixed Hardware address
+ * spaces. OSPM support for this more flexible register space scheme is
+ * indicated by the “Flexible Address Space for CPPC Registers” _OSC bit.
+ *
+ * Otherwise (cf ACPI 6.1, s8.4.7.1.1.X), _CPC registers must be in:
+ * - PCC or Functional Fixed Hardware address space if defined
+ * - SystemMemory address space (NULL register) if not defined
+ */
+bool osc_cpc_flexible_adr_space_confirmed;
+EXPORT_SYMBOL_GPL(osc_cpc_flexible_adr_space_confirmed);
+
/*
* ACPI 6.4 Operating System Capabilities for USB.
*/
@@ -321,6 +335,8 @@ static void acpi_bus_osc_negotiate_platform_control(void)
}
#endif
+ capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_FLEXIBLE_ADR_SPACE;
+
if (IS_ENABLED(CONFIG_SCHED_MC_PRIO))
capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_DIVERSE_HIGH_SUPPORT;
@@ -366,6 +382,8 @@ static void acpi_bus_osc_negotiate_platform_control(void)
capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT;
osc_sb_native_usb4_support_confirmed =
capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_NATIVE_USB4_SUPPORT;
+ osc_cpc_flexible_adr_space_confirmed =
+ capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_CPC_FLEXIBLE_ADR_SPACE;
}
kfree(context.ret.pointer);
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 34576ab0e2e1..840223c12540 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -746,6 +746,11 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
if (gas_t->address) {
void __iomem *addr;
+ if (!osc_cpc_flexible_adr_space_confirmed) {
+ pr_debug("Flexible address space capability not supported\n");
+ goto out_free;
+ }
+
addr = ioremap(gas_t->address, gas_t->bit_width/8);
if (!addr)
goto out_free;
@@ -768,6 +773,10 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
gas_t->address);
goto out_free;
}
+ if (!osc_cpc_flexible_adr_space_confirmed) {
+ pr_debug("Flexible address space capability not supported\n");
+ goto out_free;
+ }
} else {
if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) {
/* Support only PCC, SystemMemory, SystemIO, and FFH type regs. */
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index d7136d13aa44..03465db16b68 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -574,6 +574,7 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context);
#define OSC_SB_OSLPI_SUPPORT 0x00000100
#define OSC_SB_CPC_DIVERSE_HIGH_SUPPORT 0x00001000
#define OSC_SB_GENERIC_INITIATOR_SUPPORT 0x00002000
+#define OSC_SB_CPC_FLEXIBLE_ADR_SPACE 0x00004000
#define OSC_SB_NATIVE_USB4_SUPPORT 0x00040000
#define OSC_SB_PRM_SUPPORT 0x00200000
@@ -581,6 +582,7 @@ extern bool osc_sb_apei_support_acked;
extern bool osc_pc_lpi_support_confirmed;
extern bool osc_sb_native_usb4_support_confirmed;
extern bool osc_sb_cppc_not_supported;
+extern bool osc_cpc_flexible_adr_space_confirmed;
/* USB4 Capabilities */
#define OSC_USB_USB3_TUNNELING 0x00000001
