From: Pierre Gondois <pierre.gondois@arm.com>
Date: Wed, 18 May 2022 11:08:57 +0200
Subject: ACPI: CPPC: Check _OSC for flexible address space
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Patch-mainline: v5.19-rc1
Git-commit: 0651ab90e4ade17f1d4f4367b70f6120480410f3
References: jsc#PED-1408

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@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 drivers/acpi/bus.c       |   18 ++++++++++++++++++
 drivers/acpi/cppc_acpi.c |    9 +++++++++
 include/linux/acpi.h     |    2 ++
 3 files changed, 29 insertions(+)

--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -279,6 +279,20 @@ 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.
  */
 bool osc_sb_native_usb4_support_confirmed;
@@ -321,6 +335,8 @@ static void acpi_bus_osc_negotiate_platf
 	}
 #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_platf
 			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);
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -749,6 +749,11 @@ int acpi_cppc_processor_probe(struct acp
 				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;
@@ -771,6 +776,10 @@ int acpi_cppc_processor_probe(struct acp
 						 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. */
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -574,6 +574,7 @@ acpi_status acpi_run_osc(acpi_handle han
 #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