[PATCH v3 1/7] platform/x86/amd/pmf: Use per-SoC smu_regs struct for SMU mailbox registers

Shyam Sundar S K <[email protected]> Thu, 23 Jul 2026 16:45:28 +0530
Newsgroups org.kernel.vger.platform-driver-x86
Message-ID <[email protected]>
Different AMD platforms use varying SMU register layouts for PMF-SMU
mailbox communication. The register offsets are currently hardcoded as
AMD_PMF_REGISTER_MESSAGE, AMD_PMF_REGISTER_RESPONSE and
AMD_PMF_REGISTER_ARGUMENT directly in amd_pmf_send_cmd() and
amd_pmf_dump_registers(), making it difficult to support platforms that
use a different mailbox register layout without scattering per-platform
conditionals across the send path.

Introduce struct amd_pmf_smu_regs to capture the SoC-specific SMU
mailbox register offsets (msg_reg, resp_reg, arg_reg) and add a
pointer to it in struct amd_pmf_dev. RMB, PS, 1AH_M20H and 1AH_M60H
all share the same legacy register layout and point to a single shared
amd_pmf_smu_regs_v1 instance, avoiding redundant struct definitions.

Convert the pmf_pci_ids[] table from PCI_DEVICE() to PCI_DEVICE_DATA(),
embedding the smu_regs pointer directly as driver_data. Introduce
amd_pmf_get_smu_mb_offset() which resolves the matching PCI entry via
pci_match_id() at probe time and assigns driver_data to dev->smu_regs.

Update all SMU register accesses in amd_pmf_send_cmd() and
amd_pmf_dump_registers() to go through dev->smu_regs. Remove the
hardcoded register offset references from the send path. New platform
support requires only a new smu_regs instance and a corresponding
PCI_DEVICE_DATA() entry.

No functional changes for existing platforms.

Reviewed-by: Mario Limonciello (AMD) <[email protected]>
Co-developed-by: Patil Rajesh Reddy <[email protected]>
Signed-off-by: Patil Rajesh Reddy <[email protected]>
Signed-off-by: Shyam Sundar S K <[email protected]>
---
 drivers/platform/x86/amd/pmf/core.c | 51 +++++++++++++++++++++--------
 drivers/platform/x86/amd/pmf/pmf.h  | 12 +++++++
 2 files changed, 50 insertions(+), 13 deletions(-)

diff --git a/drivers/platform/x86/amd/pmf/core.c b/drivers/platform/x86/amd/pmf/core.c
index 58d86b4c2828..3018c861776b 100644
--- a/drivers/platform/x86/amd/pmf/core.c
+++ b/drivers/platform/x86/amd/pmf/core.c
@@ -176,13 +176,13 @@ static void __maybe_unused amd_pmf_dump_registers(struct amd_pmf_dev *dev)
 {
 	u32 value;
 
-	value = amd_pmf_reg_read(dev, AMD_PMF_REGISTER_RESPONSE);
+	value = amd_pmf_reg_read(dev, dev->smu_regs->resp_reg);
 	dev_dbg(dev->dev, "AMD_PMF_REGISTER_RESPONSE:%x\n", value);
 
-	value = amd_pmf_reg_read(dev, AMD_PMF_REGISTER_ARGUMENT);
+	value = amd_pmf_reg_read(dev, dev->smu_regs->arg_reg);
 	dev_dbg(dev->dev, "AMD_PMF_REGISTER_ARGUMENT:%d\n", value);
 
-	value = amd_pmf_reg_read(dev, AMD_PMF_REGISTER_MESSAGE);
+	value = amd_pmf_reg_read(dev, dev->smu_regs->msg_reg);
 	dev_dbg(dev->dev, "AMD_PMF_REGISTER_MESSAGE:%x\n", value);
 }
 
@@ -208,7 +208,7 @@ int amd_pmf_send_cmd(struct amd_pmf_dev *dev, u8 message, bool get, u32 arg, u32
 	guard(mutex)(&dev->lock);
 
 	/* Wait until we get a valid response */
-	rc = readx_poll_timeout(ioread32, dev->regbase + AMD_PMF_REGISTER_RESPONSE,
+	rc = readx_poll_timeout(ioread32, dev->regbase + dev->smu_regs->resp_reg,
 				val, val != 0, PMF_MSG_DELAY_MIN_US,
 				PMF_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX);
 	if (rc) {
@@ -217,16 +217,16 @@ int amd_pmf_send_cmd(struct amd_pmf_dev *dev, u8 message, bool get, u32 arg, u32
 	}
 
 	/* Write zero to response register */
-	amd_pmf_reg_write(dev, AMD_PMF_REGISTER_RESPONSE, 0);
+	amd_pmf_reg_write(dev, dev->smu_regs->resp_reg, 0);
 
 	/* Write argument into argument register */
-	amd_pmf_reg_write(dev, AMD_PMF_REGISTER_ARGUMENT, arg);
+	amd_pmf_reg_write(dev, dev->smu_regs->arg_reg, arg);
 
 	/* Write message ID to message ID register */
-	amd_pmf_reg_write(dev, AMD_PMF_REGISTER_MESSAGE, message);
+	amd_pmf_reg_write(dev, dev->smu_regs->msg_reg, message);
 
 	/* Wait until we get a valid response */
-	rc = readx_poll_timeout(ioread32, dev->regbase + AMD_PMF_REGISTER_RESPONSE,
+	rc = readx_poll_timeout(ioread32, dev->regbase + dev->smu_regs->resp_reg,
 				val, val != 0, PMF_MSG_DELAY_MIN_US,
 				PMF_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX);
 	if (rc) {
@@ -239,7 +239,7 @@ int amd_pmf_send_cmd(struct amd_pmf_dev *dev, u8 message, bool get, u32 arg, u32
 		if (get) {
 			/* PMFW may take longer time to return back the data */
 			usleep_range(DELAY_MIN_US, 10 * DELAY_MAX_US);
-			*data = amd_pmf_reg_read(dev, AMD_PMF_REGISTER_ARGUMENT);
+			*data = amd_pmf_reg_read(dev, dev->smu_regs->arg_reg);
 		}
 		break;
 	case AMD_PMF_RESULT_CMD_REJECT_BUSY:
@@ -262,11 +262,18 @@ int amd_pmf_send_cmd(struct amd_pmf_dev *dev, u8 message, bool get, u32 arg, u32
 	return rc;
 }
 
+/* RMB, PS, 1AH_M20H and 1AH_M60H share the same v1 SMU mailbox registers */
+static const struct amd_pmf_smu_regs amd_pmf_smu_regs_v1 = {
+	.msg_reg	= AMD_PMF_REGISTER_MESSAGE,
+	.resp_reg	= AMD_PMF_REGISTER_RESPONSE,
+	.arg_reg	= AMD_PMF_REGISTER_ARGUMENT,
+};
+
 static const struct pci_device_id pmf_pci_ids[] = {
-	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_CPU_ID_RMB) },
-	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_CPU_ID_PS) },
-	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M20H_ROOT) },
-	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M60H_ROOT) },
+	{ PCI_DEVICE_DATA(AMD, CPU_ID_RMB,    &amd_pmf_smu_regs_v1) },
+	{ PCI_DEVICE_DATA(AMD, CPU_ID_PS,     &amd_pmf_smu_regs_v1) },
+	{ PCI_DEVICE_DATA(AMD, 1AH_M20H_ROOT, &amd_pmf_smu_regs_v1) },
+	{ PCI_DEVICE_DATA(AMD, 1AH_M60H_ROOT, &amd_pmf_smu_regs_v1) },
 	{ }
 };
 
@@ -536,6 +543,19 @@ static void amd_pmf_deinit_features(struct amd_pmf_dev *dev)
 	}
 }
 
+static int amd_pmf_get_smu_mb_offset(struct amd_pmf_dev *pdev, struct pci_dev *rdev)
+{
+	const struct pci_device_id *id;
+
+	id = pci_match_id(pmf_pci_ids, rdev);
+	if (!id)
+		return -ENODEV;
+
+	pdev->smu_regs = (const struct amd_pmf_smu_regs *)id->driver_data;
+
+	return 0;
+}
+
 static const struct acpi_device_id amd_pmf_acpi_ids[] = {
 	{"AMDI0100", 0x100},
 	{"AMDI0102", 0},
@@ -624,6 +644,11 @@ static int amd_pmf_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	/* Populate smu_regs with SoC-specific SMU mailbox register offsets */
+	err = amd_pmf_get_smu_mb_offset(dev, rdev);
+	if (err)
+		return err;
+
 	apmf_acpi_init(dev);
 	platform_set_drvdata(pdev, dev);
 	amd_pmf_dbgfs_register(dev);
diff --git a/drivers/platform/x86/amd/pmf/pmf.h b/drivers/platform/x86/amd/pmf/pmf.h
index 752fa5dd2267..7a8fd9d399de 100644
--- a/drivers/platform/x86/amd/pmf/pmf.h
+++ b/drivers/platform/x86/amd/pmf/pmf.h
@@ -29,6 +29,10 @@
 #define PCI_DEVICE_ID_AMD_1AH_M20H_ROOT 0x1507
 #define PCI_DEVICE_ID_AMD_1AH_M60H_ROOT 0x1122
 
+/* Aliases required by PCI_DEVICE_DATA() macro naming convention */
+#define PCI_DEVICE_ID_AMD_CPU_ID_RMB	AMD_CPU_ID_RMB
+#define PCI_DEVICE_ID_AMD_CPU_ID_PS	AMD_CPU_ID_PS
+
 struct cookie_header {
 	u32 sign;
 	u32 length;
@@ -392,6 +396,13 @@ struct pmf_cbi_ring_buffer {
 	int tail;
 };
 
+/* SoC-specific SMU mailbox register offsets */
+struct amd_pmf_smu_regs {
+	u32 msg_reg;
+	u32 resp_reg;
+	u32 arg_reg;
+};
+
 struct amd_pmf_dev {
 	void __iomem *regbase;
 	void __iomem *smu_virt_addr;
@@ -444,6 +455,7 @@ struct amd_pmf_dev {
 	struct mutex cbi_mutex;		     /* Protects ring buffer access */
 	struct mutex metrics_mutex;
 	u32 bios_output[BIOS_OUTPUT_MAX];
+	const struct amd_pmf_smu_regs *smu_regs;
 };
 
 struct apmf_sps_prop_granular_v2 {
-- 
2.34.1