platform/x86/amd/pmf: Add support for PMF APCI layer

PMF driver implements the ACPI methods as defined by AMD for PMF Support.
The ACPI layer acts as a glue that helps in providing the infrastructure
for OEMs customization.

OEMs can refer to PMF support documentation to decide on the list of
functions to be supported on their specific platform model.

AMD mandates that PMF ACPI fn0 and fn1 to be implemented which
provides the set of functions, params and the notifications that
would be sent to PMF driver so that PMF driver can adapt and
react.

Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20220802151149.2123699-3-Shyam-sundar.S-k@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/amd/pmf/Makefile b/drivers/platform/x86/amd/pmf/Makefile
index 459005f659e55f6c509daf8feb06dafc56587e76..2617eba773ceb40202f59748838ea9555356132e 100644 (file)
--- a/drivers/platform/x86/amd/pmf/Makefile
+++ b/drivers/platform/x86/amd/pmf/Makefile
@@ -5,4 +5,4 @@
 #
 
 obj-$(CONFIG_AMD_PMF) += amd-pmf.o
-amd-pmf-objs := core.o
+amd-pmf-objs := core.o acpi.o

diff --git a/drivers/platform/x86/amd/pmf/acpi.c b/drivers/platform/x86/amd/pmf/acpi.c
new file mode 100644 (file)
index 0000000..b378f9e
--- /dev/null
+++ b/drivers/platform/x86/amd/pmf/acpi.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD Platform Management Framework Driver
+ *
+ * Copyright (c) 2022, Advanced Micro Devices, Inc.
+ * All Rights Reserved.
+ *
+ * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ */
+
+#include <linux/acpi.h>
+#include "pmf.h"
+
+static union acpi_object *apmf_if_call(struct amd_pmf_dev *pdev, int fn, struct acpi_buffer *param)
+{
+       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+       acpi_handle ahandle = ACPI_HANDLE(pdev->dev);
+       struct acpi_object_list apmf_if_arg_list;
+       union acpi_object apmf_if_args[2];
+       acpi_status status;
+
+       apmf_if_arg_list.count = 2;
+       apmf_if_arg_list.pointer = &apmf_if_args[0];
+
+       apmf_if_args[0].type = ACPI_TYPE_INTEGER;
+       apmf_if_args[0].integer.value = fn;
+
+       if (param) {
+               apmf_if_args[1].type = ACPI_TYPE_BUFFER;
+               apmf_if_args[1].buffer.length = param->length;
+               apmf_if_args[1].buffer.pointer = param->pointer;
+       } else {
+               apmf_if_args[1].type = ACPI_TYPE_INTEGER;
+               apmf_if_args[1].integer.value = 0;
+       }
+
+       status = acpi_evaluate_object(ahandle, "APMF", &apmf_if_arg_list, &buffer);
+       if (ACPI_FAILURE(status)) {
+               dev_err(pdev->dev, "APMF method:%d call failed\n", fn);
+               kfree(buffer.pointer);
+               return NULL;
+       }
+
+       return buffer.pointer;
+}
+
+static int apmf_if_call_store_buffer(struct amd_pmf_dev *pdev, int fn, void *dest, size_t out_sz)
+{
+       union acpi_object *info;
+       size_t size;
+       int err = 0;
+
+       info = apmf_if_call(pdev, fn, NULL);
+       if (!info)
+               return -EIO;
+
+       if (info->type != ACPI_TYPE_BUFFER) {
+               dev_err(pdev->dev, "object is not a buffer\n");
+               err = -EINVAL;
+               goto out;
+       }
+
+       if (info->buffer.length < 2) {
+               dev_err(pdev->dev, "buffer too small\n");
+               err = -EINVAL;
+               goto out;
+       }
+
+       size = *(u16 *)info->buffer.pointer;
+       if (info->buffer.length < size) {
+               dev_err(pdev->dev, "buffer smaller then headersize %u < %zu\n",
+                       info->buffer.length, size);
+               err = -EINVAL;
+               goto out;
+       }
+
+       if (size < out_sz) {
+               dev_err(pdev->dev, "buffer too small %zu\n", size);
+               err = -EINVAL;
+               goto out;
+       }
+
+       memcpy(dest, info->buffer.pointer, out_sz);
+
+out:
+       kfree(info);
+       return err;
+}
+
+int is_apmf_func_supported(struct amd_pmf_dev *pdev, unsigned long index)
+{
+       /* If bit-n is set, that indicates function n+1 is supported */
+       return !!(pdev->supported_func & BIT(index - 1));
+}
+
+static int apmf_if_verify_interface(struct amd_pmf_dev *pdev)
+{
+       struct apmf_verify_interface output;
+       int err;
+
+       err = apmf_if_call_store_buffer(pdev, APMF_FUNC_VERIFY_INTERFACE, &output, sizeof(output));
+       if (err)
+               return err;
+
+       pdev->supported_func = output.supported_functions;
+       dev_dbg(pdev->dev, "supported functions:0x%x notifications:0x%x\n",
+               output.supported_functions, output.notification_mask);
+
+       return 0;
+}
+
+static int apmf_get_system_params(struct amd_pmf_dev *dev)
+{
+       struct apmf_system_params params;
+       int err;
+
+       if (!is_apmf_func_supported(dev, APMF_FUNC_GET_SYS_PARAMS))
+               return -EINVAL;
+
+       err = apmf_if_call_store_buffer(dev, APMF_FUNC_GET_SYS_PARAMS, &params, sizeof(params));
+       if (err)
+               return err;
+
+       dev_dbg(dev->dev, "system params mask:0x%x flags:0x%x cmd_code:0x%x\n",
+               params.valid_mask,
+               params.flags,
+               params.command_code);
+       params.flags = params.flags & params.valid_mask;
+
+       return 0;
+}
+
+int apmf_acpi_init(struct amd_pmf_dev *pmf_dev)
+{
+       int ret;
+
+       ret = apmf_if_verify_interface(pmf_dev);
+       if (ret) {
+               dev_err(pmf_dev->dev, "APMF verify interface failed :%d\n", ret);
+               goto out;
+       }
+
+       ret = apmf_get_system_params(pmf_dev);
+       if (ret) {
+               dev_err(pmf_dev->dev, "APMF apmf_get_system_params failed :%d\n", ret);
+               goto out;
+       }
+
+out:
+       return ret;
+}

diff --git a/drivers/platform/x86/amd/pmf/core.c b/drivers/platform/x86/amd/pmf/core.c
index aef97965c181247ae7062256d69957e6bba9fabd..c5002b7bb9046b5bd1ab2a671575e3461e619617 100644 (file)
--- a/drivers/platform/x86/amd/pmf/core.c
+++ b/drivers/platform/x86/amd/pmf/core.c
@@ -204,6 +204,7 @@ static int amd_pmf_probe(struct platform_device *pdev)
        if (!dev->regbase)
                return -ENOMEM;
 
+       apmf_acpi_init(dev);
        platform_set_drvdata(pdev, dev);
 
        mutex_init(&dev->lock);

diff --git a/drivers/platform/x86/amd/pmf/pmf.h b/drivers/platform/x86/amd/pmf/pmf.h
index 1c2e942e5096eec596f194b9f4672bcaa362f5b4..bdadbff168ee3217279a3d7ec3ffbb2891ab323a 100644 (file)
--- a/drivers/platform/x86/amd/pmf/pmf.h
+++ b/drivers/platform/x86/amd/pmf/pmf.h
@@ -11,6 +11,12 @@
 #ifndef PMF_H
 #define PMF_H
 
+#include <linux/acpi.h>
+
+/* APMF Functions */
+#define APMF_FUNC_VERIFY_INTERFACE                     0
+#define APMF_FUNC_GET_SYS_PARAMS                       1
+
 /* Message Definitions */
 #define SET_SPL                                0x03 /* SPL: Sustained Power Limit */
 #define SET_SPPT                       0x05 /* SPPT: Slow Package Power Tracking */
@@ -30,6 +36,21 @@
 #define GET_STT_LIMIT_APU      0x20
 #define GET_STT_LIMIT_HS2      0x21
 
+/* AMD PMF BIOS interfaces */
+struct apmf_verify_interface {
+       u16 size;
+       u16 version;
+       u32 notification_mask;
+       u32 supported_functions;
+} __packed;
+
+struct apmf_system_params {
+       u16 size;
+       u32 valid_mask;
+       u32 flags;
+       u8 command_code;
+} __packed;
+
 struct amd_pmf_dev {
        void __iomem *regbase;
        void __iomem *smu_virt_addr;
@@ -38,9 +59,11 @@ struct amd_pmf_dev {
        u32 cpu_id;
        struct device *dev;
        struct mutex lock; /* protects the PMF interface */
+       u32 supported_func;
 };
 
 /* Core Layer */
+int apmf_acpi_init(struct amd_pmf_dev *pmf_dev);
 int amd_pmf_send_cmd(struct amd_pmf_dev *dev, u8 message, bool get, u32 arg, u32 *data);
 
 #endif /* PMF_H */