1 files changed, 296 insertions, 0 deletions
diff --git a/drivers/platform/x86/amd/pmc/mp1_stb.c b/drivers/platform/x86/amd/pmc/mp1_stb.c
new file mode 100644
index 000000000000..29e0241190e4
--- /dev/null
+++ b/drivers/platform/x86/amd/pmc/mp1_stb.c
@@ -0,0 +1,296 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AMD MP1 Smart Trace Buffer (STB) Layer
+ *
+ * Copyright (c) 2024, Advanced Micro Devices, Inc.
+ * All Rights Reserved.
+ *
+ * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ *          Sanket Goswami <Sanket.Goswami@amd.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <asm/amd_nb.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+
+#include "pmc.h"
+
+/* STB Spill to DRAM Parameters */
+#define S2D_TELEMETRY_DRAMBYTES_MAX	0x1000000
+#define S2D_TELEMETRY_BYTES_MAX		0x100000U
+#define S2D_RSVD_RAM_SPACE		0x100000
+
+/* STB Registers */
+#define AMD_PMC_STB_PMI_0		0x03E30600
+#define AMD_PMC_STB_DUMMY_PC	0xC6000007
+
+/* STB Spill to DRAM Message Definition */
+#define STB_FORCE_FLUSH_DATA		0xCF
+#define FIFO_SIZE		4096
+
+static bool enable_stb;
+module_param(enable_stb, bool, 0644);
+MODULE_PARM_DESC(enable_stb, "Enable the STB debug mechanism");
+
+static bool dump_custom_stb;
+module_param(dump_custom_stb, bool, 0644);
+MODULE_PARM_DESC(dump_custom_stb, "Enable to dump full STB buffer");
+
+enum s2d_arg {
+	S2D_TELEMETRY_SIZE = 0x01,
+	S2D_PHYS_ADDR_LOW,
+	S2D_PHYS_ADDR_HIGH,
+	S2D_NUM_SAMPLES,
+	S2D_DRAM_SIZE,
+};
+
+struct amd_pmc_stb_v2_data {
+	size_t size;
+	u8 data[] __counted_by(size);
+};
+
+int amd_pmc_write_stb(struct amd_pmc_dev *dev, u32 data)
+{
+	int err;
+
+	err = amd_smn_write(0, AMD_PMC_STB_PMI_0, data);
+	if (err) {
+		dev_err(dev->dev, "failed to write data in stb: 0x%X\n", AMD_PMC_STB_PMI_0);
+		return pcibios_err_to_errno(err);
+	}
+
+	return 0;
+}
+
+int amd_pmc_read_stb(struct amd_pmc_dev *dev, u32 *buf)
+{
+	int i, err;
+
+	for (i = 0; i < FIFO_SIZE; i++) {
+		err = amd_smn_read(0, AMD_PMC_STB_PMI_0, buf++);
+		if (err) {
+			dev_err(dev->dev, "error reading data from stb: 0x%X\n", AMD_PMC_STB_PMI_0);
+			return pcibios_err_to_errno(err);
+		}
+	}
+
+	return 0;
+}
+
+static int amd_pmc_stb_debugfs_open(struct inode *inode, struct file *filp)
+{
+	struct amd_pmc_dev *dev = filp->f_inode->i_private;
+	u32 size = FIFO_SIZE * sizeof(u32);
+	u32 *buf;
+	int rc;
+
+	buf = kzalloc(size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	rc = amd_pmc_read_stb(dev, buf);
+	if (rc) {
+		kfree(buf);
+		return rc;
+	}
+
+	filp->private_data = buf;
+	return rc;
+}
+
+static ssize_t amd_pmc_stb_debugfs_read(struct file *filp, char __user *buf, size_t size,
+					loff_t *pos)
+{
+	if (!filp->private_data)
+		return -EINVAL;
+
+	return simple_read_from_buffer(buf, size, pos, filp->private_data,
+				       FIFO_SIZE * sizeof(u32));
+}
+
+static int amd_pmc_stb_debugfs_release(struct inode *inode, struct file *filp)
+{
+	kfree(filp->private_data);
+	return 0;
+}
+
+static const struct file_operations amd_pmc_stb_debugfs_fops = {
+	.owner = THIS_MODULE,
+	.open = amd_pmc_stb_debugfs_open,
+	.read = amd_pmc_stb_debugfs_read,
+	.release = amd_pmc_stb_debugfs_release,
+};
+
+/* Enhanced STB Firmware Reporting Mechanism */
+static int amd_pmc_stb_handle_efr(struct file *filp)
+{
+	struct amd_pmc_dev *dev = filp->f_inode->i_private;
+	struct amd_pmc_stb_v2_data *stb_data_arr;
+	u32 fsize;
+
+	fsize = dev->dram_size - S2D_RSVD_RAM_SPACE;
+	stb_data_arr = kmalloc(struct_size(stb_data_arr, data, fsize), GFP_KERNEL);
+	if (!stb_data_arr)
+		return -ENOMEM;
+
+	stb_data_arr->size = fsize;
+	memcpy_fromio(stb_data_arr->data, dev->stb_virt_addr, fsize);
+	filp->private_data = stb_data_arr;
+
+	return 0;
+}
+
+static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp)
+{
+	struct amd_pmc_dev *dev = filp->f_inode->i_private;
+	u32 fsize, num_samples, val, stb_rdptr_offset = 0;
+	struct amd_pmc_stb_v2_data *stb_data_arr;
+	int ret;
+
+	/* Write dummy postcode while reading the STB buffer */
+	ret = amd_pmc_write_stb(dev, AMD_PMC_STB_DUMMY_PC);
+	if (ret)
+		dev_err(dev->dev, "error writing to STB: %d\n", ret);
+
+	/* Spill to DRAM num_samples uses separate SMU message port */
+	dev->msg_port = 1;
+
+	ret = amd_pmc_send_cmd(dev, 0, &val, STB_FORCE_FLUSH_DATA, 1);
+	if (ret)
+		dev_dbg_once(dev->dev, "S2D force flush not supported: %d\n", ret);
+
+	/*
+	 * We have a custom stb size and the PMFW is supposed to give
+	 * the enhanced dram size. Note that we land here only for the
+	 * platforms that support enhanced dram size reporting.
+	 */
+	if (dump_custom_stb)
+		return amd_pmc_stb_handle_efr(filp);
+
+	/* Get the num_samples to calculate the last push location */
+	ret = amd_pmc_send_cmd(dev, S2D_NUM_SAMPLES, &num_samples, dev->s2d_msg_id, true);
+	/* Clear msg_port for other SMU operation */
+	dev->msg_port = 0;
+	if (ret) {
+		dev_err(dev->dev, "error: S2D_NUM_SAMPLES not supported : %d\n", ret);
+		return ret;
+	}
+
+	fsize = min(num_samples, S2D_TELEMETRY_BYTES_MAX);
+	stb_data_arr = kmalloc(struct_size(stb_data_arr, data, fsize), GFP_KERNEL);
+	if (!stb_data_arr)
+		return -ENOMEM;
+
+	stb_data_arr->size = fsize;
+
+	/*
+	 * Start capturing data from the last push location.
+	 * This is for general cases, where the stb limits
+	 * are meant for standard usage.
+	 */
+	if (num_samples > S2D_TELEMETRY_BYTES_MAX) {
+		/* First read oldest data starting 1 behind last write till end of ringbuffer */
+		stb_rdptr_offset = num_samples % S2D_TELEMETRY_BYTES_MAX;
+		fsize = S2D_TELEMETRY_BYTES_MAX - stb_rdptr_offset;
+
+		memcpy_fromio(stb_data_arr->data, dev->stb_virt_addr + stb_rdptr_offset, fsize);
+		/* Second copy the newer samples from offset 0 - last write */
+		memcpy_fromio(stb_data_arr->data + fsize, dev->stb_virt_addr, stb_rdptr_offset);
+	} else {
+		memcpy_fromio(stb_data_arr->data, dev->stb_virt_addr, fsize);
+	}
+
+	filp->private_data = stb_data_arr;
+
+	return 0;
+}
+
+static ssize_t amd_pmc_stb_debugfs_read_v2(struct file *filp, char __user *buf, size_t size,
+					   loff_t *pos)
+{
+	struct amd_pmc_stb_v2_data *data = filp->private_data;
+
+	return simple_read_from_buffer(buf, size, pos, data->data, data->size);
+}
+
+static int amd_pmc_stb_debugfs_release_v2(struct inode *inode, struct file *filp)
+{
+	kfree(filp->private_data);
+	return 0;
+}
+
+static const struct file_operations amd_pmc_stb_debugfs_fops_v2 = {
+	.owner = THIS_MODULE,
+	.open = amd_pmc_stb_debugfs_open_v2,
+	.read = amd_pmc_stb_debugfs_read_v2,
+	.release = amd_pmc_stb_debugfs_release_v2,
+};
+
+static bool amd_pmc_is_stb_supported(struct amd_pmc_dev *dev)
+{
+	switch (dev->cpu_id) {
+	case AMD_CPU_ID_YC:
+	case AMD_CPU_ID_CB:
+		dev->s2d_msg_id = 0xBE;
+		return true;
+	case AMD_CPU_ID_PS:
+		dev->s2d_msg_id = 0x85;
+		return true;
+	case PCI_DEVICE_ID_AMD_1AH_M20H_ROOT:
+	case PCI_DEVICE_ID_AMD_1AH_M60H_ROOT:
+		dev->s2d_msg_id = 0xDE;
+		return true;
+	default:
+		return false;
+	}
+}
+
+int amd_pmc_s2d_init(struct amd_pmc_dev *dev)
+{
+	u32 phys_addr_low, phys_addr_hi;
+	u64 stb_phys_addr;
+	u32 size = 0;
+	int ret;
+
+	if (!enable_stb)
+		return 0;
+
+	if (amd_pmc_is_stb_supported(dev)) {
+		debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev,
+				    &amd_pmc_stb_debugfs_fops_v2);
+	} else {
+		debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev,
+				    &amd_pmc_stb_debugfs_fops);
+		return 0;
+	}
+
+	/* Spill to DRAM feature uses separate SMU message port */
+	dev->msg_port = 1;
+
+	amd_pmc_send_cmd(dev, S2D_TELEMETRY_SIZE, &size, dev->s2d_msg_id, true);
+	if (size != S2D_TELEMETRY_BYTES_MAX)
+		return -EIO;
+
+	/* Get DRAM size */
+	ret = amd_pmc_send_cmd(dev, S2D_DRAM_SIZE, &dev->dram_size, dev->s2d_msg_id, true);
+	if (ret || !dev->dram_size)
+		dev->dram_size = S2D_TELEMETRY_DRAMBYTES_MAX;
+
+	/* Get STB DRAM address */
+	amd_pmc_send_cmd(dev, S2D_PHYS_ADDR_LOW, &phys_addr_low, dev->s2d_msg_id, true);
+	amd_pmc_send_cmd(dev, S2D_PHYS_ADDR_HIGH, &phys_addr_hi, dev->s2d_msg_id, true);
+
+	stb_phys_addr = ((u64)phys_addr_hi << 32 | phys_addr_low);
+
+	/* Clear msg_port for other SMU operation */
+	dev->msg_port = 0;
+
+	dev->stb_virt_addr = devm_ioremap(dev->dev, stb_phys_addr, dev->dram_size);
+	if (!dev->stb_virt_addr)
+		return -ENOMEM;
+
+	return 0;
+}