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path: root/drivers/platform/x86/amd/pmc/mp2_stb.c
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Diffstat (limited to 'drivers/platform/x86/amd/pmc/mp2_stb.c')
-rw-r--r--drivers/platform/x86/amd/pmc/mp2_stb.c280
1 files changed, 280 insertions, 0 deletions
diff --git a/drivers/platform/x86/amd/pmc/mp2_stb.c b/drivers/platform/x86/amd/pmc/mp2_stb.c
new file mode 100644
index 000000000000..9775ddc1b27a
--- /dev/null
+++ b/drivers/platform/x86/amd/pmc/mp2_stb.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD MP2 STB layer
+ *
+ * Copyright (c) 2024, Advanced Micro Devices, Inc.
+ * All Rights Reserved.
+ *
+ * Author: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/iopoll.h>
+#include <linux/pci.h>
+#include <linux/sizes.h>
+#include <linux/time.h>
+
+#include "pmc.h"
+
+#define VALID_MSG 0xA
+#define VALID_RESPONSE 2
+
+#define AMD_C2P_MSG0 0x10500
+#define AMD_C2P_MSG1 0x10504
+#define AMD_P2C_MSG0 0x10680
+#define AMD_P2C_MSG1 0x10684
+
+#define MP2_RESP_SLEEP_US 500
+#define MP2_RESP_TIMEOUT_US (1600 * USEC_PER_MSEC)
+
+#define MP2_STB_DATA_LEN_2KB 1
+#define MP2_STB_DATA_LEN_16KB 4
+
+#define MP2_MMIO_BAR 2
+
+struct mp2_cmd_base {
+ union {
+ u32 ul;
+ struct {
+ u32 cmd_id : 4;
+ u32 intr_disable : 1;
+ u32 is_dma_used : 1;
+ u32 rsvd : 26;
+ } field;
+ };
+};
+
+struct mp2_cmd_response {
+ union {
+ u32 resp;
+ struct {
+ u32 cmd_id : 4;
+ u32 status : 4;
+ u32 response : 4;
+ u32 rsvd2 : 20;
+ } field;
+ };
+};
+
+struct mp2_stb_data_valid {
+ union {
+ u32 data_valid;
+ struct {
+ u32 valid : 16;
+ u32 length : 16;
+ } val;
+ };
+};
+
+static int amd_mp2_wait_response(struct amd_mp2_dev *mp2, u8 cmd_id, u32 command_sts)
+{
+ struct mp2_cmd_response cmd_resp;
+
+ if (!readl_poll_timeout(mp2->mmio + AMD_P2C_MSG0, cmd_resp.resp,
+ (cmd_resp.field.response == 0x0 &&
+ cmd_resp.field.status == command_sts &&
+ cmd_resp.field.cmd_id == cmd_id), MP2_RESP_SLEEP_US,
+ MP2_RESP_TIMEOUT_US))
+ return cmd_resp.field.status;
+
+ return -ETIMEDOUT;
+}
+
+static void amd_mp2_stb_send_cmd(struct amd_mp2_dev *mp2, u8 cmd_id, bool is_dma_used)
+{
+ struct mp2_cmd_base cmd_base;
+
+ cmd_base.ul = 0;
+ cmd_base.field.cmd_id = cmd_id;
+ cmd_base.field.intr_disable = 1;
+ cmd_base.field.is_dma_used = is_dma_used;
+
+ writeq(mp2->dma_addr, mp2->mmio + AMD_C2P_MSG1);
+ writel(cmd_base.ul, mp2->mmio + AMD_C2P_MSG0);
+}
+
+static int amd_mp2_stb_region(struct amd_mp2_dev *mp2)
+{
+ struct device *dev = &mp2->pdev->dev;
+ unsigned int len = mp2->stb_len;
+
+ if (!mp2->stbdata) {
+ mp2->vslbase = dmam_alloc_coherent(dev, len, &mp2->dma_addr, GFP_KERNEL);
+ if (!mp2->vslbase)
+ return -ENOMEM;
+
+ mp2->stbdata = devm_kzalloc(dev, len, GFP_KERNEL);
+ if (!mp2->stbdata)
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int amd_mp2_process_cmd(struct amd_mp2_dev *mp2, struct file *filp)
+{
+ struct device *dev = &mp2->pdev->dev;
+ struct mp2_stb_data_valid stb_dv;
+ int status;
+
+ stb_dv.data_valid = readl(mp2->mmio + AMD_P2C_MSG1);
+
+ if (stb_dv.val.valid != VALID_MSG) {
+ dev_dbg(dev, "Invalid STB data\n");
+ return -EBADMSG;
+ }
+
+ if (stb_dv.val.length != MP2_STB_DATA_LEN_2KB &&
+ stb_dv.val.length != MP2_STB_DATA_LEN_16KB) {
+ dev_dbg(dev, "Unsupported length\n");
+ return -EMSGSIZE;
+ }
+
+ mp2->stb_len = BIT(stb_dv.val.length) * SZ_1K;
+
+ status = amd_mp2_stb_region(mp2);
+ if (status) {
+ dev_err(dev, "Failed to init STB region, status %d\n", status);
+ return status;
+ }
+
+ amd_mp2_stb_send_cmd(mp2, VALID_MSG, true);
+ status = amd_mp2_wait_response(mp2, VALID_MSG, VALID_RESPONSE);
+ if (status == VALID_RESPONSE) {
+ memcpy_fromio(mp2->stbdata, mp2->vslbase, mp2->stb_len);
+ filp->private_data = mp2->stbdata;
+ mp2->is_stb_data = true;
+ } else {
+ dev_err(dev, "Failed to start STB dump, status %d\n", status);
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int amd_mp2_stb_debugfs_open(struct inode *inode, struct file *filp)
+{
+ struct amd_pmc_dev *dev = filp->f_inode->i_private;
+ struct amd_mp2_dev *mp2 = dev->mp2;
+
+ if (mp2) {
+ if (!mp2->is_stb_data)
+ return amd_mp2_process_cmd(mp2, filp);
+
+ filp->private_data = mp2->stbdata;
+
+ return 0;
+ }
+
+ return -ENODEV;
+}
+
+static ssize_t amd_mp2_stb_debugfs_read(struct file *filp, char __user *buf, size_t size,
+ loff_t *pos)
+{
+ struct amd_pmc_dev *dev = filp->f_inode->i_private;
+ struct amd_mp2_dev *mp2 = dev->mp2;
+
+ if (!mp2)
+ return -ENODEV;
+
+ if (!filp->private_data)
+ return -EINVAL;
+
+ return simple_read_from_buffer(buf, size, pos, filp->private_data, mp2->stb_len);
+}
+
+static const struct file_operations amd_mp2_stb_debugfs_fops = {
+ .owner = THIS_MODULE,
+ .open = amd_mp2_stb_debugfs_open,
+ .read = amd_mp2_stb_debugfs_read,
+};
+
+static void amd_mp2_dbgfs_register(struct amd_pmc_dev *dev)
+{
+ if (!dev->dbgfs_dir)
+ return;
+
+ debugfs_create_file("stb_read_previous_boot", 0644, dev->dbgfs_dir, dev,
+ &amd_mp2_stb_debugfs_fops);
+}
+
+void amd_mp2_stb_deinit(struct amd_pmc_dev *dev)
+{
+ struct amd_mp2_dev *mp2 = dev->mp2;
+ struct pci_dev *pdev;
+
+ if (mp2 && mp2->pdev) {
+ pdev = mp2->pdev;
+
+ if (mp2->mmio)
+ pci_clear_master(pdev);
+
+ pci_dev_put(pdev);
+
+ if (mp2->devres_gid)
+ devres_release_group(&pdev->dev, mp2->devres_gid);
+
+ dev->mp2 = NULL;
+ }
+}
+
+void amd_mp2_stb_init(struct amd_pmc_dev *dev)
+{
+ struct amd_mp2_dev *mp2 = NULL;
+ struct pci_dev *pdev;
+ int rc;
+
+ mp2 = devm_kzalloc(dev->dev, sizeof(*mp2), GFP_KERNEL);
+ if (!mp2)
+ return;
+
+ pdev = pci_get_device(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MP2_STB, NULL);
+ if (!pdev)
+ return;
+
+ dev->mp2 = mp2;
+ mp2->pdev = pdev;
+
+ mp2->devres_gid = devres_open_group(&pdev->dev, NULL, GFP_KERNEL);
+ if (!mp2->devres_gid) {
+ dev_err(&pdev->dev, "devres_open_group failed\n");
+ goto mp2_error;
+ }
+
+ rc = pcim_enable_device(pdev);
+ if (rc) {
+ dev_err(&pdev->dev, "pcim_enable_device failed\n");
+ goto mp2_error;
+ }
+
+ rc = pcim_iomap_regions(pdev, BIT(MP2_MMIO_BAR), "mp2 stb");
+ if (rc) {
+ dev_err(&pdev->dev, "pcim_iomap_regions failed\n");
+ goto mp2_error;
+ }
+
+ mp2->mmio = pcim_iomap_table(pdev)[MP2_MMIO_BAR];
+ if (!mp2->mmio) {
+ dev_err(&pdev->dev, "pcim_iomap_table failed\n");
+ goto mp2_error;
+ }
+
+ pci_set_master(pdev);
+
+ rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+ if (rc) {
+ dev_err(&pdev->dev, "failed to set DMA mask\n");
+ goto mp2_error;
+ }
+
+ amd_mp2_dbgfs_register(dev);
+
+ return;
+
+mp2_error:
+ amd_mp2_stb_deinit(dev);
+}