diff options
Diffstat (limited to 'drivers/platform/x86/amd/pmc/mp2_stb.c')
| -rw-r--r-- | drivers/platform/x86/amd/pmc/mp2_stb.c | 279 |
1 files changed, 279 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..dfa55327e5f1 --- /dev/null +++ b/drivers/platform/x86/amd/pmc/mp2_stb.c @@ -0,0 +1,279 @@ +// 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/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); +} |