diff options
Diffstat (limited to 'drivers/platform/x86/amd/hsmp.c')
-rw-r--r-- | drivers/platform/x86/amd/hsmp.c | 423 |
1 files changed, 423 insertions, 0 deletions
diff --git a/drivers/platform/x86/amd/hsmp.c b/drivers/platform/x86/amd/hsmp.c new file mode 100644 index 0000000000..31382ef52e --- /dev/null +++ b/drivers/platform/x86/amd/hsmp.c @@ -0,0 +1,423 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * AMD HSMP Platform Driver + * Copyright (c) 2022, AMD. + * All Rights Reserved. + * + * This file provides a device implementation for HSMP interface + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <asm/amd_hsmp.h> +#include <asm/amd_nb.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/semaphore.h> + +#define DRIVER_NAME "amd_hsmp" +#define DRIVER_VERSION "1.0" + +/* HSMP Status / Error codes */ +#define HSMP_STATUS_NOT_READY 0x00 +#define HSMP_STATUS_OK 0x01 +#define HSMP_ERR_INVALID_MSG 0xFE +#define HSMP_ERR_INVALID_INPUT 0xFF + +/* Timeout in millsec */ +#define HSMP_MSG_TIMEOUT 100 +#define HSMP_SHORT_SLEEP 1 + +#define HSMP_WR true +#define HSMP_RD false + +/* + * To access specific HSMP mailbox register, s/w writes the SMN address of HSMP mailbox + * register into the SMN_INDEX register, and reads/writes the SMN_DATA reg. + * Below are required SMN address for HSMP Mailbox register offsets in SMU address space + */ +#define SMN_HSMP_MSG_ID 0x3B10534 +#define SMN_HSMP_MSG_RESP 0x3B10980 +#define SMN_HSMP_MSG_DATA 0x3B109E0 + +#define HSMP_INDEX_REG 0xc4 +#define HSMP_DATA_REG 0xc8 + +static struct semaphore *hsmp_sem; + +static struct miscdevice hsmp_device; + +static int amd_hsmp_rdwr(struct pci_dev *root, u32 address, + u32 *value, bool write) +{ + int ret; + + ret = pci_write_config_dword(root, HSMP_INDEX_REG, address); + if (ret) + return ret; + + ret = (write ? pci_write_config_dword(root, HSMP_DATA_REG, *value) + : pci_read_config_dword(root, HSMP_DATA_REG, value)); + + return ret; +} + +/* + * Send a message to the HSMP port via PCI-e config space registers. + * + * The caller is expected to zero out any unused arguments. + * If a response is expected, the number of response words should be greater than 0. + * + * Returns 0 for success and populates the requested number of arguments. + * Returns a negative error code for failure. + */ +static int __hsmp_send_message(struct pci_dev *root, struct hsmp_message *msg) +{ + unsigned long timeout, short_sleep; + u32 mbox_status; + u32 index; + int ret; + + /* Clear the status register */ + mbox_status = HSMP_STATUS_NOT_READY; + ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_RESP, &mbox_status, HSMP_WR); + if (ret) { + pr_err("Error %d clearing mailbox status register\n", ret); + return ret; + } + + index = 0; + /* Write any message arguments */ + while (index < msg->num_args) { + ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_DATA + (index << 2), + &msg->args[index], HSMP_WR); + if (ret) { + pr_err("Error %d writing message argument %d\n", ret, index); + return ret; + } + index++; + } + + /* Write the message ID which starts the operation */ + ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_ID, &msg->msg_id, HSMP_WR); + if (ret) { + pr_err("Error %d writing message ID %u\n", ret, msg->msg_id); + return ret; + } + + /* + * Depending on when the trigger write completes relative to the SMU + * firmware 1 ms cycle, the operation may take from tens of us to 1 ms + * to complete. Some operations may take more. Therefore we will try + * a few short duration sleeps and switch to long sleeps if we don't + * succeed quickly. + */ + short_sleep = jiffies + msecs_to_jiffies(HSMP_SHORT_SLEEP); + timeout = jiffies + msecs_to_jiffies(HSMP_MSG_TIMEOUT); + + while (time_before(jiffies, timeout)) { + ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_RESP, &mbox_status, HSMP_RD); + if (ret) { + pr_err("Error %d reading mailbox status\n", ret); + return ret; + } + + if (mbox_status != HSMP_STATUS_NOT_READY) + break; + if (time_before(jiffies, short_sleep)) + usleep_range(50, 100); + else + usleep_range(1000, 2000); + } + + if (unlikely(mbox_status == HSMP_STATUS_NOT_READY)) { + return -ETIMEDOUT; + } else if (unlikely(mbox_status == HSMP_ERR_INVALID_MSG)) { + return -ENOMSG; + } else if (unlikely(mbox_status == HSMP_ERR_INVALID_INPUT)) { + return -EINVAL; + } else if (unlikely(mbox_status != HSMP_STATUS_OK)) { + pr_err("Message ID %u unknown failure (status = 0x%X)\n", + msg->msg_id, mbox_status); + return -EIO; + } + + /* + * SMU has responded OK. Read response data. + * SMU reads the input arguments from eight 32 bit registers starting + * from SMN_HSMP_MSG_DATA and writes the response data to the same + * SMN_HSMP_MSG_DATA address. + * We copy the response data if any, back to the args[]. + */ + index = 0; + while (index < msg->response_sz) { + ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_DATA + (index << 2), + &msg->args[index], HSMP_RD); + if (ret) { + pr_err("Error %d reading response %u for message ID:%u\n", + ret, index, msg->msg_id); + break; + } + index++; + } + + return ret; +} + +static int validate_message(struct hsmp_message *msg) +{ + /* msg_id against valid range of message IDs */ + if (msg->msg_id < HSMP_TEST || msg->msg_id >= HSMP_MSG_ID_MAX) + return -ENOMSG; + + /* msg_id is a reserved message ID */ + if (hsmp_msg_desc_table[msg->msg_id].type == HSMP_RSVD) + return -ENOMSG; + + /* num_args and response_sz against the HSMP spec */ + if (msg->num_args != hsmp_msg_desc_table[msg->msg_id].num_args || + msg->response_sz != hsmp_msg_desc_table[msg->msg_id].response_sz) + return -EINVAL; + + return 0; +} + +int hsmp_send_message(struct hsmp_message *msg) +{ + struct amd_northbridge *nb; + int ret; + + if (!msg) + return -EINVAL; + + nb = node_to_amd_nb(msg->sock_ind); + if (!nb || !nb->root) + return -ENODEV; + + ret = validate_message(msg); + if (ret) + return ret; + + /* + * The time taken by smu operation to complete is between + * 10us to 1ms. Sometime it may take more time. + * In SMP system timeout of 100 millisecs should + * be enough for the previous thread to finish the operation + */ + ret = down_timeout(&hsmp_sem[msg->sock_ind], + msecs_to_jiffies(HSMP_MSG_TIMEOUT)); + if (ret < 0) + return ret; + + ret = __hsmp_send_message(nb->root, msg); + + up(&hsmp_sem[msg->sock_ind]); + + return ret; +} +EXPORT_SYMBOL_GPL(hsmp_send_message); + +static int hsmp_test(u16 sock_ind, u32 value) +{ + struct hsmp_message msg = { 0 }; + struct amd_northbridge *nb; + int ret = -ENODEV; + + nb = node_to_amd_nb(sock_ind); + if (!nb || !nb->root) + return ret; + + /* + * Test the hsmp port by performing TEST command. The test message + * takes one argument and returns the value of that argument + 1. + */ + msg.msg_id = HSMP_TEST; + msg.num_args = 1; + msg.response_sz = 1; + msg.args[0] = value; + msg.sock_ind = sock_ind; + + ret = __hsmp_send_message(nb->root, &msg); + if (ret) + return ret; + + /* Check the response value */ + if (msg.args[0] != (value + 1)) { + pr_err("Socket %d test message failed, Expected 0x%08X, received 0x%08X\n", + sock_ind, (value + 1), msg.args[0]); + return -EBADE; + } + + return ret; +} + +static long hsmp_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) +{ + int __user *arguser = (int __user *)arg; + struct hsmp_message msg = { 0 }; + int ret; + + if (copy_struct_from_user(&msg, sizeof(msg), arguser, sizeof(struct hsmp_message))) + return -EFAULT; + + /* + * Check msg_id is within the range of supported msg ids + * i.e within the array bounds of hsmp_msg_desc_table + */ + if (msg.msg_id < HSMP_TEST || msg.msg_id >= HSMP_MSG_ID_MAX) + return -ENOMSG; + + switch (fp->f_mode & (FMODE_WRITE | FMODE_READ)) { + case FMODE_WRITE: + /* + * Device is opened in O_WRONLY mode + * Execute only set/configure commands + */ + if (hsmp_msg_desc_table[msg.msg_id].type != HSMP_SET) + return -EINVAL; + break; + case FMODE_READ: + /* + * Device is opened in O_RDONLY mode + * Execute only get/monitor commands + */ + if (hsmp_msg_desc_table[msg.msg_id].type != HSMP_GET) + return -EINVAL; + break; + case FMODE_READ | FMODE_WRITE: + /* + * Device is opened in O_RDWR mode + * Execute both get/monitor and set/configure commands + */ + break; + default: + return -EINVAL; + } + + ret = hsmp_send_message(&msg); + if (ret) + return ret; + + if (hsmp_msg_desc_table[msg.msg_id].response_sz > 0) { + /* Copy results back to user for get/monitor commands */ + if (copy_to_user(arguser, &msg, sizeof(struct hsmp_message))) + return -EFAULT; + } + + return 0; +} + +static const struct file_operations hsmp_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = hsmp_ioctl, + .compat_ioctl = hsmp_ioctl, +}; + +static int hsmp_pltdrv_probe(struct platform_device *pdev) +{ + int i; + + hsmp_sem = devm_kzalloc(&pdev->dev, + (amd_nb_num() * sizeof(struct semaphore)), + GFP_KERNEL); + if (!hsmp_sem) + return -ENOMEM; + + for (i = 0; i < amd_nb_num(); i++) + sema_init(&hsmp_sem[i], 1); + + hsmp_device.name = "hsmp_cdev"; + hsmp_device.minor = MISC_DYNAMIC_MINOR; + hsmp_device.fops = &hsmp_fops; + hsmp_device.parent = &pdev->dev; + hsmp_device.nodename = "hsmp"; + hsmp_device.mode = 0644; + + return misc_register(&hsmp_device); +} + +static void hsmp_pltdrv_remove(struct platform_device *pdev) +{ + misc_deregister(&hsmp_device); +} + +static struct platform_driver amd_hsmp_driver = { + .probe = hsmp_pltdrv_probe, + .remove_new = hsmp_pltdrv_remove, + .driver = { + .name = DRIVER_NAME, + }, +}; + +static struct platform_device *amd_hsmp_platdev; + +static int __init hsmp_plt_init(void) +{ + int ret = -ENODEV; + u16 num_sockets; + int i; + + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD || boot_cpu_data.x86 < 0x19) { + pr_err("HSMP is not supported on Family:%x model:%x\n", + boot_cpu_data.x86, boot_cpu_data.x86_model); + return ret; + } + + /* + * amd_nb_num() returns number of SMN/DF interfaces present in the system + * if we have N SMN/DF interfaces that ideally means N sockets + */ + num_sockets = amd_nb_num(); + if (num_sockets == 0) + return ret; + + /* Test the hsmp interface on each socket */ + for (i = 0; i < num_sockets; i++) { + ret = hsmp_test(i, 0xDEADBEEF); + if (ret) { + pr_err("HSMP is not supported on Fam:%x model:%x\n", + boot_cpu_data.x86, boot_cpu_data.x86_model); + pr_err("Or Is HSMP disabled in BIOS ?\n"); + return -EOPNOTSUPP; + } + } + + ret = platform_driver_register(&amd_hsmp_driver); + if (ret) + return ret; + + amd_hsmp_platdev = platform_device_alloc(DRIVER_NAME, PLATFORM_DEVID_NONE); + if (!amd_hsmp_platdev) { + ret = -ENOMEM; + goto drv_unregister; + } + + ret = platform_device_add(amd_hsmp_platdev); + if (ret) { + platform_device_put(amd_hsmp_platdev); + goto drv_unregister; + } + + return 0; + +drv_unregister: + platform_driver_unregister(&amd_hsmp_driver); + return ret; +} + +static void __exit hsmp_plt_exit(void) +{ + platform_device_unregister(amd_hsmp_platdev); + platform_driver_unregister(&amd_hsmp_driver); +} + +device_initcall(hsmp_plt_init); +module_exit(hsmp_plt_exit); + +MODULE_DESCRIPTION("AMD HSMP Platform Interface Driver"); +MODULE_VERSION(DRIVER_VERSION); +MODULE_LICENSE("GPL v2"); |