From 31a166fe9c269af17977e650846ee4ea50361c07 Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Wed, 26 Jun 2019 15:38:47 -0700 Subject: platform/x86: ISST: Add Intel Speed Select mailbox interface via PCI Add an IOCTL to send mailbox commands to PUNIT using PUNIT PCI device. A limited set of mailbox commands can be sent to PUNIT. This MMIO interface is used by the intel-speed-select tool under tools/x86/power to enumerate and control Intel Speed Select features. The MBOX commands ids and semantics of the message can be checked from the source code of the tool. Signed-off-by: Srinivas Pandruvada Signed-off-by: Andy Shevchenko --- .../platform/x86/intel_speed_select_if/Makefile | 1 + .../x86/intel_speed_select_if/isst_if_common.c | 85 +++++++++ .../x86/intel_speed_select_if/isst_if_common.h | 3 + .../x86/intel_speed_select_if/isst_if_mbox_pci.c | 199 +++++++++++++++++++++ 4 files changed, 288 insertions(+) create mode 100644 drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c (limited to 'drivers/platform') diff --git a/drivers/platform/x86/intel_speed_select_if/Makefile b/drivers/platform/x86/intel_speed_select_if/Makefile index 7e94919208d3..8dec8c858649 100644 --- a/drivers/platform/x86/intel_speed_select_if/Makefile +++ b/drivers/platform/x86/intel_speed_select_if/Makefile @@ -6,3 +6,4 @@ obj-$(CONFIG_INTEL_SPEED_SELECT_INTERFACE) += isst_if_common.o obj-$(CONFIG_INTEL_SPEED_SELECT_INTERFACE) += isst_if_mmio.o +obj-$(CONFIG_INTEL_SPEED_SELECT_INTERFACE) += isst_if_mbox_pci.o diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_common.c b/drivers/platform/x86/intel_speed_select_if/isst_if_common.c index 3f96a3925bc6..391fc3f12161 100644 --- a/drivers/platform/x86/intel_speed_select_if/isst_if_common.c +++ b/drivers/platform/x86/intel_speed_select_if/isst_if_common.c @@ -25,6 +25,86 @@ static struct isst_if_cmd_cb punit_callbacks[ISST_IF_DEV_MAX]; +struct isst_valid_cmd_ranges { + u16 cmd; + u16 sub_cmd_beg; + u16 sub_cmd_end; +}; + +struct isst_cmd_set_req_type { + u16 cmd; + u16 sub_cmd; + u16 param; +}; + +static const struct isst_valid_cmd_ranges isst_valid_cmds[] = { + {0xD0, 0x00, 0x03}, + {0x7F, 0x00, 0x0B}, + {0x7F, 0x10, 0x12}, + {0x7F, 0x20, 0x23}, +}; + +static const struct isst_cmd_set_req_type isst_cmd_set_reqs[] = { + {0xD0, 0x00, 0x08}, + {0xD0, 0x01, 0x08}, + {0xD0, 0x02, 0x08}, + {0xD0, 0x03, 0x08}, + {0x7F, 0x02, 0x00}, + {0x7F, 0x08, 0x00}, +}; + +/** + * isst_if_mbox_cmd_invalid() - Check invalid mailbox commands + * @cmd: Pointer to the command structure to verify. + * + * Invalid command to PUNIT to may result in instability of the platform. + * This function has a whitelist of commands, which are allowed. + * + * Return: Return true if the command is invalid, else false. + */ +bool isst_if_mbox_cmd_invalid(struct isst_if_mbox_cmd *cmd) +{ + int i; + + if (cmd->logical_cpu >= nr_cpu_ids) + return true; + + for (i = 0; i < ARRAY_SIZE(isst_valid_cmds); ++i) { + if (cmd->command == isst_valid_cmds[i].cmd && + (cmd->sub_command >= isst_valid_cmds[i].sub_cmd_beg && + cmd->sub_command <= isst_valid_cmds[i].sub_cmd_end)) { + return false; + } + } + + return true; +} +EXPORT_SYMBOL_GPL(isst_if_mbox_cmd_invalid); + +/** + * isst_if_mbox_cmd_set_req() - Check mailbox command is a set request + * @cmd: Pointer to the command structure to verify. + * + * Check if the given mail box level is set request and not a get request. + * + * Return: Return true if the command is set_req, else false. + */ +bool isst_if_mbox_cmd_set_req(struct isst_if_mbox_cmd *cmd) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(isst_cmd_set_reqs); ++i) { + if (cmd->command == isst_cmd_set_reqs[i].cmd && + cmd->sub_command == isst_cmd_set_reqs[i].sub_cmd && + cmd->parameter == isst_cmd_set_reqs[i].param) { + return true; + } + } + + return false; +} +EXPORT_SYMBOL_GPL(isst_if_mbox_cmd_set_req); + static int isst_if_get_platform_info(void __user *argp) { struct isst_if_platform_info info; @@ -224,6 +304,11 @@ static long isst_if_def_ioctl(struct file *file, unsigned int cmd, if (cb->registered) ret = isst_if_exec_multi_cmd(argp, cb); break; + case ISST_IF_MBOX_COMMAND: + cb = &punit_callbacks[ISST_IF_DEV_MBOX]; + if (cb->registered) + ret = isst_if_exec_multi_cmd(argp, cb); + break; default: break; } diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_common.h b/drivers/platform/x86/intel_speed_select_if/isst_if_common.h index cdc7d019748a..7c0f71221da7 100644 --- a/drivers/platform/x86/intel_speed_select_if/isst_if_common.h +++ b/drivers/platform/x86/intel_speed_select_if/isst_if_common.h @@ -11,6 +11,7 @@ #define __ISST_IF_COMMON_H #define INTEL_RAPL_PRIO_DEVID_0 0x3451 +#define INTEL_CFG_MBOX_DEVID_0 0x3459 /* * Validate maximum commands in a single request. @@ -60,4 +61,6 @@ struct isst_if_cmd_cb { int isst_if_cdev_register(int type, struct isst_if_cmd_cb *cb); void isst_if_cdev_unregister(int type); struct pci_dev *isst_if_get_pci_dev(int cpu, int bus, int dev, int fn); +bool isst_if_mbox_cmd_set_req(struct isst_if_mbox_cmd *mbox_cmd); +bool isst_if_mbox_cmd_invalid(struct isst_if_mbox_cmd *cmd); #endif diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c b/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c new file mode 100644 index 000000000000..1c4f2893cd80 --- /dev/null +++ b/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c @@ -0,0 +1,199 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Intel Speed Select Interface: Mbox via PCI Interface + * Copyright (c) 2019, Intel Corporation. + * All rights reserved. + * + * Author: Srinivas Pandruvada + */ + +#include +#include +#include +#include +#include +#include + +#include "isst_if_common.h" + +#define PUNIT_MAILBOX_DATA 0xA0 +#define PUNIT_MAILBOX_INTERFACE 0xA4 +#define PUNIT_MAILBOX_BUSY_BIT 31 + +/* + * Commands has variable amount of processing time. Most of the commands will + * be done in 0-3 tries, but some takes up to 50. + * The real processing time was observed as 25us for the most of the commands + * at 2GHz. It is possible to optimize this count taking samples on customer + * systems. + */ +#define OS_MAILBOX_RETRY_COUNT 50 + +struct isst_if_device { + struct mutex mutex; +}; + +static int isst_if_mbox_cmd(struct pci_dev *pdev, + struct isst_if_mbox_cmd *mbox_cmd) +{ + u32 retries, data; + int ret; + + /* Poll for rb bit == 0 */ + retries = OS_MAILBOX_RETRY_COUNT; + do { + ret = pci_read_config_dword(pdev, PUNIT_MAILBOX_INTERFACE, + &data); + if (ret) + return ret; + + if (data & BIT_ULL(PUNIT_MAILBOX_BUSY_BIT)) { + ret = -EBUSY; + continue; + } + ret = 0; + break; + } while (--retries); + + if (ret) + return ret; + + /* Write DATA register */ + ret = pci_write_config_dword(pdev, PUNIT_MAILBOX_DATA, + mbox_cmd->req_data); + if (ret) + return ret; + + /* Write command register */ + data = BIT_ULL(PUNIT_MAILBOX_BUSY_BIT) | + (mbox_cmd->parameter & GENMASK_ULL(13, 0)) << 16 | + (mbox_cmd->sub_command << 8) | + mbox_cmd->command; + + ret = pci_write_config_dword(pdev, PUNIT_MAILBOX_INTERFACE, data); + if (ret) + return ret; + + /* Poll for rb bit == 0 */ + retries = OS_MAILBOX_RETRY_COUNT; + do { + ret = pci_read_config_dword(pdev, PUNIT_MAILBOX_INTERFACE, + &data); + if (ret) + return ret; + + if (data & BIT_ULL(PUNIT_MAILBOX_BUSY_BIT)) { + ret = -EBUSY; + continue; + } + + if (data & 0xff) + return -ENXIO; + + ret = pci_read_config_dword(pdev, PUNIT_MAILBOX_DATA, &data); + if (ret) + return ret; + + mbox_cmd->resp_data = data; + ret = 0; + break; + } while (--retries); + + return ret; +} + +static long isst_if_mbox_proc_cmd(u8 *cmd_ptr, int *write_only, int resume) +{ + struct isst_if_mbox_cmd *mbox_cmd; + struct isst_if_device *punit_dev; + struct pci_dev *pdev; + int ret; + + mbox_cmd = (struct isst_if_mbox_cmd *)cmd_ptr; + + if (isst_if_mbox_cmd_invalid(mbox_cmd)) + return -EINVAL; + + if (isst_if_mbox_cmd_set_req(mbox_cmd) && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + pdev = isst_if_get_pci_dev(mbox_cmd->logical_cpu, 1, 30, 1); + if (!pdev) + return -EINVAL; + + punit_dev = pci_get_drvdata(pdev); + if (!punit_dev) + return -EINVAL; + + /* + * Basically we are allowing one complete mailbox transaction on + * a mapped PCI device at a time. + */ + mutex_lock(&punit_dev->mutex); + ret = isst_if_mbox_cmd(pdev, mbox_cmd); + mutex_unlock(&punit_dev->mutex); + if (ret) + return ret; + + *write_only = 0; + + return 0; +} + +static const struct pci_device_id isst_if_mbox_ids[] = { + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, INTEL_CFG_MBOX_DEVID_0)}, + { 0 }, +}; +MODULE_DEVICE_TABLE(pci, isst_if_mbox_ids); + +static int isst_if_mbox_probe(struct pci_dev *pdev, + const struct pci_device_id *ent) +{ + struct isst_if_device *punit_dev; + struct isst_if_cmd_cb cb; + int ret; + + punit_dev = devm_kzalloc(&pdev->dev, sizeof(*punit_dev), GFP_KERNEL); + if (!punit_dev) + return -ENOMEM; + + ret = pcim_enable_device(pdev); + if (ret) + return ret; + + mutex_init(&punit_dev->mutex); + pci_set_drvdata(pdev, punit_dev); + + memset(&cb, 0, sizeof(cb)); + cb.cmd_size = sizeof(struct isst_if_mbox_cmd); + cb.offset = offsetof(struct isst_if_mbox_cmds, mbox_cmd); + cb.cmd_callback = isst_if_mbox_proc_cmd; + cb.owner = THIS_MODULE; + ret = isst_if_cdev_register(ISST_IF_DEV_MBOX, &cb); + + if (ret) + mutex_destroy(&punit_dev->mutex); + + return ret; +} + +static void isst_if_mbox_remove(struct pci_dev *pdev) +{ + struct isst_if_device *punit_dev; + + punit_dev = pci_get_drvdata(pdev); + isst_if_cdev_unregister(ISST_IF_DEV_MBOX); + mutex_destroy(&punit_dev->mutex); +} + +static struct pci_driver isst_if_pci_driver = { + .name = "isst_if_mbox_pci", + .id_table = isst_if_mbox_ids, + .probe = isst_if_mbox_probe, + .remove = isst_if_mbox_remove, +}; + +module_pci_driver(isst_if_pci_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Intel speed select interface pci mailbox driver"); -- cgit v1.2.3-59-g8ed1b