peci: Add support for PECI device drivers
authorIwona Winiarska <iwona.winiarska@intel.com>
Tue, 8 Feb 2022 15:36:34 +0000 (16:36 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 9 Feb 2022 07:04:44 +0000 (08:04 +0100)
Add support for PECI device drivers, which unlike PECI controller
drivers are actually able to provide functionalities to userspace.

Also, extend peci_request API to allow querying more details about PECI
device (e.g. model/family), that's going to be used to find a compatible
peci_driver.

Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20220208153639.255278-9-iwona.winiarska@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/peci/core.c
drivers/peci/device.c
drivers/peci/internal.h
drivers/peci/request.c
include/linux/peci.h

index e993615cf521f504d2ed28f13dcb4df82d25ca20..9c8cf07e51c75d15910daf68e3b2a2323f179fe0 100644 (file)
@@ -160,8 +160,52 @@ err_put:
 }
 EXPORT_SYMBOL_NS_GPL(devm_peci_controller_add, PECI);
 
+static const struct peci_device_id *
+peci_bus_match_device_id(const struct peci_device_id *id, struct peci_device *device)
+{
+       while (id->family != 0) {
+               if (id->family == device->info.family &&
+                   id->model == device->info.model)
+                       return id;
+               id++;
+       }
+
+       return NULL;
+}
+
+static int peci_bus_device_match(struct device *dev, struct device_driver *drv)
+{
+       struct peci_device *device = to_peci_device(dev);
+       struct peci_driver *peci_drv = to_peci_driver(drv);
+
+       if (dev->type != &peci_device_type)
+               return 0;
+
+       return !!peci_bus_match_device_id(peci_drv->id_table, device);
+}
+
+static int peci_bus_device_probe(struct device *dev)
+{
+       struct peci_device *device = to_peci_device(dev);
+       struct peci_driver *driver = to_peci_driver(dev->driver);
+
+       return driver->probe(device, peci_bus_match_device_id(driver->id_table, device));
+}
+
+static void peci_bus_device_remove(struct device *dev)
+{
+       struct peci_device *device = to_peci_device(dev);
+       struct peci_driver *driver = to_peci_driver(dev->driver);
+
+       if (driver->remove)
+               driver->remove(device);
+}
+
 struct bus_type peci_bus_type = {
        .name           = "peci",
+       .match          = peci_bus_device_match,
+       .probe          = peci_bus_device_probe,
+       .remove         = peci_bus_device_remove,
        .bus_groups     = peci_bus_groups,
 };
 
index d10ed1cfcd483f3d3d5f0ce6068f452b5cc9835d..184b5e650b0b92ff77d6523e0ce87118a5a20613 100644 (file)
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 // Copyright (c) 2018-2021 Intel Corporation
 
+#include <linux/bitfield.h>
 #include <linux/peci.h>
 #include <linux/slab.h>
 
  */
 static DEFINE_MUTEX(peci_device_del_lock);
 
+#define REVISION_NUM_MASK GENMASK(15, 8)
+static int peci_get_revision(struct peci_device *device, u8 *revision)
+{
+       struct peci_request *req;
+       u64 dib;
+
+       req = peci_xfer_get_dib(device);
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       /*
+        * PECI device may be in a state where it is unable to return a proper
+        * DIB, in which case it returns 0 as DIB value.
+        * Let's treat this as an error to avoid carrying on with the detection
+        * using invalid revision.
+        */
+       dib = peci_request_dib_read(req);
+       if (dib == 0) {
+               peci_request_free(req);
+               return -EIO;
+       }
+
+       *revision = FIELD_GET(REVISION_NUM_MASK, dib);
+
+       peci_request_free(req);
+
+       return 0;
+}
+
+static int peci_get_cpu_id(struct peci_device *device, u32 *cpu_id)
+{
+       struct peci_request *req;
+       int ret;
+
+       req = peci_xfer_pkg_cfg_readl(device, PECI_PCS_PKG_ID, PECI_PKG_ID_CPU_ID);
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       ret = peci_request_status(req);
+       if (ret)
+               goto out_req_free;
+
+       *cpu_id = peci_request_data_readl(req);
+out_req_free:
+       peci_request_free(req);
+
+       return ret;
+}
+
+static unsigned int peci_x86_cpu_family(unsigned int sig)
+{
+       unsigned int x86;
+
+       x86 = (sig >> 8) & 0xf;
+
+       if (x86 == 0xf)
+               x86 += (sig >> 20) & 0xff;
+
+       return x86;
+}
+
+static unsigned int peci_x86_cpu_model(unsigned int sig)
+{
+       unsigned int fam, model;
+
+       fam = peci_x86_cpu_family(sig);
+
+       model = (sig >> 4) & 0xf;
+
+       if (fam >= 0x6)
+               model += ((sig >> 16) & 0xf) << 4;
+
+       return model;
+}
+
+static int peci_device_info_init(struct peci_device *device)
+{
+       u8 revision;
+       u32 cpu_id;
+       int ret;
+
+       ret = peci_get_cpu_id(device, &cpu_id);
+       if (ret)
+               return ret;
+
+       device->info.family = peci_x86_cpu_family(cpu_id);
+       device->info.model = peci_x86_cpu_model(cpu_id);
+
+       ret = peci_get_revision(device, &revision);
+       if (ret)
+               return ret;
+       device->info.peci_revision = revision;
+
+       device->info.socket_id = device->addr - PECI_BASE_ADDR;
+
+       return 0;
+}
+
 static int peci_detect(struct peci_controller *controller, u8 addr)
 {
        /*
@@ -82,6 +181,10 @@ int peci_device_create(struct peci_controller *controller, u8 addr)
        device->dev.bus = &peci_bus_type;
        device->dev.type = &peci_device_type;
 
+       ret = peci_device_info_init(device);
+       if (ret)
+               goto err_put;
+
        ret = dev_set_name(&device->dev, "%d-%02x", controller->id, device->addr);
        if (ret)
                goto err_put;
@@ -108,6 +211,33 @@ void peci_device_destroy(struct peci_device *device)
        mutex_unlock(&peci_device_del_lock);
 }
 
+int __peci_driver_register(struct peci_driver *driver, struct module *owner,
+                          const char *mod_name)
+{
+       driver->driver.bus = &peci_bus_type;
+       driver->driver.owner = owner;
+       driver->driver.mod_name = mod_name;
+
+       if (!driver->probe) {
+               pr_err("peci: trying to register driver without probe callback\n");
+               return -EINVAL;
+       }
+
+       if (!driver->id_table) {
+               pr_err("peci: trying to register driver without device id table\n");
+               return -EINVAL;
+       }
+
+       return driver_register(&driver->driver);
+}
+EXPORT_SYMBOL_NS_GPL(__peci_driver_register, PECI);
+
+void peci_driver_unregister(struct peci_driver *driver)
+{
+       driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL_NS_GPL(peci_driver_unregister, PECI);
+
 static void peci_device_release(struct device *dev)
 {
        struct peci_device *device = to_peci_device(dev);
index 978e12c8e1d363e5f12e7348d4fb16e9cca6e74d..52c02e12874ffbd2ded4c187d22d6bb3bfe9226f 100644 (file)
@@ -19,6 +19,35 @@ struct peci_request;
 struct peci_request *peci_request_alloc(struct peci_device *device, u8 tx_len, u8 rx_len);
 void peci_request_free(struct peci_request *req);
 
+int peci_request_status(struct peci_request *req);
+
+u64 peci_request_dib_read(struct peci_request *req);
+
+u8 peci_request_data_readb(struct peci_request *req);
+u16 peci_request_data_readw(struct peci_request *req);
+u32 peci_request_data_readl(struct peci_request *req);
+u64 peci_request_data_readq(struct peci_request *req);
+
+struct peci_request *peci_xfer_get_dib(struct peci_device *device);
+struct peci_request *peci_xfer_get_temp(struct peci_device *device);
+
+struct peci_request *peci_xfer_pkg_cfg_readb(struct peci_device *device, u8 index, u16 param);
+struct peci_request *peci_xfer_pkg_cfg_readw(struct peci_device *device, u8 index, u16 param);
+struct peci_request *peci_xfer_pkg_cfg_readl(struct peci_device *device, u8 index, u16 param);
+struct peci_request *peci_xfer_pkg_cfg_readq(struct peci_device *device, u8 index, u16 param);
+
+/**
+ * struct peci_device_id - PECI device data to match
+ * @data: pointer to driver private data specific to device
+ * @family: device family
+ * @model: device model
+ */
+struct peci_device_id {
+       const void *data;
+       u16 family;
+       u8 model;
+};
+
 extern struct device_type peci_device_type;
 extern const struct attribute_group *peci_device_groups[];
 
@@ -28,6 +57,51 @@ void peci_device_destroy(struct peci_device *device);
 extern struct bus_type peci_bus_type;
 extern const struct attribute_group *peci_bus_groups[];
 
+/**
+ * struct peci_driver - PECI driver
+ * @driver: inherit device driver
+ * @probe: probe callback
+ * @remove: remove callback
+ * @id_table: PECI device match table to decide which device to bind
+ */
+struct peci_driver {
+       struct device_driver driver;
+       int (*probe)(struct peci_device *device, const struct peci_device_id *id);
+       void (*remove)(struct peci_device *device);
+       const struct peci_device_id *id_table;
+};
+
+static inline struct peci_driver *to_peci_driver(struct device_driver *d)
+{
+       return container_of(d, struct peci_driver, driver);
+}
+
+int __peci_driver_register(struct peci_driver *driver, struct module *owner,
+                          const char *mod_name);
+/**
+ * peci_driver_register() - register PECI driver
+ * @driver: the driver to be registered
+ *
+ * PECI drivers that don't need to do anything special in module init should
+ * use the convenience "module_peci_driver" macro instead
+ *
+ * Return: zero on success, else a negative error code.
+ */
+#define peci_driver_register(driver) \
+       __peci_driver_register(driver, THIS_MODULE, KBUILD_MODNAME)
+void peci_driver_unregister(struct peci_driver *driver);
+
+/**
+ * module_peci_driver() - helper macro for registering a modular PECI driver
+ * @__peci_driver: peci_driver struct
+ *
+ * Helper macro for PECI drivers which do not do anything special in module
+ * init/exit. This eliminates a lot of boilerplate. Each module may only
+ * use this macro once, and calling it replaces module_init() and module_exit()
+ */
+#define module_peci_driver(__peci_driver) \
+       module_driver(__peci_driver, peci_driver_register, peci_driver_unregister)
+
 extern struct device_type peci_controller_type;
 
 int peci_controller_scan_devices(struct peci_controller *controller);
index 7dee51c50dd23c3bc8bebd7e26839b76d503478b..a49eb351cda31001cf2f4737f48fac32dcfc2d9b 100644 (file)
 // SPDX-License-Identifier: GPL-2.0-only
 // Copyright (c) 2021 Intel Corporation
 
+#include <linux/bug.h>
 #include <linux/export.h>
 #include <linux/peci.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 
+#include <asm/unaligned.h>
+
 #include "internal.h"
 
+#define PECI_GET_DIB_CMD               0xf7
+#define  PECI_GET_DIB_WR_LEN           1
+#define  PECI_GET_DIB_RD_LEN           8
+
+#define PECI_RDPKGCFG_CMD              0xa1
+#define  PECI_RDPKGCFG_WR_LEN          5
+#define  PECI_RDPKGCFG_RD_LEN_BASE     1
+#define PECI_WRPKGCFG_CMD              0xa5
+#define  PECI_WRPKGCFG_WR_LEN_BASE     6
+#define  PECI_WRPKGCFG_RD_LEN          1
+
+/* Device Specific Completion Code (CC) Definition */
+#define PECI_CC_SUCCESS                                0x40
+#define PECI_CC_NEED_RETRY                     0x80
+#define PECI_CC_OUT_OF_RESOURCE                        0x81
+#define PECI_CC_UNAVAIL_RESOURCE               0x82
+#define PECI_CC_INVALID_REQ                    0x90
+#define PECI_CC_MCA_ERROR                      0x91
+#define PECI_CC_CATASTROPHIC_MCA_ERROR         0x93
+#define PECI_CC_FATAL_MCA_ERROR                        0x94
+#define PECI_CC_PARITY_ERR_GPSB_OR_PMSB                0x98
+#define PECI_CC_PARITY_ERR_GPSB_OR_PMSB_IERR   0x9B
+#define PECI_CC_PARITY_ERR_GPSB_OR_PMSB_MCA    0x9C
+
+#define PECI_RETRY_BIT                 BIT(0)
+
+#define PECI_RETRY_TIMEOUT             msecs_to_jiffies(700)
+#define PECI_RETRY_INTERVAL_MIN                msecs_to_jiffies(1)
+#define PECI_RETRY_INTERVAL_MAX                msecs_to_jiffies(128)
+
+static u8 peci_request_data_cc(struct peci_request *req)
+{
+       return req->rx.buf[0];
+}
+
+/**
+ * peci_request_status() - return -errno based on PECI completion code
+ * @req: the PECI request that contains response data with completion code
+ *
+ * It can't be used for Ping(), GetDIB() and GetTemp() - for those commands we
+ * don't expect completion code in the response.
+ *
+ * Return: -errno
+ */
+int peci_request_status(struct peci_request *req)
+{
+       u8 cc = peci_request_data_cc(req);
+
+       if (cc != PECI_CC_SUCCESS)
+               dev_dbg(&req->device->dev, "ret: %#02x\n", cc);
+
+       switch (cc) {
+       case PECI_CC_SUCCESS:
+               return 0;
+       case PECI_CC_NEED_RETRY:
+       case PECI_CC_OUT_OF_RESOURCE:
+       case PECI_CC_UNAVAIL_RESOURCE:
+               return -EAGAIN;
+       case PECI_CC_INVALID_REQ:
+               return -EINVAL;
+       case PECI_CC_MCA_ERROR:
+       case PECI_CC_CATASTROPHIC_MCA_ERROR:
+       case PECI_CC_FATAL_MCA_ERROR:
+       case PECI_CC_PARITY_ERR_GPSB_OR_PMSB:
+       case PECI_CC_PARITY_ERR_GPSB_OR_PMSB_IERR:
+       case PECI_CC_PARITY_ERR_GPSB_OR_PMSB_MCA:
+               return -EIO;
+       }
+
+       WARN_ONCE(1, "Unknown PECI completion code: %#02x\n", cc);
+
+       return -EIO;
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_status, PECI);
+
+static int peci_request_xfer(struct peci_request *req)
+{
+       struct peci_device *device = req->device;
+       struct peci_controller *controller = to_peci_controller(device->dev.parent);
+       int ret;
+
+       mutex_lock(&controller->bus_lock);
+       ret = controller->ops->xfer(controller, device->addr, req);
+       mutex_unlock(&controller->bus_lock);
+
+       return ret;
+}
+
+static int peci_request_xfer_retry(struct peci_request *req)
+{
+       long wait_interval = PECI_RETRY_INTERVAL_MIN;
+       struct peci_device *device = req->device;
+       struct peci_controller *controller = to_peci_controller(device->dev.parent);
+       unsigned long start = jiffies;
+       int ret;
+
+       /* Don't try to use it for ping */
+       if (WARN_ON(req->tx.len == 0))
+               return 0;
+
+       do {
+               ret = peci_request_xfer(req);
+               if (ret) {
+                       dev_dbg(&controller->dev, "xfer error: %d\n", ret);
+                       return ret;
+               }
+
+               if (peci_request_status(req) != -EAGAIN)
+                       return 0;
+
+               /* Set the retry bit to indicate a retry attempt */
+               req->tx.buf[1] |= PECI_RETRY_BIT;
+
+               if (schedule_timeout_interruptible(wait_interval))
+                       return -ERESTARTSYS;
+
+               wait_interval = min_t(long, wait_interval * 2, PECI_RETRY_INTERVAL_MAX);
+       } while (time_before(jiffies, start + PECI_RETRY_TIMEOUT));
+
+       dev_dbg(&controller->dev, "request timed out\n");
+
+       return -ETIMEDOUT;
+}
+
 /**
  * peci_request_alloc() - allocate &struct peci_requests
  * @device: PECI device to which request is going to be sent
@@ -53,3 +180,90 @@ void peci_request_free(struct peci_request *req)
        kfree(req);
 }
 EXPORT_SYMBOL_NS_GPL(peci_request_free, PECI);
+
+struct peci_request *peci_xfer_get_dib(struct peci_device *device)
+{
+       struct peci_request *req;
+       int ret;
+
+       req = peci_request_alloc(device, PECI_GET_DIB_WR_LEN, PECI_GET_DIB_RD_LEN);
+       if (!req)
+               return ERR_PTR(-ENOMEM);
+
+       req->tx.buf[0] = PECI_GET_DIB_CMD;
+
+       ret = peci_request_xfer(req);
+       if (ret) {
+               peci_request_free(req);
+               return ERR_PTR(ret);
+       }
+
+       return req;
+}
+EXPORT_SYMBOL_NS_GPL(peci_xfer_get_dib, PECI);
+
+static struct peci_request *
+__pkg_cfg_read(struct peci_device *device, u8 index, u16 param, u8 len)
+{
+       struct peci_request *req;
+       int ret;
+
+       req = peci_request_alloc(device, PECI_RDPKGCFG_WR_LEN, PECI_RDPKGCFG_RD_LEN_BASE + len);
+       if (!req)
+               return ERR_PTR(-ENOMEM);
+
+       req->tx.buf[0] = PECI_RDPKGCFG_CMD;
+       req->tx.buf[1] = 0;
+       req->tx.buf[2] = index;
+       put_unaligned_le16(param, &req->tx.buf[3]);
+
+       ret = peci_request_xfer_retry(req);
+       if (ret) {
+               peci_request_free(req);
+               return ERR_PTR(ret);
+       }
+
+       return req;
+}
+
+u8 peci_request_data_readb(struct peci_request *req)
+{
+       return req->rx.buf[1];
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_data_readb, PECI);
+
+u16 peci_request_data_readw(struct peci_request *req)
+{
+       return get_unaligned_le16(&req->rx.buf[1]);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_data_readw, PECI);
+
+u32 peci_request_data_readl(struct peci_request *req)
+{
+       return get_unaligned_le32(&req->rx.buf[1]);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_data_readl, PECI);
+
+u64 peci_request_data_readq(struct peci_request *req)
+{
+       return get_unaligned_le64(&req->rx.buf[1]);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_data_readq, PECI);
+
+u64 peci_request_dib_read(struct peci_request *req)
+{
+       return get_unaligned_le64(&req->rx.buf[0]);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_dib_read, PECI);
+
+#define __read_pkg_config(x, type) \
+struct peci_request *peci_xfer_pkg_cfg_##x(struct peci_device *device, u8 index, u16 param) \
+{ \
+       return __pkg_cfg_read(device, index, param, sizeof(type)); \
+} \
+EXPORT_SYMBOL_NS_GPL(peci_xfer_pkg_cfg_##x, PECI)
+
+__read_pkg_config(readb, u8);
+__read_pkg_config(readw, u16);
+__read_pkg_config(readl, u32);
+__read_pkg_config(readq, u64);
index 7e35673f37868fc12fa2af4bdf00fee937352569..4eda423ba10c3b4397b0a4c259af3d0f868f7fc8 100644 (file)
  */
 #define PECI_REQUEST_MAX_BUF_SIZE 32
 
+#define PECI_PCS_PKG_ID                        0  /* Package Identifier Read */
+#define  PECI_PKG_ID_CPU_ID            0x0000  /* CPUID Info */
+#define  PECI_PKG_ID_PLATFORM_ID       0x0001  /* Platform ID */
+#define  PECI_PKG_ID_DEVICE_ID         0x0002  /* Uncore Device ID */
+#define  PECI_PKG_ID_MAX_THREAD_ID     0x0003  /* Max Thread ID */
+#define  PECI_PKG_ID_MICROCODE_REV     0x0004  /* CPU Microcode Update Revision */
+#define  PECI_PKG_ID_MCA_ERROR_LOG     0x0005  /* Machine Check Status */
+
 struct peci_controller;
 struct peci_request;
 
@@ -59,6 +67,11 @@ static inline struct peci_controller *to_peci_controller(void *d)
  * struct peci_device - PECI device
  * @dev: device object to register PECI device to the device model
  * @controller: manages the bus segment hosting this PECI device
+ * @info: PECI device characteristics
+ * @info.family: device family
+ * @info.model: device model
+ * @info.peci_revision: PECI revision supported by the PECI device
+ * @info.socket_id: the socket ID represented by the PECI device
  * @addr: address used on the PECI bus connected to the parent controller
  * @deleted: indicates that PECI device was already deleted
  *
@@ -68,6 +81,12 @@ static inline struct peci_controller *to_peci_controller(void *d)
  */
 struct peci_device {
        struct device dev;
+       struct {
+               u16 family;
+               u8 model;
+               u8 peci_revision;
+               u8 socket_id;
+       } info;
        u8 addr;
        bool deleted;
 };