From 48a6c7bced2a781c911497f073347bec5ab4d7a5 Mon Sep 17 00:00:00 2001 From: Nipun Gupta Date: Mon, 13 Mar 2023 18:56:36 +0530 Subject: [PATCH] cdx: add device attributes Create sysfs entry for CDX devices. Sysfs entries provided in each of the CDX device detected by the CDX controller - vendor id - device id - remove - reset of the device. - driver override Signed-off-by: Puneet Gupta Signed-off-by: Nipun Gupta Signed-off-by: Tarak Reddy Reviewed-by: Pieter Jansen van Vuuren Tested-by: Nikhil Agarwal Link: https://lore.kernel.org/r/20230313132636.31850-8-nipun.gupta@amd.com Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-bus-cdx | 44 +++++++++++ drivers/cdx/cdx.c | 127 ++++++++++++++++++++++++++++++++ drivers/cdx/controller/cdx_controller.c | 18 +++++ drivers/cdx/controller/mcdi_functions.c | 14 ++++ drivers/cdx/controller/mcdi_functions.h | 11 +++ include/linux/cdx/cdx_bus.h | 27 +++++++ 6 files changed, 241 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-cdx b/Documentation/ABI/testing/sysfs-bus-cdx index 43b4e161f226..7af477f49998 100644 --- a/Documentation/ABI/testing/sysfs-bus-cdx +++ b/Documentation/ABI/testing/sysfs-bus-cdx @@ -10,3 +10,47 @@ Description: For example:: # echo 1 > /sys/bus/cdx/rescan + +What: /sys/bus/cdx/devices/.../vendor +Date: March 2023 +Contact: nipun.gupta@amd.com +Description: + Vendor ID for this CDX device, in hexadecimal. Vendor ID is + 16 bit identifier which is specific to the device manufacturer. + Combination of Vendor ID and Device ID identifies a device. + +What: /sys/bus/cdx/devices/.../device +Date: March 2023 +Contact: nipun.gupta@amd.com +Description: + Device ID for this CDX device, in hexadecimal. Device ID is + 16 bit identifier to identify a device type within the range + of a device manufacturer. + Combination of Vendor ID and Device ID identifies a device. + +What: /sys/bus/cdx/devices/.../reset +Date: March 2023 +Contact: nipun.gupta@amd.com +Description: + Writing y/1/on to this file resets the CDX device. + On resetting the device, the corresponding driver is notified + twice, once before the device is being reset, and again after + the reset has been complete. + + For example:: + + # echo 1 > /sys/bus/cdx/.../reset + +What: /sys/bus/cdx/devices/.../remove +Date: March 2023 +Contact: tarak.reddy@amd.com +Description: + Writing y/1/on to this file removes the corresponding + device from the CDX bus. If the device is to be reconfigured + reconfigured in the Hardware, the device can be removed, so + that the device driver does not access the device while it is + being reconfigured. + + For example:: + + # echo 1 > /sys/bus/cdx/devices/.../remove diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c index 6b162bbb9b25..67c32cb2c006 100644 --- a/drivers/cdx/cdx.c +++ b/drivers/cdx/cdx.c @@ -72,6 +72,39 @@ static DEFINE_XARRAY_ALLOC(cdx_controllers); /** + * cdx_dev_reset - Reset a CDX device + * @dev: CDX device + * + * Return: -errno on failure, 0 on success. + */ +int cdx_dev_reset(struct device *dev) +{ + struct cdx_device *cdx_dev = to_cdx_device(dev); + struct cdx_controller *cdx = cdx_dev->cdx; + struct cdx_device_config dev_config = {0}; + struct cdx_driver *cdx_drv; + int ret; + + cdx_drv = to_cdx_driver(dev->driver); + /* Notify driver that device is being reset */ + if (cdx_drv && cdx_drv->reset_prepare) + cdx_drv->reset_prepare(cdx_dev); + + dev_config.type = CDX_DEV_RESET_CONF; + ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num, + cdx_dev->dev_num, &dev_config); + if (ret) + dev_err(dev, "cdx device reset failed\n"); + + /* Notify driver that device reset is complete */ + if (cdx_drv && cdx_drv->reset_done) + cdx_drv->reset_done(cdx_dev); + + return ret; +} +EXPORT_SYMBOL_GPL(cdx_dev_reset); + +/** * cdx_unregister_device - Unregister a CDX device * @dev: CDX device * @data: This is always passed as NULL, and is not used in this API, @@ -237,6 +270,99 @@ static int cdx_dma_configure(struct device *dev) return 0; } +/* show configuration fields */ +#define cdx_config_attr(field, format_string) \ +static ssize_t \ +field##_show(struct device *dev, struct device_attribute *attr, char *buf) \ +{ \ + struct cdx_device *cdx_dev = to_cdx_device(dev); \ + return sysfs_emit(buf, format_string, cdx_dev->field); \ +} \ +static DEVICE_ATTR_RO(field) + +cdx_config_attr(vendor, "0x%04x\n"); +cdx_config_attr(device, "0x%04x\n"); + +static ssize_t remove_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + bool val; + + if (kstrtobool(buf, &val) < 0) + return -EINVAL; + + if (!val) + return -EINVAL; + + if (device_remove_file_self(dev, attr)) { + int ret; + + ret = cdx_unregister_device(dev, NULL); + if (ret) + return ret; + } + + return count; +} +static DEVICE_ATTR_WO(remove); + +static ssize_t reset_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + bool val; + int ret; + + if (kstrtobool(buf, &val) < 0) + return -EINVAL; + + if (!val) + return -EINVAL; + + ret = cdx_dev_reset(dev); + if (ret) + return ret; + + return count; +} +static DEVICE_ATTR_WO(reset); + +static ssize_t driver_override_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct cdx_device *cdx_dev = to_cdx_device(dev); + int ret; + + if (WARN_ON(dev->bus != &cdx_bus_type)) + return -EINVAL; + + ret = driver_set_override(dev, &cdx_dev->driver_override, buf, count); + if (ret) + return ret; + + return count; +} + +static ssize_t driver_override_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cdx_device *cdx_dev = to_cdx_device(dev); + + return sysfs_emit(buf, "%s\n", cdx_dev->driver_override); +} +static DEVICE_ATTR_RW(driver_override); + +static struct attribute *cdx_dev_attrs[] = { + &dev_attr_remove.attr, + &dev_attr_reset.attr, + &dev_attr_vendor.attr, + &dev_attr_device.attr, + &dev_attr_driver_override.attr, + NULL, +}; +ATTRIBUTE_GROUPS(cdx_dev); + static ssize_t rescan_store(struct bus_type *bus, const char *buf, size_t count) { @@ -280,6 +406,7 @@ struct bus_type cdx_bus_type = { .shutdown = cdx_shutdown, .dma_configure = cdx_dma_configure, .bus_groups = cdx_bus_groups, + .dev_groups = cdx_dev_groups, }; EXPORT_SYMBOL_GPL(cdx_bus_type); diff --git a/drivers/cdx/controller/cdx_controller.c b/drivers/cdx/controller/cdx_controller.c index 0d1826980935..dc52f95f8978 100644 --- a/drivers/cdx/controller/cdx_controller.c +++ b/drivers/cdx/controller/cdx_controller.c @@ -45,6 +45,23 @@ void cdx_rpmsg_pre_remove(struct cdx_controller *cdx) cdx_mcdi_wait_for_quiescence(cdx->priv, MCDI_RPC_TIMEOUT); } +static int cdx_configure_device(struct cdx_controller *cdx, + u8 bus_num, u8 dev_num, + struct cdx_device_config *dev_config) +{ + int ret = 0; + + switch (dev_config->type) { + case CDX_DEV_RESET_CONF: + ret = cdx_mcdi_reset_device(cdx->priv, bus_num, dev_num); + break; + default: + ret = -EINVAL; + } + + return ret; +} + static int cdx_scan_devices(struct cdx_controller *cdx) { struct cdx_mcdi *cdx_mcdi = cdx->priv; @@ -104,6 +121,7 @@ static int cdx_scan_devices(struct cdx_controller *cdx) static struct cdx_ops cdx_ops = { .scan = cdx_scan_devices, + .dev_configure = cdx_configure_device, }; static int xlnx_cdx_probe(struct platform_device *pdev) diff --git a/drivers/cdx/controller/mcdi_functions.c b/drivers/cdx/controller/mcdi_functions.c index 012b52881dd5..0158f26533dd 100644 --- a/drivers/cdx/controller/mcdi_functions.c +++ b/drivers/cdx/controller/mcdi_functions.c @@ -123,3 +123,17 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx, return 0; } + +int cdx_mcdi_reset_device(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num) +{ + MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_RESET_IN_LEN); + int ret; + + MCDI_SET_DWORD(inbuf, CDX_DEVICE_RESET_IN_BUS, bus_num); + MCDI_SET_DWORD(inbuf, CDX_DEVICE_RESET_IN_DEVICE, dev_num); + + ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_DEVICE_RESET, inbuf, sizeof(inbuf), + NULL, 0, NULL); + + return ret; +} diff --git a/drivers/cdx/controller/mcdi_functions.h b/drivers/cdx/controller/mcdi_functions.h index 6bf5a4a0778f..7440ace5539a 100644 --- a/drivers/cdx/controller/mcdi_functions.h +++ b/drivers/cdx/controller/mcdi_functions.h @@ -47,4 +47,15 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num, struct cdx_dev_params *dev_params); +/** + * cdx_mcdi_reset_device - Reset cdx device represented by bus_num:dev_num + * @cdx: pointer to MCDI interface. + * @bus_num: Bus number. + * @dev_num: Device number. + * + * Return: 0 on success, <0 on failure + */ +int cdx_mcdi_reset_device(struct cdx_mcdi *cdx, + u8 bus_num, u8 dev_num); + #endif /* CDX_MCDI_FUNCTIONS_H */ diff --git a/include/linux/cdx/cdx_bus.h b/include/linux/cdx/cdx_bus.h index d134e0104724..35ef41d8a61a 100644 --- a/include/linux/cdx/cdx_bus.h +++ b/include/linux/cdx/cdx_bus.h @@ -21,8 +21,20 @@ /* Forward declaration for CDX controller */ struct cdx_controller; +enum { + CDX_DEV_RESET_CONF, +}; + +struct cdx_device_config { + u8 type; +}; + typedef int (*cdx_scan_cb)(struct cdx_controller *cdx); +typedef int (*cdx_dev_configure_cb)(struct cdx_controller *cdx, + u8 bus_num, u8 dev_num, + struct cdx_device_config *dev_config); + /** * CDX_DEVICE_DRIVER_OVERRIDE - macro used to describe a CDX device with * override_only flags. @@ -39,9 +51,12 @@ typedef int (*cdx_scan_cb)(struct cdx_controller *cdx); /** * struct cdx_ops - Callbacks supported by CDX controller. * @scan: scan the devices on the controller + * @dev_configure: configuration like reset, master_enable, + * msi_config etc for a CDX device */ struct cdx_ops { cdx_scan_cb scan; + cdx_dev_configure_cb dev_configure; }; /** @@ -101,6 +116,8 @@ struct cdx_device { * @probe: Function called when a device is added * @remove: Function called when a device is removed * @shutdown: Function called at shutdown time to quiesce the device + * @reset_prepare: Function called before is reset to notify driver + * @reset_done: Function called after reset is complete to notify driver * @driver_managed_dma: Device driver doesn't use kernel DMA API for DMA. * For most device drivers, no need to care about this flag * as long as all DMAs are handled through the kernel DMA API. @@ -115,6 +132,8 @@ struct cdx_driver { int (*probe)(struct cdx_device *dev); int (*remove)(struct cdx_device *dev); void (*shutdown)(struct cdx_device *dev); + void (*reset_prepare)(struct cdx_device *dev); + void (*reset_done)(struct cdx_device *dev); bool driver_managed_dma; }; @@ -144,4 +163,12 @@ void cdx_driver_unregister(struct cdx_driver *cdx_driver); extern struct bus_type cdx_bus_type; +/** + * cdx_dev_reset - Reset CDX device + * @dev: device pointer + * + * Return: 0 for success, -errno on failure + */ +int cdx_dev_reset(struct device *dev); + #endif /* _CDX_BUS_H_ */ -- 2.11.0