From 2959ab247061e67485d83b6af8feb3761ec08cb9 Mon Sep 17 00:00:00 2001 From: Nipun Gupta Date: Mon, 13 Mar 2023 18:56:30 +0530 Subject: cdx: add the cdx bus driver Introduce AMD CDX bus, which provides a mechanism for scanning and probing CDX devices. These devices are memory mapped on system bus for Application Processors(APUs). CDX devices can be changed dynamically in the Fabric and CDX bus interacts with CDX controller to rescan the bus and rediscover the devices. Signed-off-by: Nipun Gupta Reviewed-by: Pieter Jansen van Vuuren Tested-by: Nikhil Agarwal Link: https://lore.kernel.org/r/20230313132636.31850-2-nipun.gupta@amd.com Signed-off-by: Greg Kroah-Hartman --- include/linux/cdx/cdx_bus.h | 147 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 include/linux/cdx/cdx_bus.h (limited to 'include/linux/cdx/cdx_bus.h') diff --git a/include/linux/cdx/cdx_bus.h b/include/linux/cdx/cdx_bus.h new file mode 100644 index 000000000000..d134e0104724 --- /dev/null +++ b/include/linux/cdx/cdx_bus.h @@ -0,0 +1,147 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * CDX bus public interface + * + * Copyright (C) 2022-2023, Advanced Micro Devices, Inc. + * + */ + +#ifndef _CDX_BUS_H_ +#define _CDX_BUS_H_ + +#include +#include +#include + +#define MAX_CDX_DEV_RESOURCES 4 +#define CDX_ANY_ID (0xFFFF) +#define CDX_CONTROLLER_ID_SHIFT 4 +#define CDX_BUS_NUM_MASK 0xF + +/* Forward declaration for CDX controller */ +struct cdx_controller; + +typedef int (*cdx_scan_cb)(struct cdx_controller *cdx); + +/** + * CDX_DEVICE_DRIVER_OVERRIDE - macro used to describe a CDX device with + * override_only flags. + * @vend: the 16 bit CDX Vendor ID + * @dev: the 16 bit CDX Device ID + * @driver_override: the 32 bit CDX Device override_only + * + * This macro is used to create a struct cdx_device_id that matches only a + * driver_override device. + */ +#define CDX_DEVICE_DRIVER_OVERRIDE(vend, dev, driver_override) \ + .vendor = (vend), .device = (dev), .override_only = (driver_override) + +/** + * struct cdx_ops - Callbacks supported by CDX controller. + * @scan: scan the devices on the controller + */ +struct cdx_ops { + cdx_scan_cb scan; +}; + +/** + * struct cdx_controller: CDX controller object + * @dev: Linux device associated with the CDX controller. + * @priv: private data + * @id: Controller ID + * @ops: CDX controller ops + */ +struct cdx_controller { + struct device *dev; + void *priv; + u32 id; + struct cdx_ops *ops; +}; + +/** + * struct cdx_device - CDX device object + * @dev: Linux driver model device object + * @cdx: CDX controller associated with the device + * @vendor: Vendor ID for CDX device + * @device: Device ID for CDX device + * @bus_num: Bus number for this CDX device + * @dev_num: Device number for this device + * @res: array of MMIO region entries + * @res_attr: resource binary attribute + * @res_count: number of valid MMIO regions + * @dma_mask: Default DMA mask + * @flags: CDX device flags + * @req_id: Requestor ID associated with CDX device + * @driver_override: driver name to force a match; do not set directly, + * because core frees it; use driver_set_override() to + * set or clear it. + */ +struct cdx_device { + struct device dev; + struct cdx_controller *cdx; + u16 vendor; + u16 device; + u8 bus_num; + u8 dev_num; + struct resource res[MAX_CDX_DEV_RESOURCES]; + u8 res_count; + u64 dma_mask; + u16 flags; + u32 req_id; + const char *driver_override; +}; + +#define to_cdx_device(_dev) \ + container_of(_dev, struct cdx_device, dev) + +/** + * struct cdx_driver - CDX device driver + * @driver: Generic device driver + * @match_id_table: table of supported device matching Ids + * @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 + * @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. + * For some special ones, for example VFIO drivers, they know + * how to manage the DMA themselves and set this flag so that + * the IOMMU layer will allow them to setup and manage their + * own I/O address space. + */ +struct cdx_driver { + struct device_driver driver; + const struct cdx_device_id *match_id_table; + int (*probe)(struct cdx_device *dev); + int (*remove)(struct cdx_device *dev); + void (*shutdown)(struct cdx_device *dev); + bool driver_managed_dma; +}; + +#define to_cdx_driver(_drv) \ + container_of(_drv, struct cdx_driver, driver) + +/* Macro to avoid include chaining to get THIS_MODULE */ +#define cdx_driver_register(drv) \ + __cdx_driver_register(drv, THIS_MODULE) + +/** + * __cdx_driver_register - registers a CDX device driver + * @cdx_driver: CDX driver to register + * @owner: module owner + * + * Return: -errno on failure, 0 on success. + */ +int __must_check __cdx_driver_register(struct cdx_driver *cdx_driver, + struct module *owner); + +/** + * cdx_driver_unregister - unregisters a device driver from the + * CDX bus. + * @cdx_driver: CDX driver to register + */ +void cdx_driver_unregister(struct cdx_driver *cdx_driver); + +extern struct bus_type cdx_bus_type; + +#endif /* _CDX_BUS_H_ */ -- cgit v1.2.3-70-g09d2 From 48a6c7bced2a781c911497f073347bec5ab4d7a5 Mon Sep 17 00:00:00 2001 From: Nipun Gupta Date: Mon, 13 Mar 2023 18:56:36 +0530 Subject: 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(+) (limited to 'include/linux/cdx/cdx_bus.h') 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 @@ -71,6 +71,39 @@ /* CDX controllers registered with the CDX bus */ 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 @@ -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_ */ -- cgit v1.2.3-70-g09d2