From e3cfd49cb9491ac1cc233a4b9e098688b4ab281d Mon Sep 17 00:00:00 2001 From: Abhijit Gangurde Date: Tue, 17 Oct 2023 21:35:03 +0530 Subject: cdx: add support for bus enable and disable CDX bus needs to be disabled before updating/writing devices in the FPGA. Once the devices are written, the bus shall be rescanned. This change provides sysfs entry to enable/disable the CDX bus. Co-developed-by: Nipun Gupta Signed-off-by: Nipun Gupta Signed-off-by: Abhijit Gangurde Link: https://lore.kernel.org/r/20231017160505.10640-6-abhijit.gangurde@amd.com Signed-off-by: Greg Kroah-Hartman --- drivers/cdx/cdx.c | 72 +++++++++++++++++++++++++++++++++ drivers/cdx/controller/cdx_controller.c | 12 ++++++ drivers/cdx/controller/mc_cdx_pcol.h | 54 +++++++++++++++++++++++++ drivers/cdx/controller/mcdi_functions.c | 24 +++++++++++ drivers/cdx/controller/mcdi_functions.h | 18 +++++++++ 5 files changed, 180 insertions(+) (limited to 'drivers/cdx') diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c index cf5306580c21..8eb484c37e97 100644 --- a/drivers/cdx/cdx.c +++ b/drivers/cdx/cdx.c @@ -124,9 +124,12 @@ static int cdx_unregister_device(struct device *dev, void *data) { struct cdx_device *cdx_dev = to_cdx_device(dev); + struct cdx_controller *cdx = cdx_dev->cdx; if (cdx_dev->is_bus) { device_for_each_child(dev, NULL, cdx_unregister_device); + if (cdx_dev->enabled && cdx->ops->bus_disable) + cdx->ops->bus_disable(cdx, cdx_dev->bus_num); } else { kfree(cdx_dev->driver_override); cdx_dev->driver_override = NULL; @@ -383,6 +386,41 @@ static ssize_t driver_override_show(struct device *dev, } static DEVICE_ATTR_RW(driver_override); +static ssize_t enable_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct cdx_device *cdx_dev = to_cdx_device(dev); + struct cdx_controller *cdx = cdx_dev->cdx; + bool enable; + int ret; + + if (kstrtobool(buf, &enable) < 0) + return -EINVAL; + + if (enable == cdx_dev->enabled) + return count; + + if (enable && cdx->ops->bus_enable) + ret = cdx->ops->bus_enable(cdx, cdx_dev->bus_num); + else if (!enable && cdx->ops->bus_disable) + ret = cdx->ops->bus_disable(cdx, cdx_dev->bus_num); + else + ret = -EOPNOTSUPP; + + if (!ret) + cdx_dev->enabled = enable; + + return ret < 0 ? ret : count; +} + +static ssize_t enable_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct cdx_device *cdx_dev = to_cdx_device(dev); + + return sysfs_emit(buf, "%u\n", cdx_dev->enabled); +} +static DEVICE_ATTR_RW(enable); + static umode_t cdx_dev_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = kobj_to_dev(kobj); @@ -395,6 +433,18 @@ static umode_t cdx_dev_attrs_are_visible(struct kobject *kobj, struct attribute return 0; } +static umode_t cdx_bus_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct cdx_device *cdx_dev; + + cdx_dev = to_cdx_device(dev); + if (cdx_dev->is_bus) + return a->mode; + + return 0; +} + static struct attribute *cdx_dev_attrs[] = { &dev_attr_remove.attr, &dev_attr_reset.attr, @@ -409,8 +459,19 @@ static const struct attribute_group cdx_dev_group = { .is_visible = cdx_dev_attrs_are_visible, }; +static struct attribute *cdx_bus_dev_attrs[] = { + &dev_attr_enable.attr, + NULL, +}; + +static const struct attribute_group cdx_bus_dev_group = { + .attrs = cdx_bus_dev_attrs, + .is_visible = cdx_bus_attrs_are_visible, +}; + static const struct attribute_group *cdx_dev_groups[] = { &cdx_dev_group, + &cdx_bus_dev_group, NULL, }; @@ -588,8 +649,19 @@ struct device *cdx_bus_add(struct cdx_controller *cdx, u8 bus_num) goto device_add_fail; } + if (cdx->ops->bus_enable) { + ret = cdx->ops->bus_enable(cdx, bus_num); + if (ret && ret != -EALREADY) { + dev_err(cdx->dev, "cdx bus enable failed: %d\n", ret); + goto bus_enable_fail; + } + } + + cdx_dev->enabled = true; return &cdx_dev->dev; +bus_enable_fail: + device_del(&cdx_dev->dev); device_add_fail: put_device(&cdx_dev->dev); diff --git a/drivers/cdx/controller/cdx_controller.c b/drivers/cdx/controller/cdx_controller.c index b4e0d6b40339..f2a691efd1f1 100644 --- a/drivers/cdx/controller/cdx_controller.c +++ b/drivers/cdx/controller/cdx_controller.c @@ -33,6 +33,16 @@ static const struct cdx_mcdi_ops mcdi_ops = { .mcdi_request = cdx_mcdi_request, }; +static int cdx_bus_enable(struct cdx_controller *cdx, u8 bus_num) +{ + return cdx_mcdi_bus_enable(cdx->priv, bus_num); +} + +static int cdx_bus_disable(struct cdx_controller *cdx, u8 bus_num) +{ + return cdx_mcdi_bus_disable(cdx->priv, bus_num); +} + void cdx_rpmsg_post_probe(struct cdx_controller *cdx) { /* Register CDX controller with CDX bus driver */ @@ -128,6 +138,8 @@ static int cdx_scan_devices(struct cdx_controller *cdx) } static struct cdx_ops cdx_ops = { + .bus_enable = cdx_bus_enable, + .bus_disable = cdx_bus_disable, .scan = cdx_scan_devices, .dev_configure = cdx_configure_device, }; diff --git a/drivers/cdx/controller/mc_cdx_pcol.h b/drivers/cdx/controller/mc_cdx_pcol.h index 4ccb7b52951b..2de019406b57 100644 --- a/drivers/cdx/controller/mc_cdx_pcol.h +++ b/drivers/cdx/controller/mc_cdx_pcol.h @@ -455,6 +455,60 @@ #define MC_CMD_CDX_BUS_GET_DEVICE_CONFIG_OUT_REQUESTER_ID_OFST 84 #define MC_CMD_CDX_BUS_GET_DEVICE_CONFIG_OUT_REQUESTER_ID_LEN 4 +/***********************************/ +/* + * MC_CMD_CDX_BUS_DOWN + * Asserting reset on the CDX bus causes all devices on the bus to be quiesced. + * DMA bus mastering is disabled and any pending DMA request are flushed. Once + * the response is returned, the devices are guaranteed to no longer issue DMA + * requests or raise MSI interrupts. Further device MMIO accesses may have + * undefined results. While the bus reset is asserted, any of the enumeration + * or device configuration MCDIs will fail with EAGAIN. It is only legal to + * reload the relevant PL region containing CDX devices if the corresponding CDX + * bus is in reset. Depending on the implementation, the firmware may or may + * not enforce this restriction and it is up to the caller to make sure this + * requirement is satisfied. + */ +#define MC_CMD_CDX_BUS_DOWN 0x4 +#define MC_CMD_CDX_BUS_DOWN_MSGSET 0x4 + +/* MC_CMD_CDX_BUS_DOWN_IN msgrequest */ +#define MC_CMD_CDX_BUS_DOWN_IN_LEN 4 +/* Bus number to put in reset, in range 0 to BUS_COUNT-1 */ +#define MC_CMD_CDX_BUS_DOWN_IN_BUS_OFST 0 +#define MC_CMD_CDX_BUS_DOWN_IN_BUS_LEN 4 + +/* + * MC_CMD_CDX_BUS_DOWN_OUT msgresponse: The bus is quiesced, no further + * upstream traffic for devices on this bus. + */ +#define MC_CMD_CDX_BUS_DOWN_OUT_LEN 0 + +/***********************************/ +/* + * MC_CMD_CDX_BUS_UP + * After bus reset is de-asserted, devices are in a state which is functionally + * equivalent to each device having been reset with MC_CMD_CDX_DEVICE_RESET. In + * other words, device logic is reset in a hardware-specific way, MMIO accesses + * are forwarded to the device, DMA bus mastering is disabled and needs to be + * re-enabled with MC_CMD_CDX_DEVICE_DMA_ENABLE once the driver is ready to + * start servicing DMA. If the underlying number of devices or device resources + * changed (e.g. if PL was reloaded) while the bus was in reset, the bus driver + * is expected to re-enumerate the bus. Returns EALREADY if the bus was already + * up before the call. + */ +#define MC_CMD_CDX_BUS_UP 0x5 +#define MC_CMD_CDX_BUS_UP_MSGSET 0x5 + +/* MC_CMD_CDX_BUS_UP_IN msgrequest */ +#define MC_CMD_CDX_BUS_UP_IN_LEN 4 +/* Bus number to take out of reset, in range 0 to BUS_COUNT-1 */ +#define MC_CMD_CDX_BUS_UP_IN_BUS_OFST 0 +#define MC_CMD_CDX_BUS_UP_IN_BUS_LEN 4 + +/* MC_CMD_CDX_BUS_UP_OUT msgresponse: The bus can now be enumerated. */ +#define MC_CMD_CDX_BUS_UP_OUT_LEN 0 + /***********************************/ /* * MC_CMD_CDX_DEVICE_RESET diff --git a/drivers/cdx/controller/mcdi_functions.c b/drivers/cdx/controller/mcdi_functions.c index 0158f26533dd..0e1e35d91242 100644 --- a/drivers/cdx/controller/mcdi_functions.c +++ b/drivers/cdx/controller/mcdi_functions.c @@ -124,6 +124,30 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx, return 0; } +int cdx_mcdi_bus_enable(struct cdx_mcdi *cdx, u8 bus_num) +{ + MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_BUS_UP_IN_LEN); + int ret; + + MCDI_SET_DWORD(inbuf, CDX_BUS_UP_IN_BUS, bus_num); + ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_BUS_UP, inbuf, sizeof(inbuf), + NULL, 0, NULL); + + return ret; +} + +int cdx_mcdi_bus_disable(struct cdx_mcdi *cdx, u8 bus_num) +{ + MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_BUS_DOWN_IN_LEN); + int ret; + + MCDI_SET_DWORD(inbuf, CDX_BUS_DOWN_IN_BUS, bus_num); + ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_BUS_DOWN, inbuf, sizeof(inbuf), + NULL, 0, NULL); + + return ret; +} + 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); diff --git a/drivers/cdx/controller/mcdi_functions.h b/drivers/cdx/controller/mcdi_functions.h index 7440ace5539a..28973d5ec3ab 100644 --- a/drivers/cdx/controller/mcdi_functions.h +++ b/drivers/cdx/controller/mcdi_functions.h @@ -47,6 +47,24 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num, struct cdx_dev_params *dev_params); +/** + * cdx_mcdi_bus_enable - Enable CDX bus represented by bus_num + * @cdx: pointer to MCDI interface. + * @bus_num: Bus number. + * + * Return: 0 on success, <0 on failure + */ +int cdx_mcdi_bus_enable(struct cdx_mcdi *cdx, u8 bus_num); + +/** + * cdx_mcdi_bus_disable - Disable CDX bus represented by bus_num + * @cdx: pointer to MCDI interface. + * @bus_num: Bus number. + * + * Return: 0 on success, <0 on failure + */ +int cdx_mcdi_bus_disable(struct cdx_mcdi *cdx, u8 bus_num); + /** * cdx_mcdi_reset_device - Reset cdx device represented by bus_num:dev_num * @cdx: pointer to MCDI interface. -- cgit