Messages in this thread Patch in this message | | | From | Nipun Gupta <> | Subject | [PATCH 1/2 v4] cdx: add support for bus mastering | Date | Wed, 26 Jul 2023 16:32:19 +0530 |
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Introduce cdx_set_master() and cdx_clear_master() APIs to support enable and disable of bus mastering. Drivers need to use these APIs to enable/disable DMAs from the CDX devices.
Signed-off-by: Nipun Gupta <nipun.gupta@amd.com> Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com> --- Changes v3->v4: - Added user of the Bus master enable and disable APIs in patch 2/2. There is no change in this patch.
Changes v2->v3: - Changed return value from EOPNOTSUPP to -EOPNOTSUPP in cdx_set_master()
Changes v1->v2: - Replace bme with bus_master_enable - Added check for dev_configure API callback - remove un-necessary error prints - changed conditional to if-else - updated commit message to use 72 columns
drivers/cdx/cdx.c | 29 +++++++++++++ drivers/cdx/controller/cdx_controller.c | 4 ++ drivers/cdx/controller/mcdi_functions.c | 58 +++++++++++++++++++++++++ drivers/cdx/controller/mcdi_functions.h | 13 ++++++ include/linux/cdx/cdx_bus.h | 16 +++++++ 5 files changed, 120 insertions(+)
diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c index d2cad4c670a0..10c6281b59c3 100644 --- a/drivers/cdx/cdx.c +++ b/drivers/cdx/cdx.c @@ -182,6 +182,35 @@ cdx_match_id(const struct cdx_device_id *ids, struct cdx_device *dev) return NULL; } +int cdx_set_master(struct cdx_device *cdx_dev) +{ + struct cdx_controller *cdx = cdx_dev->cdx; + struct cdx_device_config dev_config; + int ret = -EOPNOTSUPP; + + dev_config.type = CDX_DEV_BUS_MASTER_CONF; + dev_config.bus_master_enable = true; + if (cdx->ops->dev_configure) + ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num, + cdx_dev->dev_num, &dev_config); + + return ret; +} +EXPORT_SYMBOL_GPL(cdx_set_master); + +void cdx_clear_master(struct cdx_device *cdx_dev) +{ + struct cdx_controller *cdx = cdx_dev->cdx; + struct cdx_device_config dev_config; + + dev_config.type = CDX_DEV_BUS_MASTER_CONF; + dev_config.bus_master_enable = false; + if (cdx->ops->dev_configure) + cdx->ops->dev_configure(cdx, cdx_dev->bus_num, + cdx_dev->dev_num, &dev_config); +} +EXPORT_SYMBOL_GPL(cdx_clear_master); + /** * cdx_bus_match - device to driver matching callback * @dev: the cdx device to match against diff --git a/drivers/cdx/controller/cdx_controller.c b/drivers/cdx/controller/cdx_controller.c index dc52f95f8978..39aa569d8e07 100644 --- a/drivers/cdx/controller/cdx_controller.c +++ b/drivers/cdx/controller/cdx_controller.c @@ -55,6 +55,10 @@ static int cdx_configure_device(struct cdx_controller *cdx, case CDX_DEV_RESET_CONF: ret = cdx_mcdi_reset_device(cdx->priv, bus_num, dev_num); break; + case CDX_DEV_BUS_MASTER_CONF: + ret = cdx_mcdi_bus_master_enable(cdx->priv, bus_num, dev_num, + dev_config->bus_master_enable); + break; default: ret = -EINVAL; } diff --git a/drivers/cdx/controller/mcdi_functions.c b/drivers/cdx/controller/mcdi_functions.c index 0158f26533dd..6acd8fea4586 100644 --- a/drivers/cdx/controller/mcdi_functions.c +++ b/drivers/cdx/controller/mcdi_functions.c @@ -137,3 +137,61 @@ int cdx_mcdi_reset_device(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num) return ret; } + +static int cdx_mcdi_ctrl_flag_get(struct cdx_mcdi *cdx, u8 bus_num, + u8 dev_num, u32 *flags) +{ + MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_CONTROL_GET_IN_LEN); + MCDI_DECLARE_BUF(outbuf, MC_CMD_CDX_DEVICE_CONTROL_GET_OUT_LEN); + size_t outlen; + int ret; + + MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_GET_IN_BUS, bus_num); + MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_GET_IN_DEVICE, dev_num); + ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_DEVICE_CONTROL_GET, inbuf, + sizeof(inbuf), outbuf, sizeof(outbuf), &outlen); + if (ret) + return ret; + + if (outlen != MC_CMD_CDX_DEVICE_CONTROL_GET_OUT_LEN) + return -EIO; + + *flags = MCDI_DWORD(outbuf, CDX_DEVICE_CONTROL_GET_OUT_FLAGS); + + return 0; +} + +static int cdx_mcdi_ctrl_flag_set(struct cdx_mcdi *cdx, u8 bus_num, + u8 dev_num, bool enable, int lbn) +{ + MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_CONTROL_SET_IN_LEN); + u32 flags; + int ret; + + /* + * Get flags and then set/reset BUS_MASTER_BIT according to + * the input params. + */ + ret = cdx_mcdi_ctrl_flag_get(cdx, bus_num, dev_num, &flags); + if (ret) + return ret; + + flags = flags & (u32)(~(BIT(lbn))); + if (enable) + flags |= (1 << lbn); + + MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_SET_IN_BUS, bus_num); + MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_SET_IN_DEVICE, dev_num); + MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_SET_IN_FLAGS, flags); + ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_DEVICE_CONTROL_SET, inbuf, + sizeof(inbuf), NULL, 0, NULL); + + return ret; +} + +int cdx_mcdi_bus_master_enable(struct cdx_mcdi *cdx, u8 bus_num, + u8 dev_num, bool enable) +{ + return cdx_mcdi_ctrl_flag_set(cdx, bus_num, dev_num, enable, + MC_CMD_CDX_DEVICE_CONTROL_SET_IN_BUS_MASTER_ENABLE_LBN); +} diff --git a/drivers/cdx/controller/mcdi_functions.h b/drivers/cdx/controller/mcdi_functions.h index 7440ace5539a..a448d6581eb4 100644 --- a/drivers/cdx/controller/mcdi_functions.h +++ b/drivers/cdx/controller/mcdi_functions.h @@ -58,4 +58,17 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx, int cdx_mcdi_reset_device(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num); +/** + * cdx_mcdi_bus_master_enable - Set/Reset bus mastering for cdx device + * represented by bus_num:dev_num + * @cdx: pointer to MCDI interface. + * @bus_num: Bus number. + * @dev_num: Device number. + * @enable: Enable bus mastering if set, disable otherwise. + * + * Return: 0 on success, <0 on failure + */ +int cdx_mcdi_bus_master_enable(struct cdx_mcdi *cdx, u8 bus_num, + u8 dev_num, bool enable); + #endif /* CDX_MCDI_FUNCTIONS_H */ diff --git a/include/linux/cdx/cdx_bus.h b/include/linux/cdx/cdx_bus.h index bead71b7bc73..1816c279879e 100644 --- a/include/linux/cdx/cdx_bus.h +++ b/include/linux/cdx/cdx_bus.h @@ -21,11 +21,13 @@ struct cdx_controller; enum { + CDX_DEV_BUS_MASTER_CONF, CDX_DEV_RESET_CONF, }; struct cdx_device_config { u8 type; + bool bus_master_enable; }; typedef int (*cdx_scan_cb)(struct cdx_controller *cdx); @@ -170,4 +172,18 @@ extern struct bus_type cdx_bus_type; */ int cdx_dev_reset(struct device *dev); +/** + * cdx_set_master - enables bus-mastering for CDX device + * @cdx_dev: the CDX device to enable + * + * Return: 0 for success, -errno on failure + */ +int cdx_set_master(struct cdx_device *cdx_dev); + +/** + * cdx_clear_master - disables bus-mastering for CDX device + * @cdx_dev: the CDX device to disable + */ +void cdx_clear_master(struct cdx_device *cdx_dev); + #endif /* _CDX_BUS_H_ */ -- 2.17.1
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