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 <[email protected]>
Reviewed-by: Pieter Jansen van Vuuren <[email protected]>
---
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..71ddb56a5d08 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
On Mon, Jul 24, 2023 at 05:34:33PM +0530, Nipun Gupta wrote:
> 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 <[email protected]>
> Reviewed-by: Pieter Jansen van Vuuren <[email protected]>
> ---
You are adding apis here that no one is actually using, making it pretty
impossible to see if they are being used properly, or if they are even
needed at all.
Please submit this as part of a patch series that uses the apis,
otherwise there's no need for anyone to accept this patch.
thanks,
greg k-h