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]>
---
drivers/cdx/cdx.c | 32 ++++++++++++++
drivers/cdx/controller/cdx_controller.c | 4 ++
drivers/cdx/controller/mcdi_functions.c | 57 +++++++++++++++++++++++++
drivers/cdx/controller/mcdi_functions.h | 13 ++++++
include/linux/cdx/cdx_bus.h | 16 +++++++
5 files changed, 122 insertions(+)
diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
index d2cad4c670a0..efb24672b7d9 100644
--- a/drivers/cdx/cdx.c
+++ b/drivers/cdx/cdx.c
@@ -182,6 +182,38 @@ 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;
+
+ dev_config.type = CDX_DEV_BUS_MASTER_CONF;
+ dev_config.bme = true;
+ ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
+ cdx_dev->dev_num, &dev_config);
+ if (ret)
+ dev_err(&cdx_dev->dev, "device master enable failed\n");
+
+ 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;
+ int ret;
+
+ dev_config.type = CDX_DEV_BUS_MASTER_CONF;
+ dev_config.bme = false;
+ ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
+ cdx_dev->dev_num, &dev_config);
+ if (ret)
+ dev_err(&cdx_dev->dev, "device master disable failed\n");
+}
+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..ba670f0427d3 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->bme);
+ break;
default:
ret = -EINVAL;
}
diff --git a/drivers/cdx/controller/mcdi_functions.c b/drivers/cdx/controller/mcdi_functions.c
index 0158f26533dd..c4c00f376006 100644
--- a/drivers/cdx/controller/mcdi_functions.c
+++ b/drivers/cdx/controller/mcdi_functions.c
@@ -137,3 +137,60 @@ 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);
+ int ret, en;
+ u32 flags;
+
+ /*
+ * 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;
+
+ en = enable ? 1 : 0;
+ flags = (flags & (u32)(~(BIT(lbn)))) | (en << 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..acb4e40bd20e 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 bme;
};
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 Tue, Jul 18, 2023 at 03:36:51PM +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.
You do have a full 72 columns, why not use that?
> Signed-off-by: Nipun Gupta <[email protected]>
> Reviewed-by: Pieter Jansen van Vuuren <[email protected]>
> ---
> drivers/cdx/cdx.c | 32 ++++++++++++++
> drivers/cdx/controller/cdx_controller.c | 4 ++
> drivers/cdx/controller/mcdi_functions.c | 57 +++++++++++++++++++++++++
> drivers/cdx/controller/mcdi_functions.h | 13 ++++++
> include/linux/cdx/cdx_bus.h | 16 +++++++
> 5 files changed, 122 insertions(+)
>
> diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
> index d2cad4c670a0..efb24672b7d9 100644
> --- a/drivers/cdx/cdx.c
> +++ b/drivers/cdx/cdx.c
> @@ -182,6 +182,38 @@ 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;
> +
> + dev_config.type = CDX_DEV_BUS_MASTER_CONF;
> + dev_config.bme = true;
What is "bme"?
And are you sure that the config can be on the stack?
> + ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
> + cdx_dev->dev_num, &dev_config);
Will dev_configure always be there?
> + if (ret)
> + dev_err(&cdx_dev->dev, "device master enable failed\n");
Why error out here, shouldn't the call have printed something if it
wanted to?
> +
> + 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;
> + int ret;
> +
> + dev_config.type = CDX_DEV_BUS_MASTER_CONF;
> + dev_config.bme = false;
> + ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
> + cdx_dev->dev_num, &dev_config);
> + if (ret)
> + dev_err(&cdx_dev->dev, "device master disable failed\n");
Same question as above.
> +}
> +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..ba670f0427d3 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->bme);
> + break;
> default:
> ret = -EINVAL;
> }
> diff --git a/drivers/cdx/controller/mcdi_functions.c b/drivers/cdx/controller/mcdi_functions.c
> index 0158f26533dd..c4c00f376006 100644
> --- a/drivers/cdx/controller/mcdi_functions.c
> +++ b/drivers/cdx/controller/mcdi_functions.c
> @@ -137,3 +137,60 @@ 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);
How big are these buffers?
> + 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);
> + int ret, en;
> + u32 flags;
> +
> + /*
> + * 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;
> +
> + en = enable ? 1 : 0;
if/then/else?
> + flags = (flags & (u32)(~(BIT(lbn)))) | (en << 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..acb4e40bd20e 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 bme;
What does "bme" mean?
thanks,
greg k-h
On 7/18/2023 7:16 PM, Greg KH wrote:
> On Tue, Jul 18, 2023 at 03:36:51PM +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.
>
> You do have a full 72 columns, why not use that?
sure, will update accordingly.
>
>> Signed-off-by: Nipun Gupta <[email protected]>
>> Reviewed-by: Pieter Jansen van Vuuren <[email protected]>
>> ---
>> drivers/cdx/cdx.c | 32 ++++++++++++++
>> drivers/cdx/controller/cdx_controller.c | 4 ++
>> drivers/cdx/controller/mcdi_functions.c | 57 +++++++++++++++++++++++++
>> drivers/cdx/controller/mcdi_functions.h | 13 ++++++
>> include/linux/cdx/cdx_bus.h | 16 +++++++
>> 5 files changed, 122 insertions(+)
>>
>> diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
>> index d2cad4c670a0..efb24672b7d9 100644
>> --- a/drivers/cdx/cdx.c
>> +++ b/drivers/cdx/cdx.c
>> @@ -182,6 +182,38 @@ 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;
>> +
>> + dev_config.type = CDX_DEV_BUS_MASTER_CONF;
>> + dev_config.bme = true;
>
> What is "bme"?
This is bus master enable. I will add a comment on the structure definition.
>
> And are you sure that the config can be on the stack?
Yes, as this information is used by the controller and a new created
command is sent to the Firmware/Hardware.
>
>> + ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
>> + cdx_dev->dev_num, &dev_config);
>
> Will dev_configure always be there?
This is expected to be there, but will add a check for further assurance.
>
>> + if (ret)
>> + dev_err(&cdx_dev->dev, "device master enable failed\n");
>
> Why error out here, shouldn't the call have printed something if it
> wanted to?
Agree, will remove
>
>> +
>> + 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;
>> + int ret;
>> +
>> + dev_config.type = CDX_DEV_BUS_MASTER_CONF;
>> + dev_config.bme = false;
>> + ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
>> + cdx_dev->dev_num, &dev_config);
>> + if (ret)
>> + dev_err(&cdx_dev->dev, "device master disable failed\n");
>
> Same question as above.
sure will remove
>
>> +}
>> +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..ba670f0427d3 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->bme);
>> + break;
>> default:
>> ret = -EINVAL;
>> }
>> diff --git a/drivers/cdx/controller/mcdi_functions.c b/drivers/cdx/controller/mcdi_functions.c
>> index 0158f26533dd..c4c00f376006 100644
>> --- a/drivers/cdx/controller/mcdi_functions.c
>> +++ b/drivers/cdx/controller/mcdi_functions.c
>> @@ -137,3 +137,60 @@ 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);
>
> How big are these buffers?
The defines are as follows in mc_cdx_pcol.h:
#define MC_CMD_CDX_DEVICE_CONTROL_GET_IN_LEN 8
#define MC_CMD_CDX_DEVICE_CONTROL_GET_OUT_LEN 4
where MCDI_DECLARE_BUF leads to creation of a variable of data structure:
/* A doubleword (i.e. 4 byte) datatype - little-endian in HW */
struct cdx_dword {
__le32 cdx_u32;
};
so inbuf is of 32 bytes (8 * 4) and outbuf is 16 bytes (4 * 4).
>
>> + 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);
>> + int ret, en;
>> + u32 flags;
>> +
>> + /*
>> + * 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;
>> +
>> + en = enable ? 1 : 0;
>
> if/then/else?
okay. will update
>
>
>> + flags = (flags & (u32)(~(BIT(lbn)))) | (en << 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..acb4e40bd20e 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 bme;
>
> What does "bme" mean?
This is bus master enable bit. Will add comment.
Thanks,
Nipun
>
> thanks,
>
> greg k-h
On Wed, Jul 19, 2023 at 06:06:40PM +0530, Gupta, Nipun wrote:
>
>
> On 7/18/2023 7:16 PM, Greg KH wrote:
> > On Tue, Jul 18, 2023 at 03:36:51PM +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.
> >
> > You do have a full 72 columns, why not use that?
>
> sure, will update accordingly.
>
> >
> > > Signed-off-by: Nipun Gupta <[email protected]>
> > > Reviewed-by: Pieter Jansen van Vuuren <[email protected]>
> > > ---
> > > drivers/cdx/cdx.c | 32 ++++++++++++++
> > > drivers/cdx/controller/cdx_controller.c | 4 ++
> > > drivers/cdx/controller/mcdi_functions.c | 57 +++++++++++++++++++++++++
> > > drivers/cdx/controller/mcdi_functions.h | 13 ++++++
> > > include/linux/cdx/cdx_bus.h | 16 +++++++
> > > 5 files changed, 122 insertions(+)
> > >
> > > diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
> > > index d2cad4c670a0..efb24672b7d9 100644
> > > --- a/drivers/cdx/cdx.c
> > > +++ b/drivers/cdx/cdx.c
> > > @@ -182,6 +182,38 @@ 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;
> > > +
> > > + dev_config.type = CDX_DEV_BUS_MASTER_CONF;
> > > + dev_config.bme = true;
> >
> > What is "bme"?
>
> This is bus master enable. I will add a comment on the structure definition.
Better yet, spell it out "bus_master_enable" so no one has to look up
the comment, no need to try to make cryptic variable names :)
thanks,
greg k-h