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| author | Nipun Gupta <nipun.gupta@amd.com> | 2023-09-15 07:54:21 +0300 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2023-09-28 21:12:07 +0300 |
| commit | a941b784b15ff65e1a3b6a259c6d6cf7fa0bb3c3 (patch) | |
| tree | 10bcc48828fc5741e1cbce64efe13916ab971288 /drivers/cdx/controller/mcdi_functions.c | |
| parent | a1e16a38968806b5fc855e17bc124d752a6b7fc8 (diff) | |
| download | linux-a941b784b15ff65e1a3b6a259c6d6cf7fa0bb3c3.tar.xz | |
cdx: add support for bus mastering
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>
Link: https://lore.kernel.org/r/20230915045423.31630-1-nipun.gupta@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/cdx/controller/mcdi_functions.c')
| -rw-r--r-- | drivers/cdx/controller/mcdi_functions.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/cdx/controller/mcdi_functions.c b/drivers/cdx/controller/mcdi_functions.c index 0158f26533dd..fc82435d5dea 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 bit_pos) +{ + MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_CONTROL_SET_IN_LEN); + u32 flags; + int ret; + + /* + * Get flags and then set/reset bit at bit_pos 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(bit_pos))); + if (enable) + flags |= (1 << bit_pos); + + 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); +} |