On 11.12.2024 9:29 AM, Neil Armstrong wrote:
> The Adreno GPU Management Unit (GMU) can also scale the ddr
> bandwidth along the frequency and power domain level, but for
> now we statically fill the bw_table with values from the
> downstream driver.
>
> Only the first entry is used, which is a disable vote, so we
> currently rely on scaling via the linux interconnect paths.
>
> Let's dynamically generate the bw_table with the vote values
> previously calculated from the OPPs.
>
> Those entries will then be used by the GMU when passing the
> appropriate bandwidth level while voting for a gpu frequency.
>
> Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/adreno/a6xx_hfi.c | 48 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 47 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> index cb8844ed46b29c4569d05eb7a24f7b27e173190f..995526620d678cd05020315f771213e4a6943bec 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> @@ -6,6 +6,7 @@
> #include <linux/list.h>
>
> #include <soc/qcom/cmd-db.h>
> +#include <soc/qcom/tcs.h>
>
> #include "a6xx_gmu.h"
> #include "a6xx_gmu.xml.h"
> @@ -259,6 +260,48 @@ static int a6xx_hfi_send_perf_table(struct a6xx_gmu *gmu)
> NULL, 0);
> }
>
> +static void a6xx_generate_bw_table(const struct a6xx_info *info, struct a6xx_gmu *gmu,
> + struct a6xx_hfi_msg_bw_table *msg)
> +{
> + unsigned int i, j;
> +
> + for (i = 0; i < GMU_MAX_BCMS; i++) {
> + if (!info->bcms[i].name)
> + break;
> + msg->ddr_cmds_addrs[i] = cmd_db_read_addr(info->bcms[i].name);
> + }
> + msg->ddr_cmds_num = i;
> +
> + for (i = 0; i < gmu->nr_gpu_bws; ++i)
> + for (j = 0; j < msg->ddr_cmds_num; j++)
> + msg->ddr_cmds_data[i][j] = gmu->gpu_ib_votes[i][j];
> + msg->bw_level_num = gmu->nr_gpu_bws;
> +
> + /* Compute the wait bitmask with each BCM having the commit bit */
> + msg->ddr_wait_bitmask = 0;
> + for (j = 0; j < msg->ddr_cmds_num; j++)
> + if (msg->ddr_cmds_data[0][j] & BCM_TCS_CMD_COMMIT_MASK)
> + msg->ddr_wait_bitmask |= BIT(j);
> +
> + /*
> + * These are the CX (CNOC) votes - these are used by the GMU
> + * The 'CN0' BCM is used on all targets, and votes are basically
> + * 'off' and 'on' states with first bit to enable the path.
> + */
> +
/* The CNoC BCM only needs a simple off/on vote pair on all platforms */
> + msg->cnoc_cmds_addrs[0] = cmd_db_read_addr("CN0");
> + msg->cnoc_cmds_num = 1;
> +
> + msg->cnoc_cmds_data[0][0] = BCM_TCS_CMD(true, false, 0, 0);
> + msg->cnoc_cmds_data[1][0] = BCM_TCS_CMD(true, true, 0, BIT(0));
While it evaluates to the same, I think this is logically 1 (as in, one
unit of bus rate). The question of which bit that corresponds to is
handled by the macro.
Also, a7xx sets values in both x and y parts here, while a6xx only does
so in the y part.
> +
> + /* Compute the wait bitmask with each BCM having the commit bit */
> + msg->cnoc_wait_bitmask = 0;
> + for (j = 0; j < msg->cnoc_cmds_num; j++)
> + if (msg->cnoc_cmds_data[0][j] & BCM_TCS_CMD_COMMIT_MASK)
> + msg->cnoc_wait_bitmask |= BIT(j);
This is a very fancy way to say msg->cnoc_wait_bitmask = BIT(0)
Konrad
