On 12/5/2024 8:31 PM, 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 | 41 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 40 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..fc4bfad51de9a3b6617fbbd03471a5851d43ce88 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> @@ -5,7 +5,10 @@
> #include <linux/circ_buf.h>
> #include <linux/list.h>
>
> +#include <dt-bindings/interconnect/qcom,icc.h>
> +
> #include <soc/qcom/cmd-db.h>
> +#include <soc/qcom/tcs.h>
>
> #include "a6xx_gmu.h"
> #include "a6xx_gmu.xml.h"
> @@ -259,6 +262,39 @@ 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;
> +
> + msg->ddr_wait_bitmask = QCOM_ICC_TAG_ALWAYS;
Why this is QCOM_ICC_TAG_ALWAYS?
IIRC, this bitmask informs RPMH whether it should wait for previous BCM
vote to complete. Can we implement the same logic from kgsl to create
this bitmask?
> +
> + 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;
> +
> + /*
> + * 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.
> + */
> +
> + msg->cnoc_cmds_num = 1;
> + msg->cnoc_wait_bitmask = QCOM_ICC_TAG_AMC;
Same here.
Rest looks fine to me.
-Akhil
> +
> + msg->cnoc_cmds_addrs[0] = cmd_db_read_addr("CN0");
> + 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));
> +}
> +
> static void a618_build_bw_table(struct a6xx_hfi_msg_bw_table *msg)
> {
> /* Send a single "off" entry since the 618 GMU doesn't do bus scaling */
> @@ -664,6 +700,7 @@ static int a6xx_hfi_send_bw_table(struct a6xx_gmu *gmu)
> struct a6xx_hfi_msg_bw_table *msg;
> struct a6xx_gpu *a6xx_gpu = container_of(gmu, struct a6xx_gpu, gmu);
> struct adreno_gpu *adreno_gpu = &a6xx_gpu->base;
> + const struct a6xx_info *info = adreno_gpu->info->a6xx;
>
> if (gmu->bw_table)
> goto send;
> @@ -672,7 +709,9 @@ static int a6xx_hfi_send_bw_table(struct a6xx_gmu *gmu)
> if (!msg)
> return -ENOMEM;
>
> - if (adreno_is_a618(adreno_gpu))
> + if (info->bcms && gmu->nr_gpu_bws > 1)
> + a6xx_generate_bw_table(info, gmu, msg);
> + else if (adreno_is_a618(adreno_gpu))
> a618_build_bw_table(msg);
> else if (adreno_is_a619(adreno_gpu))
> a619_build_bw_table(msg);
>
