On Tue, Nov 19, 2024 at 06:56:40PM +0100, Neil Armstrong wrote:
> The Adreno GMU Management Unit (GMU) can also scale DDR Bandwidth along
> the Frequency and Power Domain level, but by default we leave the
> OPP core scale the interconnect ddr path.
>
> In order to calculate vote values used by the GPU Management
> Unit (GMU), we need to parse all the possible OPP Bandwidths and
> create a vote value to be sent to the appropriate Bus Control
> Modules (BCMs) declared in the GPU info struct.
>
> The vote array will then be used to dynamically generate the GMU
> bw_table sent during the GMU power-up.
>
> Signed-off-by: Neil Armstrong <neil.armstr...@linaro.org>
LGTM, two minor nits below.
> ---
> drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 153
> ++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/msm/adreno/a6xx_gmu.h | 14 ++++
> drivers/gpu/drm/msm/adreno/a6xx_gpu.h | 1 +
> 3 files changed, 168 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> index
> 14db7376c712d19446b38152e480bd5a1e0a5198..f6814d92a4edb29ba8a34a34aabb8b2324e9c6a4
> 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> @@ -9,6 +9,7 @@
> #include <linux/pm_domain.h>
> #include <linux/pm_opp.h>
> #include <soc/qcom/cmd-db.h>
> +#include <soc/qcom/tcs.h>
> #include <drm/drm_gem.h>
>
> #include "a6xx_gpu.h"
> @@ -1287,6 +1288,109 @@ static int a6xx_gmu_memory_probe(struct a6xx_gmu *gmu)
> return 0;
> }
>
> +/**
> + * struct bcm_db - Auxiliary data pertaining to each Bus Clock Manager (BCM)
> + * @unit: divisor used to convert bytes/sec bw value to an RPMh msg
> + * @width: multiplier used to convert bytes/sec bw value to an RPMh msg
> + * @vcd: virtual clock domain that this bcm belongs to
> + * @reserved: reserved field
> + */
> +struct bcm_db {
> + __le32 unit;
> + __le16 width;
> + u8 vcd;
> + u8 reserved;
> +};
> +
> +static u64 bcm_div(u64 num, u32 base)
> +{
> + /* Ensure that small votes aren't lost. */
> + if (num && num < base)
> + return 1;
> +
> + do_div(num, base);
> +
> + return num;
> +}
> +
> +static int a6xx_gmu_rpmh_bw_votes_init(const struct a6xx_info *info,
> + struct a6xx_gmu *gmu)
> +{
> + const struct bcm_db *bcm_data[GMU_MAX_BCMS] = { 0 };
> + unsigned int bcm_index, bw_index;
> +
> + /* Retrieve BCM data from cmd-db */
> + for (bcm_index = 0; bcm_index < GMU_MAX_BCMS; bcm_index++) {
> + size_t count;
> +
> + /* Skip unconfigured BCM */
> + if (!info->bcm[bcm_index].name)
> + continue;
> +
> + bcm_data[bcm_index] = cmd_db_read_aux_data(
> + info->bcm[bcm_index].name,
> + &count);
> + if (IS_ERR(bcm_data[bcm_index]))
> + return PTR_ERR(bcm_data[bcm_index]);
> +
> + if (!count)
> + return -EINVAL;
> + }
> +
> + /* Generate BCM votes values for each bandwidth & BCM */
> + for (bw_index = 0; bw_index < gmu->nr_gpu_bws; bw_index++) {
> + u32 *data = gmu->gpu_bw_votes[bw_index];
> + u32 bw = gmu->gpu_bw_table[bw_index];
> +
> + /* Calculations loosely copied from bcm_aggregate() &
> tcs_cmd_gen() */
> + for (bcm_index = 0; bcm_index < GMU_MAX_BCMS; bcm_index++) {
> + bool commit = false;
> + u64 peak, vote;
> + u16 width;
> + u32 unit;
> +
> + /* Skip unconfigured BCM */
> + if (!info->bcm[bcm_index].name || !bcm_data[bcm_index])
> + continue;
Nit: you don't care about the .name anymore, the first check can be
dropped.
> +
> + if (bcm_index == GMU_MAX_BCMS - 1 ||
> + (bcm_data[bcm_index + 1] &&
> + bcm_data[bcm_index]->vcd != bcm_data[bcm_index +
> 1]->vcd))
> + commit = true;
> +
> + if (!bw) {
> + data[bcm_index] = BCM_TCS_CMD(commit, false, 0,
> 0);
> + continue;
> + }
> +
> + if (info->bcm[bcm_index].fixed) {
> + u32 perfmode = 0;
> +
> + if (bw >= info->bcm[bcm_index].perfmode_bw)
> + perfmode =
> info->bcm[bcm_index].perfmode;
> +
> + data[bcm_index] = BCM_TCS_CMD(commit, true, 0,
> perfmode);
> + continue;
> + }
> +
> + /* Multiply the bandwidth by the width of the
> connection */
> + width = le16_to_cpu(bcm_data[bcm_index]->width);
> + peak = bcm_div((u64)bw * width,
> info->bcm[bcm_index].buswidth);
> +
> + /* Input bandwidth value is in KBps, scale the value to
> BCM unit */
> + unit = le32_to_cpu(bcm_data[bcm_index]->unit);
> + vote = bcm_div(peak * 1000ULL, unit);
> +
> + if (vote > BCM_TCS_CMD_VOTE_MASK)
> + vote = BCM_TCS_CMD_VOTE_MASK;
> +
> + data[bcm_index] = BCM_TCS_CMD(commit, true, vote, vote);
> + }
> + }
> +
> + return 0;
> +}
> +
> /* Return the 'arc-level' for the given frequency */
> static unsigned int a6xx_gmu_get_arc_level(struct device *dev,
> unsigned long freq)
> @@ -1390,12 +1494,15 @@ static int a6xx_gmu_rpmh_arc_votes_init(struct device
> *dev, u32 *votes,
> * The GMU votes with the RPMh for itself and on behalf of the GPU but we
> need
> * to construct the list of votes on the CPU and send it over. Query the RPMh
> * voltage levels and build the votes
> + * The GMU can also vote for DDR interconnects, use the OPP bandwidth entries
> + * and BCM parameters to build the votes.
> */
>
> static int a6xx_gmu_rpmh_votes_init(struct a6xx_gmu *gmu)
> {
> 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;
> struct msm_gpu *gpu = &adreno_gpu->base;
> int ret;
>
> @@ -1407,6 +1514,10 @@ static int a6xx_gmu_rpmh_votes_init(struct a6xx_gmu
> *gmu)
> ret |= a6xx_gmu_rpmh_arc_votes_init(gmu->dev, gmu->cx_arc_votes,
> gmu->gmu_freqs, gmu->nr_gmu_freqs, "cx.lvl");
>
> + /* Build the interconnect votes */
> + if (adreno_gpu->info->features & ADRENO_FEAT_GMU_BW_VOTE)
> + ret |= a6xx_gmu_rpmh_bw_votes_init(info, gmu);
> +
> return ret;
> }
>
> @@ -1442,6 +1553,38 @@ static int a6xx_gmu_build_freq_table(struct device
> *dev, unsigned long *freqs,
> return index;
> }
>
> +static int a6xx_gmu_build_bw_table(struct device *dev, unsigned long
> *bandwidths,
> + u32 size)
> +{
> + int count = dev_pm_opp_get_opp_count(dev);
> + struct dev_pm_opp *opp;
> + int i, index = 0;
> + unsigned int bandwidth = 1;
> +
> + /*
> + * The OPP table doesn't contain the "off" bandwidth level so we need to
> + * add 1 to the table size to account for it
> + */
> +
> + if (WARN(count + 1 > size,
> + "The GMU bandwidth table is being truncated\n"))
> + count = size - 1;
> +
> + /* Set the "off" bandwidth */
> + bandwidths[index++] = 0;
> +
> + for (i = 0; i < count; i++) {
> + opp = dev_pm_opp_find_bw_ceil(dev, &bandwidth, 0);
> + if (IS_ERR(opp))
> + break;
> +
> + dev_pm_opp_put(opp);
> + bandwidths[index++] = bandwidth++;
> + }
> +
> + return index;
> +}
> +
> static int a6xx_gmu_pwrlevels_probe(struct a6xx_gmu *gmu)
> {
> struct a6xx_gpu *a6xx_gpu = container_of(gmu, struct a6xx_gpu, gmu);
> @@ -1472,6 +1615,16 @@ static int a6xx_gmu_pwrlevels_probe(struct a6xx_gmu
> *gmu)
>
> gmu->current_perf_index = gmu->nr_gpu_freqs - 1;
>
> + /*
> + * The GMU also handles GPU Interconnect Votes so build a list
> + * of DDR bandwidths from the GPU OPP table
> + */
> + if (adreno_gpu->info->features & ADRENO_FEAT_GMU_BW_VOTE)
> + gmu->nr_gpu_bws = a6xx_gmu_build_bw_table(&gpu->pdev->dev,
> + gmu->gpu_bw_table, ARRAY_SIZE(gmu->gpu_bw_table));
> +
> + gmu->current_perf_index = gmu->nr_gpu_freqs - 1;
> +
> /* Build the list of RPMh votes that we'll send to the GMU */
> return a6xx_gmu_rpmh_votes_init(gmu);
> }
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> index
> b4a79f88ccf45cfe651c86d2a9da39541c5772b3..03603eadc0f9ed866899c95e99f333a511ebc3c1
> 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> @@ -19,6 +19,16 @@ struct a6xx_gmu_bo {
> u64 iova;
> };
>
> +#define GMU_MAX_BCMS 3
> +
> +struct a6xx_bcm {
> + char *name;
> + unsigned int buswidth;
> + bool fixed;
> + unsigned int perfmode;
> + unsigned int perfmode_bw;
> +};
> +
> /*
> * These define the different GMU wake up options - these define how both the
> * CPU and the GMU bring up the hardware
> @@ -82,6 +92,10 @@ struct a6xx_gmu {
> unsigned long gpu_freqs[16];
> u32 gx_arc_votes[16];
>
> + int nr_gpu_bws;
> + unsigned long gpu_bw_table[16];
> + u32 gpu_bw_votes[16][GMU_MAX_BCMS];
We still have magic 16 here. GPU_MAX_FREQUENCIES? GPU_FREQ_TABLE_SIZE?
> +
> int nr_gmu_freqs;
> unsigned long gmu_freqs[4];
> u32 cx_arc_votes[4];
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
> b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
> index
> 4aceffb6aae89c781facc2a6e4a82b20b341b6cb..5b80919e595fa1ba0a3afcca55feb89e60870cb1
> 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
> @@ -44,6 +44,7 @@ struct a6xx_info {
> u32 gmu_chipid;
> u32 gmu_cgc_mode;
> u32 prim_fifo_threshold;
> + const struct a6xx_bcm bcm[GMU_MAX_BCMS];
> };
>
> struct a6xx_gpu {
>
> --
> 2.34.1
>
--
With best wishes
Dmitry
