[PATCH 3/5] drm: msm: scale DDR BW along with GPU frequency

Sharat Masetty
2020-03-31T07:56:49Z

This patch adds support to parse the OPP tables attached the GPU device,
the main opp table and the DDR bandwidth opp table. Additionally, vote
for the GPU->DDR bandwidth when setting the GPU frequency by querying
the linked DDR BW opp to the GPU opp.

Signed-off-by: Sharat Masetty <smasetty@codeaurora.org>
---
drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 41 ++++++++++++++++++++++++++----
drivers/gpu/drm/msm/adreno/adreno_gpu.c | 44 +++++++++++++++++++++++++++++----
drivers/gpu/drm/msm/msm_gpu.h | 9 +++++++
3 files changed, 84 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 748cd37..489d9b6 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -100,6 +100,40 @@ bool a6xx_gmu_gx_is_on(struct a6xx_gmu *gmu)
A6XX_GMU_SPTPRAC_PWR_CLK_STATUS_GX_HM_CLK_OFF));
}

+void a6xx_gmu_set_icc_vote(struct msm_gpu *gpu, unsigned long gpu_freq)
+{
+ struct dev_pm_opp *gpu_opp, *ddr_opp;
+ struct opp_table **tables = gpu->opp_tables;
+ unsigned long peak_bw;
+
+ if (!gpu->opp_tables[GPU_DDR_OPP_TABLE_INDEX])
+ goto done;
+
+ gpu_opp = dev_pm_opp_find_freq_exact(&gpu->pdev->dev, gpu_freq, true);
+ if (IS_ERR_OR_NULL(gpu_opp))
+ goto done;
+
+ ddr_opp = dev_pm_opp_xlate_required_opp(tables[GPU_OPP_TABLE_INDEX],
+ tables[GPU_DDR_OPP_TABLE_INDEX],
+ gpu_opp);
+ dev_pm_opp_put(gpu_opp);
+
+ if (IS_ERR_OR_NULL(ddr_opp))
+ goto done;
+
+ peak_bw = dev_pm_opp_get_bw(ddr_opp, NULL);
+ dev_pm_opp_put(ddr_opp);
+
+ icc_set_bw(gpu->icc_path, 0, peak_bw);
+ return;
+done:
+ /*
+ * If there is a problem, for now leave it at max so that the
+ * performance is nominal.
+ */
+ icc_set_bw(gpu->icc_path, 0, MBps_to_icc(7216));
+}
+
static void __a6xx_gmu_set_freq(struct a6xx_gmu *gmu, int index)
{
struct a6xx_gpu *a6xx_gpu = container_of(gmu, struct a6xx_gpu, gmu);
@@ -128,11 +162,8 @@ static void __a6xx_gmu_set_freq(struct a6xx_gmu *gmu, int index)

gmu->freq = gmu->gpu_freqs[index];

- /*
- * Eventually we will want to scale the path vote with the frequency but
- * for now leave it at max so that the performance is nominal.
- */
- icc_set_bw(gpu->icc_path, 0, MBps_to_icc(7216));
+ if (gpu->icc_path)
+ a6xx_gmu_set_icc_vote(gpu, gmu->freq);
}

void a6xx_gmu_set_freq(struct msm_gpu *gpu, unsigned long freq)
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 2d13694..bbbcc7a 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -882,7 +882,7 @@ static int adreno_get_pwrlevels(struct device *dev,
{
unsigned long freq = ULONG_MAX;
struct dev_pm_opp *opp;
- int ret;
+ int ret, i;

gpu->fast_rate = 0;

@@ -890,9 +890,29 @@ static int adreno_get_pwrlevels(struct device *dev,
if (!of_find_property(dev->of_node, "operating-points-v2", NULL))
ret = adreno_get_legacy_pwrlevels(dev);
else {
- ret = dev_pm_opp_of_add_table(dev);
- if (ret)
- DRM_DEV_ERROR(dev, "Unable to set the OPP table\n");
+ int count = of_count_phandle_with_args(dev->of_node,
+ "operating-points-v2", NULL);
+
+ count = min(count, GPU_DDR_OPP_TABLE_INDEX + 1);
+ count = max(count, 1);
+
+ for (i = 0; i < count; i++) {
+ ret = dev_pm_opp_of_add_table_indexed(dev, i);
+ if (ret) {
+ DRM_DEV_ERROR(dev, "Add OPP table %d: failed %d\n",
+ i, ret);
+ goto err;
+ }
+
+ gpu->opp_tables[i] =
+ dev_pm_opp_get_opp_table_indexed(dev, i);
+ if (!gpu->opp_tables[i]) {
+ DRM_DEV_ERROR(dev, "Get OPP table failed index %d\n",
+ i);
+ ret = -EINVAL;
+ goto err;
+ }
+ }
}

if (!ret) {
@@ -919,12 +939,24 @@ static int adreno_get_pwrlevels(struct device *dev,
gpu->icc_path = NULL;

return 0;
+err:
+ for (; i >= 0; i--) {
+ if (gpu->opp_tables[i]) {
+ dev_pm_opp_put_opp_table(gpu->opp_tables[i]);
+ gpu->opp_tables[i] = NULL;
+ }
+ }
+
+ dev_pm_opp_remove_table(dev);
+ return ret;
}

int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
struct adreno_gpu *adreno_gpu,
const struct adreno_gpu_funcs *funcs, int nr_rings)
{
+ int ret = 0;
+
struct adreno_platform_config *config = pdev->dev.platform_data;
struct msm_gpu_config adreno_gpu_config = { 0 };
struct msm_gpu *gpu = &adreno_gpu->base;
@@ -945,7 +977,9 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,

adreno_gpu_config.nr_rings = nr_rings;

- adreno_get_pwrlevels(&pdev->dev, gpu);
+ ret = adreno_get_pwrlevels(&pdev->dev, gpu);
+ if (ret)
+ return ret;

pm_runtime_set_autosuspend_delay(&pdev->dev,
adreno_gpu->info->inactive_period);
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index ab8f0f9c..5b98b48 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -66,6 +66,12 @@ struct msm_gpu_funcs {
void (*gpu_set_freq)(struct msm_gpu *gpu, unsigned long freq);
};

+/* opp table indices */
+enum {
+ GPU_OPP_TABLE_INDEX,
+ GPU_DDR_OPP_TABLE_INDEX,
+};
+
struct msm_gpu {
const char *name;
struct drm_device *dev;
@@ -113,6 +119,9 @@ struct msm_gpu {

struct icc_path *icc_path;

+ /* gpu/ddr opp tables */
+ struct opp_table *opp_tables[2];
+
/* Hang and Inactivity Detection:
*/
#define DRM_MSM_INACTIVE_PERIOD 66 /* in ms (roughly four frames) */
--
2.7.4