[PATCH v5 0/7] drm/msm: adreno: add support for DDR bandwidth scaling via GMU

[PATCH v5 0/7] drm/msm: adreno: add support for DDR bandwidth scaling via GMU

[Neil Armstrong]

The Adreno GPU Management Unit (GMU) can also vote for DDR Bandwidth
along the Frequency and Power Domain level, but by default we leave the
OPP core scale the interconnect ddr path.

While scaling the interconnect path was sufficient, newer GPUs
like the A750 requires specific vote parameters and bandwidth to
achieve full functionnality.

In order to get the vote values to be used by the GPU Management
Unit (GMU), we need to parse all the possible OPP Bandwidths and
create a vote value to be send to the appropriate Bus Control
Modules (BCMs) declared in the GPU info struct.
The added dev_pm_opp_get_bw() is used in this case.

The vote array will then be used to dynamically generate the GMU
bw_table sent during the GMU power-up.

Those entries will then be used by passing the appropriate
bandwidth level when voting for a GPU frequency.

This will make sure all resources are equally voted for a
same OPP, whatever decision is done by the GMU, it will
ensure all resources votes are synchronized.

Depends on [1] to avoid crashing when getting OPP bandwidths.

[1] https://lore.kernel.org/all/20241203-topic-opp-fix-assert-index-check-v3-0-1d4f6f763138@linaro.org/

Ran full vulkan-cts-1.3.7.3-0-gd71a36db16d98313c431829432a136dbda692a08 with mesa 25.0.0+git3ecf2a0518 on:
- QRD8550
- QRD8650
- HDK8650

Any feedback is welcome.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
Changes in v5:
- Dropped bogus qcom,icc.h flags
- Properly calculate _wait_bitmask from votes
- Switch DT to qcom,bus-freq values from downstream
- Added review tags
- Link to v4: https://lore.kernel.org/r/20241205-topic-sm8x50-gpu-bw-vote-v4-0-9650d15dd435@linaro.org

Changes in v4:
- Collected review tags
- Dropped bcm_div() and switched to clamp() instead
- Dropped pre-calculation of AB votes
- Instead calculate a 25% floor vote in a6xx_gmu_set_freq() as recommended
- Use QCOM_ICC_TAG_ALWAYS in DT
- Made a740_generate_bw_table() generic, using defines to fill the table
- Link to v3: https://lore.kernel.org/r/20241128-topic-sm8x50-gpu-bw-vote-v3-0-81d60c10fb73@linaro.org

Changes in v3:
- I didn't take Dmitry's review tags since I significantly changed the patches
- Dropped applied OPP change
- Dropped QUIRK/FEATURE addition/rename in favor of checking the a6xx_info->bcms pointer
- Switch a6xx_info->bcms to a pointer, so it can be easy to share the table
- Generate AB votes in advance, the voting was wrong in v2 we need to quantitiwe each bandwidth value
- Do not vote via GMU is there's only the OFF vote because DT doesn't have the right properties
- Added defines for the a6xx_gmu freqs tables to not have magic 16 and 4 values
- Renamed gpu_bw_votes to gpu_ib_votes to match the downstream naming
- Changed the parameters of a6xx_hfi_set_freq() to u32 to match the data type we pass
- Drop "request for maximum bus bandwidth usage" and merge it in previous changes
- Link to v2: https://lore.kernel.org/r/20241119-topic-sm8x50-gpu-bw-vote-v2-0-4deb87be2498@linaro.org

Changes in v2:
- opp: rename to dev_pm_opp_get_bw, fix commit message and kerneldoc
- remove quirks that are features and move them to a dedicated .features bitfield
- get icc bcm kerneldoc, and simplify/cleanup a6xx_gmu_rpmh_bw_votes_init()
  - no more copies of data
  - take calculations from icc-rpmh/bcm-voter
  - move into a single cleaner function
- fix a6xx_gmu_set_freq() but not calling dev_pm_opp_set_opp() if !bw_index
- also vote for maximum bus bandwidth usage (AB)
- overall fix typos in commit messages
- Link to v1: https://lore.kernel.org/r/20241113-topic-sm8x50-gpu-bw-vote-v1-0-3b8d39737a9b@linaro.org

---
Neil Armstrong (7):
      drm/msm: adreno: add defines for gpu & gmu frequency table sizes
      drm/msm: adreno: add plumbing to generate bandwidth vote table for GMU
      drm/msm: adreno: dynamically generate GMU bw table
      drm/msm: adreno: find bandwidth index of OPP and set it along freq index
      drm/msm: adreno: enable GMU bandwidth for A740 and A750
      arm64: qcom: dts: sm8550: add interconnect and opp-peak-kBps for GPU
      arm64: qcom: dts: sm8650: add interconnect and opp-peak-kBps for GPU

 arch/arm64/boot/dts/qcom/sm8550.dtsi      |  13 +++
 arch/arm64/boot/dts/qcom/sm8650.dtsi      |  15 +++
 drivers/gpu/drm/msm/adreno/a6xx_catalog.c |  22 ++++
 drivers/gpu/drm/msm/adreno/a6xx_gmu.c     | 183 +++++++++++++++++++++++++++++-
 drivers/gpu/drm/msm/adreno/a6xx_gmu.h     |  26 ++++-
 drivers/gpu/drm/msm/adreno/a6xx_gpu.h     |   1 +
 drivers/gpu/drm/msm/adreno/a6xx_hfi.c     |  54 ++++++++-
 drivers/gpu/drm/msm/adreno/a6xx_hfi.h     |   5 +
 8 files changed, 308 insertions(+), 11 deletions(-)
---
base-commit: df210b30304e9113866a213363894a6d768411ec
change-id: 20241113-topic-sm8x50-gpu-bw-vote-f5e022fe7a47

Best regards,
-- 
Neil Armstrong <neil.armstrong@linaro.org>

[PATCH v5 1/7] drm/msm: adreno: add defines for gpu & gmu frequency table sizes

[Neil Armstrong]

Even if the code uses ARRAY_SIZE() to fill those tables,
it's still a best practice to not use magic values for
tables in structs.

Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_gmu.h | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
index b4a79f88ccf45cfe651c86d2a9da39541c5772b3..88f18ea6a38a08b5b171709e5020010947a5d347 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
@@ -19,6 +19,9 @@ struct a6xx_gmu_bo {
 	u64 iova;
 };
 
+#define GMU_MAX_GX_FREQS	16
+#define GMU_MAX_CX_FREQS	4
+
 /*
  * These define the different GMU wake up options - these define how both the
  * CPU and the GMU bring up the hardware
@@ -79,12 +82,12 @@ struct a6xx_gmu {
 	int current_perf_index;
 
 	int nr_gpu_freqs;
-	unsigned long gpu_freqs[16];
-	u32 gx_arc_votes[16];
+	unsigned long gpu_freqs[GMU_MAX_GX_FREQS];
+	u32 gx_arc_votes[GMU_MAX_GX_FREQS];
 
 	int nr_gmu_freqs;
-	unsigned long gmu_freqs[4];
-	u32 cx_arc_votes[4];
+	unsigned long gmu_freqs[GMU_MAX_CX_FREQS];
+	u32 cx_arc_votes[GMU_MAX_CX_FREQS];
 
 	unsigned long freq;
 

-- 
2.34.1

[PATCH v5 2/7] drm/msm: adreno: add plumbing to generate bandwidth vote table for GMU

[Neil Armstrong]

The Adreno GPU 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.

While scaling via the interconnect path was sufficient, newer GPUs
like the A750 requires specific vote paremeters and bandwidth to
achieve full functionality.

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.

This vote value is called IB, while on the other side the GMU also
takes another vote called AB which is a 16bit quantized value
of the floor bandwidth against the maximum supported bandwidth.
The AB vote will be calculated later when setting the frequency.

The vote array will then be used to dynamically generate the GMU
bw_table sent during the GMU power-up.

Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 144 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  13 +++
 drivers/gpu/drm/msm/adreno/a6xx_gpu.h |   1 +
 3 files changed, 158 insertions(+)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 14db7376c712d19446b38152e480bd5a1e0a5198..36696d372a42a27b26a018b19e73bc6d8a4a5235 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 +1288,101 @@ 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 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, bcm_count = 0;
+
+	if (!info->bcms)
+		return 0;
+
+	/* Retrieve BCM data from cmd-db */
+	for (bcm_index = 0; bcm_index < GMU_MAX_BCMS; bcm_index++) {
+		size_t count;
+
+		/* Stop at first unconfigured bcm */
+		if (!info->bcms[bcm_index].name)
+			break;
+
+		bcm_data[bcm_index] = cmd_db_read_aux_data(
+						info->bcms[bcm_index].name,
+						&count);
+		if (IS_ERR(bcm_data[bcm_index]))
+			return PTR_ERR(bcm_data[bcm_index]);
+
+		if (!count)
+			return -EINVAL;
+
+		++bcm_count;
+	}
+
+	/* Generate BCM votes values for each bandwidth & BCM */
+	for (bw_index = 0; bw_index < gmu->nr_gpu_bws; bw_index++) {
+		u32 *data = gmu->gpu_ib_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 < bcm_count; bcm_index++) {
+			bool commit = false;
+			u64 peak;
+			u32 vote;
+
+			/* Skip unconfigured BCM */
+			if (!bcm_data[bcm_index])
+				continue;
+
+			if (bcm_index == bcm_count - 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->bcms[bcm_index].fixed) {
+				u32 perfmode = 0;
+
+				if (bw >= info->bcms[bcm_index].perfmode_bw)
+					perfmode = info->bcms[bcm_index].perfmode;
+
+				data[bcm_index] = BCM_TCS_CMD(commit, true, 0, perfmode);
+				continue;
+			}
+
+			/* Multiply the bandwidth by the width of the connection */
+			peak = (u64)bw * le16_to_cpu(bcm_data[bcm_index]->width);
+			do_div(peak, info->bcms[bcm_index].buswidth);
+
+			/* Input bandwidth value is in KBps, scale the value to BCM unit */
+			peak *= 1000ULL;
+			do_div(peak, le32_to_cpu(bcm_data[bcm_index]->unit));
+
+			vote = clamp(peak, 1, 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 +1486,15 @@ 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 +1506,10 @@ 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 (info->bcms && gmu->nr_gpu_bws > 1)
+		ret |= a6xx_gmu_rpmh_bw_votes_init(info, gmu);
+
 	return ret;
 }
 
@@ -1442,10 +1545,43 @@ 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);
 	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 = 0;
@@ -1472,6 +1608,14 @@ 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 (info->bcms)
+		gmu->nr_gpu_bws = a6xx_gmu_build_bw_table(&gpu->pdev->dev,
+			gmu->gpu_bw_table, ARRAY_SIZE(gmu->gpu_bw_table));
+
 	/* 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 88f18ea6a38a08b5b171709e5020010947a5d347..2062a2be224768c1937d7768f7b8439920e9e127 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
@@ -21,6 +21,15 @@ struct a6xx_gmu_bo {
 
 #define GMU_MAX_GX_FREQS	16
 #define GMU_MAX_CX_FREQS	4
+#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
@@ -85,6 +94,10 @@ struct a6xx_gmu {
 	unsigned long gpu_freqs[GMU_MAX_GX_FREQS];
 	u32 gx_arc_votes[GMU_MAX_GX_FREQS];
 
+	int nr_gpu_bws;
+	unsigned long gpu_bw_table[GMU_MAX_GX_FREQS];
+	u32 gpu_ib_votes[GMU_MAX_GX_FREQS][GMU_MAX_BCMS];
+
 	int nr_gmu_freqs;
 	unsigned long gmu_freqs[GMU_MAX_CX_FREQS];
 	u32 cx_arc_votes[GMU_MAX_CX_FREQS];
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
index 4aceffb6aae89c781facc2a6e4a82b20b341b6cb..9201a53dd341bf432923ffb44947e015208a3d02 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 *bcms;
 };
 
 struct a6xx_gpu {

-- 
2.34.1

[PATCH v5 3/7] drm/msm: adreno: dynamically generate GMU bw table

[Neil Armstrong]

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@linaro.org>
---
 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.
+	 */
+
+	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));
+
+	/* 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);
+}
+
 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 +707,7 @@ 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 +716,9 @@ 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);

-- 
2.34.1

[PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[Neil Armstrong]

The Adreno GPU Management Unit (GMU) can also scale the DDR Bandwidth
along the Frequency and Power Domain level, until now we left the OPP
core scale the OPP bandwidth via the interconnect path.

In order to enable bandwidth voting via the GPU Management
Unit (GMU), when an opp is set by devfreq we also look for
the corresponding bandwidth index in the previously generated
bw_table and pass this value along the frequency index to the GMU.

The GMU also takes another vote called AB which is a 16bit quantized
value of the floor bandwidth against the maximum supported bandwidth.

The AB is calculated with a default 25% of the bandwidth like the
downstream implementation too inform the GMU firmware the minimal
quantity of bandwidth we require for this OPP.

Since we now vote for all resources via the GMU, setting the OPP
is no more needed, so we can completely skip calling
dev_pm_opp_set_opp() in this situation.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 +++++++++++++++++++++++++++++++++--
 drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
 drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
 drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
 4 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
 		       bool suspended)
 {
 	struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+	const struct a6xx_info *info = adreno_gpu->info->a6xx;
 	struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
 	struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
 	u32 perf_index;
+	u32 bw_index = 0;
 	unsigned long gpu_freq;
 	int ret = 0;
 
@@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
 		if (gpu_freq == gmu->gpu_freqs[perf_index])
 			break;
 
+	/* If enabled, find the corresponding DDR bandwidth index */
+	if (info->bcms && gmu->nr_gpu_bws > 1) {
+		unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
+
+		for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1; bw_index++) {
+			if (bw == gmu->gpu_bw_table[bw_index])
+				break;
+		}
+
+		/* Vote AB as a fraction of the max bandwidth */
+		if (bw) {
+			u64 tmp;
+
+			/* For now, vote for 25% of the bandwidth */
+			tmp = bw * 25;
+			do_div(tmp, 100);
+
+			/*
+			 * The AB vote consists of a 16 bit wide quantized level
+			 * against the maximum supported bandwidth.
+			 * Quantization can be calculated as below:
+			 * vote = (bandwidth * 2^16) / max bandwidth
+			 */
+			tmp *= MAX_AB_VOTE;
+			do_div(tmp, gmu->gpu_bw_table[gmu->nr_gpu_bws - 1]);
+
+			bw_index |= AB_VOTE(clamp(tmp, 1, MAX_AB_VOTE));
+			bw_index |= AB_VOTE_ENABLE;
+		}
+	}
+
 	gmu->current_perf_index = perf_index;
 	gmu->freq = gmu->gpu_freqs[perf_index];
 
@@ -140,8 +173,10 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
 		return;
 
 	if (!gmu->legacy) {
-		a6xx_hfi_set_freq(gmu, perf_index);
-		dev_pm_opp_set_opp(&gpu->pdev->dev, opp);
+		a6xx_hfi_set_freq(gmu, perf_index, bw_index);
+		/* With Bandwidth voting, we now vote for all resources, so skip OPP set */
+		if (!bw_index)
+			dev_pm_opp_set_opp(&gpu->pdev->dev, opp);
 		return;
 	}
 
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
index 2062a2be224768c1937d7768f7b8439920e9e127..0c888b326cfb485400118f3601fa5f1949b03374 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
@@ -209,7 +209,7 @@ void a6xx_hfi_init(struct a6xx_gmu *gmu);
 int a6xx_hfi_start(struct a6xx_gmu *gmu, int boot_state);
 void a6xx_hfi_stop(struct a6xx_gmu *gmu);
 int a6xx_hfi_send_prep_slumber(struct a6xx_gmu *gmu);
-int a6xx_hfi_set_freq(struct a6xx_gmu *gmu, int index);
+int a6xx_hfi_set_freq(struct a6xx_gmu *gmu, u32 perf_index, u32 bw_index);
 
 bool a6xx_gmu_gx_is_on(struct a6xx_gmu *gmu);
 bool a6xx_gmu_sptprac_is_on(struct a6xx_gmu *gmu);
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
index 995526620d678cd05020315f771213e4a6943bec..0989aee3dd2cf9bc3405c3b25a595c22e6f06387 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
@@ -772,13 +772,13 @@ static int a6xx_hfi_send_core_fw_start(struct a6xx_gmu *gmu)
 		sizeof(msg), NULL, 0);
 }
 
-int a6xx_hfi_set_freq(struct a6xx_gmu *gmu, int index)
+int a6xx_hfi_set_freq(struct a6xx_gmu *gmu, u32 freq_index, u32 bw_index)
 {
 	struct a6xx_hfi_gx_bw_perf_vote_cmd msg = { 0 };
 
 	msg.ack_type = 1; /* blocking */
-	msg.freq = index;
-	msg.bw = 0; /* TODO: bus scaling */
+	msg.freq = freq_index;
+	msg.bw = bw_index;
 
 	return a6xx_hfi_send_msg(gmu, HFI_H2F_MSG_GX_BW_PERF_VOTE, &msg,
 		sizeof(msg), NULL, 0);
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_hfi.h b/drivers/gpu/drm/msm/adreno/a6xx_hfi.h
index 528110169398f69f16443a29a1594d19c36fb595..52ba4a07d7b9a709289acd244a751ace9bdaab5d 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_hfi.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_hfi.h
@@ -173,6 +173,11 @@ struct a6xx_hfi_gx_bw_perf_vote_cmd {
 	u32 bw;
 };
 
+#define AB_VOTE_MASK		GENMASK(31, 16)
+#define MAX_AB_VOTE		(FIELD_MAX(AB_VOTE_MASK) - 1)
+#define AB_VOTE(vote)		FIELD_PREP(AB_VOTE_MASK, (vote))
+#define AB_VOTE_ENABLE		BIT(8)
+
 #define HFI_H2F_MSG_PREPARE_SLUMBER 33
 
 struct a6xx_hfi_prep_slumber_cmd {

-- 
2.34.1

[PATCH v5 5/7] drm/msm: adreno: enable GMU bandwidth for A740 and A750

[Neil Armstrong]

Now all the DDR bandwidth voting via the GPU Management Unit (GMU)
is in place, declare the Bus Control Modules (BCMs) and the
corresponding parameters in the GPU info struct.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
index 0c560e84ad5a53bb4e8a49ba4e153ce9cf33f7ae..edffb7737a97b268bb2986d557969e651988a344 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
@@ -1388,6 +1388,17 @@ static const struct adreno_info a7xx_gpus[] = {
 			.pwrup_reglist = &a7xx_pwrup_reglist,
 			.gmu_chipid = 0x7020100,
 			.gmu_cgc_mode = 0x00020202,
+			.bcms = (const struct a6xx_bcm[]) {
+				{ .name = "SH0", .buswidth = 16 },
+				{ .name = "MC0", .buswidth = 4 },
+				{
+					.name = "ACV",
+					.fixed = true,
+					.perfmode = BIT(3),
+					.perfmode_bw = 16500000,
+				},
+				{ /* sentinel */ },
+			},
 		},
 		.address_space_size = SZ_16G,
 		.preempt_record_size = 4192 * SZ_1K,
@@ -1432,6 +1443,17 @@ static const struct adreno_info a7xx_gpus[] = {
 			.pwrup_reglist = &a7xx_pwrup_reglist,
 			.gmu_chipid = 0x7090100,
 			.gmu_cgc_mode = 0x00020202,
+			.bcms = (const struct a6xx_bcm[]) {
+				{ .name = "SH0", .buswidth = 16 },
+				{ .name = "MC0", .buswidth = 4 },
+				{
+					.name = "ACV",
+					.fixed = true,
+					.perfmode = BIT(2),
+					.perfmode_bw = 10687500,
+				},
+				{ /* sentinel */ },
+			},
 		},
 		.address_space_size = SZ_16G,
 		.preempt_record_size = 3572 * SZ_1K,

-- 
2.34.1

[PATCH v5 6/7] arm64: qcom: dts: sm8550: add interconnect and opp-peak-kBps for GPU

[Neil Armstrong]

Each GPU OPP requires a specific peak DDR bandwidth, let's add
those to each OPP and also the related interconnect path.

Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 arch/arm64/boot/dts/qcom/sm8550.dtsi | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sm8550.dtsi b/arch/arm64/boot/dts/qcom/sm8550.dtsi
index e7774d32fb6d2288748ecec00bf525b2b3c40fbb..dedd4a2a58f2c89b6e1b12d955da9ef8734604c2 100644
--- a/arch/arm64/boot/dts/qcom/sm8550.dtsi
+++ b/arch/arm64/boot/dts/qcom/sm8550.dtsi
@@ -14,6 +14,7 @@
 #include <dt-bindings/firmware/qcom,scm.h>
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/interrupt-controller/arm-gic.h>
+#include <dt-bindings/interconnect/qcom,icc.h>
 #include <dt-bindings/interconnect/qcom,sm8550-rpmh.h>
 #include <dt-bindings/mailbox/qcom-ipcc.h>
 #include <dt-bindings/power/qcom-rpmpd.h>
@@ -2114,6 +2115,10 @@ gpu: gpu@3d00000 {
 			qcom,gmu = <&gmu>;
 			#cooling-cells = <2>;
 
+			interconnects = <&gem_noc MASTER_GFX3D QCOM_ICC_TAG_ALWAYS
+					 &mc_virt SLAVE_EBI1 QCOM_ICC_TAG_ALWAYS>;
+			interconnect-names = "gfx-mem";
+
 			status = "disabled";
 
 			zap-shader {
@@ -2127,41 +2132,49 @@ gpu_opp_table: opp-table {
 				opp-680000000 {
 					opp-hz = /bits/ 64 <680000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_SVS_L1>;
+					opp-peak-kBps = <16500000>;
 				};
 
 				opp-615000000 {
 					opp-hz = /bits/ 64 <615000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_SVS_L0>;
+					opp-peak-kBps = <12449218>;
 				};
 
 				opp-550000000 {
 					opp-hz = /bits/ 64 <550000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_SVS>;
+					opp-peak-kBps = <10687500>;
 				};
 
 				opp-475000000 {
 					opp-hz = /bits/ 64 <475000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS_L1>;
+					opp-peak-kBps = <6074218>;
 				};
 
 				opp-401000000 {
 					opp-hz = /bits/ 64 <401000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
+					opp-peak-kBps = <6074218>;
 				};
 
 				opp-348000000 {
 					opp-hz = /bits/ 64 <348000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS_D0>;
+					opp-peak-kBps = <6074218>;
 				};
 
 				opp-295000000 {
 					opp-hz = /bits/ 64 <295000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS_D1>;
+					opp-peak-kBps = <6074218>;
 				};
 
 				opp-220000000 {
 					opp-hz = /bits/ 64 <220000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS_D2>;
+					opp-peak-kBps = <2136718>;
 				};
 			};
 		};

-- 
2.34.1

[PATCH v5 7/7] arm64: qcom: dts: sm8650: add interconnect and opp-peak-kBps for GPU

[Neil Armstrong]

Each GPU OPP requires a specific peak DDR bandwidth, let's add
those to each OPP and also the related interconnect path.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 arch/arm64/boot/dts/qcom/sm8650.dtsi | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sm8650.dtsi b/arch/arm64/boot/dts/qcom/sm8650.dtsi
index 25e47505adcb790d09f1d2726386438487255824..c76c0038c35ab048c88be9870b14c3a0b24b4183 100644
--- a/arch/arm64/boot/dts/qcom/sm8650.dtsi
+++ b/arch/arm64/boot/dts/qcom/sm8650.dtsi
@@ -2636,6 +2636,10 @@ gpu: gpu@3d00000 {
 			qcom,gmu = <&gmu>;
 			#cooling-cells = <2>;
 
+			interconnects = <&gem_noc MASTER_GFX3D QCOM_ICC_TAG_ALWAYS
+					 &mc_virt SLAVE_EBI1 QCOM_ICC_TAG_ALWAYS>;
+			interconnect-names = "gfx-mem";
+
 			status = "disabled";
 
 			zap-shader {
@@ -2649,56 +2653,67 @@ gpu_opp_table: opp-table {
 				opp-231000000 {
 					opp-hz = /bits/ 64 <231000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS_D2>;
+					opp-peak-kBps = <2136718>;
 				};
 
 				opp-310000000 {
 					opp-hz = /bits/ 64 <310000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS_D1>;
+					opp-peak-kBps = <2136718>;
 				};
 
 				opp-366000000 {
 					opp-hz = /bits/ 64 <366000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS_D0>;
+					opp-peak-kBps = <6074218>;
 				};
 
 				opp-422000000 {
 					opp-hz = /bits/ 64 <422000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
+					opp-peak-kBps = <8171875>;
 				};
 
 				opp-500000000 {
 					opp-hz = /bits/ 64 <500000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS_L1>;
+					opp-peak-kBps = <8171875>;
 				};
 
 				opp-578000000 {
 					opp-hz = /bits/ 64 <578000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_SVS>;
+					opp-peak-kBps = <8171875>;
 				};
 
 				opp-629000000 {
 					opp-hz = /bits/ 64 <629000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_SVS_L0>;
+					opp-peak-kBps = <10687500>;
 				};
 
 				opp-680000000 {
 					opp-hz = /bits/ 64 <680000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_SVS_L1>;
+					opp-peak-kBps = <12449218>;
 				};
 
 				opp-720000000 {
 					opp-hz = /bits/ 64 <720000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_SVS_L2>;
+					opp-peak-kBps = <12449218>;
 				};
 
 				opp-770000000 {
 					opp-hz = /bits/ 64 <770000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_NOM>;
+					opp-peak-kBps = <12449218>;
 				};
 
 				opp-834000000 {
 					opp-hz = /bits/ 64 <834000000>;
 					opp-level = <RPMH_REGULATOR_LEVEL_NOM_L1>;
+					opp-peak-kBps = <14398437>;
 				};
 			};
 		};

-- 
2.34.1

Re: [PATCH v5 2/7] drm/msm: adreno: add plumbing to generate bandwidth vote table for GMU

[Konrad Dybcio]

On 11.12.2024 9:29 AM, Neil Armstrong wrote:
> The Adreno GPU 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.
> 
> While scaling via the interconnect path was sufficient, newer GPUs
> like the A750 requires specific vote paremeters and bandwidth to
> achieve full functionality.
> 
> 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.
> 
> This vote value is called IB, while on the other side the GMU also
> takes another vote called AB which is a 16bit quantized value
> of the floor bandwidth against the maximum supported bandwidth.
> The AB vote will be calculated later when setting the frequency.
> 
> The vote array will then be used to dynamically generate the GMU
> bw_table sent during the GMU power-up.
> 
> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 144 ++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  13 +++
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.h |   1 +
>  3 files changed, 158 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> index 14db7376c712d19446b38152e480bd5a1e0a5198..36696d372a42a27b26a018b19e73bc6d8a4a5235 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 +1288,101 @@ 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;
> +};

No. This is a direct copypasta of drivers/interconnect/qcom/icc-rpmh.h
You cannot just randomly duplicate things..

Move it out to a shared header in include/ (and remove the duplicate from
clk-rpmh.c while at it)


I'd also really prefer if you took

drivers/interconnect/qcom/bcm-voter.c : tcs_list_gen()

and abstracted it to operate on struct bcm_db with any additional
required parameters passed as arguments.. Still left some comments
on this version if you decide to go with it

> +
> +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, bcm_count = 0;
> +
> +	if (!info->bcms)
> +		return 0;

You already checked that from the caller

> +
> +	/* Retrieve BCM data from cmd-db */
> +	for (bcm_index = 0; bcm_index < GMU_MAX_BCMS; bcm_index++) {
> +		size_t count;
> +
> +		/* Stop at first unconfigured bcm */
> +		if (!info->bcms[bcm_index].name)
> +			break;

Unconfigured doesn't really fit here.. Maybe just mention the list is NULL
-terminated

> +
> +		bcm_data[bcm_index] = cmd_db_read_aux_data(
> +						info->bcms[bcm_index].name,
> +						&count);
> +		if (IS_ERR(bcm_data[bcm_index]))
> +			return PTR_ERR(bcm_data[bcm_index]);
> +
> +		if (!count)
> +			return -EINVAL;

If this condition ever happens, it'll be impossible to track down,
please add an err message

> +
> +		++bcm_count;

I've heard somewhere that prefixed increments are discouraged for
"reasons" and my OCD would like to support that

> +	}
> +
> +	/* Generate BCM votes values for each bandwidth & BCM */
> +	for (bw_index = 0; bw_index < gmu->nr_gpu_bws; bw_index++) {
> +		u32 *data = gmu->gpu_ib_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 < bcm_count; bcm_index++) {
> +			bool commit = false;
> +			u64 peak;
> +			u32 vote;
> +
> +			/* Skip unconfigured BCM */
> +			if (!bcm_data[bcm_index])
> +				continue;

I don't see how this is useful here

> +
> +			if (bcm_index == bcm_count - 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->bcms[bcm_index].fixed) {

You may want to take a pointer to info->bcms[bcm_index]

> +				u32 perfmode = 0;
> +
> +				if (bw >= info->bcms[bcm_index].perfmode_bw)
> +					perfmode = info->bcms[bcm_index].perfmode;
> +
> +				data[bcm_index] = BCM_TCS_CMD(commit, true, 0, perfmode);
> +				continue;
> +			}
> +
> +			/* Multiply the bandwidth by the width of the connection */
> +			peak = (u64)bw * le16_to_cpu(bcm_data[bcm_index]->width);
> +			do_div(peak, info->bcms[bcm_index].buswidth);
> +
> +			/* Input bandwidth value is in KBps, scale the value to BCM unit */
> +			peak *= 1000ULL;

I don't think this needs to be ULL since the other argument is an u64

> +			do_div(peak, le32_to_cpu(bcm_data[bcm_index]->unit));
> +
> +			vote = clamp(peak, 1, BCM_TCS_CMD_VOTE_MASK);
> +
> +			data[bcm_index] = BCM_TCS_CMD(commit, true, vote, vote);

x is the avg vote, y is the peak vote

Just noting down for my future self I guess, a6xx sets ab=0,
a7xx sets ab=ib like you did here

Konrad

Re: [PATCH v5 3/7] drm/msm: adreno: dynamically generate GMU bw table

[Konrad Dybcio]

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@linaro.org>
> ---
>  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

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[Konrad Dybcio]

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, until now we left the OPP
> core scale the OPP bandwidth via the interconnect path.
> 
> In order to enable bandwidth voting via the GPU Management
> Unit (GMU), when an opp is set by devfreq we also look for
> the corresponding bandwidth index in the previously generated
> bw_table and pass this value along the frequency index to the GMU.
> 
> The GMU also takes another vote called AB which is a 16bit quantized
> value of the floor bandwidth against the maximum supported bandwidth.
> 
> The AB is calculated with a default 25% of the bandwidth like the
> downstream implementation too inform the GMU firmware the minimal
> quantity of bandwidth we require for this OPP.
> 
> Since we now vote for all resources via the GMU, setting the OPP
> is no more needed, so we can completely skip calling
> dev_pm_opp_set_opp() in this situation.
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 +++++++++++++++++++++++++++++++++--
>  drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>  drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>  drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>  4 files changed, 46 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> index 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
>  		       bool suspended)
>  {
>  	struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
> +	const struct a6xx_info *info = adreno_gpu->info->a6xx;
>  	struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>  	struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>  	u32 perf_index;
> +	u32 bw_index = 0;
>  	unsigned long gpu_freq;
>  	int ret = 0;
>  
> @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
>  		if (gpu_freq == gmu->gpu_freqs[perf_index])
>  			break;
>  
> +	/* If enabled, find the corresponding DDR bandwidth index */
> +	if (info->bcms && gmu->nr_gpu_bws > 1) {

if (gmu->nr_gpu_bws)

> +		unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
> +
> +		for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1; bw_index++) {
> +			if (bw == gmu->gpu_bw_table[bw_index])
> +				break;
> +		}
> +
> +		/* Vote AB as a fraction of the max bandwidth */
> +		if (bw) {

This seems to only be introduced with certain a7xx too.. you should
ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported

> +			u64 tmp;
> +
> +			/* For now, vote for 25% of the bandwidth */
> +			tmp = bw * 25;
> +			do_div(tmp, 100);
> +
> +			/*
> +			 * The AB vote consists of a 16 bit wide quantized level
> +			 * against the maximum supported bandwidth.
> +			 * Quantization can be calculated as below:
> +			 * vote = (bandwidth * 2^16) / max bandwidth
> +			 */
> +			tmp *= MAX_AB_VOTE;
> +			do_div(tmp, gmu->gpu_bw_table[gmu->nr_gpu_bws - 1]);
> +
> +			bw_index |= AB_VOTE(clamp(tmp, 1, MAX_AB_VOTE));
> +			bw_index |= AB_VOTE_ENABLE;
> +		}
> +	}

BTW, did you dump the values we send to the GMU here and in the RPMh
builder part & validate against downstream?

Konrad

Re: [PATCH v5 5/7] drm/msm: adreno: enable GMU bandwidth for A740 and A750

[Konrad Dybcio]

On 11.12.2024 9:29 AM, Neil Armstrong wrote:
> Now all the DDR bandwidth voting via the GPU Management Unit (GMU)
> is in place, declare the Bus Control Modules (BCMs) and the
> corresponding parameters in the GPU info struct.
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
> index 0c560e84ad5a53bb4e8a49ba4e153ce9cf33f7ae..edffb7737a97b268bb2986d557969e651988a344 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
> @@ -1388,6 +1388,17 @@ static const struct adreno_info a7xx_gpus[] = {
>  			.pwrup_reglist = &a7xx_pwrup_reglist,
>  			.gmu_chipid = 0x7020100,
>  			.gmu_cgc_mode = 0x00020202,
> +			.bcms = (const struct a6xx_bcm[]) {
> +				{ .name = "SH0", .buswidth = 16 },

All a7xx targets use the same BCMs with the only difference being
the ACV voting mask. You may want to make these non-anonymous structs.

> +				{ .name = "MC0", .buswidth = 4 },
> +				{
> +					.name = "ACV",
> +					.fixed = true,
> +					.perfmode = BIT(3),
> +					.perfmode_bw = 16500000,

I think perfmode is simply supposed to be set when bw == max_bw

Konrad

Re: [PATCH v5 5/7] drm/msm: adreno: enable GMU bandwidth for A740 and A750

[Neil Armstrong]

On 12/12/2024 21:32, Konrad Dybcio wrote:
> On 11.12.2024 9:29 AM, Neil Armstrong wrote:
>> Now all the DDR bandwidth voting via the GPU Management Unit (GMU)
>> is in place, declare the Bus Control Modules (BCMs) and the
>> corresponding parameters in the GPU info struct.
>>
>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 22 ++++++++++++++++++++++
>>   1 file changed, 22 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>> index 0c560e84ad5a53bb4e8a49ba4e153ce9cf33f7ae..edffb7737a97b268bb2986d557969e651988a344 100644
>> --- a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>> @@ -1388,6 +1388,17 @@ static const struct adreno_info a7xx_gpus[] = {
>>   			.pwrup_reglist = &a7xx_pwrup_reglist,
>>   			.gmu_chipid = 0x7020100,
>>   			.gmu_cgc_mode = 0x00020202,
>> +			.bcms = (const struct a6xx_bcm[]) {
>> +				{ .name = "SH0", .buswidth = 16 },
> 
> All a7xx targets use the same BCMs with the only difference being
> the ACV voting mask. You may want to make these non-anonymous structs.

it can be done in a second step

> 
>> +				{ .name = "MC0", .buswidth = 4 },
>> +				{
>> +					.name = "ACV",
>> +					.fixed = true,
>> +					.perfmode = BIT(3),
>> +					.perfmode_bw = 16500000,
> 
> I think perfmode is simply supposed to be set when bw == max_bw

Not for a750

> 
> Konrad

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[Neil Armstrong]

On 12/12/2024 21:21, Konrad Dybcio wrote:
> 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, until now we left the OPP
>> core scale the OPP bandwidth via the interconnect path.
>>
>> In order to enable bandwidth voting via the GPU Management
>> Unit (GMU), when an opp is set by devfreq we also look for
>> the corresponding bandwidth index in the previously generated
>> bw_table and pass this value along the frequency index to the GMU.
>>
>> The GMU also takes another vote called AB which is a 16bit quantized
>> value of the floor bandwidth against the maximum supported bandwidth.
>>
>> The AB is calculated with a default 25% of the bandwidth like the
>> downstream implementation too inform the GMU firmware the minimal
>> quantity of bandwidth we require for this OPP.
>>
>> Since we now vote for all resources via the GMU, setting the OPP
>> is no more needed, so we can completely skip calling
>> dev_pm_opp_set_opp() in this situation.
>>
>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 +++++++++++++++++++++++++++++++++--
>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>   drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>   drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>   4 files changed, 46 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> index 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
>>   		       bool suspended)
>>   {
>>   	struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>> +	const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>   	struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>   	struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>   	u32 perf_index;
>> +	u32 bw_index = 0;
>>   	unsigned long gpu_freq;
>>   	int ret = 0;
>>   
>> @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
>>   		if (gpu_freq == gmu->gpu_freqs[perf_index])
>>   			break;
>>   
>> +	/* If enabled, find the corresponding DDR bandwidth index */
>> +	if (info->bcms && gmu->nr_gpu_bws > 1) {
> 
> if (gmu->nr_gpu_bws)

gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the "off" state)

> 
>> +		unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>> +
>> +		for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1; bw_index++) {
>> +			if (bw == gmu->gpu_bw_table[bw_index])
>> +				break;
>> +		}
>> +
>> +		/* Vote AB as a fraction of the max bandwidth */
>> +		if (bw) {
> 
> This seems to only be introduced with certain a7xx too.. you should
> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported

Good point

> 
>> +			u64 tmp;
>> +
>> +			/* For now, vote for 25% of the bandwidth */
>> +			tmp = bw * 25;
>> +			do_div(tmp, 100);
>> +
>> +			/*
>> +			 * The AB vote consists of a 16 bit wide quantized level
>> +			 * against the maximum supported bandwidth.
>> +			 * Quantization can be calculated as below:
>> +			 * vote = (bandwidth * 2^16) / max bandwidth
>> +			 */
>> +			tmp *= MAX_AB_VOTE;
>> +			do_div(tmp, gmu->gpu_bw_table[gmu->nr_gpu_bws - 1]);
>> +
>> +			bw_index |= AB_VOTE(clamp(tmp, 1, MAX_AB_VOTE));
>> +			bw_index |= AB_VOTE_ENABLE;
>> +		}
>> +	}
> 
> BTW, did you dump the values we send to the GMU here and in the RPMh
> builder part & validate against downstream?

It matches how downstream builds the Ab vote yes

> 
> Konrad

Re: [PATCH v5 3/7] drm/msm: adreno: dynamically generate GMU bw table

[Neil Armstrong]

On 12/12/2024 21:10, Konrad Dybcio wrote:
> 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@linaro.org>
>> ---
>>   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.

"1" has not meaning, especially when we're supposed sending a bandwidth value, bit(0) means this bit has a special value

> 
> 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)

Fancy but we know how it's calculated...

> 
> Konrad

Re: [PATCH v5 2/7] drm/msm: adreno: add plumbing to generate bandwidth vote table for GMU

[Neil Armstrong]

On 12/12/2024 20:55, Konrad Dybcio wrote:
> On 11.12.2024 9:29 AM, Neil Armstrong wrote:
>> The Adreno GPU 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.
>>
>> While scaling via the interconnect path was sufficient, newer GPUs
>> like the A750 requires specific vote paremeters and bandwidth to
>> achieve full functionality.
>>
>> 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.
>>
>> This vote value is called IB, while on the other side the GMU also
>> takes another vote called AB which is a 16bit quantized value
>> of the floor bandwidth against the maximum supported bandwidth.
>> The AB vote will be calculated later when setting the frequency.
>>
>> The vote array will then be used to dynamically generate the GMU
>> bw_table sent during the GMU power-up.
>>
>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 144 ++++++++++++++++++++++++++++++++++
>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  13 +++
>>   drivers/gpu/drm/msm/adreno/a6xx_gpu.h |   1 +
>>   3 files changed, 158 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> index 14db7376c712d19446b38152e480bd5a1e0a5198..36696d372a42a27b26a018b19e73bc6d8a4a5235 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 +1288,101 @@ 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;
>> +};
> 
> No. This is a direct copypasta of drivers/interconnect/qcom/icc-rpmh.h
> You cannot just randomly duplicate things..
> 
> Move it out to a shared header in include/ (and remove the duplicate from
> clk-rpmh.c while at it)
> 

Not sure if this a good idea

> 
> I'd also really prefer if you took
> 
> drivers/interconnect/qcom/bcm-voter.c : tcs_list_gen()
> 
> and abstracted it to operate on struct bcm_db with any additional
> required parameters passed as arguments.. Still left some comments
> on this version if you decide to go with it

They are still very different, look closely, tcs_list_gen is designed to
operate on BW aggregations + scsaling, it would make no sense to unify them.

The calculation is simple enough, I made it explicitely easy to read and
maintain, but honestly there's nothing special.

> 
>> +
>> +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, bcm_count = 0;
>> +
>> +	if (!info->bcms)
>> +		return 0;
> 
> You already checked that from the caller

Good catch

> 
>> +
>> +	/* Retrieve BCM data from cmd-db */
>> +	for (bcm_index = 0; bcm_index < GMU_MAX_BCMS; bcm_index++) {
>> +		size_t count;
>> +
>> +		/* Stop at first unconfigured bcm */
>> +		if (!info->bcms[bcm_index].name)
>> +			break;
> 
> Unconfigured doesn't really fit here.. Maybe just mention the list is NULL
> -terminated

Ack

> 
>> +
>> +		bcm_data[bcm_index] = cmd_db_read_aux_data(
>> +						info->bcms[bcm_index].name,
>> +						&count);
>> +		if (IS_ERR(bcm_data[bcm_index]))
>> +			return PTR_ERR(bcm_data[bcm_index]);
>> +
>> +		if (!count)
>> +			return -EINVAL;
> 
> If this condition ever happens, it'll be impossible to track down,
> please add an err message

Hmm sure

> 
>> +
>> +		++bcm_count;
> 
> I've heard somewhere that prefixed increments are discouraged for
> "reasons" and my OCD would like to support that

Never got this memo...

> 
>> +	}
>> +
>> +	/* Generate BCM votes values for each bandwidth & BCM */
>> +	for (bw_index = 0; bw_index < gmu->nr_gpu_bws; bw_index++) {
>> +		u32 *data = gmu->gpu_ib_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 < bcm_count; bcm_index++) {
>> +			bool commit = false;
>> +			u64 peak;
>> +			u32 vote;
>> +
>> +			/* Skip unconfigured BCM */
>> +			if (!bcm_data[bcm_index])
>> +				continue;
> 
> I don't see how this is useful here

It's a leftover, will drop

> 
>> +
>> +			if (bcm_index == bcm_count - 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->bcms[bcm_index].fixed) {
> 
> You may want to take a pointer to info->bcms[bcm_index]

Sure, will help

> 
>> +				u32 perfmode = 0;
>> +
>> +				if (bw >= info->bcms[bcm_index].perfmode_bw)
>> +					perfmode = info->bcms[bcm_index].perfmode;
>> +
>> +				data[bcm_index] = BCM_TCS_CMD(commit, true, 0, perfmode);
>> +				continue;
>> +			}
>> +
>> +			/* Multiply the bandwidth by the width of the connection */
>> +			peak = (u64)bw * le16_to_cpu(bcm_data[bcm_index]->width);
>> +			do_div(peak, info->bcms[bcm_index].buswidth);
>> +
>> +			/* Input bandwidth value is in KBps, scale the value to BCM unit */
>> +			peak *= 1000ULL;
> 
> I don't think this needs to be ULL since the other argument is an u64
> 
>> +			do_div(peak, le32_to_cpu(bcm_data[bcm_index]->unit));
>> +
>> +			vote = clamp(peak, 1, BCM_TCS_CMD_VOTE_MASK);
>> +
>> +			data[bcm_index] = BCM_TCS_CMD(commit, true, vote, vote);
> 
> x is the avg vote, y is the peak vote

downstream sets both calculated from the exact same value and the same way...

> 
> Just noting down for my future self I guess, a6xx sets ab=0,
> a7xx sets ab=ib like you did here

Probably, I'll need to check on that, but it can be done in a second step when enabling it on a6xx

> 
> Konrad

Re: [PATCH v5 5/7] drm/msm: adreno: enable GMU bandwidth for A740 and A750

[Konrad Dybcio]

On 12.12.2024 10:36 PM, Neil Armstrong wrote:
> On 12/12/2024 21:32, Konrad Dybcio wrote:
>> On 11.12.2024 9:29 AM, Neil Armstrong wrote:
>>> Now all the DDR bandwidth voting via the GPU Management Unit (GMU)
>>> is in place, declare the Bus Control Modules (BCMs) and the
>>> corresponding parameters in the GPU info struct.
>>>
>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>> ---
>>>   drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 22 ++++++++++++++++++++++
>>>   1 file changed, 22 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>>> index 0c560e84ad5a53bb4e8a49ba4e153ce9cf33f7ae..edffb7737a97b268bb2986d557969e651988a344 100644
>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>>> @@ -1388,6 +1388,17 @@ static const struct adreno_info a7xx_gpus[] = {
>>>               .pwrup_reglist = &a7xx_pwrup_reglist,
>>>               .gmu_chipid = 0x7020100,
>>>               .gmu_cgc_mode = 0x00020202,
>>> +            .bcms = (const struct a6xx_bcm[]) {
>>> +                { .name = "SH0", .buswidth = 16 },
>>
>> All a7xx targets use the same BCMs with the only difference being
>> the ACV voting mask. You may want to make these non-anonymous structs.
> 
> it can be done in a second step
> 
>>
>>> +                { .name = "MC0", .buswidth = 4 },
>>> +                {
>>> +                    .name = "ACV",
>>> +                    .fixed = true,
>>> +                    .perfmode = BIT(3),
>>> +                    .perfmode_bw = 16500000,
>>
>> I think perfmode is simply supposed to be set when bw == max_bw
> 
> Not for a750

Akhil, is there any way to determine a suitable OPP for this
dynamically?

Konrad

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[Akhil P Oommen]

On 12/13/2024 3:07 AM, Neil Armstrong wrote:
> On 12/12/2024 21:21, Konrad Dybcio wrote:
>> 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, until now we left the OPP
>>> core scale the OPP bandwidth via the interconnect path.
>>>
>>> In order to enable bandwidth voting via the GPU Management
>>> Unit (GMU), when an opp is set by devfreq we also look for
>>> the corresponding bandwidth index in the previously generated
>>> bw_table and pass this value along the frequency index to the GMU.
>>>
>>> The GMU also takes another vote called AB which is a 16bit quantized
>>> value of the floor bandwidth against the maximum supported bandwidth.
>>>
>>> The AB is calculated with a default 25% of the bandwidth like the
>>> downstream implementation too inform the GMU firmware the minimal
>>> quantity of bandwidth we require for this OPP.
>>>
>>> Since we now vote for all resources via the GMU, setting the OPP
>>> is no more needed, so we can completely skip calling
>>> dev_pm_opp_set_opp() in this situation.
>>>
>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>> ---
>>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 ++++++++++++++++++++++++
>>> +++++++++--
>>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>   drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>   drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>   4 files changed, 46 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/
>>> msm/adreno/a6xx_gmu.c
>>> index
>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>> struct dev_pm_opp *opp,
>>>                  bool suspended)
>>>   {
>>>       struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>       struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>       struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>       u32 perf_index;
>>> +    u32 bw_index = 0;
>>>       unsigned long gpu_freq;
>>>       int ret = 0;
>>>   @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>> struct dev_pm_opp *opp,
>>>           if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>               break;
>>>   +    /* If enabled, find the corresponding DDR bandwidth index */
>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>
>> if (gmu->nr_gpu_bws)
> 
> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the
> "off" state)
> 
>>
>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>> +
>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1; bw_index+
>>> +) {
>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>> +                break;
>>> +        }
>>> +
>>> +        /* Vote AB as a fraction of the max bandwidth */
>>> +        if (bw) {
>>
>> This seems to only be introduced with certain a7xx too.. you should
>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported
> 
> Good point

No no. Doing this will trigger some assert in pre-A750 gmu firmwares. We
learned it the hard way. No improvisation please. :)

-Akhil.

> 
>>
>>> +            u64 tmp;
>>> +
>>> +            /* For now, vote for 25% of the bandwidth */
>>> +            tmp = bw * 25;
>>> +            do_div(tmp, 100);
>>> +
>>> +            /*
>>> +             * The AB vote consists of a 16 bit wide quantized level
>>> +             * against the maximum supported bandwidth.
>>> +             * Quantization can be calculated as below:
>>> +             * vote = (bandwidth * 2^16) / max bandwidth
>>> +             */
>>> +            tmp *= MAX_AB_VOTE;
>>> +            do_div(tmp, gmu->gpu_bw_table[gmu->nr_gpu_bws - 1]);
>>> +
>>> +            bw_index |= AB_VOTE(clamp(tmp, 1, MAX_AB_VOTE));
>>> +            bw_index |= AB_VOTE_ENABLE;
>>> +        }
>>> +    }
>>
>> BTW, did you dump the values we send to the GMU here and in the RPMh
>> builder part & validate against downstream?
> 
> It matches how downstream builds the Ab vote yes
> 
>>
>> Konrad
> 

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[Konrad Dybcio]

On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
> On 12/13/2024 3:07 AM, Neil Armstrong wrote:
>> On 12/12/2024 21:21, Konrad Dybcio wrote:
>>> 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, until now we left the OPP
>>>> core scale the OPP bandwidth via the interconnect path.
>>>>
>>>> In order to enable bandwidth voting via the GPU Management
>>>> Unit (GMU), when an opp is set by devfreq we also look for
>>>> the corresponding bandwidth index in the previously generated
>>>> bw_table and pass this value along the frequency index to the GMU.
>>>>
>>>> The GMU also takes another vote called AB which is a 16bit quantized
>>>> value of the floor bandwidth against the maximum supported bandwidth.
>>>>
>>>> The AB is calculated with a default 25% of the bandwidth like the
>>>> downstream implementation too inform the GMU firmware the minimal
>>>> quantity of bandwidth we require for this OPP.
>>>>
>>>> Since we now vote for all resources via the GMU, setting the OPP
>>>> is no more needed, so we can completely skip calling
>>>> dev_pm_opp_set_opp() in this situation.
>>>>
>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>> ---
>>>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 ++++++++++++++++++++++++
>>>> +++++++++--
>>>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>>   drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>>   drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>>   4 files changed, 46 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/
>>>> msm/adreno/a6xx_gmu.c
>>>> index
>>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>> struct dev_pm_opp *opp,
>>>>                  bool suspended)
>>>>   {
>>>>       struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>>       struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>>       struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>>       u32 perf_index;
>>>> +    u32 bw_index = 0;
>>>>       unsigned long gpu_freq;
>>>>       int ret = 0;
>>>>   @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>> struct dev_pm_opp *opp,
>>>>           if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>>               break;
>>>>   +    /* If enabled, find the corresponding DDR bandwidth index */
>>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>>
>>> if (gmu->nr_gpu_bws)
>>
>> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the
>> "off" state)
>>
>>>
>>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>>> +
>>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1; bw_index+
>>>> +) {
>>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>>> +                break;
>>>> +        }
>>>> +
>>>> +        /* Vote AB as a fraction of the max bandwidth */
>>>> +        if (bw) {
>>>
>>> This seems to only be introduced with certain a7xx too.. you should
>>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported
>>
>> Good point
> 
> No no. Doing this will trigger some assert in pre-A750 gmu firmwares. We
> learned it the hard way. No improvisation please. :)

We shouldn't be sending that AB data to firmware that doesn't expect
it either too, though..

Konrad

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[neil.armstrong]

On 13/12/2024 16:37, Konrad Dybcio wrote:
> On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
>> On 12/13/2024 3:07 AM, Neil Armstrong wrote:
>>> On 12/12/2024 21:21, Konrad Dybcio wrote:
>>>> 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, until now we left the OPP
>>>>> core scale the OPP bandwidth via the interconnect path.
>>>>>
>>>>> In order to enable bandwidth voting via the GPU Management
>>>>> Unit (GMU), when an opp is set by devfreq we also look for
>>>>> the corresponding bandwidth index in the previously generated
>>>>> bw_table and pass this value along the frequency index to the GMU.
>>>>>
>>>>> The GMU also takes another vote called AB which is a 16bit quantized
>>>>> value of the floor bandwidth against the maximum supported bandwidth.
>>>>>
>>>>> The AB is calculated with a default 25% of the bandwidth like the
>>>>> downstream implementation too inform the GMU firmware the minimal
>>>>> quantity of bandwidth we require for this OPP.
>>>>>
>>>>> Since we now vote for all resources via the GMU, setting the OPP
>>>>> is no more needed, so we can completely skip calling
>>>>> dev_pm_opp_set_opp() in this situation.
>>>>>
>>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>> ---
>>>>>    drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 ++++++++++++++++++++++++
>>>>> +++++++++--
>>>>>    drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>>>    drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>>>    drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>>>    4 files changed, 46 insertions(+), 6 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/
>>>>> msm/adreno/a6xx_gmu.c
>>>>> index
>>>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>> struct dev_pm_opp *opp,
>>>>>                   bool suspended)
>>>>>    {
>>>>>        struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>>>        struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>>>        struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>>>        u32 perf_index;
>>>>> +    u32 bw_index = 0;
>>>>>        unsigned long gpu_freq;
>>>>>        int ret = 0;
>>>>>    @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>> struct dev_pm_opp *opp,
>>>>>            if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>>>                break;
>>>>>    +    /* If enabled, find the corresponding DDR bandwidth index */
>>>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>>>
>>>> if (gmu->nr_gpu_bws)
>>>
>>> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the
>>> "off" state)
>>>
>>>>
>>>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>>>> +
>>>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1; bw_index+
>>>>> +) {
>>>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>>>> +                break;
>>>>> +        }
>>>>> +
>>>>> +        /* Vote AB as a fraction of the max bandwidth */
>>>>> +        if (bw) {
>>>>
>>>> This seems to only be introduced with certain a7xx too.. you should
>>>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported
>>>
>>> Good point
>>
>> No no. Doing this will trigger some assert in pre-A750 gmu firmwares. We
>> learned it the hard way. No improvisation please. :)
> 
> We shouldn't be sending that AB data to firmware that doesn't expect
> it either too, though..

Well we don't !

> 
> Konrad

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[Konrad Dybcio]

On 13.12.2024 5:28 PM, neil.armstrong@linaro.org wrote:
> On 13/12/2024 16:37, Konrad Dybcio wrote:
>> On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
>>> On 12/13/2024 3:07 AM, Neil Armstrong wrote:
>>>> On 12/12/2024 21:21, Konrad Dybcio wrote:
>>>>> 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, until now we left the OPP
>>>>>> core scale the OPP bandwidth via the interconnect path.
>>>>>>
>>>>>> In order to enable bandwidth voting via the GPU Management
>>>>>> Unit (GMU), when an opp is set by devfreq we also look for
>>>>>> the corresponding bandwidth index in the previously generated
>>>>>> bw_table and pass this value along the frequency index to the GMU.
>>>>>>
>>>>>> The GMU also takes another vote called AB which is a 16bit quantized
>>>>>> value of the floor bandwidth against the maximum supported bandwidth.
>>>>>>
>>>>>> The AB is calculated with a default 25% of the bandwidth like the
>>>>>> downstream implementation too inform the GMU firmware the minimal
>>>>>> quantity of bandwidth we require for this OPP.
>>>>>>
>>>>>> Since we now vote for all resources via the GMU, setting the OPP
>>>>>> is no more needed, so we can completely skip calling
>>>>>> dev_pm_opp_set_opp() in this situation.
>>>>>>
>>>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>>> ---
>>>>>>    drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 ++++++++++++++++++++++++
>>>>>> +++++++++--
>>>>>>    drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>>>>    drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>>>>    drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>>>>    4 files changed, 46 insertions(+), 6 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/
>>>>>> msm/adreno/a6xx_gmu.c
>>>>>> index
>>>>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>>> struct dev_pm_opp *opp,
>>>>>>                   bool suspended)
>>>>>>    {
>>>>>>        struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>>>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>>>>        struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>>>>        struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>>>>        u32 perf_index;
>>>>>> +    u32 bw_index = 0;
>>>>>>        unsigned long gpu_freq;
>>>>>>        int ret = 0;
>>>>>>    @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>>> struct dev_pm_opp *opp,
>>>>>>            if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>>>>                break;
>>>>>>    +    /* If enabled, find the corresponding DDR bandwidth index */
>>>>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>>>>
>>>>> if (gmu->nr_gpu_bws)
>>>>
>>>> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the
>>>> "off" state)
>>>>
>>>>>
>>>>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>>>>> +
>>>>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1; bw_index+
>>>>>> +) {
>>>>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>>>>> +                break;
>>>>>> +        }
>>>>>> +
>>>>>> +        /* Vote AB as a fraction of the max bandwidth */
>>>>>> +        if (bw) {
>>>>>
>>>>> This seems to only be introduced with certain a7xx too.. you should
>>>>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported
>>>>
>>>> Good point
>>>
>>> No no. Doing this will trigger some assert in pre-A750 gmu firmwares. We
>>> learned it the hard way. No improvisation please. :)
>>
>> We shouldn't be sending that AB data to firmware that doesn't expect
>> it either too, though..
> 
> Well we don't !

The code in the scope that I quoted above does that

see the full explanation here

https://git.codelinaro.org/clo/le/platform/vendor/qcom/opensource/graphics-kernel/-/commit/6026c31a54444b712f7ea36ac1aafaaeef07fa4e

Konrad

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[neil.armstrong]

On 13/12/2024 17:31, Konrad Dybcio wrote:
> On 13.12.2024 5:28 PM, neil.armstrong@linaro.org wrote:
>> On 13/12/2024 16:37, Konrad Dybcio wrote:
>>> On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
>>>> On 12/13/2024 3:07 AM, Neil Armstrong wrote:
>>>>> On 12/12/2024 21:21, Konrad Dybcio wrote:
>>>>>> 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, until now we left the OPP
>>>>>>> core scale the OPP bandwidth via the interconnect path.
>>>>>>>
>>>>>>> In order to enable bandwidth voting via the GPU Management
>>>>>>> Unit (GMU), when an opp is set by devfreq we also look for
>>>>>>> the corresponding bandwidth index in the previously generated
>>>>>>> bw_table and pass this value along the frequency index to the GMU.
>>>>>>>
>>>>>>> The GMU also takes another vote called AB which is a 16bit quantized
>>>>>>> value of the floor bandwidth against the maximum supported bandwidth.
>>>>>>>
>>>>>>> The AB is calculated with a default 25% of the bandwidth like the
>>>>>>> downstream implementation too inform the GMU firmware the minimal
>>>>>>> quantity of bandwidth we require for this OPP.
>>>>>>>
>>>>>>> Since we now vote for all resources via the GMU, setting the OPP
>>>>>>> is no more needed, so we can completely skip calling
>>>>>>> dev_pm_opp_set_opp() in this situation.
>>>>>>>
>>>>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>>>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>>>> ---
>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 ++++++++++++++++++++++++
>>>>>>> +++++++++--
>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>>>>>     4 files changed, 46 insertions(+), 6 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/
>>>>>>> msm/adreno/a6xx_gmu.c
>>>>>>> index
>>>>>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>>>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>>>> struct dev_pm_opp *opp,
>>>>>>>                    bool suspended)
>>>>>>>     {
>>>>>>>         struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>>>>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>>>>>         struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>>>>>         struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>>>>>         u32 perf_index;
>>>>>>> +    u32 bw_index = 0;
>>>>>>>         unsigned long gpu_freq;
>>>>>>>         int ret = 0;
>>>>>>>     @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>>>> struct dev_pm_opp *opp,
>>>>>>>             if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>>>>>                 break;
>>>>>>>     +    /* If enabled, find the corresponding DDR bandwidth index */
>>>>>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>>>>>
>>>>>> if (gmu->nr_gpu_bws)
>>>>>
>>>>> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the
>>>>> "off" state)
>>>>>
>>>>>>
>>>>>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>>>>>> +
>>>>>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1; bw_index+
>>>>>>> +) {
>>>>>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>>>>>> +                break;
>>>>>>> +        }
>>>>>>> +
>>>>>>> +        /* Vote AB as a fraction of the max bandwidth */
>>>>>>> +        if (bw) {
>>>>>>
>>>>>> This seems to only be introduced with certain a7xx too.. you should
>>>>>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported
>>>>>
>>>>> Good point
>>>>
>>>> No no. Doing this will trigger some assert in pre-A750 gmu firmwares. We
>>>> learned it the hard way. No improvisation please. :)
>>>
>>> We shouldn't be sending that AB data to firmware that doesn't expect
>>> it either too, though..
>>
>> Well we don't !
> 
> The code in the scope that I quoted above does that

No it doesn't, if the proper bcms are not declared in the gpu_info, it won't

Neil

> 
> see the full explanation here
> 
> https://git.codelinaro.org/clo/le/platform/vendor/qcom/opensource/graphics-kernel/-/commit/6026c31a54444b712f7ea36ac1aafaaeef07fa4e
> 
> Konrad

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[Akhil P Oommen]

On 12/13/2024 10:10 PM, neil.armstrong@linaro.org wrote:
> On 13/12/2024 17:31, Konrad Dybcio wrote:
>> On 13.12.2024 5:28 PM, neil.armstrong@linaro.org wrote:
>>> On 13/12/2024 16:37, Konrad Dybcio wrote:
>>>> On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
>>>>> On 12/13/2024 3:07 AM, Neil Armstrong wrote:
>>>>>> On 12/12/2024 21:21, Konrad Dybcio wrote:
>>>>>>> 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, until now we left
>>>>>>>> the OPP
>>>>>>>> core scale the OPP bandwidth via the interconnect path.
>>>>>>>>
>>>>>>>> In order to enable bandwidth voting via the GPU Management
>>>>>>>> Unit (GMU), when an opp is set by devfreq we also look for
>>>>>>>> the corresponding bandwidth index in the previously generated
>>>>>>>> bw_table and pass this value along the frequency index to the GMU.
>>>>>>>>
>>>>>>>> The GMU also takes another vote called AB which is a 16bit
>>>>>>>> quantized
>>>>>>>> value of the floor bandwidth against the maximum supported
>>>>>>>> bandwidth.
>>>>>>>>
>>>>>>>> The AB is calculated with a default 25% of the bandwidth like the
>>>>>>>> downstream implementation too inform the GMU firmware the minimal
>>>>>>>> quantity of bandwidth we require for this OPP.
>>>>>>>>
>>>>>>>> Since we now vote for all resources via the GMU, setting the OPP
>>>>>>>> is no more needed, so we can completely skip calling
>>>>>>>> dev_pm_opp_set_opp() in this situation.
>>>>>>>>
>>>>>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>>>>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>>>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>>>>> ---
>>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 +++++++++++++++++
>>>>>>>> +++++++
>>>>>>>> +++++++++--
>>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>>>>>>     4 files changed, 46 insertions(+), 6 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/
>>>>>>>> gpu/drm/
>>>>>>>> msm/adreno/a6xx_gmu.c
>>>>>>>> index
>>>>>>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>>>>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>                    bool suspended)
>>>>>>>>     {
>>>>>>>>         struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>>>>>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>>>>>>         struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>>>>>>         struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>>>>>>         u32 perf_index;
>>>>>>>> +    u32 bw_index = 0;
>>>>>>>>         unsigned long gpu_freq;
>>>>>>>>         int ret = 0;
>>>>>>>>     @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu
>>>>>>>> *gpu,
>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>             if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>>>>>>                 break;
>>>>>>>>     +    /* If enabled, find the corresponding DDR bandwidth
>>>>>>>> index */
>>>>>>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>>>>>>
>>>>>>> if (gmu->nr_gpu_bws)
>>>>>>
>>>>>> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the
>>>>>> "off" state)
>>>>>>
>>>>>>>
>>>>>>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>>>>>>> +
>>>>>>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1;
>>>>>>>> bw_index+
>>>>>>>> +) {
>>>>>>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>>>>>>> +                break;
>>>>>>>> +        }
>>>>>>>> +
>>>>>>>> +        /* Vote AB as a fraction of the max bandwidth */
>>>>>>>> +        if (bw) {
>>>>>>>
>>>>>>> This seems to only be introduced with certain a7xx too.. you should
>>>>>>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported
>>>>>>
>>>>>> Good point
>>>>>
>>>>> No no. Doing this will trigger some assert in pre-A750 gmu
>>>>> firmwares. We
>>>>> learned it the hard way. No improvisation please. :)
>>>>
>>>> We shouldn't be sending that AB data to firmware that doesn't expect
>>>> it either too, though..
>>>
>>> Well we don't !
>>
>> The code in the scope that I quoted above does that
> 
> No it doesn't, if the proper bcms are not declared in the gpu_info, it
> won't

I think what Konrad meant was that IB voting is supported from a650+,
but AB voting is support only from a750+. So we can add bcm nodes to
enable IB voting, but how do we ensure AB voting via GMU is done only on
a750+.

-Akhil

> 
> Neil
> 
>>
>> see the full explanation here
>>
>> https://git.codelinaro.org/clo/le/platform/vendor/qcom/opensource/
>> graphics-kernel/-/commit/6026c31a54444b712f7ea36ac1aafaaeef07fa4e
>>
>> Konrad
> 

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[Konrad Dybcio]

On 13.12.2024 5:55 PM, Akhil P Oommen wrote:
> On 12/13/2024 10:10 PM, neil.armstrong@linaro.org wrote:
>> On 13/12/2024 17:31, Konrad Dybcio wrote:
>>> On 13.12.2024 5:28 PM, neil.armstrong@linaro.org wrote:
>>>> On 13/12/2024 16:37, Konrad Dybcio wrote:
>>>>> On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
>>>>>> On 12/13/2024 3:07 AM, Neil Armstrong wrote:
>>>>>>> On 12/12/2024 21:21, Konrad Dybcio wrote:
>>>>>>>> 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, until now we left
>>>>>>>>> the OPP
>>>>>>>>> core scale the OPP bandwidth via the interconnect path.
>>>>>>>>>
>>>>>>>>> In order to enable bandwidth voting via the GPU Management
>>>>>>>>> Unit (GMU), when an opp is set by devfreq we also look for
>>>>>>>>> the corresponding bandwidth index in the previously generated
>>>>>>>>> bw_table and pass this value along the frequency index to the GMU.
>>>>>>>>>
>>>>>>>>> The GMU also takes another vote called AB which is a 16bit
>>>>>>>>> quantized
>>>>>>>>> value of the floor bandwidth against the maximum supported
>>>>>>>>> bandwidth.
>>>>>>>>>
>>>>>>>>> The AB is calculated with a default 25% of the bandwidth like the
>>>>>>>>> downstream implementation too inform the GMU firmware the minimal
>>>>>>>>> quantity of bandwidth we require for this OPP.
>>>>>>>>>
>>>>>>>>> Since we now vote for all resources via the GMU, setting the OPP
>>>>>>>>> is no more needed, so we can completely skip calling
>>>>>>>>> dev_pm_opp_set_opp() in this situation.
>>>>>>>>>
>>>>>>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>>>>>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>>>>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>>>>>> ---
>>>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 +++++++++++++++++
>>>>>>>>> +++++++
>>>>>>>>> +++++++++--
>>>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>>>>>>>     drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>>>>>>>     4 files changed, 46 insertions(+), 6 deletions(-)
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/
>>>>>>>>> gpu/drm/
>>>>>>>>> msm/adreno/a6xx_gmu.c
>>>>>>>>> index
>>>>>>>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>>>>>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>>                    bool suspended)
>>>>>>>>>     {
>>>>>>>>>         struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>>>>>>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>>>>>>>         struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>>>>>>>         struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>>>>>>>         u32 perf_index;
>>>>>>>>> +    u32 bw_index = 0;
>>>>>>>>>         unsigned long gpu_freq;
>>>>>>>>>         int ret = 0;
>>>>>>>>>     @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu
>>>>>>>>> *gpu,
>>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>>             if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>>>>>>>                 break;
>>>>>>>>>     +    /* If enabled, find the corresponding DDR bandwidth
>>>>>>>>> index */
>>>>>>>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>>>>>>>
>>>>>>>> if (gmu->nr_gpu_bws)
>>>>>>>
>>>>>>> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the
>>>>>>> "off" state)
>>>>>>>
>>>>>>>>
>>>>>>>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>>>>>>>> +
>>>>>>>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1;
>>>>>>>>> bw_index+
>>>>>>>>> +) {
>>>>>>>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>>>>>>>> +                break;
>>>>>>>>> +        }
>>>>>>>>> +
>>>>>>>>> +        /* Vote AB as a fraction of the max bandwidth */
>>>>>>>>> +        if (bw) {
>>>>>>>>
>>>>>>>> This seems to only be introduced with certain a7xx too.. you should
>>>>>>>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported
>>>>>>>
>>>>>>> Good point
>>>>>>
>>>>>> No no. Doing this will trigger some assert in pre-A750 gmu
>>>>>> firmwares. We
>>>>>> learned it the hard way. No improvisation please. :)
>>>>>
>>>>> We shouldn't be sending that AB data to firmware that doesn't expect
>>>>> it either too, though..
>>>>
>>>> Well we don't !
>>>
>>> The code in the scope that I quoted above does that
>>
>> No it doesn't, if the proper bcms are not declared in the gpu_info, it
>> won't
> 
> I think what Konrad meant was that IB voting is supported from a650+,
> but AB voting is support only from a750+. So we can add bcm nodes to
> enable IB voting, but how do we ensure AB voting via GMU is done only on
> a750+.

Yep, relying on incomplete data in the catalog is not a great way
to ensure that

Konrad

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[neil.armstrong]

On 14/12/2024 00:46, Konrad Dybcio wrote:
> On 13.12.2024 5:55 PM, Akhil P Oommen wrote:
>> On 12/13/2024 10:10 PM, neil.armstrong@linaro.org wrote:
>>> On 13/12/2024 17:31, Konrad Dybcio wrote:
>>>> On 13.12.2024 5:28 PM, neil.armstrong@linaro.org wrote:
>>>>> On 13/12/2024 16:37, Konrad Dybcio wrote:
>>>>>> On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
>>>>>>> On 12/13/2024 3:07 AM, Neil Armstrong wrote:
>>>>>>>> On 12/12/2024 21:21, Konrad Dybcio wrote:
>>>>>>>>> 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, until now we left
>>>>>>>>>> the OPP
>>>>>>>>>> core scale the OPP bandwidth via the interconnect path.
>>>>>>>>>>
>>>>>>>>>> In order to enable bandwidth voting via the GPU Management
>>>>>>>>>> Unit (GMU), when an opp is set by devfreq we also look for
>>>>>>>>>> the corresponding bandwidth index in the previously generated
>>>>>>>>>> bw_table and pass this value along the frequency index to the GMU.
>>>>>>>>>>
>>>>>>>>>> The GMU also takes another vote called AB which is a 16bit
>>>>>>>>>> quantized
>>>>>>>>>> value of the floor bandwidth against the maximum supported
>>>>>>>>>> bandwidth.
>>>>>>>>>>
>>>>>>>>>> The AB is calculated with a default 25% of the bandwidth like the
>>>>>>>>>> downstream implementation too inform the GMU firmware the minimal
>>>>>>>>>> quantity of bandwidth we require for this OPP.
>>>>>>>>>>
>>>>>>>>>> Since we now vote for all resources via the GMU, setting the OPP
>>>>>>>>>> is no more needed, so we can completely skip calling
>>>>>>>>>> dev_pm_opp_set_opp() in this situation.
>>>>>>>>>>
>>>>>>>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>>>>>>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>>>>>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>>>>>>> ---
>>>>>>>>>>      drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 +++++++++++++++++
>>>>>>>>>> +++++++
>>>>>>>>>> +++++++++--
>>>>>>>>>>      drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>>>>>>>>      drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>>>>>>>>      drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>>>>>>>>      4 files changed, 46 insertions(+), 6 deletions(-)
>>>>>>>>>>
>>>>>>>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/
>>>>>>>>>> gpu/drm/
>>>>>>>>>> msm/adreno/a6xx_gmu.c
>>>>>>>>>> index
>>>>>>>>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>>>>>>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>>>                     bool suspended)
>>>>>>>>>>      {
>>>>>>>>>>          struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>>>>>>>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>>>>>>>>          struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>>>>>>>>          struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>>>>>>>>          u32 perf_index;
>>>>>>>>>> +    u32 bw_index = 0;
>>>>>>>>>>          unsigned long gpu_freq;
>>>>>>>>>>          int ret = 0;
>>>>>>>>>>      @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu
>>>>>>>>>> *gpu,
>>>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>>>              if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>>>>>>>>                  break;
>>>>>>>>>>      +    /* If enabled, find the corresponding DDR bandwidth
>>>>>>>>>> index */
>>>>>>>>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>>>>>>>>
>>>>>>>>> if (gmu->nr_gpu_bws)
>>>>>>>>
>>>>>>>> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the
>>>>>>>> "off" state)
>>>>>>>>
>>>>>>>>>
>>>>>>>>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>>>>>>>>> +
>>>>>>>>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1;
>>>>>>>>>> bw_index+
>>>>>>>>>> +) {
>>>>>>>>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>>>>>>>>> +                break;
>>>>>>>>>> +        }
>>>>>>>>>> +
>>>>>>>>>> +        /* Vote AB as a fraction of the max bandwidth */
>>>>>>>>>> +        if (bw) {
>>>>>>>>>
>>>>>>>>> This seems to only be introduced with certain a7xx too.. you should
>>>>>>>>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported
>>>>>>>>
>>>>>>>> Good point
>>>>>>>
>>>>>>> No no. Doing this will trigger some assert in pre-A750 gmu
>>>>>>> firmwares. We
>>>>>>> learned it the hard way. No improvisation please. :)
>>>>>>
>>>>>> We shouldn't be sending that AB data to firmware that doesn't expect
>>>>>> it either too, though..
>>>>>
>>>>> Well we don't !
>>>>
>>>> The code in the scope that I quoted above does that
>>>
>>> No it doesn't, if the proper bcms are not declared in the gpu_info, it
>>> won't
>>
>> I think what Konrad meant was that IB voting is supported from a650+,
>> but AB voting is support only from a750+. So we can add bcm nodes to
>> enable IB voting, but how do we ensure AB voting via GMU is done only on
>> a750+.
> 
> Yep, relying on incomplete data in the catalog is not a great way
> to ensure that

I understood correctly, so I'll add a bool to enable AB voting, but please
don't ask me to remove it because it's dead code and useless if only
enabled on a750+...

Neil

> 
> Konrad

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[Akhil P Oommen]

On 12/16/2024 3:13 PM, neil.armstrong@linaro.org wrote:
> On 14/12/2024 00:46, Konrad Dybcio wrote:
>> On 13.12.2024 5:55 PM, Akhil P Oommen wrote:
>>> On 12/13/2024 10:10 PM, neil.armstrong@linaro.org wrote:
>>>> On 13/12/2024 17:31, Konrad Dybcio wrote:
>>>>> On 13.12.2024 5:28 PM, neil.armstrong@linaro.org wrote:
>>>>>> On 13/12/2024 16:37, Konrad Dybcio wrote:
>>>>>>> On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
>>>>>>>> On 12/13/2024 3:07 AM, Neil Armstrong wrote:
>>>>>>>>> On 12/12/2024 21:21, Konrad Dybcio wrote:
>>>>>>>>>> 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, until now we left
>>>>>>>>>>> the OPP
>>>>>>>>>>> core scale the OPP bandwidth via the interconnect path.
>>>>>>>>>>>
>>>>>>>>>>> In order to enable bandwidth voting via the GPU Management
>>>>>>>>>>> Unit (GMU), when an opp is set by devfreq we also look for
>>>>>>>>>>> the corresponding bandwidth index in the previously generated
>>>>>>>>>>> bw_table and pass this value along the frequency index to the
>>>>>>>>>>> GMU.
>>>>>>>>>>>
>>>>>>>>>>> The GMU also takes another vote called AB which is a 16bit
>>>>>>>>>>> quantized
>>>>>>>>>>> value of the floor bandwidth against the maximum supported
>>>>>>>>>>> bandwidth.
>>>>>>>>>>>
>>>>>>>>>>> The AB is calculated with a default 25% of the bandwidth like
>>>>>>>>>>> the
>>>>>>>>>>> downstream implementation too inform the GMU firmware the
>>>>>>>>>>> minimal
>>>>>>>>>>> quantity of bandwidth we require for this OPP.
>>>>>>>>>>>
>>>>>>>>>>> Since we now vote for all resources via the GMU, setting the OPP
>>>>>>>>>>> is no more needed, so we can completely skip calling
>>>>>>>>>>> dev_pm_opp_set_opp() in this situation.
>>>>>>>>>>>
>>>>>>>>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>>>>>>>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>>>>>>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>>>>>>>> ---
>>>>>>>>>>>      drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 +++++++++++++
>>>>>>>>>>> ++++
>>>>>>>>>>> +++++++
>>>>>>>>>>> +++++++++--
>>>>>>>>>>>      drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>>>>>>>>>      drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>>>>>>>>>      drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>>>>>>>>>      4 files changed, 46 insertions(+), 6 deletions(-)
>>>>>>>>>>>
>>>>>>>>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/
>>>>>>>>>>> gpu/drm/
>>>>>>>>>>> msm/adreno/a6xx_gmu.c
>>>>>>>>>>> index
>>>>>>>>>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>>>>>>>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>>>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>>>>                     bool suspended)
>>>>>>>>>>>      {
>>>>>>>>>>>          struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>>>>>>>>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>>>>>>>>>          struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>>>>>>>>>          struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>>>>>>>>>          u32 perf_index;
>>>>>>>>>>> +    u32 bw_index = 0;
>>>>>>>>>>>          unsigned long gpu_freq;
>>>>>>>>>>>          int ret = 0;
>>>>>>>>>>>      @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu
>>>>>>>>>>> *gpu,
>>>>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>>>>              if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>>>>>>>>>                  break;
>>>>>>>>>>>      +    /* If enabled, find the corresponding DDR bandwidth
>>>>>>>>>>> index */
>>>>>>>>>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>>>>>>>>>
>>>>>>>>>> if (gmu->nr_gpu_bws)
>>>>>>>>>
>>>>>>>>> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0
>>>>>>>>> is the
>>>>>>>>> "off" state)
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>>>>>>>>>> +
>>>>>>>>>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1;
>>>>>>>>>>> bw_index+
>>>>>>>>>>> +) {
>>>>>>>>>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>>>>>>>>>> +                break;
>>>>>>>>>>> +        }
>>>>>>>>>>> +
>>>>>>>>>>> +        /* Vote AB as a fraction of the max bandwidth */
>>>>>>>>>>> +        if (bw) {
>>>>>>>>>>
>>>>>>>>>> This seems to only be introduced with certain a7xx too.. you
>>>>>>>>>> should
>>>>>>>>>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's
>>>>>>>>>> supported
>>>>>>>>>
>>>>>>>>> Good point
>>>>>>>>
>>>>>>>> No no. Doing this will trigger some assert in pre-A750 gmu
>>>>>>>> firmwares. We
>>>>>>>> learned it the hard way. No improvisation please. :)
>>>>>>>
>>>>>>> We shouldn't be sending that AB data to firmware that doesn't expect
>>>>>>> it either too, though..
>>>>>>
>>>>>> Well we don't !
>>>>>
>>>>> The code in the scope that I quoted above does that
>>>>
>>>> No it doesn't, if the proper bcms are not declared in the gpu_info, it
>>>> won't
>>>
>>> I think what Konrad meant was that IB voting is supported from a650+,
>>> but AB voting is support only from a750+. So we can add bcm nodes to
>>> enable IB voting, but how do we ensure AB voting via GMU is done only on
>>> a750+.
>>
>> Yep, relying on incomplete data in the catalog is not a great way
>> to ensure that
> 
> I understood correctly, so I'll add a bool to enable AB voting, but please
> don't ask me to remove it because it's dead code and useless if only
> enabled on a750+...

Can't we just add ">= A7XX_GEN3" check here to decide on GMU AB VOTE?
For older generation, AB vote should be via icc driver. And that I guess
is out of the scope of this series.

-Akhil.

> 
> Neil
> 
>>
>> Konrad
> 

Re: [PATCH v5 4/7] drm/msm: adreno: find bandwidth index of OPP and set it along freq index

[neil.armstrong]

On 16/12/2024 11:40, Akhil P Oommen wrote:
> On 12/16/2024 3:13 PM, neil.armstrong@linaro.org wrote:
>> On 14/12/2024 00:46, Konrad Dybcio wrote:
>>> On 13.12.2024 5:55 PM, Akhil P Oommen wrote:
>>>> On 12/13/2024 10:10 PM, neil.armstrong@linaro.org wrote:
>>>>> On 13/12/2024 17:31, Konrad Dybcio wrote:
>>>>>> On 13.12.2024 5:28 PM, neil.armstrong@linaro.org wrote:
>>>>>>> On 13/12/2024 16:37, Konrad Dybcio wrote:
>>>>>>>> On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
>>>>>>>>> On 12/13/2024 3:07 AM, Neil Armstrong wrote:
>>>>>>>>>> On 12/12/2024 21:21, Konrad Dybcio wrote:
>>>>>>>>>>> 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, until now we left
>>>>>>>>>>>> the OPP
>>>>>>>>>>>> core scale the OPP bandwidth via the interconnect path.
>>>>>>>>>>>>
>>>>>>>>>>>> In order to enable bandwidth voting via the GPU Management
>>>>>>>>>>>> Unit (GMU), when an opp is set by devfreq we also look for
>>>>>>>>>>>> the corresponding bandwidth index in the previously generated
>>>>>>>>>>>> bw_table and pass this value along the frequency index to the
>>>>>>>>>>>> GMU.
>>>>>>>>>>>>
>>>>>>>>>>>> The GMU also takes another vote called AB which is a 16bit
>>>>>>>>>>>> quantized
>>>>>>>>>>>> value of the floor bandwidth against the maximum supported
>>>>>>>>>>>> bandwidth.
>>>>>>>>>>>>
>>>>>>>>>>>> The AB is calculated with a default 25% of the bandwidth like
>>>>>>>>>>>> the
>>>>>>>>>>>> downstream implementation too inform the GMU firmware the
>>>>>>>>>>>> minimal
>>>>>>>>>>>> quantity of bandwidth we require for this OPP.
>>>>>>>>>>>>
>>>>>>>>>>>> Since we now vote for all resources via the GMU, setting the OPP
>>>>>>>>>>>> is no more needed, so we can completely skip calling
>>>>>>>>>>>> dev_pm_opp_set_opp() in this situation.
>>>>>>>>>>>>
>>>>>>>>>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>>>>>>>>>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>>>>>>>>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>>>>>>>>> ---
>>>>>>>>>>>>       drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 +++++++++++++
>>>>>>>>>>>> ++++
>>>>>>>>>>>> +++++++
>>>>>>>>>>>> +++++++++--
>>>>>>>>>>>>       drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  2 +-
>>>>>>>>>>>>       drivers/gpu/drm/msm/adreno/a6xx_hfi.c |  6 +++---
>>>>>>>>>>>>       drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
>>>>>>>>>>>>       4 files changed, 46 insertions(+), 6 deletions(-)
>>>>>>>>>>>>
>>>>>>>>>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/
>>>>>>>>>>>> gpu/drm/
>>>>>>>>>>>> msm/adreno/a6xx_gmu.c
>>>>>>>>>>>> index
>>>>>>>>>>>> 36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
>>>>>>>>>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>>>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>>>>>>>>>>>> @@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
>>>>>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>>>>>                      bool suspended)
>>>>>>>>>>>>       {
>>>>>>>>>>>>           struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>>>>>>>>>>>> +    const struct a6xx_info *info = adreno_gpu->info->a6xx;
>>>>>>>>>>>>           struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>>>>>>>>>>           struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>>>>>>>>>>           u32 perf_index;
>>>>>>>>>>>> +    u32 bw_index = 0;
>>>>>>>>>>>>           unsigned long gpu_freq;
>>>>>>>>>>>>           int ret = 0;
>>>>>>>>>>>>       @@ -125,6 +127,37 @@ void a6xx_gmu_set_freq(struct msm_gpu
>>>>>>>>>>>> *gpu,
>>>>>>>>>>>> struct dev_pm_opp *opp,
>>>>>>>>>>>>               if (gpu_freq == gmu->gpu_freqs[perf_index])
>>>>>>>>>>>>                   break;
>>>>>>>>>>>>       +    /* If enabled, find the corresponding DDR bandwidth
>>>>>>>>>>>> index */
>>>>>>>>>>>> +    if (info->bcms && gmu->nr_gpu_bws > 1) {
>>>>>>>>>>>
>>>>>>>>>>> if (gmu->nr_gpu_bws)
>>>>>>>>>>
>>>>>>>>>> gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0
>>>>>>>>>> is the
>>>>>>>>>> "off" state)
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>> +        unsigned int bw = dev_pm_opp_get_bw(opp, true, 0);
>>>>>>>>>>>> +
>>>>>>>>>>>> +        for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1;
>>>>>>>>>>>> bw_index+
>>>>>>>>>>>> +) {
>>>>>>>>>>>> +            if (bw == gmu->gpu_bw_table[bw_index])
>>>>>>>>>>>> +                break;
>>>>>>>>>>>> +        }
>>>>>>>>>>>> +
>>>>>>>>>>>> +        /* Vote AB as a fraction of the max bandwidth */
>>>>>>>>>>>> +        if (bw) {
>>>>>>>>>>>
>>>>>>>>>>> This seems to only be introduced with certain a7xx too.. you
>>>>>>>>>>> should
>>>>>>>>>>> ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's
>>>>>>>>>>> supported
>>>>>>>>>>
>>>>>>>>>> Good point
>>>>>>>>>
>>>>>>>>> No no. Doing this will trigger some assert in pre-A750 gmu
>>>>>>>>> firmwares. We
>>>>>>>>> learned it the hard way. No improvisation please. :)
>>>>>>>>
>>>>>>>> We shouldn't be sending that AB data to firmware that doesn't expect
>>>>>>>> it either too, though..
>>>>>>>
>>>>>>> Well we don't !
>>>>>>
>>>>>> The code in the scope that I quoted above does that
>>>>>
>>>>> No it doesn't, if the proper bcms are not declared in the gpu_info, it
>>>>> won't
>>>>
>>>> I think what Konrad meant was that IB voting is supported from a650+,
>>>> but AB voting is support only from a750+. So we can add bcm nodes to
>>>> enable IB voting, but how do we ensure AB voting via GMU is done only on
>>>> a750+.
>>>
>>> Yep, relying on incomplete data in the catalog is not a great way
>>> to ensure that
>>
>> I understood correctly, so I'll add a bool to enable AB voting, but please
>> don't ask me to remove it because it's dead code and useless if only
>> enabled on a750+...
> 
> Can't we just add ">= A7XX_GEN3" check here to decide on GMU AB VOTE?
> For older generation, AB vote should be via icc driver. And that I guess
> is out of the scope of this series.

Sure, I'll do that.

Thanks,
Neil

> 
> -Akhil.
> 
>>
>> Neil
>>
>>>
>>> Konrad
>>
>