[PATCH v2 06/11] drm/msm: adreno: dynamically generate GMU bw table

Neil Armstrong neil.armstrong at linaro.org
Tue Nov 19 17:56:41 UTC 2024


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 entried 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 at linaro.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_hfi.c | 39 ++++++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
index cb8844ed46b29c4569d05eb7a24f7b27e173190f..0c8aa9f8cabe1d9cb20445a4274b728236a99fad 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
@@ -621,6 +621,36 @@ static void a740_build_bw_table(struct a6xx_hfi_msg_bw_table *msg)
 	msg->cnoc_cmds_data[1][0] = 0x60000001;
 }
 
+static void a740_generate_bw_table(struct adreno_gpu *adreno_gpu, struct a6xx_gmu *gmu,
+				   struct a6xx_hfi_msg_bw_table *msg)
+{
+	const struct a6xx_info *info = adreno_gpu->info->a6xx;
+	unsigned int i, j;
+
+	msg->ddr_wait_bitmask = 0x7;
+
+	for (i = 0; i < 3; i++) {
+		if (!info->bcm[i].name)
+			break;
+		msg->ddr_cmds_addrs[i] = cmd_db_read_addr(info->bcm[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_bw_votes[i][j];
+	msg->bw_level_num = gmu->nr_gpu_bws;
+
+	/* TODO also generate CNOC commands */
+
+	msg->cnoc_cmds_num = 1;
+	msg->cnoc_wait_bitmask = 0x1;
+
+	msg->cnoc_cmds_addrs[0] = cmd_db_read_addr("CN0");
+	msg->cnoc_cmds_data[0][0] = 0x40000000;
+	msg->cnoc_cmds_data[1][0] = 0x60000001;
+}
+
 static void a6xx_build_bw_table(struct a6xx_hfi_msg_bw_table *msg)
 {
 	/* Send a single "off" entry since the 630 GMU doesn't do bus scaling */
@@ -690,9 +720,12 @@ static int a6xx_hfi_send_bw_table(struct a6xx_gmu *gmu)
 		a690_build_bw_table(msg);
 	else if (adreno_is_a730(adreno_gpu))
 		a730_build_bw_table(msg);
-	else if (adreno_is_a740_family(adreno_gpu))
-		a740_build_bw_table(msg);
-	else
+	else if (adreno_is_a740_family(adreno_gpu)) {
+		if ((adreno_gpu->info->features & ADRENO_FEAT_GMU_BW_VOTE) && gmu->nr_gpu_bws)
+			a740_generate_bw_table(adreno_gpu, gmu, msg);
+		else
+			a740_build_bw_table(msg);
+	} else
 		a6xx_build_bw_table(msg);
 
 	gmu->bw_table = msg;

-- 
2.34.1



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