[PATCH v6 3/7] drm/msm: adreno: dynamically generate GMU bw table

Neil Armstrong neil.armstrong at linaro.org
Tue Dec 17 14:51:16 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 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 at 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



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