[PATCH i-g-t 5/5] tools/intel_display_bandwidth: Tool for measuring display memory bandwidth utilization

[Ville Syrjala <ville.syrjala@linux.intel.com>]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Introduce a small tool for measing the display enging
memory bandwidth utilization. Generally this is available
on SNB+, except on TGL/derivatives where the relevant
registers weren't updated to cope with the new ABOX layout
in the hardware.

Quite handy for confirming that FBC/CCS/etc. are doing their
job.

Not 100% sure about the required scaling factor because
bspec claims it's only needed for MTL, but my ADL definitely
needs it already.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 lib/intel_reg.h                 |   5 +
 tools/intel_display_bandwidth.c | 171 ++++++++++++++++++++++++++++++++
 tools/meson.build               |   1 +
 3 files changed, 177 insertions(+)
 create mode 100644 tools/intel_display_bandwidth.c

diff --git a/lib/intel_reg.h b/lib/intel_reg.h
index 26833c66f8e7..5e049d8b14d6 100644
--- a/lib/intel_reg.h
+++ b/lib/intel_reg.h
@@ -1413,6 +1413,11 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define PCH_3DRAMCGDIS0		0x46028
 #define SOUTH_DSPCLK_GATE_D	0xc2020
 
+#define DE_POWER1	0x42400
+#define DE_POWER2	0x42404
+#define DE_POWER2_ABOX0	0x42404
+#define DE_POWER2_ABOX1	0x42408
+
 #define CPU_eDP_A		0x64000
 #define PCH_DP_B		0xe4100
 #define PCH_DP_C		0xe4200
diff --git a/tools/intel_display_bandwidth.c b/tools/intel_display_bandwidth.c
new file mode 100644
index 000000000000..c7be3c390d08
--- /dev/null
+++ b/tools/intel_display_bandwidth.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+#include <getopt.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "intel_io.h"
+#include "intel_chipset.h"
+#include "intel_reg.h"
+
+static bool has_de_power2(uint32_t devid)
+{
+	/*
+	 * TGL has DE_POWER2 but it measures the low priority traffic
+	 * on ABOX, not not actual display traffic on ABOX0/ABOX1.
+	 */
+	if (intel_display_ver(devid) == 12)
+		return false;
+
+	return intel_display_ver(devid) >= 6 &&
+		!IS_VALLEYVIEW(devid) && !IS_CHERRYVIEW(devid);
+}
+
+static bool has_de_power2_abox0_abox1(uint32_t devid)
+{
+	/*
+	 * Despite having ABOX0/ABOX1 TGL lacks the
+	 * accompanying DE_POWER2_ABOX* registers.
+	 */
+	return intel_display_ver(devid) >= 13;
+}
+
+static int de_power2_scale(uint32_t devid)
+{
+	/*
+	 * FIXME should perhaps use something like
+	 * is_intel_dgfx() but that one wants to open the device :(
+	 */
+	switch (intel_display_ver(devid)) {
+	case 13:
+		return IS_DG2(devid) ? 1 : 2;
+	case 14:
+		return IS_BATTLEMAGE(devid) ? 1 : 2;
+	default:
+		return 1;
+	}
+}
+
+static int de_power2_unit(uint32_t devid)
+{
+	return 64 * de_power2_scale(devid);
+}
+
+static float bandwidth(uint32_t devid, int duration,
+		       uint32_t pre, uint32_t post)
+{
+	return (float)(post - pre) * de_power2_unit(devid) / (duration << 20);
+}
+
+static void measure_de_power2_abox0_abox1(uint32_t devid, unsigned int sleep_duration)
+{
+	uint32_t pre_abox0, post_abox0;
+	uint32_t pre_abox1, post_abox1;
+
+	pre_abox0 = INREG(DE_POWER2_ABOX0);
+	pre_abox1 = INREG(DE_POWER2_ABOX1);
+
+	if (sleep_duration) {
+		sleep(sleep_duration);
+
+		post_abox0 = INREG(DE_POWER2_ABOX0);
+		post_abox1 = INREG(DE_POWER2_ABOX1);
+
+		printf("DE_POWER2_ABOX0: 0x%08x->0x%08x\n",
+		       pre_abox0, post_abox0);
+		printf("DE_POWER2_ABOX1: 0x%08x->0x%08x\n",
+		       pre_abox1, post_abox1);
+
+		printf("ABOX0 bandwidth: %.2f MiB/s\n",
+		       bandwidth(devid, sleep_duration,
+				 pre_abox0, post_abox0));
+		printf("ABOX1 bandwidth: %.2f MiB/s\n",
+		       bandwidth(devid, sleep_duration,
+				 pre_abox1, post_abox1));
+		printf("Total bandwidth: %.2f MiB/s\n",
+		       bandwidth(devid, sleep_duration,
+				 pre_abox0 + pre_abox1, post_abox0 + post_abox1));
+	} else {
+		printf("DE_POWER2_ABOX0: 0x%08x\n", pre_abox0);
+		printf("DE_POWER2_ABOX1: 0x%08x\n", pre_abox1);
+	}
+}
+
+static void measure_de_power2(uint32_t devid, unsigned int sleep_duration)
+{
+	uint32_t pre, post;
+
+	pre = INREG(DE_POWER2);
+
+	if (sleep_duration) {
+		sleep(sleep_duration);
+
+		post = INREG(DE_POWER2);
+
+		printf("DE_POWER2: 0x%08x->0x%08x\n", pre, post);
+
+		printf("Total bandwidth: %.2f MiB/s\n",
+		       bandwidth(devid, sleep_duration, pre, post));
+	} else {
+		printf("DE_POWER2: 0x%08x\n", pre);
+	}
+}
+
+static void __attribute__((noreturn)) usage(const char *name)
+{
+	fprintf(stderr, "Usage: %s [options]\n"
+		" -s,--sleep <seconds>\n",
+		name);
+	exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+	struct intel_mmio_data mmio_data;
+	unsigned int sleep_duration = 0;
+	uint32_t devid;
+
+	for (;;) {
+		static const struct option long_options[] = {
+			{ .name = "sleep", .has_arg = required_argument, },
+			{}
+		};
+
+		int opt = getopt_long(argc, argv, "s:", long_options, NULL);
+		if (opt == -1)
+			break;
+
+		switch (opt) {
+		case 's':
+			sleep_duration = atoi(optarg);
+			break;
+		default:
+			usage(argv[0]);
+			break;
+		}
+	}
+
+	devid = intel_get_pci_device()->device_id;
+
+	if (!has_de_power2(devid)) {
+		fprintf(stderr, "Display bandwidth counter not available\n");
+		return 2;
+	}
+
+	intel_register_access_init(&mmio_data, intel_get_pci_device(), 0, -1);
+
+	if (has_de_power2_abox0_abox1(devid))
+		measure_de_power2_abox0_abox1(devid, sleep_duration);
+	else
+		measure_de_power2(devid, sleep_duration);
+
+	intel_register_access_fini(&mmio_data);
+
+	return 0;
+}
diff --git a/tools/meson.build b/tools/meson.build
index 48c9a4b5089e..4e9100ddb2b7 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -16,6 +16,7 @@ tools_progs = [
 	'intel_audio_dump',
 	'intel_backlight',
 	'intel_bios_dumper',
+	'intel_display_bandwidth',
 	'intel_display_crc',
 	'intel_display_poller',
 	'intel_dump_decode',
-- 
2.44.2