pm_rps: Add load helper for loading gpu

The load helper submits repeated dword store commands to keep the
gpu loaded while subtests running in the parent process check for
expected rps response.

Signed-off-by: Jeff McGee <jeff.mcgee@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 137 insertions, 3 deletions

diff --git a/tests/pm_rps.c b/tests/pm_rps.c
index dabc2ba5..555bb7c4 100644
--- a/tests/pm_rps.c
+++ b/tests/pm_rps.c
@@ -33,9 +33,14 @@
 #include <unistd.h>
 #include <getopt.h>
 #include "drmtest.h"
+#include "intel_gpu_tools.h"
+#include "intel_bufmgr.h"
+#include "intel_batchbuffer.h"
 
 static bool verbose = false;
 
+static int drm_fd;
+
 static const char sysfs_base_path[] = "/sys/class/drm/card%d/gt_%s_freq_mhz";
 enum {
 	CUR,
@@ -137,6 +142,131 @@ static void dumpit(const int *freqs)
 #define dump(x) if (verbose) dumpit(x)
 #define log(...) if (verbose) printf(__VA_ARGS__)
 
+static struct load_helper {
+	int devid;
+	int has_ppgtt;
+	drm_intel_bufmgr *bufmgr;
+	struct intel_batchbuffer *batch;
+	drm_intel_bo *target_buffer;
+	bool ready;
+	bool exit;
+	struct igt_helper_process igt_proc;
+} lh;
+
+static void load_helper_signal_handler(int sig)
+{
+	lh.exit = true;
+}
+
+static void emit_store_dword_imm(uint32_t val)
+{
+	int cmd;
+	struct intel_batchbuffer *batch = lh.batch;
+
+	cmd = MI_STORE_DWORD_IMM;
+	if (!lh.has_ppgtt)
+		cmd |= MI_MEM_VIRTUAL;
+
+	if (intel_gen(lh.devid) >= 8) {
+		BEGIN_BATCH(4);
+		OUT_BATCH(cmd);
+		OUT_RELOC(lh.target_buffer, I915_GEM_DOMAIN_INSTRUCTION,
+			  I915_GEM_DOMAIN_INSTRUCTION, 0);
+		OUT_BATCH(0);
+		OUT_BATCH(val);
+		ADVANCE_BATCH();
+	} else {
+		BEGIN_BATCH(4);
+		OUT_BATCH(cmd);
+		OUT_BATCH(0); /* reserved */
+		OUT_RELOC(lh.target_buffer, I915_GEM_DOMAIN_INSTRUCTION,
+			  I915_GEM_DOMAIN_INSTRUCTION, 0);
+		OUT_BATCH(val);
+		ADVANCE_BATCH();
+	}
+}
+
+static void load_helper_run(void)
+{
+	assert(!lh.igt_proc.running);
+
+	igt_require(lh.ready == true);
+
+	igt_fork_helper(&lh.igt_proc) {
+		uint32_t val = 0;
+
+		signal(SIGUSR1, load_helper_signal_handler);
+
+		while (!lh.exit) {
+			emit_store_dword_imm(val);
+			intel_batchbuffer_flush_on_ring(lh.batch, 0);
+			val++;
+		}
+
+		log("load helper sent %u dword writes\n", val);
+	}
+}
+
+static void load_helper_stop(void)
+{
+	assert(lh.igt_proc.running);
+	kill(lh.igt_proc.pid, SIGUSR1);
+	igt_wait_helper(&lh.igt_proc);
+}
+
+/* The load helper resource is used by only some subtests. We attempt to
+ * initialize in igt_fixture but do our igt_require check only if a
+ * subtest attempts to run it */
+static void load_helper_init(void)
+{
+	lh.devid = intel_get_drm_devid(drm_fd);
+	lh.has_ppgtt = gem_uses_aliasing_ppgtt(drm_fd);
+
+	/* MI_STORE_DATA can only use GTT address on gen4+/g33 and needs
+	 * snoopable mem on pre-gen6. */
+	if (intel_gen(lh.devid) < 6) {
+		log("load helper init failed: pre-gen6 not supported\n");
+		return;
+	}
+
+	lh.bufmgr = drm_intel_bufmgr_gem_init(drm_fd, 4096);
+	if (!lh.bufmgr) {
+		log("load helper init failed: buffer manager init\n");
+		return;
+	}
+	drm_intel_bufmgr_gem_enable_reuse(lh.bufmgr);
+
+	lh.batch = intel_batchbuffer_alloc(lh.bufmgr, lh.devid);
+	if (!lh.batch) {
+		log("load helper init failed: batch buffer alloc\n");
+		return;
+	}
+
+	lh.target_buffer = drm_intel_bo_alloc(lh.bufmgr, "target bo",
+					      4096, 4096);
+	if (!lh.target_buffer) {
+		log("load helper init failed: target buffer alloc\n");
+		return;
+	}
+
+	lh.ready = true;
+}
+
+static void load_helper_deinit(void)
+{
+	if (lh.igt_proc.running)
+		load_helper_stop();
+
+	if (lh.target_buffer)
+		drm_intel_bo_unreference(lh.target_buffer);
+
+	if (lh.batch)
+		intel_batchbuffer_free(lh.batch);
+
+	if (lh.bufmgr)
+		drm_intel_bufmgr_destroy(lh.bufmgr);
+}
+
 static void min_max_config(void (*check)(void))
 {
 	int fmid = (origfreqs[RPn] + origfreqs[RP0]) / 2;
@@ -250,6 +380,9 @@ static void pm_rps_exit_handler(int sig)
 		writeval(stuff[MIN].filp, origfreqs[MIN]);
 		writeval(stuff[MAX].filp, origfreqs[MAX]);
 	}
+
+	load_helper_deinit();
+	close(drm_fd);
 }
 
 static int opt_handler(int opt, int opt_index)
@@ -291,11 +424,10 @@ int main(int argc, char **argv)
 	igt_fixture {
 		const int device = drm_get_card();
 		struct junk *junk = stuff;
-		int fd, ret;
+		int ret;
 
 		/* Use drm_open_any to verify device existence */
-		fd = drm_open_any();
-		close(fd);
+		drm_fd = drm_open_any();
 
 		do {
 			int val = -1;
@@ -314,6 +446,8 @@ int main(int argc, char **argv)
 		read_freqs(origfreqs);
 
 		igt_install_exit_handler(pm_rps_exit_handler);
+
+		load_helper_init();
 	}
 
 	igt_subtest("basic-api")