drm/amdgpu: Convert to common fdinfo format v5

Convert fdinfo format to one documented in drm-usage-stats.rst.

It turned out that the existing implementation was actually completely
nonsense. The calculated percentages indeed represented the usage of the
engine, but with varying time slices.

So 10% usage for application A could mean something completely different
than 10% usage for application B.

Completely nuke that and just use the now standardized nanosecond
interface.

v2: drop the documentation change for now, nuke percentage calculation
v3: only account for each hw_ip, move the time_spend to the ctx mgr.
v4: move general ctx changes into separate patch, rework the fdinfo to
    ctx_mgr interface so that all usages are calculated at once, drop
    some unecessary and dangerous refcount dance.
v5: add one more comment how we calculate the time spend

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Shashank Sharma <shashank.sharma@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 25 insertions, 32 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
index 5a6857c44bb6..4d453845235c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
@@ -32,6 +32,7 @@
 
 #include <drm/amdgpu_drm.h>
 #include <drm/drm_debugfs.h>
+#include <drm/drm_drv.h>
 
 #include "amdgpu.h"
 #include "amdgpu_vm.h"
@@ -54,26 +55,23 @@ static const char *amdgpu_ip_name[AMDGPU_HW_IP_NUM] = {
 
 void amdgpu_show_fdinfo(struct seq_file *m, struct file *f)
 {
-	struct amdgpu_fpriv *fpriv;
-	uint32_t bus, dev, fn, i, domain;
-	uint64_t vram_mem = 0, gtt_mem = 0, cpu_mem = 0;
 	struct drm_file *file = f->private_data;
 	struct amdgpu_device *adev = drm_to_adev(file->minor->dev);
+	struct amdgpu_fpriv *fpriv = file->driver_priv;
+
+	uint64_t vram_mem = 0, gtt_mem = 0, cpu_mem = 0;
+	ktime_t usage[AMDGPU_HW_IP_NUM];
+	uint32_t bus, dev, fn, domain;
 	struct amdgpu_bo *root;
+	unsigned int hw_ip;
 	int ret;
 
-	ret = amdgpu_file_to_fpriv(f, &fpriv);
-	if (ret)
-		return;
 	bus = adev->pdev->bus->number;
 	domain = pci_domain_nr(adev->pdev->bus);
 	dev = PCI_SLOT(adev->pdev->devfn);
 	fn = PCI_FUNC(adev->pdev->devfn);
 
-	root = amdgpu_bo_ref(fpriv->vm.root.bo);
-	if (!root)
-		return;
-
+	root = fpriv->vm.root.bo;
 	ret = amdgpu_bo_reserve(root, false);
 	if (ret) {
 		DRM_ERROR("Fail to reserve bo\n");
@@ -81,31 +79,26 @@ void amdgpu_show_fdinfo(struct seq_file *m, struct file *f)
 	}
 	amdgpu_vm_get_memory(&fpriv->vm, &vram_mem, &gtt_mem, &cpu_mem);
 	amdgpu_bo_unreserve(root);
-	amdgpu_bo_unref(&root);
 
-	seq_printf(m, "pdev:\t%04x:%02x:%02x.%d\npasid:\t%u\n", domain, bus,
-			dev, fn, fpriv->vm.pasid);
-	seq_printf(m, "vram mem:\t%llu kB\n", vram_mem/1024UL);
-	seq_printf(m, "gtt mem:\t%llu kB\n", gtt_mem/1024UL);
-	seq_printf(m, "cpu mem:\t%llu kB\n", cpu_mem/1024UL);
-	for (i = 0; i < AMDGPU_HW_IP_NUM; i++) {
-		uint32_t count = amdgpu_ctx_num_entities[i];
-		int idx = 0;
-		uint64_t total = 0, min = 0;
-		uint32_t perc, frac;
+	amdgpu_ctx_mgr_usage(&fpriv->ctx_mgr, usage);
 
-		for (idx = 0; idx < count; idx++) {
-			total = amdgpu_ctx_mgr_fence_usage(&fpriv->ctx_mgr,
-				i, idx, &min);
-			if ((total == 0) || (min == 0))
-				continue;
+	/*
+	 * ******************************************************************
+	 * For text output format description please see drm-usage-stats.rst!
+	 * ******************************************************************
+	 */
 
-			perc = div64_u64(10000 * total, min);
-			frac = perc % 100;
+	seq_printf(m, "pasid:\t%u\n", fpriv->vm.pasid);
+	seq_printf(m, "drm-driver:\t%s\n", file->minor->dev->driver->name);
+	seq_printf(m, "drm-pdev:\t%04x:%02x:%02x.%d\n", domain, bus, dev, fn);
+	seq_printf(m, "drm-memory-vram:\t%llu KiB\n", vram_mem/1024UL);
+	seq_printf(m, "drm-memory-gtt: \t%llu KiB\n", gtt_mem/1024UL);
+	seq_printf(m, "drm-memory-cpu: \t%llu KiB\n", cpu_mem/1024UL);
+	for (hw_ip = 0; hw_ip < AMDGPU_HW_IP_NUM; ++hw_ip) {
+		if (!usage[hw_ip])
+			continue;
 
-			seq_printf(m, "%s%d:\t%d.%d%%\n",
-					amdgpu_ip_name[i],
-					idx, perc/100, frac);
-		}
+		seq_printf(m, "drm-engine-%s:\t%Ld ns\n", amdgpu_ip_name[hw_ip],
+			   ktime_to_ns(usage[hw_ip]));
 	}
 }