From: Nils Wallménius <nils.wallmenius@gmail.com>
Date: Mon, 16 Jan 2017 20:56:48 +0000 (+0100)
Subject: drm/amdgpu: simplify allocation of scratch regs
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=50261151a13176a99ee6117dbbb2e557fd0b608b;p=linux.git

drm/amdgpu: simplify allocation of scratch regs

The scratch regs are sequential so there's no need to keep
them in an array, we can just return the index of the first
free register + the base register. Also change the array
of bools for keeping track of the free regs to a bitfield.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Nils Wallménius <nils.wallmenius@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index ffeda245f38ba..953148058bdba 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -794,8 +794,7 @@ struct amdgpu_kiq {
 struct amdgpu_scratch {
 	unsigned		num_reg;
 	uint32_t                reg_base;
-	bool			free[32];
-	uint32_t		reg[32];
+	uint32_t		free_mask;
 };
 
 /*
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index 01a42b6a69a4b..19943356cca77 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -42,12 +42,12 @@ int amdgpu_gfx_scratch_get(struct amdgpu_device *adev, uint32_t *reg)
 {
 	int i;
 
-	for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-		if (adev->gfx.scratch.free[i]) {
-			adev->gfx.scratch.free[i] = false;
-			*reg = adev->gfx.scratch.reg[i];
-			return 0;
-		}
+	i = ffs(adev->gfx.scratch.free_mask);
+	if (i != 0 && i <= adev->gfx.scratch.num_reg) {
+		i--;
+		adev->gfx.scratch.free_mask &= ~(1u << i);
+		*reg = adev->gfx.scratch.reg_base + i;
+		return 0;
 	}
 	return -EINVAL;
 }
@@ -62,14 +62,7 @@ int amdgpu_gfx_scratch_get(struct amdgpu_device *adev, uint32_t *reg)
  */
 void amdgpu_gfx_scratch_free(struct amdgpu_device *adev, uint32_t reg)
 {
-	int i;
-
-	for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-		if (adev->gfx.scratch.reg[i] == reg) {
-			adev->gfx.scratch.free[i] = true;
-			return;
-		}
-	}
+	adev->gfx.scratch.free_mask |= 1u << (reg - adev->gfx.scratch.reg_base);
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
index b323f5ef64d21..e0132436c76f7 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
@@ -1794,14 +1794,9 @@ static void gfx_v6_0_gpu_init(struct amdgpu_device *adev)
 
 static void gfx_v6_0_scratch_init(struct amdgpu_device *adev)
 {
-	int i;
-
 	adev->gfx.scratch.num_reg = 7;
 	adev->gfx.scratch.reg_base = mmSCRATCH_REG0;
-	for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-		adev->gfx.scratch.free[i] = true;
-		adev->gfx.scratch.reg[i] = adev->gfx.scratch.reg_base + i;
-	}
+	adev->gfx.scratch.free_mask = (1u << adev->gfx.scratch.num_reg) - 1;
 }
 
 static int gfx_v6_0_ring_test_ring(struct amdgpu_ring *ring)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
index c4e14015ec5be..cfed6db69b930 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
@@ -2003,14 +2003,9 @@ static void gfx_v7_0_gpu_init(struct amdgpu_device *adev)
  */
 static void gfx_v7_0_scratch_init(struct amdgpu_device *adev)
 {
-	int i;
-
 	adev->gfx.scratch.num_reg = 7;
 	adev->gfx.scratch.reg_base = mmSCRATCH_REG0;
-	for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-		adev->gfx.scratch.free[i] = true;
-		adev->gfx.scratch.reg[i] = adev->gfx.scratch.reg_base + i;
-	}
+	adev->gfx.scratch.free_mask = (1u << adev->gfx.scratch.num_reg) - 1;
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index c8c45ba952c82..69543d4eef343 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -749,14 +749,9 @@ static void gfx_v8_0_init_golden_registers(struct amdgpu_device *adev)
 
 static void gfx_v8_0_scratch_init(struct amdgpu_device *adev)
 {
-	int i;
-
 	adev->gfx.scratch.num_reg = 7;
 	adev->gfx.scratch.reg_base = mmSCRATCH_REG0;
-	for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-		adev->gfx.scratch.free[i] = true;
-		adev->gfx.scratch.reg[i] = adev->gfx.scratch.reg_base + i;
-	}
+	adev->gfx.scratch.free_mask = (1u << adev->gfx.scratch.num_reg) - 1;
 }
 
 static int gfx_v8_0_ring_test_ring(struct amdgpu_ring *ring)