[PATCH] drm/amdgpu: refine kiq read register
Liu, Monk
Monk.Liu at amd.com
Fri Apr 17 07:01:23 UTC 2020
The change Looks good with me, you can put my RB to your patch .
Since this patch impact on general logic (not SRIOV only) I would like you wait a little longer for @Kuehling, Felix and @Deucher, Alexander and @Koenig, Christian @Zhang, Hawking
If any of them gave you a RB I think we can go this way
_____________________________________
Monk Liu|GPU Virtualization Team |AMD
-----Original Message-----
From: Yintian Tao <yttao at amd.com>
Sent: Friday, April 17, 2020 2:53 PM
To: Liu, Monk <Monk.Liu at amd.com>
Cc: amd-gfx at lists.freedesktop.org; Tao, Yintian <Yintian.Tao at amd.com>
Subject: [PATCH] drm/amdgpu: refine kiq read register
According to the current kiq read register method, there will be race condition when using KIQ to read register if multiple clients want to read at same time just like the expample below:
1. client-A start to read REG-0 throguh KIQ 2. client-A poll the seqno-0 3. client-B start to read REG-1 through KIQ 4. client-B poll the seqno-1 5. the kiq complete these two read operation 6. client-A to read the register at the wb buffer and
get REG-1 value
Therefore, directly make kiq write the register value at the ring buffer then there will be no race condition for the wb buffer.
v2: supply the read_clock and move the reg_val_offs back
Signed-off-by: Yintian Tao <yttao at amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 11 ++++------ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h | 1 - drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 5 +++--
drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 14 +++++-------
drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c | 14 +++++-------
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 28 ++++++++++++------------
6 files changed, 33 insertions(+), 40 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index ea576b4260a4..4e1c0239e561 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -304,10 +304,6 @@ int amdgpu_gfx_kiq_init_ring(struct amdgpu_device *adev,
spin_lock_init(&kiq->ring_lock);
- r = amdgpu_device_wb_get(adev, &kiq->reg_val_offs);
- if (r)
- return r;
-
ring->adev = NULL;
ring->ring_obj = NULL;
ring->use_doorbell = true;
@@ -331,7 +327,6 @@ int amdgpu_gfx_kiq_init_ring(struct amdgpu_device *adev,
void amdgpu_gfx_kiq_free_ring(struct amdgpu_ring *ring) {
- amdgpu_device_wb_free(ring->adev, ring->adev->gfx.kiq.reg_val_offs);
amdgpu_ring_fini(ring);
}
@@ -675,12 +670,14 @@ uint32_t amdgpu_kiq_rreg(struct amdgpu_device *adev, uint32_t reg)
uint32_t seq;
struct amdgpu_kiq *kiq = &adev->gfx.kiq;
struct amdgpu_ring *ring = &kiq->ring;
+ uint64_t reg_val_offs = 0;
BUG_ON(!ring->funcs->emit_rreg);
spin_lock_irqsave(&kiq->ring_lock, flags);
amdgpu_ring_alloc(ring, 32);
- amdgpu_ring_emit_rreg(ring, reg);
+ reg_val_offs = (ring->wptr & ring->buf_mask) + 30;
+ amdgpu_ring_emit_rreg(ring, reg, reg_val_offs);
amdgpu_fence_emit_polling(ring, &seq);
amdgpu_ring_commit(ring);
spin_unlock_irqrestore(&kiq->ring_lock, flags); @@ -707,7 +704,7 @@ uint32_t amdgpu_kiq_rreg(struct amdgpu_device *adev, uint32_t reg)
if (cnt > MAX_KIQ_REG_TRY)
goto failed_kiq_read;
- return adev->wb.wb[kiq->reg_val_offs];
+ return ring->ring[reg_val_offs];
failed_kiq_read:
pr_err("failed to read reg:%x\n", reg); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
index 634746829024..ee698f0246d8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
@@ -103,7 +103,6 @@ struct amdgpu_kiq {
struct amdgpu_ring ring;
struct amdgpu_irq_src irq;
const struct kiq_pm4_funcs *pmf;
- uint32_t reg_val_offs;
};
/*
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
index f61664ee4940..a3d88f2aa9f4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
@@ -181,7 +181,8 @@ struct amdgpu_ring_funcs {
void (*end_use)(struct amdgpu_ring *ring);
void (*emit_switch_buffer) (struct amdgpu_ring *ring);
void (*emit_cntxcntl) (struct amdgpu_ring *ring, uint32_t flags);
- void (*emit_rreg)(struct amdgpu_ring *ring, uint32_t reg);
+ void (*emit_rreg)(struct amdgpu_ring *ring, uint32_t reg,
+ uint64_t reg_val_offs);
void (*emit_wreg)(struct amdgpu_ring *ring, uint32_t reg, uint32_t val);
void (*emit_reg_wait)(struct amdgpu_ring *ring, uint32_t reg,
uint32_t val, uint32_t mask);
@@ -265,7 +266,7 @@ struct amdgpu_ring { #define amdgpu_ring_emit_hdp_flush(r) (r)->funcs->emit_hdp_flush((r)) #define amdgpu_ring_emit_switch_buffer(r) (r)->funcs->emit_switch_buffer((r))
#define amdgpu_ring_emit_cntxcntl(r, d) (r)->funcs->emit_cntxcntl((r), (d)) -#define amdgpu_ring_emit_rreg(r, d) (r)->funcs->emit_rreg((r), (d))
+#define amdgpu_ring_emit_rreg(r, d, o) (r)->funcs->emit_rreg((r), (d),
+(o))
#define amdgpu_ring_emit_wreg(r, d, v) (r)->funcs->emit_wreg((r), (d), (v)) #define amdgpu_ring_emit_reg_wait(r, d, v, m) (r)->funcs->emit_reg_wait((r), (d), (v), (m)) #define amdgpu_ring_emit_reg_write_reg_wait(r, d0, d1, v, m) (r)->funcs->emit_reg_write_reg_wait((r), (d0), (d1), (v), (m)) diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
index 0a03e2ad5d95..7c9a5e440509 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
@@ -7594,21 +7594,19 @@ static void gfx_v10_0_ring_emit_frame_cntl(struct amdgpu_ring *ring, bool start,
amdgpu_ring_write(ring, v | FRAME_CMD(start ? 0 : 1)); }
-static void gfx_v10_0_ring_emit_rreg(struct amdgpu_ring *ring, uint32_t reg)
+static void gfx_v10_0_ring_emit_rreg(struct amdgpu_ring *ring, uint32_t reg,
+ uint64_t reg_val_offs)
{
- struct amdgpu_device *adev = ring->adev;
- struct amdgpu_kiq *kiq = &adev->gfx.kiq;
-
amdgpu_ring_write(ring, PACKET3(PACKET3_COPY_DATA, 4));
amdgpu_ring_write(ring, 0 | /* src: register*/
(5 << 8) | /* dst: memory */
(1 << 20)); /* write confirm */
amdgpu_ring_write(ring, reg);
amdgpu_ring_write(ring, 0);
- amdgpu_ring_write(ring, lower_32_bits(adev->wb.gpu_addr +
- kiq->reg_val_offs * 4));
- amdgpu_ring_write(ring, upper_32_bits(adev->wb.gpu_addr +
- kiq->reg_val_offs * 4));
+ amdgpu_ring_write(ring, lower_32_bits(ring->gpu_addr +
+ reg_val_offs * 4));
+ amdgpu_ring_write(ring, upper_32_bits(ring->gpu_addr +
+ reg_val_offs * 4));
}
static void gfx_v10_0_ring_emit_wreg(struct amdgpu_ring *ring, uint32_t reg, diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index fc6c2f2bc76c..8e7eee7838e0 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -6383,21 +6383,19 @@ static void gfx_v8_0_ring_emit_patch_cond_exec(struct amdgpu_ring *ring, unsigne
ring->ring[offset] = (ring->ring_size >> 2) - offset + cur; }
-static void gfx_v8_0_ring_emit_rreg(struct amdgpu_ring *ring, uint32_t reg)
+static void gfx_v8_0_ring_emit_rreg(struct amdgpu_ring *ring, uint32_t reg,
+ uint64_t reg_val_offs)
{
- struct amdgpu_device *adev = ring->adev;
- struct amdgpu_kiq *kiq = &adev->gfx.kiq;
-
amdgpu_ring_write(ring, PACKET3(PACKET3_COPY_DATA, 4));
amdgpu_ring_write(ring, 0 | /* src: register*/
(5 << 8) | /* dst: memory */
(1 << 20)); /* write confirm */
amdgpu_ring_write(ring, reg);
amdgpu_ring_write(ring, 0);
- amdgpu_ring_write(ring, lower_32_bits(adev->wb.gpu_addr +
- kiq->reg_val_offs * 4));
- amdgpu_ring_write(ring, upper_32_bits(adev->wb.gpu_addr +
- kiq->reg_val_offs * 4));
+ amdgpu_ring_write(ring, lower_32_bits(ring->gpu_addr +
+ reg_val_offs * 4));
+ amdgpu_ring_write(ring, upper_32_bits(ring->gpu_addr +
+ reg_val_offs * 4));
}
static void gfx_v8_0_ring_emit_wreg(struct amdgpu_ring *ring, uint32_t reg, diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 84fcf842316d..ff279b1f5c24 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -4046,11 +4046,13 @@ static uint64_t gfx_v9_0_kiq_read_clock(struct amdgpu_device *adev)
uint32_t seq;
struct amdgpu_kiq *kiq = &adev->gfx.kiq;
struct amdgpu_ring *ring = &kiq->ring;
+ uint64_t reg_val_offs = 0;
BUG_ON(!ring->funcs->emit_rreg);
spin_lock_irqsave(&kiq->ring_lock, flags);
amdgpu_ring_alloc(ring, 32);
+ reg_val_offs = (ring->wptr & ring->buf_mask) + 30;
amdgpu_ring_write(ring, PACKET3(PACKET3_COPY_DATA, 4));
amdgpu_ring_write(ring, 9 | /* src: register*/
(5 << 8) | /* dst: memory */
@@ -4058,10 +4060,10 @@ static uint64_t gfx_v9_0_kiq_read_clock(struct amdgpu_device *adev)
(1 << 20)); /* write confirm */
amdgpu_ring_write(ring, 0);
amdgpu_ring_write(ring, 0);
- amdgpu_ring_write(ring, lower_32_bits(adev->wb.gpu_addr +
- kiq->reg_val_offs * 4));
- amdgpu_ring_write(ring, upper_32_bits(adev->wb.gpu_addr +
- kiq->reg_val_offs * 4));
+ amdgpu_ring_write(ring, lower_32_bits(ring->gpu_addr +
+ reg_val_offs * 4));
+ amdgpu_ring_write(ring, upper_32_bits(ring->gpu_addr +
+ reg_val_offs * 4));
amdgpu_fence_emit_polling(ring, &seq);
amdgpu_ring_commit(ring);
spin_unlock_irqrestore(&kiq->ring_lock, flags); @@ -4088,8 +4090,8 @@ static uint64_t gfx_v9_0_kiq_read_clock(struct amdgpu_device *adev)
if (cnt > MAX_KIQ_REG_TRY)
goto failed_kiq_read;
- return (uint64_t)adev->wb.wb[kiq->reg_val_offs] |
- (uint64_t)adev->wb.wb[kiq->reg_val_offs + 1 ] << 32ULL;
+ return (uint64_t)ring->ring[reg_val_offs] |
+ (uint64_t)ring->ring[reg_val_offs + 1 ] << 32ULL;
failed_kiq_read:
pr_err("failed to read gpu clock\n");
@@ -5482,21 +5484,19 @@ static void gfx_v9_0_ring_emit_patch_cond_exec(struct amdgpu_ring *ring, unsigne
ring->ring[offset] = (ring->ring_size>>2) - offset + cur; }
-static void gfx_v9_0_ring_emit_rreg(struct amdgpu_ring *ring, uint32_t reg)
+static void gfx_v9_0_ring_emit_rreg(struct amdgpu_ring *ring, uint32_t reg,
+ uint64_t reg_val_offs)
{
- struct amdgpu_device *adev = ring->adev;
- struct amdgpu_kiq *kiq = &adev->gfx.kiq;
-
amdgpu_ring_write(ring, PACKET3(PACKET3_COPY_DATA, 4));
amdgpu_ring_write(ring, 0 | /* src: register*/
(5 << 8) | /* dst: memory */
(1 << 20)); /* write confirm */
amdgpu_ring_write(ring, reg);
amdgpu_ring_write(ring, 0);
- amdgpu_ring_write(ring, lower_32_bits(adev->wb.gpu_addr +
- kiq->reg_val_offs * 4));
- amdgpu_ring_write(ring, upper_32_bits(adev->wb.gpu_addr +
- kiq->reg_val_offs * 4));
+ amdgpu_ring_write(ring, lower_32_bits(ring->gpu_addr +
+ reg_val_offs * 4));
+ amdgpu_ring_write(ring, upper_32_bits(ring->gpu_addr +
+ reg_val_offs * 4));
}
static void gfx_v9_0_ring_emit_wreg(struct amdgpu_ring *ring, uint32_t reg,
--
2.17.1
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