From: Lucas Stach <l.st...@pengutronix.de>

commit 4900dda90af2cb13bc1d4c12ce94b98acc8fe64e upstream

If a MMU is shared between multiple GPUs, all of them need to flush their
TLBs, so a single marker that gets reset on the first flush won't do.
Replace the flush marker with a sequence number, so that it's possible to
check if the TLB is in sync with the current page table state for each GPU.

Signed-off-by: Lucas Stach <l.st...@pengutronix.de>
Reviewed-by: Philipp Zabel <p.za...@pengutronix.de>
Reviewed-by: Guido Günther <a...@sigxcpu.org>
Signed-off-by: Robert Beckett <bob.beck...@collabora.com>
---
 drivers/gpu/drm/etnaviv/etnaviv_buffer.c | 10 ++++++----
 drivers/gpu/drm/etnaviv/etnaviv_gpu.c    |  2 +-
 drivers/gpu/drm/etnaviv/etnaviv_gpu.h    |  1 +
 drivers/gpu/drm/etnaviv/etnaviv_mmu.c    |  6 +++---
 drivers/gpu/drm/etnaviv/etnaviv_mmu.h    |  2 +-
 5 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_buffer.c 
b/drivers/gpu/drm/etnaviv/etnaviv_buffer.c
index d9230132dfbc..d71fa2d9a196 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_buffer.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_buffer.c
@@ -257,6 +257,8 @@ void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, unsigned 
int event,
        unsigned int waitlink_offset = buffer->user_size - 16;
        u32 return_target, return_dwords;
        u32 link_target, link_dwords;
+       unsigned int new_flush_seq = READ_ONCE(gpu->mmu->flush_seq);
+       bool need_flush = gpu->flush_seq != new_flush_seq;
 
        if (drm_debug & DRM_UT_DRIVER)
                etnaviv_buffer_dump(gpu, buffer, 0, 0x50);
@@ -269,14 +271,14 @@ void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, 
unsigned int event,
         * need to append a mmu flush load state, followed by a new
         * link to this buffer - a total of four additional words.
         */
-       if (gpu->mmu->need_flush || gpu->switch_context) {
+       if (need_flush || gpu->switch_context) {
                u32 target, extra_dwords;
 
                /* link command */
                extra_dwords = 1;
 
                /* flush command */
-               if (gpu->mmu->need_flush) {
+               if (need_flush) {
                        if (gpu->mmu->version == ETNAVIV_IOMMU_V1)
                                extra_dwords += 1;
                        else
@@ -289,7 +291,7 @@ void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, unsigned 
int event,
 
                target = etnaviv_buffer_reserve(gpu, buffer, extra_dwords);
 
-               if (gpu->mmu->need_flush) {
+               if (need_flush) {
                        /* Add the MMU flush */
                        if (gpu->mmu->version == ETNAVIV_IOMMU_V1) {
                                CMD_LOAD_STATE(buffer, VIVS_GL_FLUSH_MMU,
@@ -309,7 +311,7 @@ void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, unsigned 
int event,
                                        SYNC_RECIPIENT_PE);
                        }
 
-                       gpu->mmu->need_flush = false;
+                       gpu->flush_seq = new_flush_seq;
                }
 
                if (gpu->switch_context) {
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c 
b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index a336754698f8..dba0d769d17a 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -1313,7 +1313,7 @@ int etnaviv_gpu_submit(struct etnaviv_gpu *gpu,
        gpu->active_fence = submit->fence;
 
        if (gpu->lastctx != cmdbuf->ctx) {
-               gpu->mmu->need_flush = true;
+               gpu->mmu->flush_seq++;
                gpu->switch_context = true;
                gpu->lastctx = cmdbuf->ctx;
        }
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h 
b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
index 73c278dc3706..416940b254a6 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
@@ -135,6 +135,7 @@ struct etnaviv_gpu {
        int irq;
 
        struct etnaviv_iommu *mmu;
+       unsigned int flush_seq;
 
        /* Power Control: */
        struct clk *clk_bus;
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c 
b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
index fe0e85b41310..ef9df6158dc1 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
@@ -134,7 +134,7 @@ static int etnaviv_iommu_find_iova(struct etnaviv_iommu 
*mmu,
                 */
                if (mmu->last_iova) {
                        mmu->last_iova = 0;
-                       mmu->need_flush = true;
+                       mmu->flush_seq++;
                        continue;
                }
 
@@ -197,7 +197,7 @@ static int etnaviv_iommu_find_iova(struct etnaviv_iommu 
*mmu,
                 * associated commit requesting this mapping, and retry the
                 * allocation one more time.
                 */
-               mmu->need_flush = true;
+               mmu->flush_seq++;
        }
 
        return ret;
@@ -354,7 +354,7 @@ u32 etnaviv_iommu_get_cmdbuf_va(struct etnaviv_gpu *gpu,
                 * that the FE MMU prefetch won't load invalid entries.
                 */
                mmu->last_iova = buf->vram_node.start + buf->size + SZ_64K;
-               gpu->mmu->need_flush = true;
+               mmu->flush_seq++;
                mutex_unlock(&mmu->lock);
 
                return (u32)buf->vram_node.start;
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.h 
b/drivers/gpu/drm/etnaviv/etnaviv_mmu.h
index e787e49c9693..5bdc5f5601b1 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.h
@@ -44,7 +44,7 @@ struct etnaviv_iommu {
        struct list_head mappings;
        struct drm_mm mm;
        u32 last_iova;
-       bool need_flush;
+       unsigned int flush_seq;
 };
 
 struct etnaviv_gem_object;
-- 
2.20.1

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