From 2b520c6104f34e3a548525173c38ebca4402cac3 Mon Sep 17 00:00:00 2001 From: Connor Abbott Date: Tue, 20 May 2025 18:28:06 -0400 Subject: [PATCH] drm/msm/a7xx: Call CP_RESET_CONTEXT_STATE Calling this packet is necessary when we switch contexts because there are various pieces of state used by userspace to synchronize between BR and BV that are persistent across submits and we need to make sure that they are in a "safe" state when switching contexts. Otherwise a userspace submission in one context could cause another context to function incorrectly and hang, effectively a denial of service (although without leaking data). This was missed during initial a7xx bringup. Fixes: af66706accdf ("drm/msm/a6xx: Add skeleton A7xx support") Signed-off-by: Connor Abbott Patchwork: https://patchwork.freedesktop.org/patch/654924/ Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c index a7ffd92de3bb..491fde0083a2 100644 --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c @@ -130,6 +130,20 @@ static void a6xx_set_pagetable(struct a6xx_gpu *a6xx_gpu, OUT_RING(ring, lower_32_bits(rbmemptr(ring, fence))); OUT_RING(ring, upper_32_bits(rbmemptr(ring, fence))); OUT_RING(ring, submit->seqno - 1); + + OUT_PKT7(ring, CP_THREAD_CONTROL, 1); + OUT_RING(ring, CP_SET_THREAD_BOTH); + + /* Reset state used to synchronize BR and BV */ + OUT_PKT7(ring, CP_RESET_CONTEXT_STATE, 1); + OUT_RING(ring, + CP_RESET_CONTEXT_STATE_0_CLEAR_ON_CHIP_TS | + CP_RESET_CONTEXT_STATE_0_CLEAR_RESOURCE_TABLE | + CP_RESET_CONTEXT_STATE_0_CLEAR_BV_BR_COUNTER | + CP_RESET_CONTEXT_STATE_0_RESET_GLOBAL_LOCAL_TS); + + OUT_PKT7(ring, CP_THREAD_CONTROL, 1); + OUT_RING(ring, CP_SET_THREAD_BR); } if (!sysprof) { -- 2.50.1