[PATCH v1 02/10] drm/msm/a6xx: Send NMI to gmu when it is hung

[Akhil P Oommen]

While capturing gmu state, first send an NMI to gmu when it is hung.
This helps to move gmu to a safe state.

Signed-off-by: Akhil P Oommen <quic_akhi...@quicinc.com>
---

 drivers/gpu/drm/msm/adreno/a6xx_gmu.c       | 37 +++++++++++++++++++++++++++++
 drivers/gpu/drm/msm/adreno/a6xx_gmu.h       |  1 +
 drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c | 14 ++++++++++-
 3 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c 
b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 3e325e2..f208a81 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -14,6 +14,37 @@
 #include "msm_gpu_trace.h"
 #include "msm_mmu.h"
 
+void a6xx_gmu_send_nmi(struct a6xx_gmu *gmu)
+{
+       struct a6xx_gpu *a6xx_gpu = container_of(gmu, struct a6xx_gpu, gmu);
+       struct adreno_gpu *adreno_gpu = &a6xx_gpu->base;
+       struct msm_gpu *gpu = &adreno_gpu->base;
+       u32 val;
+
+       if (a6xx_gmu_gx_is_on(gmu) && a6xx_is_smmu_stalled(gpu)) {
+               DRM_DEV_ERROR(gmu->dev,
+                               "Skipping GMU NMI since SMMU is stalled\n");
+       }
+
+       /* Don't retrigger NMI if gmu reset is already active */
+       val = gmu_read(gmu, REG_A6XX_GMU_CM3_FW_INIT_RESULT);
+       if (val & 0xE00)
+               return;
+
+       /* Mask all interrupts from GMU first */
+       gmu_write(gmu, REG_A6XX_GMU_GMU2HOST_INTR_MASK, 0xFFFFFFFF);
+
+       /* Trigger NMI to make gmu save it's internal state to ddr */
+       val = gmu_read(gmu, REG_A6XX_GMU_CM3_CFG);
+       gmu_write(gmu, REG_A6XX_GMU_CM3_CFG, val | BIT(9));
+
+       /* Barrier to ensure write is posted before we proceed */
+       wmb();
+
+       /* Small delay to ensure state copy is ddr is complete at GMU */
+       udelay(200);
+}
+
 static void a6xx_gmu_fault(struct a6xx_gmu *gmu)
 {
        struct a6xx_gpu *a6xx_gpu = container_of(gmu, struct a6xx_gpu, gmu);
@@ -790,6 +821,12 @@ static int a6xx_gmu_fw_start(struct a6xx_gmu *gmu, 
unsigned int state)
        gmu_write(gmu, REG_A6XX_GMU_CM3_FW_INIT_RESULT, 0);
        gmu_write(gmu, REG_A6XX_GMU_CM3_BOOT_CONFIG, 0x02);
 
+       /*
+        * Make sure that the NMI bit is cleared by configuring the reset value
+        * here
+        */
+       gmu_write(gmu, REG_A6XX_GMU_CM3_CFG, 0x4052);
+
        /* Write the iova of the HFI table */
        gmu_write(gmu, REG_A6XX_GMU_HFI_QTBL_ADDR, gmu->hfi.iova);
        gmu_write(gmu, REG_A6XX_GMU_HFI_QTBL_INFO, 1);
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h 
b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
index 84bd516..4228ec1 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
@@ -186,5 +186,6 @@ int a6xx_hfi_set_freq(struct a6xx_gmu *gmu, int index);
 
 bool a6xx_gmu_gx_is_on(struct a6xx_gmu *gmu);
 bool a6xx_gmu_sptprac_is_on(struct a6xx_gmu *gmu);
+void a6xx_gmu_send_nmi(struct a6xx_gmu *gmu);
 
 #endif
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c 
b/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c
index 7de9d2f..09b2ff0 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c
@@ -964,6 +964,18 @@ static void a6xx_get_indexed_registers(struct msm_gpu *gpu,
        a6xx_state->nr_indexed_regs = count;
 }
 
+void a6xx_get_gmu_state(struct msm_gpu *gpu, struct a6xx_gpu_state *a6xx_state)
+{
+       struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+       struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
+       struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
+
+       if (gmu->hung)
+               a6xx_gmu_send_nmi(gmu);
+
+       a6xx_get_gmu_registers(gpu, a6xx_state);
+}
+
 struct msm_gpu_state *a6xx_gpu_state_get(struct msm_gpu *gpu)
 {
        struct a6xx_crashdumper _dumper = { 0 }, *dumper = NULL;
@@ -980,7 +992,7 @@ struct msm_gpu_state *a6xx_gpu_state_get(struct msm_gpu 
*gpu)
        /* Get the generic state from the adreno core */
        adreno_gpu_state_get(gpu, &a6xx_state->base);
 
-       a6xx_get_gmu_registers(gpu, a6xx_state);
+       a6xx_get_gmu_state(gpu, a6xx_state);
 
        a6xx_state->gmu_log = a6xx_snapshot_gmu_bo(a6xx_state, 
&a6xx_gpu->gmu.log);
        a6xx_state->gmu_hfi = a6xx_snapshot_gmu_bo(a6xx_state, 
&a6xx_gpu->gmu.hfi);
-- 
2.7.4