[PATCH 10/10] drm/etnaviv: add PTA handling to MMUv2

[Lucas Stach]

The Page Table Array is a new first level structure above the MTLB
availabale on GPUs with the security feature. Use the PTa to set up
the MMU when the security related states are handled by the kernel driver.

Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
 drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c | 76 +++++++++++++++++++++++++++++-
 1 file changed, 75 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c b/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
index 1e956e266aa3..b57bdb6bc73f 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
@@ -40,6 +40,9 @@
 
 struct etnaviv_iommuv2_domain {
 	struct etnaviv_iommu_domain base;
+	/* P(age) T(able) A(rray) */
+	u64 *pta_cpu;
+	dma_addr_t pta_dma;
 	/* M(aster) TLB aka first level pagetable */
 	u32 *mtlb_cpu;
 	dma_addr_t mtlb_dma;
@@ -114,6 +117,15 @@ static int etnaviv_iommuv2_init(struct etnaviv_iommuv2_domain *etnaviv_domain)
 	for (i = 0; i < SZ_4K / 4; i++)
 		*p++ = 0xdead55aa;
 
+	etnaviv_domain->pta_cpu = dma_alloc_coherent(etnaviv_domain->base.dev,
+						     SZ_4K,
+						     &etnaviv_domain->pta_dma,
+						     GFP_KERNEL);
+	if (!etnaviv_domain->pta_cpu) {
+		ret = -ENOMEM;
+		goto fail_mem;
+	}
+
 	etnaviv_domain->mtlb_cpu = dma_alloc_coherent(etnaviv_domain->base.dev,
 						  SZ_4K,
 						  &etnaviv_domain->mtlb_dma,
@@ -150,6 +162,11 @@ static int etnaviv_iommuv2_init(struct etnaviv_iommuv2_domain *etnaviv_domain)
 				  etnaviv_domain->base.bad_page_cpu,
 				  etnaviv_domain->base.bad_page_dma);
 
+	if (etnaviv_domain->pta_cpu)
+		dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
+				  etnaviv_domain->pta_cpu,
+				  etnaviv_domain->pta_dma);
+
 	if (etnaviv_domain->mtlb_cpu)
 		dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
 				  etnaviv_domain->mtlb_cpu,
@@ -176,6 +193,10 @@ static void etnaviv_iommuv2_domain_free(struct etnaviv_iommu_domain *domain)
 			  etnaviv_domain->base.bad_page_dma);
 
 	dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
+			  etnaviv_domain->pta_cpu,
+			  etnaviv_domain->pta_dma);
+
+	dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
 			  etnaviv_domain->mtlb_cpu,
 			  etnaviv_domain->mtlb_dma);
 
@@ -216,7 +237,7 @@ static void etnaviv_iommuv2_dump(struct etnaviv_iommu_domain *domain, void *buf)
 			memcpy(buf, etnaviv_domain->stlb_cpu[i], SZ_4K);
 }
 
-void etnaviv_iommuv2_restore(struct etnaviv_gpu *gpu)
+static void etnaviv_iommuv2_restore_nonsec(struct etnaviv_gpu *gpu)
 {
 	struct etnaviv_iommuv2_domain *etnaviv_domain =
 			to_etnaviv_domain(gpu->mmu->domain);
@@ -236,6 +257,59 @@ void etnaviv_iommuv2_restore(struct etnaviv_gpu *gpu)
 	gpu_write(gpu, VIVS_MMUv2_CONTROL, VIVS_MMUv2_CONTROL_ENABLE);
 }
 
+static void etnaviv_iommuv2_restore_sec(struct etnaviv_gpu *gpu)
+{
+	struct etnaviv_iommuv2_domain *etnaviv_domain =
+				to_etnaviv_domain(gpu->mmu->domain);
+	u16 prefetch;
+
+	/* If the MMU is already enabled the state is still there. */
+	if (gpu_read(gpu, VIVS_MMUv2_SEC_CONTROL) & VIVS_MMUv2_SEC_CONTROL_ENABLE)
+		return;
+
+	gpu_write(gpu, VIVS_MMUv2_PTA_ADDRESS_LOW,
+		  lower_32_bits(etnaviv_domain->pta_dma));
+	gpu_write(gpu, VIVS_MMUv2_PTA_ADDRESS_HIGH,
+		  upper_32_bits(etnaviv_domain->pta_dma));
+	gpu_write(gpu, VIVS_MMUv2_PTA_CONTROL, VIVS_MMUv2_PTA_CONTROL_ENABLE);
+
+	gpu_write(gpu, VIVS_MMUv2_NONSEC_SAFE_ADDR_LOW,
+		  lower_32_bits(etnaviv_domain->base.bad_page_dma));
+	gpu_write(gpu, VIVS_MMUv2_SEC_SAFE_ADDR_LOW,
+		  lower_32_bits(etnaviv_domain->base.bad_page_dma));
+	gpu_write(gpu, VIVS_MMUv2_SAFE_ADDRESS_CONFIG,
+		  VIVS_MMUv2_SAFE_ADDRESS_CONFIG_NON_SEC_SAFE_ADDR_HIGH(
+		  upper_32_bits(etnaviv_domain->base.bad_page_dma)) |
+		  VIVS_MMUv2_SAFE_ADDRESS_CONFIG_SEC_SAFE_ADDR_HIGH(
+		  upper_32_bits(etnaviv_domain->base.bad_page_dma)));
+
+	etnaviv_domain->pta_cpu[0] = etnaviv_domain->mtlb_dma |
+				     VIVS_MMUv2_CONFIGURATION_MODE_MODE4_K;
+
+	/* trigger a PTA load through the FE */
+	prefetch = etnaviv_buffer_config_pta(gpu);
+	etnaviv_gpu_start_fe(gpu, (u32)etnaviv_cmdbuf_get_pa(&gpu->buffer),
+			     prefetch);
+	etnaviv_gpu_wait_idle(gpu, 100);
+
+	gpu_write(gpu, VIVS_MMUv2_SEC_CONTROL, VIVS_MMUv2_SEC_CONTROL_ENABLE);
+}
+
+void etnaviv_iommuv2_restore(struct etnaviv_gpu *gpu)
+{
+	switch (gpu->sec_mode) {
+	case ETNA_SEC_NONE:
+		etnaviv_iommuv2_restore_nonsec(gpu);
+		break;
+	case ETNA_SEC_KERNEL:
+		etnaviv_iommuv2_restore_sec(gpu);
+		break;
+	default:
+		WARN(1, "unhandled GPU security mode\n");
+		break;
+	}
+}
+
 const struct etnaviv_iommu_domain_ops etnaviv_iommuv2_ops = {
 	.free = etnaviv_iommuv2_domain_free,
 	.map = etnaviv_iommuv2_map,
-- 
2.11.0