drm/etnaviv: implement IOMMUv2 translation

All other parts are now in place, so implement the actual translation
step and hook it up, so the driver claims support for cores with
the new MMU.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

3 files changed, 260 insertions, 4 deletions

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_iommu.h b/drivers/gpu/drm/etnaviv/etnaviv_iommu.h
index 4b6212999c1e..8b51e7c16feb 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_iommu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_iommu.h
@@ -17,11 +17,12 @@
 #ifndef __ETNAVIV_IOMMU_H__
 #define __ETNAVIV_IOMMU_H__
 
-#include <linux/iommu.h>
 struct etnaviv_gpu;
 
 struct iommu_domain *etnaviv_iommuv1_domain_alloc(struct etnaviv_gpu *gpu);
 void etnaviv_iommuv1_restore(struct etnaviv_gpu *gpu);
+
 struct iommu_domain *etnaviv_iommuv2_domain_alloc(struct etnaviv_gpu *gpu);
+void etnaviv_iommuv2_restore(struct etnaviv_gpu *gpu);
 
 #endif /* __ETNAVIV_IOMMU_H__ */
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c b/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
index 8c913c83ac5e..7e9c4d210a84 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014 Christian Gmeiner <christian.gmeiner@gmail.com>
+ * Copyright (C) 2016 Etnaviv Project
   *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
@@ -22,12 +22,267 @@
 #include <linux/bitops.h>
 
 #include "etnaviv_gpu.h"
+#include "etnaviv_mmu.h"
 #include "etnaviv_iommu.h"
+#include "state.xml.h"
 #include "state_hi.xml.h"
 
+#define MMUv2_PTE_PRESENT		BIT(0)
+#define MMUv2_PTE_EXCEPTION		BIT(1)
+#define MMUv2_PTE_WRITEABLE		BIT(2)
 
+#define MMUv2_MTLB_MASK			0xffc00000
+#define MMUv2_MTLB_SHIFT		22
+#define MMUv2_STLB_MASK			0x003ff000
+#define MMUv2_STLB_SHIFT		12
+
+#define MMUv2_MAX_STLB_ENTRIES		1024
+
+struct etnaviv_iommuv2_domain {
+	struct iommu_domain domain;
+	struct device *dev;
+	void *bad_page_cpu;
+	dma_addr_t bad_page_dma;
+	/* M(aster) TLB aka first level pagetable */
+	u32 *mtlb_cpu;
+	dma_addr_t mtlb_dma;
+	/* S(lave) TLB aka second level pagetable */
+	u32 *stlb_cpu[1024];
+	dma_addr_t stlb_dma[1024];
+};
+
+static struct etnaviv_iommuv2_domain *to_etnaviv_domain(struct iommu_domain *domain)
+{
+	return container_of(domain, struct etnaviv_iommuv2_domain, domain);
+}
+
+static int etnaviv_iommuv2_map(struct iommu_domain *domain, unsigned long iova,
+	   phys_addr_t paddr, size_t size, int prot)
+{
+	struct etnaviv_iommuv2_domain *etnaviv_domain =
+			to_etnaviv_domain(domain);
+	int mtlb_entry, stlb_entry;
+	u32 entry = (u32)paddr | MMUv2_PTE_PRESENT;
+
+	if (size != SZ_4K)
+		return -EINVAL;
+
+	if (prot & IOMMU_WRITE)
+		entry |= MMUv2_PTE_WRITEABLE;
+
+	mtlb_entry = (iova & MMUv2_MTLB_MASK) >> MMUv2_MTLB_SHIFT;
+	stlb_entry = (iova & MMUv2_STLB_MASK) >> MMUv2_STLB_SHIFT;
+
+	etnaviv_domain->stlb_cpu[mtlb_entry][stlb_entry] = entry;
+
+	return 0;
+}
+
+static size_t etnaviv_iommuv2_unmap(struct iommu_domain *domain,
+	unsigned long iova, size_t size)
+{
+	struct etnaviv_iommuv2_domain *etnaviv_domain =
+			to_etnaviv_domain(domain);
+	int mtlb_entry, stlb_entry;
+
+	if (size != SZ_4K)
+		return -EINVAL;
+
+	mtlb_entry = (iova & MMUv2_MTLB_MASK) >> MMUv2_MTLB_SHIFT;
+	stlb_entry = (iova & MMUv2_STLB_MASK) >> MMUv2_STLB_SHIFT;
+
+	etnaviv_domain->stlb_cpu[mtlb_entry][stlb_entry] = MMUv2_PTE_EXCEPTION;
+
+	return SZ_4K;
+}
+
+static phys_addr_t etnaviv_iommuv2_iova_to_phys(struct iommu_domain *domain,
+	dma_addr_t iova)
+{
+	struct etnaviv_iommuv2_domain *etnaviv_domain =
+			to_etnaviv_domain(domain);
+	int mtlb_entry, stlb_entry;
+
+	mtlb_entry = (iova & MMUv2_MTLB_MASK) >> MMUv2_MTLB_SHIFT;
+	stlb_entry = (iova & MMUv2_STLB_MASK) >> MMUv2_STLB_SHIFT;
+
+	return etnaviv_domain->stlb_cpu[mtlb_entry][stlb_entry] & ~(SZ_4K - 1);
+}
+
+static int etnaviv_iommuv2_init(struct etnaviv_iommuv2_domain *etnaviv_domain)
+{
+	u32 *p;
+	int ret, i, j;
+
+	/* allocate scratch page */
+	etnaviv_domain->bad_page_cpu = dma_alloc_coherent(etnaviv_domain->dev,
+						  SZ_4K,
+						  &etnaviv_domain->bad_page_dma,
+						  GFP_KERNEL);
+	if (!etnaviv_domain->bad_page_cpu) {
+		ret = -ENOMEM;
+		goto fail_mem;
+	}
+	p = etnaviv_domain->bad_page_cpu;
+	for (i = 0; i < SZ_4K / 4; i++)
+		*p++ = 0xdead55aa;
+
+	etnaviv_domain->mtlb_cpu = dma_alloc_coherent(etnaviv_domain->dev,
+						  SZ_4K,
+						  &etnaviv_domain->mtlb_dma,
+						  GFP_KERNEL);
+	if (!etnaviv_domain->mtlb_cpu) {
+		ret = -ENOMEM;
+		goto fail_mem;
+	}
+
+	/* pre-populate STLB pages (may want to switch to on-demand later) */
+	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++) {
+		etnaviv_domain->stlb_cpu[i] =
+				dma_alloc_coherent(etnaviv_domain->dev,
+						   SZ_4K,
+						   &etnaviv_domain->stlb_dma[i],
+						   GFP_KERNEL);
+		if (!etnaviv_domain->stlb_cpu[i]) {
+			ret = -ENOMEM;
+			goto fail_mem;
+		}
+		p = etnaviv_domain->stlb_cpu[i];
+		for (j = 0; j < SZ_4K / 4; j++)
+			*p++ = MMUv2_PTE_EXCEPTION;
+
+		etnaviv_domain->mtlb_cpu[i] = etnaviv_domain->stlb_dma[i] |
+					      MMUv2_PTE_PRESENT;
+	}
+
+	return 0;
+
+fail_mem:
+	if (etnaviv_domain->bad_page_cpu)
+		dma_free_coherent(etnaviv_domain->dev, SZ_4K,
+				  etnaviv_domain->bad_page_cpu,
+				  etnaviv_domain->bad_page_dma);
+
+	if (etnaviv_domain->mtlb_cpu)
+		dma_free_coherent(etnaviv_domain->dev, SZ_4K,
+				  etnaviv_domain->mtlb_cpu,
+				  etnaviv_domain->mtlb_dma);
+
+	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++) {
+		if (etnaviv_domain->stlb_cpu[i])
+			dma_free_coherent(etnaviv_domain->dev, SZ_4K,
+					  etnaviv_domain->stlb_cpu[i],
+					  etnaviv_domain->stlb_dma[i]);
+	}
+
+	return ret;
+}
+
+static void etnaviv_iommuv2_domain_free(struct iommu_domain *domain)
+{
+	struct etnaviv_iommuv2_domain *etnaviv_domain =
+			to_etnaviv_domain(domain);
+	int i;
+
+	dma_free_coherent(etnaviv_domain->dev, SZ_4K,
+			  etnaviv_domain->bad_page_cpu,
+			  etnaviv_domain->bad_page_dma);
+
+	dma_free_coherent(etnaviv_domain->dev, SZ_4K,
+			  etnaviv_domain->mtlb_cpu,
+			  etnaviv_domain->mtlb_dma);
+
+	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++) {
+		if (etnaviv_domain->stlb_cpu[i])
+			dma_free_coherent(etnaviv_domain->dev, SZ_4K,
+					  etnaviv_domain->stlb_cpu[i],
+					  etnaviv_domain->stlb_dma[i]);
+	}
+
+	vfree(etnaviv_domain);
+}
+
+static size_t etnaviv_iommuv2_dump_size(struct iommu_domain *domain)
+{
+	struct etnaviv_iommuv2_domain *etnaviv_domain =
+			to_etnaviv_domain(domain);
+	size_t dump_size = SZ_4K;
+	int i;
+
+	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++)
+		if (etnaviv_domain->mtlb_cpu[i] & MMUv2_PTE_PRESENT)
+			dump_size += SZ_4K;
+
+	return dump_size;
+}
+
+static void etnaviv_iommuv2_dump(struct iommu_domain *domain, void *buf)
+{
+	struct etnaviv_iommuv2_domain *etnaviv_domain =
+			to_etnaviv_domain(domain);
+	int i;
+
+	memcpy(buf, etnaviv_domain->mtlb_cpu, SZ_4K);
+	buf += SZ_4K;
+	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++, buf += SZ_4K)
+		if (etnaviv_domain->mtlb_cpu[i] & MMUv2_PTE_PRESENT)
+			memcpy(buf, etnaviv_domain->stlb_cpu[i], SZ_4K);
+}
+
+static struct etnaviv_iommu_ops etnaviv_iommu_ops = {
+	.ops = {
+		.domain_free = etnaviv_iommuv2_domain_free,
+		.map = etnaviv_iommuv2_map,
+		.unmap = etnaviv_iommuv2_unmap,
+		.iova_to_phys = etnaviv_iommuv2_iova_to_phys,
+		.pgsize_bitmap = SZ_4K,
+	},
+	.dump_size = etnaviv_iommuv2_dump_size,
+	.dump = etnaviv_iommuv2_dump,
+};
+
+void etnaviv_iommuv2_restore(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_CONTROL) & VIVS_MMUv2_CONTROL_ENABLE)
+		return;
+
+	prefetch = etnaviv_buffer_config_mmuv2(gpu,
+				(u32)etnaviv_domain->mtlb_dma,
+				(u32)etnaviv_domain->bad_page_dma);
+	etnaviv_gpu_start_fe(gpu, gpu->buffer->paddr, prefetch);
+	etnaviv_gpu_wait_idle(gpu, 100);
+
+	gpu_write(gpu, VIVS_MMUv2_CONTROL, VIVS_MMUv2_CONTROL_ENABLE);
+}
 struct iommu_domain *etnaviv_iommuv2_domain_alloc(struct etnaviv_gpu *gpu)
 {
-	/* TODO */
+	struct etnaviv_iommuv2_domain *etnaviv_domain;
+	int ret;
+
+	etnaviv_domain = vzalloc(sizeof(*etnaviv_domain));
+	if (!etnaviv_domain)
+		return NULL;
+
+	etnaviv_domain->dev = gpu->dev;
+
+	etnaviv_domain->domain.type = __IOMMU_DOMAIN_PAGING;
+	etnaviv_domain->domain.ops = &etnaviv_iommu_ops.ops;
+	etnaviv_domain->domain.pgsize_bitmap = SZ_4K;
+	etnaviv_domain->domain.geometry.aperture_start = 0;
+	etnaviv_domain->domain.geometry.aperture_end = ~0UL & ~(SZ_4K - 1);
+
+	ret = etnaviv_iommuv2_init(etnaviv_domain);
+	if (ret)
+		goto out_free;
+
+	return &etnaviv_domain->domain;
+
+out_free:
+	vfree(etnaviv_domain);
 	return NULL;
 }
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
index 98c84ef862c7..304c0b4a9d58 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
@@ -313,7 +313,7 @@ void etnaviv_iommu_restore(struct etnaviv_gpu *gpu)
 	if (gpu->mmu->version == ETNAVIV_IOMMU_V1)
 		etnaviv_iommuv1_restore(gpu);
 	else
-		dev_err(gpu->dev, "IOMMUv2 restore not implemented\n");
+		etnaviv_iommuv2_restore(gpu);
 }
 
 u32 etnaviv_iommu_get_cmdbuf_va(struct etnaviv_gpu *gpu,