From: Thierry Reding <treding@xxxxxxxxxx>
When an IOMMU device is available on the platform bus, allocate an IOMMU
domain and attach the display controllers to it. The display controllers
can then scan out non-contiguous buffers by mapping them through the
IOMMU.
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
Changes in v5:
- fix PRIME export of physically non-contiguous buffers
- refactor and fix error cleanup paths
- fix checking for failed allocations
- fix build warnings on 64-bit
Changes in v4:
- error out if IOMMU attachment fails
Changes in v3:
- create write-combined mappings for mmap()
- keep non-IOMMU fallback path working
- no longer rely on iommu_attach()
Changes in v2:
- don't pass GFP_KERNEL to drm_gem_get_pages()
drivers/gpu/drm/tegra/dc.c | 17 +++
drivers/gpu/drm/tegra/drm.c | 18 +++
drivers/gpu/drm/tegra/drm.h | 5 +
drivers/gpu/drm/tegra/fb.c | 16 ++-
drivers/gpu/drm/tegra/gem.c | 277 ++++++++++++++++++++++++++++++++++++++------
drivers/gpu/drm/tegra/gem.h | 6 +
6 files changed, 302 insertions(+), 37 deletions(-)
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 4da366a4d78a..a1e7962ccbe2 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -9,6 +9,7 @@
#include <linux/clk.h>
#include <linux/debugfs.h>
+#include <linux/iommu.h>
#include <linux/reset.h>
#include <soc/tegra/pmc.h>
@@ -1287,6 +1288,17 @@ static int tegra_dc_init(struct host1x_client *client)
struct tegra_drm *tegra = drm->dev_private;
int err;
+ if (tegra->domain) {
+ err = iommu_attach_device(tegra->domain, dc->dev);
+ if (err < 0) {
+ dev_err(dc->dev, "failed to attach to domain: %d\n",
+ err);
+ return err;
+ }
+
+ dc->domain = tegra->domain;
+ }
+
drm_crtc_init(drm, &dc->base, &tegra_crtc_funcs);
drm_mode_crtc_set_gamma_size(&dc->base, 256);
drm_crtc_helper_add(&dc->base, &tegra_crtc_helper_funcs);
@@ -1344,6 +1356,11 @@ static int tegra_dc_exit(struct host1x_client *client)
return err;
}
+ if (dc->domain) {
+ iommu_detach_device(dc->domain, dc->dev);
+ dc->domain = NULL;
+ }
+
return 0;
}
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 59736bb810cd..ce5123c2c3c5 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -8,6 +8,7 @@
*/
#include <linux/host1x.h>
+#include <linux/iommu.h>
#include "drm.h"
#include "gem.h"
@@ -33,6 +34,17 @@ static int tegra_drm_load(struct drm_device *drm, unsigned long flags)
if (!tegra)
return -ENOMEM;
+ if (iommu_present(&platform_bus_type)) {
+ tegra->domain = iommu_domain_alloc(&platform_bus_type);
+ if (IS_ERR(tegra->domain)) {
+ kfree(tegra);
+ return PTR_ERR(tegra->domain);
+ }
+
+ DRM_DEBUG("IOMMU context initialized\n");
+ drm_mm_init(&tegra->mm, 0, SZ_2G);
+ }
+
mutex_init(&tegra->clients_lock);
INIT_LIST_HEAD(&tegra->clients);
drm->dev_private = tegra;
@@ -71,6 +83,7 @@ static int tegra_drm_load(struct drm_device *drm, unsigned long flags)
static int tegra_drm_unload(struct drm_device *drm)
{
struct host1x_device *device = to_host1x_device(drm->dev);
+ struct tegra_drm *tegra = drm->dev_private;
int err;
drm_kms_helper_poll_fini(drm);
@@ -82,6 +95,11 @@ static int tegra_drm_unload(struct drm_device *drm)
if (err < 0)
return err;
+ if (tegra->domain) {
+ iommu_domain_free(tegra->domain);
+ drm_mm_takedown(&tegra->mm);
+ }
+
return 0;
}
diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index b994c017971d..2fdae404e719 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -39,6 +39,9 @@ struct tegra_fbdev {
struct tegra_drm {
struct drm_device *drm;
+ struct iommu_domain *domain;
+ struct drm_mm mm;
+
struct mutex clients_lock;
struct list_head clients;
@@ -121,6 +124,8 @@ struct tegra_dc {
struct drm_pending_vblank_event *event;
const struct tegra_dc_soc_info *soc;
+
+ struct iommu_domain *domain;
};
static inline struct tegra_dc *
diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
index 3513d12d5aa1..c5fa3c4b2ed5 100644
--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -65,8 +65,12 @@ static void tegra_fb_destroy(struct drm_framebuffer *framebuffer)
for (i = 0; i < fb->num_planes; i++) {
struct tegra_bo *bo = fb->planes[i];
- if (bo)
+ if (bo) {
+ if (bo->pages && bo->vaddr)
+ vunmap(bo->vaddr);
+
drm_gem_object_unreference_unlocked(&bo->gem);
+ }
}
drm_framebuffer_cleanup(framebuffer);
@@ -254,6 +258,16 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
offset = info->var.xoffset * bytes_per_pixel +
info->var.yoffset * fb->pitches[0];
+ if (bo->pages) {
+ bo->vaddr = vmap(bo->pages, bo->num_pages, VM_MAP,
+ pgprot_writecombine(PAGE_KERNEL));
+ if (!bo->vaddr) {
+ dev_err(drm->dev, "failed to vmap() framebuffer\n");
+ err = -ENOMEM;
+ goto destroy;
+ }
+ }
+
drm->mode_config.fb_base = (resource_size_t)bo->paddr;
info->screen_base = (void __iomem *)bo->vaddr + offset;
info->screen_size = size;
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index b513df33f17a..8b1095d05c58 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -14,6 +14,7 @@
*/
#include <linux/dma-buf.h>
+#include <linux/iommu.h>
#include <drm/tegra_drm.h>
#include "drm.h"
@@ -91,6 +92,88 @@ static const struct host1x_bo_ops tegra_bo_ops = {
.kunmap = tegra_bo_kunmap,
};
+/*
+ * A generic iommu_map_sg() function is being reviewed and will hopefully be
+ * merged soon. At that point this function can be dropped in favour of the
+ * one provided by the IOMMU API.
+ */
+static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
+ struct scatterlist *sg, unsigned int nents,
+ int prot)
+{
+ struct scatterlist *s;
+ size_t offset = 0;
+ unsigned int i;
+ int err;
+
+ for_each_sg(sg, s, nents, i) {
+ phys_addr_t phys = page_to_phys(sg_page(s));
+ size_t length = s->offset + s->length;
+
+ err = iommu_map(domain, iova + offset, phys, length, prot);
+ if (err < 0) {
+ iommu_unmap(domain, iova, offset);
+ return err;
+ }
+
+ offset += length;
+ }
+
+ return offset;
+}
+
+static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
+{
+ int prot = IOMMU_READ | IOMMU_WRITE;
+ ssize_t err;
+
+ if (bo->mm)
+ return -EBUSY;
+
+ bo->mm = kzalloc(sizeof(*bo->mm), GFP_KERNEL);
+ if (!bo->mm)
+ return -ENOMEM;
+
+ err = drm_mm_insert_node_generic(&tegra->mm, bo->mm, bo->gem.size,
+ PAGE_SIZE, 0, 0, 0);
+ if (err < 0) {
+ dev_err(tegra->drm->dev, "out of I/O virtual memory: %zd\n",
+ err);
+ goto free;
+ }
+
+ bo->paddr = bo->mm->start;
+
+ err = __iommu_map_sg(tegra->domain, bo->paddr, bo->sgt->sgl,
+ bo->sgt->nents, prot);
+ if (err < 0) {
+ dev_err(tegra->drm->dev, "failed to map buffer: %zd\n", err);
+ goto remove;
+ }
+
+ bo->size = err;
+
+ return 0;
+
+remove:
+ drm_mm_remove_node(bo->mm);
+free:
+ kfree(bo->mm);
+ return err;
+}
+
+static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
+{
+ if (!bo->mm)
+ return 0;
+
+ iommu_unmap(tegra->domain, bo->paddr, bo->size);
+ drm_mm_remove_node(bo->mm);
+ kfree(bo->mm);
+
+ return 0;
+}
+
static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
size_t size)
{
@@ -121,9 +204,64 @@ free:
return ERR_PTR(err);
}
-static void tegra_bo_destroy(struct drm_device *drm, struct tegra_bo *bo)
+static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
{
- dma_free_writecombine(drm->dev, bo->gem.size, bo->vaddr, bo->paddr);
+ if (bo->pages) {
+ drm_gem_put_pages(&bo->gem, bo->pages, true, true);
+ sg_free_table(bo->sgt);
+ kfree(bo->sgt);
+ } else {
+ dma_free_writecombine(drm->dev, bo->gem.size, bo->vaddr,
+ bo->paddr);
+ }
+}
+
+static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo,
+ size_t size)
+{
+ bo->pages = drm_gem_get_pages(&bo->gem);
+ if (IS_ERR(bo->pages))
+ return PTR_ERR(bo->pages);
+
+ bo->num_pages = size >> PAGE_SHIFT;
+
+ bo->sgt = drm_prime_pages_to_sg(bo->pages, bo->num_pages);
+ if (IS_ERR(bo->sgt)) {
+ drm_gem_put_pages(&bo->gem, bo->pages, false, false);
+ return PTR_ERR(bo->sgt);
+ }
+
+ return 0;
+}
+
+static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo,
+ size_t size)
+{
+ struct tegra_drm *tegra = drm->dev_private;
+ int err;
+
+ if (tegra->domain) {
+ err = tegra_bo_get_pages(drm, bo, size);
+ if (err < 0)
+ return err;
+
+ err = tegra_bo_iommu_map(tegra, bo);
+ if (err < 0) {
+ tegra_bo_free(drm, bo);
+ return err;
+ }
+ } else {
+ bo->vaddr = dma_alloc_writecombine(drm->dev, size, &bo->paddr,
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!bo->vaddr) {
+ dev_err(drm->dev,
+ "failed to allocate buffer of size %zu\n",
+ size);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
}
struct tegra_bo *tegra_bo_create(struct drm_device *drm, unsigned int size,
@@ -136,14 +274,9 @@ struct tegra_bo *tegra_bo_create(struct drm_device *drm, unsigned int size,
if (IS_ERR(bo))
return bo;
- bo->vaddr = dma_alloc_writecombine(drm->dev, size, &bo->paddr,
- GFP_KERNEL | __GFP_NOWARN);
- if (!bo->vaddr) {
- dev_err(drm->dev, "failed to allocate buffer with size %u\n",
- size);
- err = -ENOMEM;
- goto err_dma;
- }
+ err = tegra_bo_alloc(drm, bo, size);
+ if (err < 0)
+ goto release;
if (flags & DRM_TEGRA_GEM_CREATE_TILED)
bo->tiling.mode = TEGRA_BO_TILING_MODE_TILED;
@@ -153,13 +286,9 @@ struct tegra_bo *tegra_bo_create(struct drm_device *drm, unsigned int size,
return bo;
-err_mmap:
+release:
drm_gem_object_release(&bo->gem);
-err_init:
- tegra_bo_destroy(drm, bo);
-err_dma:
kfree(bo);
-
return ERR_PTR(err);
}
@@ -190,6 +319,7 @@ struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
struct dma_buf *buf)
{
+ struct tegra_drm *tegra = drm->dev_private;
struct dma_buf_attachment *attach;
struct tegra_bo *bo;
int err;
@@ -217,12 +347,19 @@ static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
goto detach;
}
- if (bo->sgt->nents > 1) {
- err = -EINVAL;
- goto detach;
+ if (tegra->domain) {
+ err = tegra_bo_iommu_map(tegra, bo);
+ if (err < 0)
+ goto detach;
+ } else {
+ if (bo->sgt->nents > 1) {
+ err = -EINVAL;
+ goto detach;
+ }
+
+ bo->paddr = sg_dma_address(bo->sgt->sgl);
}
- bo->paddr = sg_dma_address(bo->sgt->sgl);
bo->gem.import_attach = attach;
return bo;
@@ -241,14 +378,18 @@ free:
void tegra_bo_free_object(struct drm_gem_object *gem)
{
+ struct tegra_drm *tegra = gem->dev->dev_private;
struct tegra_bo *bo = to_tegra_bo(gem);
+ if (tegra->domain)
+ tegra_bo_iommu_unmap(tegra, bo);
+
if (gem->import_attach) {
dma_buf_unmap_attachment(gem->import_attach, bo->sgt,
DMA_TO_DEVICE);
drm_prime_gem_destroy(gem, NULL);
} else {
- tegra_bo_destroy(gem->dev, bo);
+ tegra_bo_free(gem->dev, bo);
}
drm_gem_object_release(gem);
@@ -303,14 +444,44 @@ int tegra_bo_dumb_map_offset(struct drm_file *file, struct drm_device *drm,
return 0;
}
+static int tegra_bo_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct drm_gem_object *gem = vma->vm_private_data;
+ struct tegra_bo *bo = to_tegra_bo(gem);
+ struct page *page;
+ pgoff_t offset;
+ int err;
+
+ if (!bo->pages)
+ return VM_FAULT_SIGBUS;
+
+ offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >> PAGE_SHIFT;
+ page = bo->pages[offset];
+
+ err = vm_insert_page(vma, (unsigned long)vmf->virtual_address, page);
+ switch (err) {
+ case -EAGAIN:
+ case 0:
+ case -ERESTARTSYS:
+ case -EINTR:
+ case -EBUSY:
+ return VM_FAULT_NOPAGE;
+
+ case -ENOMEM:
+ return VM_FAULT_OOM;
+ }
+
+ return VM_FAULT_SIGBUS;
+}
+
const struct vm_operations_struct tegra_bo_vm_ops = {
+ .fault = tegra_bo_fault,
.open = drm_gem_vm_open,
.close = drm_gem_vm_close,
};
int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma)
{
- unsigned long vm_pgoff = vma->vm_pgoff;
struct drm_gem_object *gem;
struct tegra_bo *bo;
int ret;
@@ -322,17 +493,28 @@ int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma)
gem = vma->vm_private_data;
bo = to_tegra_bo(gem);
- vma->vm_flags &= ~VM_PFNMAP;
- vma->vm_pgoff = 0;
+ if (!bo->pages) {
+ unsigned long vm_pgoff = vma->vm_pgoff;
- ret = dma_mmap_writecombine(gem->dev->dev, vma, bo->vaddr, bo->paddr,
- gem->size);
- if (ret) {
- drm_gem_vm_close(vma);
- return ret;
- }
+ vma->vm_flags &= ~VM_PFNMAP;
+ vma->vm_pgoff = 0;
- vma->vm_pgoff = vm_pgoff;
+ ret = dma_mmap_writecombine(gem->dev->dev, vma, bo->vaddr,
+ bo->paddr, gem->size);
+ if (ret) {
+ drm_gem_vm_close(vma);
+ return ret;
+ }
+
+ vma->vm_pgoff = vm_pgoff;
+ } else {
+ pgprot_t prot = vm_get_page_prot(vma->vm_flags);
+
+ vma->vm_flags |= VM_MIXEDMAP;
+ vma->vm_flags &= ~VM_PFNMAP;
+
+ vma->vm_page_prot = pgprot_writecombine(prot);
+ }
return 0;
}
@@ -349,21 +531,44 @@ tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
if (!sgt)
return NULL;
- if (sg_alloc_table(sgt, 1, GFP_KERNEL)) {
- kfree(sgt);
- return NULL;
- }
+ if (bo->pages) {
+ struct scatterlist *sg;
+ unsigned int i;
+
+ if (sg_alloc_table(sgt, bo->num_pages, GFP_KERNEL))
+ goto free;
- sg_dma_address(sgt->sgl) = bo->paddr;
- sg_dma_len(sgt->sgl) = gem->size;
+ for_each_sg(sgt->sgl, sg, bo->num_pages, i)
+ sg_set_page(sg, bo->pages[i], PAGE_SIZE, 0);
+
+ if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
+ goto free;
+ } else {
+ if (sg_alloc_table(sgt, 1, GFP_KERNEL))
+ goto free;
+
+ sg_dma_address(sgt->sgl) = bo->paddr;
+ sg_dma_len(sgt->sgl) = gem->size;
+ }
return sgt;
+
+free:
+ sg_free_table(sgt);
+ kfree(sgt);
+ return NULL;
}
static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
struct sg_table *sgt,
enum dma_data_direction dir)
{
+ struct drm_gem_object *gem = attach->dmabuf->priv;
+ struct tegra_bo *bo = to_tegra_bo(gem);
+
+ if (bo->pages)
+ dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
+
sg_free_table(sgt);
kfree(sgt);
}
diff --git a/drivers/gpu/drm/tegra/gem.h b/drivers/gpu/drm/tegra/gem.h
index 6538b56780c2..3dd4165f812a 100644
--- a/drivers/gpu/drm/tegra/gem.h
+++ b/drivers/gpu/drm/tegra/gem.h
@@ -38,6 +38,12 @@ struct tegra_bo {
dma_addr_t paddr;
void *vaddr;
+ struct drm_mm_node *mm;
+ unsigned long num_pages;
+ struct page **pages;
+ /* size of IOMMU mapping */
+ size_t size;
+
struct tegra_bo_tiling tiling;
};
--
2.1.2
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