Commit b306712d authored by Alexandre Courbot's avatar Alexandre Courbot Committed by Ben Skeggs
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drm/nouveau/instmem/gk20a: use DMA API CPU mapping

Commit 69c49382

 ("drm/nouveau/instmem/gk20a: use direct CPU access")
tried to be smart while using the DMA-API by managing the CPU mappings of
buffers allocated with the DMA-API by itself. In doing so, it relied
on dma_to_phys() which is an architecture-private function not
available everywhere. This broke the build on several architectures.

Since there is no reliable and portable way to obtain the physical
address of a DMA-API buffer, stop trying to be smart and just use the
CPU mapping that the DMA-API can provide. This means that buffers will
be CPU-mapped for all their life as opposed to when we need them, but
anyway using the DMA-API here is a fallback for when no IOMMU is
available so we should not expect optimal behavior.

This makes the IOMMU and DMA-API implementations of instmem diverge
enough that we should maybe put them into separate files...
Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
parent 338840ee
......@@ -56,9 +56,6 @@ struct gk20a_instobj {
/* CPU mapping */
u32 *vaddr;
struct list_head vaddr_node;
/* How many clients are using vaddr? */
u32 use_cpt;
};
#define gk20a_instobj(p) container_of((p), struct gk20a_instobj, memory)
......@@ -68,7 +65,6 @@ struct gk20a_instobj {
struct gk20a_instobj_dma {
struct gk20a_instobj base;
u32 *cpuaddr;
dma_addr_t handle;
struct nvkm_mm_node r;
};
......@@ -81,6 +77,11 @@ struct gk20a_instobj_dma {
struct gk20a_instobj_iommu {
struct gk20a_instobj base;
/* to link into gk20a_instmem::vaddr_lru */
struct list_head vaddr_node;
/* how many clients are using vaddr? */
u32 use_cpt;
/* will point to the higher half of pages */
dma_addr_t *dma_addrs;
/* array of base.mem->size pages (+ dma_addr_ts) */
......@@ -109,8 +110,6 @@ struct gk20a_instmem {
/* Only used by DMA API */
struct dma_attrs attrs;
void __iomem * (*cpu_map)(struct nvkm_memory *);
};
#define gk20a_instmem(p) container_of((p), struct gk20a_instmem, base)
......@@ -132,52 +131,19 @@ gk20a_instobj_size(struct nvkm_memory *memory)
return (u64)gk20a_instobj(memory)->mem.size << 12;
}
static void __iomem *
gk20a_instobj_cpu_map_dma(struct nvkm_memory *memory)
{
#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
struct gk20a_instobj_dma *node = gk20a_instobj_dma(memory);
struct device *dev = node->base.imem->base.subdev.device->dev;
int npages = nvkm_memory_size(memory) >> 12;
struct page *pages[npages];
int i;
/* we shouldn't see a gk20a on anything but arm/arm64 anyways */
/* phys_to_page does not exist on all platforms... */
pages[0] = pfn_to_page(dma_to_phys(dev, node->handle) >> PAGE_SHIFT);
for (i = 1; i < npages; i++)
pages[i] = pages[0] + i;
return vmap(pages, npages, VM_MAP, pgprot_writecombine(PAGE_KERNEL));
#else
BUG();
return NULL;
#endif
}
static void __iomem *
gk20a_instobj_cpu_map_iommu(struct nvkm_memory *memory)
{
struct gk20a_instobj_iommu *node = gk20a_instobj_iommu(memory);
int npages = nvkm_memory_size(memory) >> 12;
return vmap(node->pages, npages, VM_MAP,
pgprot_writecombine(PAGE_KERNEL));
}
/*
* Recycle the vaddr of obj. Must be called with gk20a_instmem::lock held.
*/
static void
gk20a_instobj_recycle_vaddr(struct gk20a_instobj *obj)
gk20a_instobj_iommu_recycle_vaddr(struct gk20a_instobj_iommu *obj)
{
struct gk20a_instmem *imem = obj->imem;
struct gk20a_instmem *imem = obj->base.imem;
/* there should not be any user left... */
WARN_ON(obj->use_cpt);
list_del(&obj->vaddr_node);
vunmap(obj->vaddr);
obj->vaddr = NULL;
imem->vaddr_use -= nvkm_memory_size(&obj->memory);
vunmap(obj->base.vaddr);
obj->base.vaddr = NULL;
imem->vaddr_use -= nvkm_memory_size(&obj->base.memory);
nvkm_debug(&imem->base.subdev, "vaddr used: %x/%x\n", imem->vaddr_use,
imem->vaddr_max);
}
......@@ -193,17 +159,30 @@ gk20a_instmem_vaddr_gc(struct gk20a_instmem *imem, const u64 size)
if (list_empty(&imem->vaddr_lru))
break;
gk20a_instobj_recycle_vaddr(list_first_entry(&imem->vaddr_lru,
struct gk20a_instobj, vaddr_node));
gk20a_instobj_iommu_recycle_vaddr(
list_first_entry(&imem->vaddr_lru,
struct gk20a_instobj_iommu, vaddr_node));
}
}
static void __iomem *
gk20a_instobj_acquire(struct nvkm_memory *memory)
gk20a_instobj_acquire_dma(struct nvkm_memory *memory)
{
struct gk20a_instobj *node = gk20a_instobj(memory);
struct gk20a_instmem *imem = node->imem;
struct nvkm_ltc *ltc = imem->base.subdev.device->ltc;
nvkm_ltc_flush(ltc);
return node->vaddr;
}
static void __iomem *
gk20a_instobj_acquire_iommu(struct nvkm_memory *memory)
{
struct gk20a_instobj_iommu *node = gk20a_instobj_iommu(memory);
struct gk20a_instmem *imem = node->base.imem;
struct nvkm_ltc *ltc = imem->base.subdev.device->ltc;
const u64 size = nvkm_memory_size(memory);
unsigned long flags;
......@@ -211,7 +190,7 @@ gk20a_instobj_acquire(struct nvkm_memory *memory)
spin_lock_irqsave(&imem->lock, flags);
if (node->vaddr) {
if (node->base.vaddr) {
if (!node->use_cpt) {
/* remove from LRU list since mapping in use again */
list_del(&node->vaddr_node);
......@@ -222,9 +201,10 @@ gk20a_instobj_acquire(struct nvkm_memory *memory)
/* try to free some address space if we reached the limit */
gk20a_instmem_vaddr_gc(imem, size);
node->vaddr = imem->cpu_map(memory);
if (!node->vaddr) {
/* map the pages */
node->base.vaddr = vmap(node->pages, size >> PAGE_SHIFT, VM_MAP,
pgprot_writecombine(PAGE_KERNEL));
if (!node->base.vaddr) {
nvkm_error(&imem->base.subdev, "cannot map instobj - "
"this is not going to end well...\n");
goto out;
......@@ -238,15 +218,25 @@ gk20a_instobj_acquire(struct nvkm_memory *memory)
node->use_cpt++;
spin_unlock_irqrestore(&imem->lock, flags);
return node->vaddr;
return node->base.vaddr;
}
static void
gk20a_instobj_release(struct nvkm_memory *memory)
gk20a_instobj_release_dma(struct nvkm_memory *memory)
{
struct gk20a_instobj *node = gk20a_instobj(memory);
struct gk20a_instmem *imem = node->imem;
struct nvkm_ltc *ltc = imem->base.subdev.device->ltc;
nvkm_ltc_invalidate(ltc);
}
static void
gk20a_instobj_release_iommu(struct nvkm_memory *memory)
{
struct gk20a_instobj_iommu *node = gk20a_instobj_iommu(memory);
struct gk20a_instmem *imem = node->base.imem;
struct nvkm_ltc *ltc = imem->base.subdev.device->ltc;
unsigned long flags;
spin_lock_irqsave(&imem->lock, flags);
......@@ -290,27 +280,6 @@ gk20a_instobj_map(struct nvkm_memory *memory, struct nvkm_vma *vma, u64 offset)
nvkm_vm_map_at(vma, offset, &node->mem);
}
/*
* Clear the CPU mapping of an instobj if it exists
*/
static void
gk20a_instobj_dtor(struct gk20a_instobj *node)
{
struct gk20a_instmem *imem = node->imem;
unsigned long flags;
spin_lock_irqsave(&imem->lock, flags);
/* vaddr has already been recycled */
if (!node->vaddr)
goto out;
gk20a_instobj_recycle_vaddr(node);
out:
spin_unlock_irqrestore(&imem->lock, flags);
}
static void *
gk20a_instobj_dtor_dma(struct nvkm_memory *memory)
{
......@@ -318,12 +287,10 @@ gk20a_instobj_dtor_dma(struct nvkm_memory *memory)
struct gk20a_instmem *imem = node->base.imem;
struct device *dev = imem->base.subdev.device->dev;
gk20a_instobj_dtor(&node->base);
if (unlikely(!node->cpuaddr))
if (unlikely(!node->base.vaddr))
goto out;
dma_free_attrs(dev, node->base.mem.size << PAGE_SHIFT, node->cpuaddr,
dma_free_attrs(dev, node->base.mem.size << PAGE_SHIFT, node->base.vaddr,
node->handle, &imem->attrs);
out:
......@@ -337,13 +304,20 @@ gk20a_instobj_dtor_iommu(struct nvkm_memory *memory)
struct gk20a_instmem *imem = node->base.imem;
struct device *dev = imem->base.subdev.device->dev;
struct nvkm_mm_node *r;
unsigned long flags;
int i;
gk20a_instobj_dtor(&node->base);
if (unlikely(list_empty(&node->base.mem.regions)))
goto out;
spin_lock_irqsave(&imem->lock, flags);
/* vaddr has already been recycled */
if (node->base.vaddr)
gk20a_instobj_iommu_recycle_vaddr(node);
spin_unlock_irqrestore(&imem->lock, flags);
r = list_first_entry(&node->base.mem.regions, struct nvkm_mm_node,
rl_entry);
......@@ -374,8 +348,8 @@ gk20a_instobj_func_dma = {
.target = gk20a_instobj_target,
.addr = gk20a_instobj_addr,
.size = gk20a_instobj_size,
.acquire = gk20a_instobj_acquire,
.release = gk20a_instobj_release,
.acquire = gk20a_instobj_acquire_dma,
.release = gk20a_instobj_release_dma,
.rd32 = gk20a_instobj_rd32,
.wr32 = gk20a_instobj_wr32,
.map = gk20a_instobj_map,
......@@ -387,8 +361,8 @@ gk20a_instobj_func_iommu = {
.target = gk20a_instobj_target,
.addr = gk20a_instobj_addr,
.size = gk20a_instobj_size,
.acquire = gk20a_instobj_acquire,
.release = gk20a_instobj_release,
.acquire = gk20a_instobj_acquire_iommu,
.release = gk20a_instobj_release_iommu,
.rd32 = gk20a_instobj_rd32,
.wr32 = gk20a_instobj_wr32,
.map = gk20a_instobj_map,
......@@ -408,10 +382,10 @@ gk20a_instobj_ctor_dma(struct gk20a_instmem *imem, u32 npages, u32 align,
nvkm_memory_ctor(&gk20a_instobj_func_dma, &node->base.memory);
node->cpuaddr = dma_alloc_attrs(dev, npages << PAGE_SHIFT,
&node->handle, GFP_KERNEL,
&imem->attrs);
if (!node->cpuaddr) {
node->base.vaddr = dma_alloc_attrs(dev, npages << PAGE_SHIFT,
&node->handle, GFP_KERNEL,
&imem->attrs);
if (!node->base.vaddr) {
nvkm_error(subdev, "cannot allocate DMA memory\n");
return -ENOMEM;
}
......@@ -617,18 +591,14 @@ gk20a_instmem_new(struct nvkm_device *device, int index,
imem->mm = &tdev->iommu.mm;
imem->domain = tdev->iommu.domain;
imem->iommu_pgshift = tdev->iommu.pgshift;
imem->cpu_map = gk20a_instobj_cpu_map_iommu;
imem->iommu_bit = tdev->func->iommu_bit;
nvkm_info(&imem->base.subdev, "using IOMMU\n");
} else {
init_dma_attrs(&imem->attrs);
/* We will access the memory through our own mapping */
dma_set_attr(DMA_ATTR_NON_CONSISTENT, &imem->attrs);
dma_set_attr(DMA_ATTR_WEAK_ORDERING, &imem->attrs);
dma_set_attr(DMA_ATTR_WRITE_COMBINE, &imem->attrs);
dma_set_attr(DMA_ATTR_NO_KERNEL_MAPPING, &imem->attrs);
imem->cpu_map = gk20a_instobj_cpu_map_dma;
nvkm_info(&imem->base.subdev, "using DMA API\n");
}
......
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