[Intel-gfx] [PATCH 08/11] drm/i915: use vmap in i915_gem_object_map

2020-10-02 Thread Christoph Hellwig
i915_gem_object_map implements fairly low-level vmap functionality in
a driver.  Split it into two helpers, one for remapping kernel memory
which can use vmap, and one for I/O memory that uses vmap_pfn.

The only practical difference is that alloc_vm_area prefeaults the
vmalloc area PTEs, which doesn't seem to be required here for the
kernel memory case (and could be added to vmap using a flag if actually
required).

Signed-off-by: Christoph Hellwig 
Reviewed-by: Tvrtko Ursulin 
---
 drivers/gpu/drm/i915/Kconfig  |   1 +
 drivers/gpu/drm/i915/gem/i915_gem_pages.c | 127 ++
 2 files changed, 60 insertions(+), 68 deletions(-)

diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 9afa5c4a6bf006..1e1cb245fca778 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -25,6 +25,7 @@ config DRM_I915
select CRC32
select SND_HDA_I915 if SND_HDA_CORE
select CEC_CORE if CEC_NOTIFIER
+   select VMAP_PFN
help
  Choose this option if you have a system that has "Intel Graphics
  Media Accelerator" or "HD Graphics" integrated graphics,
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c 
b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index 6550c0bc824ea2..f60ca6dc911f29 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -232,34 +232,21 @@ int __i915_gem_object_put_pages(struct 
drm_i915_gem_object *obj)
return err;
 }
 
-static inline pte_t iomap_pte(resource_size_t base,
- dma_addr_t offset,
- pgprot_t prot)
-{
-   return pte_mkspecial(pfn_pte((base + offset) >> PAGE_SHIFT, prot));
-}
-
 /* The 'mapping' part of i915_gem_object_pin_map() below */
-static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
-enum i915_map_type type)
+static void *i915_gem_object_map_page(struct drm_i915_gem_object *obj,
+   enum i915_map_type type)
 {
-   unsigned long n_pte = obj->base.size >> PAGE_SHIFT;
-   struct sg_table *sgt = obj->mm.pages;
-   pte_t *stack[32], **mem;
-   struct vm_struct *area;
+   unsigned long n_pages = obj->base.size >> PAGE_SHIFT, i;
+   struct page *stack[32], **pages = stack, *page;
+   struct sgt_iter iter;
pgprot_t pgprot;
+   void *vaddr;
 
-   if (!i915_gem_object_has_struct_page(obj) && type != I915_MAP_WC)
-   return NULL;
-
-   if (GEM_WARN_ON(type == I915_MAP_WC &&
-   !static_cpu_has(X86_FEATURE_PAT)))
-   return NULL;
-
-   /* A single page can always be kmapped */
-   if (n_pte == 1 && type == I915_MAP_WB) {
-   struct page *page = sg_page(sgt->sgl);
-
+   switch (type) {
+   default:
+   MISSING_CASE(type);
+   fallthrough;/* to use PAGE_KERNEL anyway */
+   case I915_MAP_WB:
/*
 * On 32b, highmem using a finite set of indirect PTE (i.e.
 * vmap) to provide virtual mappings of the high pages.
@@ -277,30 +264,8 @@ static void *i915_gem_object_map(struct 
drm_i915_gem_object *obj,
 * So if the page is beyond the 32b boundary, make an explicit
 * vmap.
 */
-   if (!PageHighMem(page))
-   return page_address(page);
-   }
-
-   mem = stack;
-   if (n_pte > ARRAY_SIZE(stack)) {
-   /* Too big for stack -- allocate temporary array instead */
-   mem = kvmalloc_array(n_pte, sizeof(*mem), GFP_KERNEL);
-   if (!mem)
-   return NULL;
-   }
-
-   area = alloc_vm_area(obj->base.size, mem);
-   if (!area) {
-   if (mem != stack)
-   kvfree(mem);
-   return NULL;
-   }
-
-   switch (type) {
-   default:
-   MISSING_CASE(type);
-   fallthrough;/* to use PAGE_KERNEL anyway */
-   case I915_MAP_WB:
+   if (n_pages == 1 && !PageHighMem(sg_page(obj->mm.pages->sgl)))
+   return page_address(sg_page(obj->mm.pages->sgl));
pgprot = PAGE_KERNEL;
break;
case I915_MAP_WC:
@@ -308,30 +273,50 @@ static void *i915_gem_object_map(struct 
drm_i915_gem_object *obj,
break;
}
 
-   if (i915_gem_object_has_struct_page(obj)) {
-   struct sgt_iter iter;
-   struct page *page;
-   pte_t **ptes = mem;
+   if (n_pages > ARRAY_SIZE(stack)) {
+   /* Too big for stack -- allocate temporary array instead */
+   pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
+   if (!pages)
+   return NULL;
+   }
 
-   for_each_sgt_page(page, iter, sgt)
-   **ptes++ = mk_pte(p

Re: [Intel-gfx] [PATCH 08/11] drm/i915: use vmap in i915_gem_object_map

2020-09-25 Thread Christoph Hellwig
On Fri, Sep 25, 2020 at 03:08:59PM +0100, Matthew Auld wrote:
> > +   i = 0;
> > +   for_each_sgt_page(page, iter, obj->mm.pages)
> > +   pages[i++] = page;
> > +   vaddr = vmap(pages, n_pages, 0, pgprot);
> > +   if (pages != stack)
> > +   kvfree(pages);
> > +   return vaddr;
> > +}

> > -   return area->addr;
> > +   for_each_sgt_daddr(addr, iter, obj->mm.pages)
> > +   pfns[i++] = (iomap + addr) >> PAGE_SHIFT;
> 
> Missing the i = 0 fix from Dan?

Yeah, looks like I only managed to apply the one in the page based
version above.
___
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Re: [Intel-gfx] [PATCH 08/11] drm/i915: use vmap in i915_gem_object_map

2020-09-25 Thread Matthew Auld
On Thu, 24 Sep 2020 at 14:59, Christoph Hellwig  wrote:
>
> i915_gem_object_map implements fairly low-level vmap functionality in
> a driver.  Split it into two helpers, one for remapping kernel memory
> which can use vmap, and one for I/O memory that uses vmap_pfn.
>
> The only practical difference is that alloc_vm_area prefeaults the
> vmalloc area PTEs, which doesn't seem to be required here for the
> kernel memory case (and could be added to vmap using a flag if actually
> required).
>
> Signed-off-by: Christoph Hellwig 
> ---
>  drivers/gpu/drm/i915/Kconfig  |   1 +
>  drivers/gpu/drm/i915/gem/i915_gem_pages.c | 126 ++
>  2 files changed, 59 insertions(+), 68 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
> index 9afa5c4a6bf006..1e1cb245fca778 100644
> --- a/drivers/gpu/drm/i915/Kconfig
> +++ b/drivers/gpu/drm/i915/Kconfig
> @@ -25,6 +25,7 @@ config DRM_I915
> select CRC32
> select SND_HDA_I915 if SND_HDA_CORE
> select CEC_CORE if CEC_NOTIFIER
> +   select VMAP_PFN
> help
>   Choose this option if you have a system that has "Intel Graphics
>   Media Accelerator" or "HD Graphics" integrated graphics,
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c 
> b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> index 6550c0bc824ea2..b519417667eb4b 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> @@ -232,34 +232,21 @@ int __i915_gem_object_put_pages(struct 
> drm_i915_gem_object *obj)
> return err;
>  }
>
> -static inline pte_t iomap_pte(resource_size_t base,
> - dma_addr_t offset,
> - pgprot_t prot)
> -{
> -   return pte_mkspecial(pfn_pte((base + offset) >> PAGE_SHIFT, prot));
> -}
> -
>  /* The 'mapping' part of i915_gem_object_pin_map() below */
> -static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
> -enum i915_map_type type)
> +static void *i915_gem_object_map_page(struct drm_i915_gem_object *obj,
> +   enum i915_map_type type)
>  {
> -   unsigned long n_pte = obj->base.size >> PAGE_SHIFT;
> -   struct sg_table *sgt = obj->mm.pages;
> -   pte_t *stack[32], **mem;
> -   struct vm_struct *area;
> +   unsigned long n_pages = obj->base.size >> PAGE_SHIFT, i;
> +   struct page *stack[32], **pages = stack, *page;
> +   struct sgt_iter iter;
> pgprot_t pgprot;
> +   void *vaddr;
>
> -   if (!i915_gem_object_has_struct_page(obj) && type != I915_MAP_WC)
> -   return NULL;
> -
> -   if (GEM_WARN_ON(type == I915_MAP_WC &&
> -   !static_cpu_has(X86_FEATURE_PAT)))
> -   return NULL;
> -
> -   /* A single page can always be kmapped */
> -   if (n_pte == 1 && type == I915_MAP_WB) {
> -   struct page *page = sg_page(sgt->sgl);
> -
> +   switch (type) {
> +   default:
> +   MISSING_CASE(type);
> +   fallthrough;/* to use PAGE_KERNEL anyway */
> +   case I915_MAP_WB:
> /*
>  * On 32b, highmem using a finite set of indirect PTE (i.e.
>  * vmap) to provide virtual mappings of the high pages.
> @@ -277,30 +264,8 @@ static void *i915_gem_object_map(struct 
> drm_i915_gem_object *obj,
>  * So if the page is beyond the 32b boundary, make an explicit
>  * vmap.
>  */
> -   if (!PageHighMem(page))
> -   return page_address(page);
> -   }
> -
> -   mem = stack;
> -   if (n_pte > ARRAY_SIZE(stack)) {
> -   /* Too big for stack -- allocate temporary array instead */
> -   mem = kvmalloc_array(n_pte, sizeof(*mem), GFP_KERNEL);
> -   if (!mem)
> -   return NULL;
> -   }
> -
> -   area = alloc_vm_area(obj->base.size, mem);
> -   if (!area) {
> -   if (mem != stack)
> -   kvfree(mem);
> -   return NULL;
> -   }
> -
> -   switch (type) {
> -   default:
> -   MISSING_CASE(type);
> -   fallthrough;/* to use PAGE_KERNEL anyway */
> -   case I915_MAP_WB:
> +   if (n_pages == 1 && !PageHighMem(sg_page(obj->mm.pages->sgl)))
> +   return page_address(sg_page(obj->mm.pages->sgl));
> pgprot = PAGE_KERNEL;
> break;
> case I915_MAP_WC:
> @@ -308,30 +273,49 @@ static void *i915_gem_object_map(struct 
> drm_i915_gem_object *obj,
> break;
> }
>
> -   if (i915_gem_object_has_struct_page(obj)) {
> -   struct sgt_iter iter;
> -   struct page *page;
> -   pte_t **ptes = mem;
> +   if (n_pages > ARRAY_SIZE(stack)) {
> +   /* Too big for stack -- allocate tempora

Re: [Intel-gfx] [PATCH 08/11] drm/i915: use vmap in i915_gem_object_map

2020-09-25 Thread Tvrtko Ursulin



On 24/09/2020 14:58, Christoph Hellwig wrote:

i915_gem_object_map implements fairly low-level vmap functionality in
a driver.  Split it into two helpers, one for remapping kernel memory
which can use vmap, and one for I/O memory that uses vmap_pfn.

The only practical difference is that alloc_vm_area prefeaults the
vmalloc area PTEs, which doesn't seem to be required here for the
kernel memory case (and could be added to vmap using a flag if actually
required).

Signed-off-by: Christoph Hellwig 
---
  drivers/gpu/drm/i915/Kconfig  |   1 +
  drivers/gpu/drm/i915/gem/i915_gem_pages.c | 126 ++
  2 files changed, 59 insertions(+), 68 deletions(-)

diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 9afa5c4a6bf006..1e1cb245fca778 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -25,6 +25,7 @@ config DRM_I915
select CRC32
select SND_HDA_I915 if SND_HDA_CORE
select CEC_CORE if CEC_NOTIFIER
+   select VMAP_PFN
help
  Choose this option if you have a system that has "Intel Graphics
  Media Accelerator" or "HD Graphics" integrated graphics,
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c 
b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index 6550c0bc824ea2..b519417667eb4b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -232,34 +232,21 @@ int __i915_gem_object_put_pages(struct 
drm_i915_gem_object *obj)
return err;
  }
  
-static inline pte_t iomap_pte(resource_size_t base,

- dma_addr_t offset,
- pgprot_t prot)
-{
-   return pte_mkspecial(pfn_pte((base + offset) >> PAGE_SHIFT, prot));
-}
-
  /* The 'mapping' part of i915_gem_object_pin_map() below */
-static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
-enum i915_map_type type)
+static void *i915_gem_object_map_page(struct drm_i915_gem_object *obj,
+   enum i915_map_type type)
  {
-   unsigned long n_pte = obj->base.size >> PAGE_SHIFT;
-   struct sg_table *sgt = obj->mm.pages;
-   pte_t *stack[32], **mem;
-   struct vm_struct *area;
+   unsigned long n_pages = obj->base.size >> PAGE_SHIFT, i;
+   struct page *stack[32], **pages = stack, *page;
+   struct sgt_iter iter;
pgprot_t pgprot;
+   void *vaddr;
  
-	if (!i915_gem_object_has_struct_page(obj) && type != I915_MAP_WC)

-   return NULL;
-
-   if (GEM_WARN_ON(type == I915_MAP_WC &&
-   !static_cpu_has(X86_FEATURE_PAT)))
-   return NULL;
-
-   /* A single page can always be kmapped */
-   if (n_pte == 1 && type == I915_MAP_WB) {
-   struct page *page = sg_page(sgt->sgl);
-
+   switch (type) {
+   default:
+   MISSING_CASE(type);
+   fallthrough;/* to use PAGE_KERNEL anyway */
+   case I915_MAP_WB:
/*
 * On 32b, highmem using a finite set of indirect PTE (i.e.
 * vmap) to provide virtual mappings of the high pages.
@@ -277,30 +264,8 @@ static void *i915_gem_object_map(struct 
drm_i915_gem_object *obj,
 * So if the page is beyond the 32b boundary, make an explicit
 * vmap.
 */
-   if (!PageHighMem(page))
-   return page_address(page);
-   }
-
-   mem = stack;
-   if (n_pte > ARRAY_SIZE(stack)) {
-   /* Too big for stack -- allocate temporary array instead */
-   mem = kvmalloc_array(n_pte, sizeof(*mem), GFP_KERNEL);
-   if (!mem)
-   return NULL;
-   }
-
-   area = alloc_vm_area(obj->base.size, mem);
-   if (!area) {
-   if (mem != stack)
-   kvfree(mem);
-   return NULL;
-   }
-
-   switch (type) {
-   default:
-   MISSING_CASE(type);
-   fallthrough;/* to use PAGE_KERNEL anyway */
-   case I915_MAP_WB:
+   if (n_pages == 1 && !PageHighMem(sg_page(obj->mm.pages->sgl)))
+   return page_address(sg_page(obj->mm.pages->sgl));
pgprot = PAGE_KERNEL;
break;
case I915_MAP_WC:
@@ -308,30 +273,49 @@ static void *i915_gem_object_map(struct 
drm_i915_gem_object *obj,
break;
}
  
-	if (i915_gem_object_has_struct_page(obj)) {

-   struct sgt_iter iter;
-   struct page *page;
-   pte_t **ptes = mem;
+   if (n_pages > ARRAY_SIZE(stack)) {
+   /* Too big for stack -- allocate temporary array instead */
+   pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
+   if (!pages)
+   return NULL;
+   }
  
-		for_each_sgt_page(page, iter, sgt)

-   **ptes++ 

[Intel-gfx] [PATCH 08/11] drm/i915: use vmap in i915_gem_object_map

2020-09-24 Thread Christoph Hellwig
i915_gem_object_map implements fairly low-level vmap functionality in
a driver.  Split it into two helpers, one for remapping kernel memory
which can use vmap, and one for I/O memory that uses vmap_pfn.

The only practical difference is that alloc_vm_area prefeaults the
vmalloc area PTEs, which doesn't seem to be required here for the
kernel memory case (and could be added to vmap using a flag if actually
required).

Signed-off-by: Christoph Hellwig 
---
 drivers/gpu/drm/i915/Kconfig  |   1 +
 drivers/gpu/drm/i915/gem/i915_gem_pages.c | 126 ++
 2 files changed, 59 insertions(+), 68 deletions(-)

diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 9afa5c4a6bf006..1e1cb245fca778 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -25,6 +25,7 @@ config DRM_I915
select CRC32
select SND_HDA_I915 if SND_HDA_CORE
select CEC_CORE if CEC_NOTIFIER
+   select VMAP_PFN
help
  Choose this option if you have a system that has "Intel Graphics
  Media Accelerator" or "HD Graphics" integrated graphics,
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c 
b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index 6550c0bc824ea2..b519417667eb4b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -232,34 +232,21 @@ int __i915_gem_object_put_pages(struct 
drm_i915_gem_object *obj)
return err;
 }
 
-static inline pte_t iomap_pte(resource_size_t base,
- dma_addr_t offset,
- pgprot_t prot)
-{
-   return pte_mkspecial(pfn_pte((base + offset) >> PAGE_SHIFT, prot));
-}
-
 /* The 'mapping' part of i915_gem_object_pin_map() below */
-static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
-enum i915_map_type type)
+static void *i915_gem_object_map_page(struct drm_i915_gem_object *obj,
+   enum i915_map_type type)
 {
-   unsigned long n_pte = obj->base.size >> PAGE_SHIFT;
-   struct sg_table *sgt = obj->mm.pages;
-   pte_t *stack[32], **mem;
-   struct vm_struct *area;
+   unsigned long n_pages = obj->base.size >> PAGE_SHIFT, i;
+   struct page *stack[32], **pages = stack, *page;
+   struct sgt_iter iter;
pgprot_t pgprot;
+   void *vaddr;
 
-   if (!i915_gem_object_has_struct_page(obj) && type != I915_MAP_WC)
-   return NULL;
-
-   if (GEM_WARN_ON(type == I915_MAP_WC &&
-   !static_cpu_has(X86_FEATURE_PAT)))
-   return NULL;
-
-   /* A single page can always be kmapped */
-   if (n_pte == 1 && type == I915_MAP_WB) {
-   struct page *page = sg_page(sgt->sgl);
-
+   switch (type) {
+   default:
+   MISSING_CASE(type);
+   fallthrough;/* to use PAGE_KERNEL anyway */
+   case I915_MAP_WB:
/*
 * On 32b, highmem using a finite set of indirect PTE (i.e.
 * vmap) to provide virtual mappings of the high pages.
@@ -277,30 +264,8 @@ static void *i915_gem_object_map(struct 
drm_i915_gem_object *obj,
 * So if the page is beyond the 32b boundary, make an explicit
 * vmap.
 */
-   if (!PageHighMem(page))
-   return page_address(page);
-   }
-
-   mem = stack;
-   if (n_pte > ARRAY_SIZE(stack)) {
-   /* Too big for stack -- allocate temporary array instead */
-   mem = kvmalloc_array(n_pte, sizeof(*mem), GFP_KERNEL);
-   if (!mem)
-   return NULL;
-   }
-
-   area = alloc_vm_area(obj->base.size, mem);
-   if (!area) {
-   if (mem != stack)
-   kvfree(mem);
-   return NULL;
-   }
-
-   switch (type) {
-   default:
-   MISSING_CASE(type);
-   fallthrough;/* to use PAGE_KERNEL anyway */
-   case I915_MAP_WB:
+   if (n_pages == 1 && !PageHighMem(sg_page(obj->mm.pages->sgl)))
+   return page_address(sg_page(obj->mm.pages->sgl));
pgprot = PAGE_KERNEL;
break;
case I915_MAP_WC:
@@ -308,30 +273,49 @@ static void *i915_gem_object_map(struct 
drm_i915_gem_object *obj,
break;
}
 
-   if (i915_gem_object_has_struct_page(obj)) {
-   struct sgt_iter iter;
-   struct page *page;
-   pte_t **ptes = mem;
+   if (n_pages > ARRAY_SIZE(stack)) {
+   /* Too big for stack -- allocate temporary array instead */
+   pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
+   if (!pages)
+   return NULL;
+   }
 
-   for_each_sgt_page(page, iter, sgt)
-   **ptes++ = mk_pte(page, pgprot);
-   } else