[PATCH 1/2] drm/vmwgfx: Remove unused hugepage support

[PATCH 1/2] drm/vmwgfx: Remove unused hugepage support

[Zack Rusin]

From: Zack Rusin <zackr@vmware.com>

There's no point in explicitly trying to align virtual memory to
facilitate huge page table entries or huge page memory in buffer objects
given that they're not being used.

Transparent hugepages support for vram allocations has been gradually
retired over the last two years making alignment of unmapped areas
unneeded and pointless.

Signed-off-by: Zack Rusin <zackr@vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 5dc02fd806db..45028e25d490 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -1423,18 +1423,6 @@ static void vmw_debugfs_resource_managers_init(struct vmw_private *vmw)
 					    root, "system_mob_ttm");
 }
 
-static unsigned long
-vmw_get_unmapped_area(struct file *file, unsigned long uaddr,
-		      unsigned long len, unsigned long pgoff,
-		      unsigned long flags)
-{
-	struct drm_file *file_priv = file->private_data;
-	struct vmw_private *dev_priv = vmw_priv(file_priv->minor->dev);
-
-	return drm_get_unmapped_area(file, uaddr, len, pgoff, flags,
-				     dev_priv->drm.vma_offset_manager);
-}
-
 static int vmwgfx_pm_notifier(struct notifier_block *nb, unsigned long val,
 			      void *ptr)
 {
@@ -1601,7 +1589,6 @@ static const struct file_operations vmwgfx_driver_fops = {
 	.compat_ioctl = vmw_compat_ioctl,
 #endif
 	.llseek = noop_llseek,
-	.get_unmapped_area = vmw_get_unmapped_area,
 };
 
 static const struct drm_driver driver = {
-- 
2.32.0

[PATCH 2/2] drm: Remove the drm_get_unmapped_area() helper

[Zack Rusin]

From: Zack Rusin <zackr@vmware.com>

This has been only used by the vmwgfx driver and vmwgfx over the last
year removed support for transparent hugepages on vram leaving
drm_get_unmapped_area completely unused.

There's no point in keeping unused code in core drm.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
---
 drivers/gpu/drm/drm_file.c | 141 -------------------------------------
 include/drm/drm_file.h     |   9 ---
 2 files changed, 150 deletions(-)

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index ed25168619fc..19af326c76f5 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -48,11 +48,6 @@
 #include "drm_internal.h"
 #include "drm_legacy.h"
 
-#if defined(CONFIG_MMU) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
-#include <uapi/asm/mman.h>
-#include <drm/drm_vma_manager.h>
-#endif
-
 /* from BKL pushdown */
 DEFINE_MUTEX(drm_global_mutex);
 
@@ -913,139 +908,3 @@ struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
 	return file;
 }
 EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);
-
-#ifdef CONFIG_MMU
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-/*
- * drm_addr_inflate() attempts to construct an aligned area by inflating
- * the area size and skipping the unaligned start of the area.
- * adapted from shmem_get_unmapped_area()
- */
-static unsigned long drm_addr_inflate(unsigned long addr,
-				      unsigned long len,
-				      unsigned long pgoff,
-				      unsigned long flags,
-				      unsigned long huge_size)
-{
-	unsigned long offset, inflated_len;
-	unsigned long inflated_addr;
-	unsigned long inflated_offset;
-
-	offset = (pgoff << PAGE_SHIFT) & (huge_size - 1);
-	if (offset && offset + len < 2 * huge_size)
-		return addr;
-	if ((addr & (huge_size - 1)) == offset)
-		return addr;
-
-	inflated_len = len + huge_size - PAGE_SIZE;
-	if (inflated_len > TASK_SIZE)
-		return addr;
-	if (inflated_len < len)
-		return addr;
-
-	inflated_addr = current->mm->get_unmapped_area(NULL, 0, inflated_len,
-						       0, flags);
-	if (IS_ERR_VALUE(inflated_addr))
-		return addr;
-	if (inflated_addr & ~PAGE_MASK)
-		return addr;
-
-	inflated_offset = inflated_addr & (huge_size - 1);
-	inflated_addr += offset - inflated_offset;
-	if (inflated_offset > offset)
-		inflated_addr += huge_size;
-
-	if (inflated_addr > TASK_SIZE - len)
-		return addr;
-
-	return inflated_addr;
-}
-
-/**
- * drm_get_unmapped_area() - Get an unused user-space virtual memory area
- * suitable for huge page table entries.
- * @file: The struct file representing the address space being mmap()'d.
- * @uaddr: Start address suggested by user-space.
- * @len: Length of the area.
- * @pgoff: The page offset into the address space.
- * @flags: mmap flags
- * @mgr: The address space manager used by the drm driver. This argument can
- * probably be removed at some point when all drivers use the same
- * address space manager.
- *
- * This function attempts to find an unused user-space virtual memory area
- * that can accommodate the size we want to map, and that is properly
- * aligned to facilitate huge page table entries matching actual
- * huge pages or huge page aligned memory in buffer objects. Buffer objects
- * are assumed to start at huge page boundary pfns (io memory) or be
- * populated by huge pages aligned to the start of the buffer object
- * (system- or coherent memory). Adapted from shmem_get_unmapped_area.
- *
- * Return: aligned user-space address.
- */
-unsigned long drm_get_unmapped_area(struct file *file,
-				    unsigned long uaddr, unsigned long len,
-				    unsigned long pgoff, unsigned long flags,
-				    struct drm_vma_offset_manager *mgr)
-{
-	unsigned long addr;
-	unsigned long inflated_addr;
-	struct drm_vma_offset_node *node;
-
-	if (len > TASK_SIZE)
-		return -ENOMEM;
-
-	/*
-	 * @pgoff is the file page-offset the huge page boundaries of
-	 * which typically aligns to physical address huge page boundaries.
-	 * That's not true for DRM, however, where physical address huge
-	 * page boundaries instead are aligned with the offset from
-	 * buffer object start. So adjust @pgoff to be the offset from
-	 * buffer object start.
-	 */
-	drm_vma_offset_lock_lookup(mgr);
-	node = drm_vma_offset_lookup_locked(mgr, pgoff, 1);
-	if (node)
-		pgoff -= node->vm_node.start;
-	drm_vma_offset_unlock_lookup(mgr);
-
-	addr = current->mm->get_unmapped_area(file, uaddr, len, pgoff, flags);
-	if (IS_ERR_VALUE(addr))
-		return addr;
-	if (addr & ~PAGE_MASK)
-		return addr;
-	if (addr > TASK_SIZE - len)
-		return addr;
-
-	if (len < HPAGE_PMD_SIZE)
-		return addr;
-	if (flags & MAP_FIXED)
-		return addr;
-	/*
-	 * Our priority is to support MAP_SHARED mapped hugely;
-	 * and support MAP_PRIVATE mapped hugely too, until it is COWed.
-	 * But if caller specified an address hint, respect that as before.
-	 */
-	if (uaddr)
-		return addr;
-
-	inflated_addr = drm_addr_inflate(addr, len, pgoff, flags,
-					 HPAGE_PMD_SIZE);
-
-	if (IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) &&
-	    len >= HPAGE_PUD_SIZE)
-		inflated_addr = drm_addr_inflate(inflated_addr, len, pgoff,
-						 flags, HPAGE_PUD_SIZE);
-	return inflated_addr;
-}
-#else /* CONFIG_TRANSPARENT_HUGEPAGE */
-unsigned long drm_get_unmapped_area(struct file *file,
-				    unsigned long uaddr, unsigned long len,
-				    unsigned long pgoff, unsigned long flags,
-				    struct drm_vma_offset_manager *mgr)
-{
-	return current->mm->get_unmapped_area(file, uaddr, len, pgoff, flags);
-}
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-EXPORT_SYMBOL_GPL(drm_get_unmapped_area);
-#endif /* CONFIG_MMU */
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index e0a73a1e2df7..d780fd151789 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -421,13 +421,4 @@ void drm_send_event_timestamp_locked(struct drm_device *dev,
 
 struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags);
 
-#ifdef CONFIG_MMU
-struct drm_vma_offset_manager;
-unsigned long drm_get_unmapped_area(struct file *file,
-				    unsigned long uaddr, unsigned long len,
-				    unsigned long pgoff, unsigned long flags,
-				    struct drm_vma_offset_manager *mgr);
-#endif /* CONFIG_MMU */
-
-
 #endif /* _DRM_FILE_H_ */
-- 
2.32.0

Re: [PATCH 1/2] drm/vmwgfx: Remove unused hugepage support

[Thomas Hellström (Intel)]

On 4/25/22 22:31, Zack Rusin wrote:
> From: Zack Rusin <zackr@vmware.com>
>
> There's no point in explicitly trying to align virtual memory to
> facilitate huge page table entries or huge page memory in buffer objects
> given that they're not being used.
>
> Transparent hugepages support for vram allocations has been gradually
> retired over the last two years making alignment of unmapped areas
> unneeded and pointless.
>
> Signed-off-by: Zack Rusin <zackr@vmware.com>

For the series:

Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>


> ---
>   drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 13 -------------
>   1 file changed, 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> index 5dc02fd806db..45028e25d490 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> @@ -1423,18 +1423,6 @@ static void vmw_debugfs_resource_managers_init(struct vmw_private *vmw)
>   					    root, "system_mob_ttm");
>   }
>   
> -static unsigned long
> -vmw_get_unmapped_area(struct file *file, unsigned long uaddr,
> -		      unsigned long len, unsigned long pgoff,
> -		      unsigned long flags)
> -{
> -	struct drm_file *file_priv = file->private_data;
> -	struct vmw_private *dev_priv = vmw_priv(file_priv->minor->dev);
> -
> -	return drm_get_unmapped_area(file, uaddr, len, pgoff, flags,
> -				     dev_priv->drm.vma_offset_manager);
> -}
> -
>   static int vmwgfx_pm_notifier(struct notifier_block *nb, unsigned long val,
>   			      void *ptr)
>   {
> @@ -1601,7 +1589,6 @@ static const struct file_operations vmwgfx_driver_fops = {
>   	.compat_ioctl = vmw_compat_ioctl,
>   #endif
>   	.llseek = noop_llseek,
> -	.get_unmapped_area = vmw_get_unmapped_area,
>   };
>   
>   static const struct drm_driver driver = {