2016-12-07 15:35 GMT+01:00 Laurent Pinchart laurent.pinchart@ideasonboard.com:

Hi Benjamin,

Thank you for the patch.

On Wednesday 07 Dec 2016 11:06:49 Benjamin Gaignard wrote:

...

Allow generic frame-buffer to provide a default get_fb_unmapped_area function if specific devices need it.

Usually this function is defined in architecture directories but define it here may limit code duplication especially for all ARM platforms without MMU.

I still would like to see an explanation why an architecture-specific version is sometimes needed, and why this implementation is a reasonable default. Furthermore, it looks very similar to the blackfin implementation, so if you can't unify the two I'd like to know why.

Obviously I don't know all the legacy behind this function but it is definitively link to architectures memory mapping strategies in no MMU cases.

I think this function is a reasonable default when the architecture is doing a direct mapping (no translation) of the memory like it is done in ARM.

Unlike what I propose blackfin implementation doesn't do any check on pgoff and length and always return fb base address even is an offset has been requested. I don't know if it is on purpose or just because nobody has never try to mmap blackfin framebuffer with an offset...

...

version 4:

• introdude a configuration flag to be independent of architecture

Signed-off-by: Benjamin Gaignard benjamin.gaignard@linaro.org

drivers/video/fbdev/Kconfig | 8 ++++++++ drivers/video/fbdev/core/fbmem.c | 15 +++++++++++++++ 2 files changed, 23 insertions(+)

diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig index 5d3b0db..922e4ea 100644 --- a/drivers/video/fbdev/Kconfig +++ b/drivers/video/fbdev/Kconfig @@ -138,6 +138,14 @@ config FB_SYS_IMAGEBLIT blitting. This is used by drivers that don't provide their own (accelerated) version and the framebuffer is in system RAM.

+config FB_PROVIDE_GET_FB_UNMAPPED_AREA

• bool
  

• depends on FB
  

• default n
  

• ---help---
  

•   Allow generic frame-buffer to provide get_fb_unmapped_area
  

•   function.
  

menuconfig FB_FOREIGN_ENDIAN bool "Framebuffer foreign endianness support" depends on FB diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 76c1ad9..22321a2 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1492,6 +1492,21 @@ static long fb_compat_ioctl(struct file *file, unsigned int cmd, return 0; }

+#ifdef CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA +unsigned long get_fb_unmapped_area(struct file *filp,

•                            unsigned long addr, unsigned long len,
  

•                            unsigned long pgoff, unsigned long flags)
  

+{

• struct fb_info * const info = filp->private_data;
  

• unsigned long fb_size = PAGE_ALIGN(info->fix.smem_len);
  

• if (pgoff > fb_size || len > fb_size - pgoff)
  

•         return -EINVAL;
  

• return (unsigned long)info->screen_base + pgoff;
  

+} +#endif

static const struct file_operations fb_fops = { .owner = THIS_MODULE, .read = fb_read,

-- Regards,

Laurent Pinchart

Hi Thomas,

in commit 59bd00c8 (Blackfin: fix framebuffer mmap bug for nommu) you have introduce get_fb_unmapped_area() for blackfin architecture.

I'm proposing a patch to have a default function in fbmem which slightly does the same.

Do you think is new function could also fit with blackfin architecture needs ? or does this architecture have specific requirements ?

Regards, Benjamin

2016-12-07 16:19 GMT+01:00 Laurent Pinchart laurent.pinchart@ideasonboard.com:

Hi Benjamin,

On Wednesday 07 Dec 2016 15:57:49 Benjamin Gaignard wrote:

...

2016-12-07 15:35 GMT+01:00 Laurent Pinchart:

...

On Wednesday 07 Dec 2016 11:06:49 Benjamin Gaignard wrote:

...

Allow generic frame-buffer to provide a default get_fb_unmapped_area function if specific devices need it.

Usually this function is defined in architecture directories but define it here may limit code duplication especially for all ARM platforms without MMU.

I still would like to see an explanation why an architecture-specific version is sometimes needed, and why this implementation is a reasonable default. Furthermore, it looks very similar to the blackfin implementation, so if you can't unify the two I'd like to know why.

Obviously I don't know all the legacy behind this function but it is definitively link to architectures memory mapping strategies in no MMU cases.

I think this function is a reasonable default when the architecture is doing a direct mapping (no translation) of the memory like it is done in ARM.

Unlike what I propose blackfin implementation doesn't do any check on pgoff and length and always return fb base address even is an offset has been requested. I don't know if it is on purpose or just because nobody has never try to mmap blackfin framebuffer with an offset...

And that's exactly what I'd like you to try and find out :-) git blame and contacting the original authors of that code could be a first step.

...

...

...

version 4:

• introdude a configuration flag to be independent of architecture

Signed-off-by: Benjamin Gaignard benjamin.gaignard@linaro.org

drivers/video/fbdev/Kconfig | 8 ++++++++ drivers/video/fbdev/core/fbmem.c | 15 +++++++++++++++ 2 files changed, 23 insertions(+)

diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig index 5d3b0db..922e4ea 100644 --- a/drivers/video/fbdev/Kconfig +++ b/drivers/video/fbdev/Kconfig @@ -138,6 +138,14 @@ config FB_SYS_IMAGEBLIT

    blitting. This is used by drivers that don't provide their own
    (accelerated) version and the framebuffer is in system RAM.

+config FB_PROVIDE_GET_FB_UNMAPPED_AREA

• bool
  

• depends on FB
  

• default n
  

• ---help---
  

•   Allow generic frame-buffer to provide get_fb_unmapped_area
  

•   function.
  

menuconfig FB_FOREIGN_ENDIAN

  bool "Framebuffer foreign endianness support"
  depends on FB

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 76c1ad9..22321a2 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1492,6 +1492,21 @@ static long fb_compat_ioctl(struct file *file, unsigned int cmd, return 0;

}

+#ifdef CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA +unsigned long get_fb_unmapped_area(struct file *filp,

•                            unsigned long addr, unsigned long len,
  

•                            unsigned long pgoff, unsigned long
  

flags) +{

• struct fb_info * const info = filp->private_data;
  

• unsigned long fb_size = PAGE_ALIGN(info->fix.smem_len);
  

• if (pgoff > fb_size || len > fb_size - pgoff)
  

•         return -EINVAL;
  

• return (unsigned long)info->screen_base + pgoff;
  

+} +#endif

static const struct file_operations fb_fops = {

  .owner =        THIS_MODULE,
  .read =         fb_read,

-- Regards,

Laurent Pinchart

-- Regards,

Laurent Pinchart

Hi Benjamin,

Thank you for the patch.

On Wednesday 07 Dec 2016 11:06:50 Benjamin Gaignard wrote:

drm_vm.c functions are only need for DRM_LEGACY and DRM_NOUVEAU. Use a new DRM_VM to define when drm_vm.c in needed.

stub drm_legacy_vma_flush() to avoid compilation issues

version 4:

• a "config DRM_VM" in Kconfig

Signed-off-by: Benjamin Gaignard benjamin.gaignard@linaro.org

Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com

---

drivers/gpu/drm/Kconfig | 5 +++++ drivers/gpu/drm/Makefile | 3 ++- drivers/gpu/drm/drm_legacy.h | 7 +++++++ drivers/gpu/drm/nouveau/Kconfig | 1 + 4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 8d9cf73..83ac815 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -121,6 +121,10 @@ config DRM_KMS_CMA_HELPER help Choose this if you need the KMS CMA helper functions

+config DRM_VM

• bool
• depends on DRM

source "drivers/gpu/drm/i2c/Kconfig"

source "drivers/gpu/drm/arm/Kconfig" @@ -246,6 +250,7 @@ source "drivers/gpu/drm/zte/Kconfig" menuconfig DRM_LEGACY bool "Enable legacy drivers (DANGEROUS)" depends on DRM

• select DRM_VM help Enable legacy DRI1 drivers. Those drivers expose unsafe and

dangerous

 APIs to user-space, which can be used to circumvent access

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index e10e935..5b73b16 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -5,7 +5,7 @@ drm-y := drm_auth.o drm_bufs.o drm_cache.o \ drm_context.o drm_dma.o \ drm_fops.o drm_gem.o drm_ioctl.o drm_irq.o \

• drm_lock.o drm_memory.o drm_drv.o drm_vm.o \
  

• drm_lock.o drm_memory.o drm_drv.o \
  

  drm_scatter.o drm_pci.o \ drm_platform.o drm_sysfs.o drm_hashtab.o drm_mm.o \ drm_crtc.o drm_fourcc.o drm_modes.o drm_edid.o \

@@ -18,6 +18,7 @@ drm-y := drm_auth.o drm_bufs.o drm_cache.o \ drm_plane.o drm_color_mgmt.o drm_print.o \ drm_dumb_buffers.o drm_mode_config.o

+drm-$(CONFIG_DRM_VM) += drm_vm.o drm-$(CONFIG_COMPAT) += drm_ioc32.o drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o drm-$(CONFIG_PCI) += ati_pcigart.o diff --git a/drivers/gpu/drm/drm_legacy.h b/drivers/gpu/drm/drm_legacy.h index c6f422e..e4bb5ad 100644 --- a/drivers/gpu/drm/drm_legacy.h +++ b/drivers/gpu/drm/drm_legacy.h @@ -74,7 +74,14 @@ int drm_legacy_getmap_ioctl(struct drm_device *dev, void *data, int drm_legacy_mapbufs(struct drm_device *d, void *v, struct drm_file *f); int drm_legacy_dma_ioctl(struct drm_device *d, void *v, struct drm_file *f);

+#ifdef CONFIG_DRM_VM void drm_legacy_vma_flush(struct drm_device *d); +#else +static inline void drm_legacy_vma_flush(struct drm_device *d) +{

• /* do nothing */

+} +#endif

/*

• AGP Support

diff --git a/drivers/gpu/drm/nouveau/Kconfig b/drivers/gpu/drm/nouveau/Kconfig index 2922a82..0f2f0af 100644 --- a/drivers/gpu/drm/nouveau/Kconfig +++ b/drivers/gpu/drm/nouveau/Kconfig @@ -16,6 +16,7 @@ config DRM_NOUVEAU select INPUT if ACPI && X86 select THERMAL if ACPI && X86 select ACPI_VIDEO if ACPI && X86

• select DRM_VM help Choose this option for open-source NVIDIA support.

On Wed, Dec 07, 2016 at 11:06:51AM +0100, Benjamin Gaignard wrote:

Some SoC without MMU have display driver where a drm/kms driver could be implemented.

Before doing such kind of thing drm/kms must allow to use mmuless devices. This patch propose to remove MMU configuration flag and add a cma helper function to help implementing mmuless display driver

version 4:

• add documentation about drm_gem_cma_get_unmapped_area()
• stub it MMU case

Signed-off-by: Benjamin Gaignard benjamin.gaignard@linaro.org

Shouldn't we also update DRM_FB_HELPER_DEFAULT_OPS? With that addressed this all looks good to me. -Daniel

---

Documentation/gpu/drm-mm.rst | 11 ++++++ drivers/gpu/drm/Kconfig | 4 +-- drivers/gpu/drm/drm_gem_cma_helper.c | 69 ++++++++++++++++++++++++++++++++++++ include/drm/drm_gem_cma_helper.h | 17 +++++++++ 4 files changed, 99 insertions(+), 2 deletions(-)

diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst index bca8085..6e7efab 100644 --- a/Documentation/gpu/drm-mm.rst +++ b/Documentation/gpu/drm-mm.rst @@ -303,6 +303,17 @@ created. Drivers that want to map the GEM object upfront instead of handling page faults can implement their own mmap file operation handler. +For platforms without MMU GEM care provides a helper method +:c:func:`drm_gem_cma_get_unmapped_area`. The mmap() routines will call +this to get a proposed address for the mapping.

+To use :c:func:`drm_gem_cma_get_unmapped_area`, drivers must fill the +struct :c:type:`struct file_operations <file_operations>` get_unmapped_area +field with a pointer on :c:func:`drm_gem_cma_get_unmapped_area`.

+More detailed information about get_unmapped_area can be found in +Documentation/nommu-mmap.txt

Memory Coherency

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 83ac815..0eae4ad 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -6,7 +6,7 @@ # menuconfig DRM tristate "Direct Rendering Manager (XFree86 4.1.0 and higher DRI support)"

• depends on (AGP || AGP=n) && !EMULATED_CMPXCHG && MMU && HAS_DMA

• depends on (AGP || AGP=n) && !EMULATED_CMPXCHG && HAS_DMA select HDMI select FB_CMDLINE select I2C

@@ -98,7 +98,7 @@ config DRM_LOAD_EDID_FIRMWARE config DRM_TTM tristate

• depends on DRM

• depends on DRM && MMU help GPU memory management subsystem for devices with multiple GPU memory types. Will be enabled automatically if a device driver

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index 1d6c335..01016b1 100644 --- a/drivers/gpu/drm/drm_gem_cma_helper.c +++ b/drivers/gpu/drm/drm_gem_cma_helper.c @@ -358,6 +358,75 @@ int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma) } EXPORT_SYMBOL_GPL(drm_gem_cma_mmap); +#ifndef CONFIG_MMU +/**

• • drm_gem_cma_get_unmapped_area - propose address for mapping in noMMU cases
• • @filp: file object
• • @addr: memory address
• • @len: buffer size
• • @pgoff: page offset
• • @flags: memory flags
• • This function is used in noMMU platforms to propose address mapping
• • for a given buffer.
• • Returns:
• • mapping address on success or a negative error code on failure
• */

+unsigned long drm_gem_cma_get_unmapped_area(struct file *filp,

• 			    unsigned long addr,
  

• 			    unsigned long len,
  

• 			    unsigned long pgoff,
  

• 			    unsigned long flags)
  

+{

• struct drm_gem_cma_object *cma_obj;
• struct drm_gem_object *obj = NULL;
• struct drm_file *priv = filp->private_data;
• struct drm_device *dev = priv->minor->dev;
• struct drm_vma_offset_node *node;
• if (drm_device_is_unplugged(dev))

• return -ENODEV;
  

• drm_vma_offset_lock_lookup(dev->vma_offset_manager);
• node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,

• 				  pgoff,
  

• 				  len >> PAGE_SHIFT);
  

• if (likely(node)) {

• obj = container_of(node, struct drm_gem_object, vma_node);
  

• /*
  

•  * When the object is being freed, after it hits 0-refcnt it
  

•  * proceeds to tear down the object. In the process it will
  

•  * attempt to remove the VMA offset and so acquire this
  

•  * mgr->vm_lock.  Therefore if we find an object with a 0-refcnt
  

•  * that matches our range, we know it is in the process of being
  

•  * destroyed and will be freed as soon as we release the lock -
  

•  * so we have to check for the 0-refcnted object and treat it as
  

•  * invalid.
  

•  */
  

• if (!kref_get_unless_zero(&obj->refcount))
  

• 	obj = NULL;
  

• }
• drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
• if (!obj)

• return -EINVAL;
  

• if (!drm_vma_node_is_allowed(node, priv)) {

• drm_gem_object_unreference_unlocked(obj);
  

• return -EACCES;
  

• }
• cma_obj = to_drm_gem_cma_obj(obj);
• drm_gem_object_unreference_unlocked(obj);
• return cma_obj->vaddr ? (unsigned long)cma_obj->vaddr : -EINVAL;

+} +EXPORT_SYMBOL_GPL(drm_gem_cma_get_unmapped_area); +#endif

#ifdef CONFIG_DEBUG_FS /**

• drm_gem_cma_describe - describe a CMA GEM object for debugfs

diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h index acd6af8..180b586 100644 --- a/include/drm/drm_gem_cma_helper.h +++ b/include/drm/drm_gem_cma_helper.h @@ -53,6 +53,23 @@ struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm, extern const struct vm_operations_struct drm_gem_cma_vm_ops; +#ifndef CONFIG_MMU +unsigned long drm_gem_cma_get_unmapped_area(struct file *filp,

• 			    unsigned long addr,
  

• 			    unsigned long len,
  

• 			    unsigned long pgoff,
  

• 			    unsigned long flags);
  

+#else +unsigned long drm_gem_cma_get_unmapped_area(struct file *filp,

• 			    unsigned long addr,
  

• 			    unsigned long len,
  

• 			    unsigned long pgoff,
  

• 			    unsigned long flags)
  

+{

• return -EINVAL;

+} +#endif

#ifdef CONFIG_DEBUG_FS void drm_gem_cma_describe(struct drm_gem_cma_object *obj, struct seq_file *m);

#endif

1.9.1

Hi Benjamin,

Thank you for the patch.

On Wednesday 07 Dec 2016 11:06:51 Benjamin Gaignard wrote:

Some SoC without MMU have display driver where a drm/kms driver could be implemented.

Before doing such kind of thing drm/kms must allow to use mmuless devices. This patch propose to remove MMU configuration flag and add a cma helper function to help implementing mmuless display driver

version 4:

• add documentation about drm_gem_cma_get_unmapped_area()
• stub it MMU case

Signed-off-by: Benjamin Gaignard benjamin.gaignard@linaro.org

Documentation/gpu/drm-mm.rst | 11 ++++++ drivers/gpu/drm/Kconfig | 4 +-- drivers/gpu/drm/drm_gem_cma_helper.c | 69 +++++++++++++++++++++++++++++++++ include/drm/drm_gem_cma_helper.h | 17 +++++++++ 4 files changed, 99 insertions(+), 2 deletions(-)

diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst index bca8085..6e7efab 100644 --- a/Documentation/gpu/drm-mm.rst +++ b/Documentation/gpu/drm-mm.rst @@ -303,6 +303,17 @@ created. Drivers that want to map the GEM object upfront instead of handling page faults can implement their own mmap file operation handler.

+For platforms without MMU GEM care provides a helper method

s/GEM care/the GEM core/

+:c:func:`drm_gem_cma_get_unmapped_area`. The mmap() routines will call +this to get a proposed address for the mapping.

+To use :c:func:`drm_gem_cma_get_unmapped_area`, drivers must fill the +struct :c:type:`struct file_operations <file_operations>` get_unmapped_area +field with a pointer on :c:func:`drm_gem_cma_get_unmapped_area`.

+More detailed information about get_unmapped_area can be found in +Documentation/nommu-mmap.txt

Memory Coherency

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 83ac815..0eae4ad 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -6,7 +6,7 @@ # menuconfig DRM tristate "Direct Rendering Manager (XFree86 4.1.0 and higher DRI

support)"

• depends on (AGP || AGP=n) && !EMULATED_CMPXCHG && MMU && HAS_DMA

• depends on (AGP || AGP=n) && !EMULATED_CMPXCHG && HAS_DMA select HDMI select FB_CMDLINE select I2C

@@ -98,7 +98,7 @@ config DRM_LOAD_EDID_FIRMWARE

config DRM_TTM tristate

• depends on DRM

• depends on DRM && MMU help GPU memory management subsystem for devices with multiple GPU memory types. Will be enabled automatically if a device driver

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index 1d6c335..01016b1 100644 --- a/drivers/gpu/drm/drm_gem_cma_helper.c +++ b/drivers/gpu/drm/drm_gem_cma_helper.c @@ -358,6 +358,75 @@ int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma) } EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);

+#ifndef CONFIG_MMU +/**

• • drm_gem_cma_get_unmapped_area - propose address for mapping in noMMU

cases

• • @filp: file object
• • @addr: memory address
• • @len: buffer size
• • @pgoff: page offset
• • @flags: memory flags
• • This function is used in noMMU platforms to propose address mapping
• • for a given buffer.

I would add

"It's intended to be used as a direct handler for the :c:type:`struct file_operations <file_operations>` .get_unmapped_area() operation."

Apart from that,

Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com

• • Returns:
• • mapping address on success or a negative error code on failure
• */

+unsigned long drm_gem_cma_get_unmapped_area(struct file *filp,

• 			    unsigned long addr,
  

• 			    unsigned long len,
  

• 			    unsigned long pgoff,
  

• 			    unsigned long flags)
  

+{

• struct drm_gem_cma_object *cma_obj;
• struct drm_gem_object *obj = NULL;
• struct drm_file *priv = filp->private_data;
• struct drm_device *dev = priv->minor->dev;
• struct drm_vma_offset_node *node;
• if (drm_device_is_unplugged(dev))

• return -ENODEV;
  

• drm_vma_offset_lock_lookup(dev->vma_offset_manager);
• node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,

• 				  pgoff,
  

• 				  len >> PAGE_SHIFT);
  

• if (likely(node)) {

• obj = container_of(node, struct drm_gem_object, vma_node);
  

• /*
  

•  * When the object is being freed, after it hits 0-refcnt it
  

•  * proceeds to tear down the object. In the process it will
  

•  * attempt to remove the VMA offset and so acquire this
  

•  * mgr->vm_lock.  Therefore if we find an object with a 0-
  

refcnt

•  * that matches our range, we know it is in the process of 
  

being

•  * destroyed and will be freed as soon as we release the lock 
  

-

•  * so we have to check for the 0-refcnted object and treat it 
  

as

•  * invalid.
  

•  */
  

• if (!kref_get_unless_zero(&obj->refcount))
  

• 	obj = NULL;
  

• }
• drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
• if (!obj)

• return -EINVAL;
  

• if (!drm_vma_node_is_allowed(node, priv)) {

• drm_gem_object_unreference_unlocked(obj);
  

• return -EACCES;
  

• }
• cma_obj = to_drm_gem_cma_obj(obj);
• drm_gem_object_unreference_unlocked(obj);
• return cma_obj->vaddr ? (unsigned long)cma_obj->vaddr : -EINVAL;

+} +EXPORT_SYMBOL_GPL(drm_gem_cma_get_unmapped_area); +#endif

#ifdef CONFIG_DEBUG_FS /**

• drm_gem_cma_describe - describe a CMA GEM object for debugfs

diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h index acd6af8..180b586 100644 --- a/include/drm/drm_gem_cma_helper.h +++ b/include/drm/drm_gem_cma_helper.h @@ -53,6 +53,23 @@ struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,

extern const struct vm_operations_struct drm_gem_cma_vm_ops;

+#ifndef CONFIG_MMU +unsigned long drm_gem_cma_get_unmapped_area(struct file *filp,

• 			    unsigned long addr,
  

• 			    unsigned long len,
  

• 			    unsigned long pgoff,
  

• 			    unsigned long flags);
  

+#else +unsigned long drm_gem_cma_get_unmapped_area(struct file *filp,

• 			    unsigned long addr,
  

• 			    unsigned long len,
  

• 			    unsigned long pgoff,
  

• 			    unsigned long flags)
  

+{

• return -EINVAL;

+} +#endif

#ifdef CONFIG_DEBUG_FS void drm_gem_cma_describe(struct drm_gem_cma_object *obj, struct seq_file *m); #endif