On Thu, Aug 06, 2020 at 10:52:37AM +0200, Thomas Zimmermann wrote:
> GEM's vmap interface now wraps memory pointers in struct drm_gem_membuf.
> The structure represents a pointer into the framebuffer, which is either
> in I/O memory or in system memory. The structure contains a flag that
> distinguishes these cases.
>
> Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
> ---
> drivers/gpu/drm/drm_client.c | 25 ++++++++++++-------------
> drivers/gpu/drm/drm_fb_helper.c | 18 +++++++++---------
> drivers/gpu/drm/drm_gem.c | 19 +++++++++++--------
> drivers/gpu/drm/drm_internal.h | 5 +++--
> drivers/gpu/drm/drm_prime.c | 16 ++++++++++------
> include/drm/drm_client.h | 7 ++++---
> include/drm/drm_device.h | 26 ++++++++++++++++++++++++++
> 7 files changed, 75 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 495f47d23d87..0359b82928c1 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -234,7 +234,7 @@ static void drm_client_buffer_delete(struct
> drm_client_buffer *buffer)
> {
> struct drm_device *dev = buffer->client->dev;
>
> - drm_gem_vunmap(buffer->gem, buffer->vaddr);
> + drm_gem_vunmap(buffer->gem, &buffer->membuf);
>
> if (buffer->gem)
> drm_gem_object_put(buffer->gem);
> @@ -302,12 +302,13 @@ drm_client_buffer_create(struct drm_client_dev *client,
> u32 width, u32 height, u
> * Returns:
> * The mapped memory's address
> */
> -void *drm_client_buffer_vmap(struct drm_client_buffer *buffer)
> +const struct drm_gem_membuf *
> +drm_client_buffer_vmap(struct drm_client_buffer *buffer)
> {
> - void *vaddr;
> + int ret;
>
> - if (buffer->vaddr)
> - return buffer->vaddr;
> + if (buffer->membuf.vaddr)
> + return &buffer->membuf;
>
> /*
> * FIXME: The dependency on GEM here isn't required, we could
> @@ -317,13 +318,11 @@ void *drm_client_buffer_vmap(struct drm_client_buffer
> *buffer)
> * fd_install step out of the driver backend hooks, to make that
> * final step optional for internal users.
> */
> - vaddr = drm_gem_vmap(buffer->gem);
> - if (IS_ERR(vaddr))
> - return vaddr;
> -
> - buffer->vaddr = vaddr;
> + ret = drm_gem_vmap(buffer->gem, &buffer->membuf);
> + if (ret)
> + return ERR_PTR(ret);
>
> - return vaddr;
> + return &buffer->membuf;
> }
> EXPORT_SYMBOL(drm_client_buffer_vmap);
>
> @@ -337,8 +336,8 @@ EXPORT_SYMBOL(drm_client_buffer_vmap);
> */
> void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
> {
> - drm_gem_vunmap(buffer->gem, buffer->vaddr);
> - buffer->vaddr = NULL;
> + drm_gem_vunmap(buffer->gem, &buffer->membuf);
> + buffer->membuf.vaddr = NULL;
> }
> EXPORT_SYMBOL(drm_client_buffer_vunmap);
>
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 8697554ccd41..da24874247e7 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -394,7 +394,7 @@ static void drm_fb_helper_dirty_blit_real(struct
> drm_fb_helper *fb_helper,
> unsigned int cpp = fb->format->cpp[0];
> size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
> void *src = fb_helper->fbdev->screen_buffer + offset;
> - void *dst = fb_helper->buffer->vaddr + offset;
> + void *dst = fb_helper->buffer->membuf.vaddr + offset;
> size_t len = (clip->x2 - clip->x1) * cpp;
> unsigned int y;
>
> @@ -416,7 +416,7 @@ static void drm_fb_helper_dirty_work(struct work_struct
> *work)
> struct drm_clip_rect *clip = &helper->dirty_clip;
> struct drm_clip_rect clip_copy;
> unsigned long flags;
> - void *vaddr;
> + const struct drm_gem_membuf *buf;
>
> spin_lock_irqsave(&helper->dirty_lock, flags);
> clip_copy = *clip;
> @@ -429,8 +429,8 @@ static void drm_fb_helper_dirty_work(struct work_struct
> *work)
>
> /* Generic fbdev uses a shadow buffer */
> if (helper->buffer) {
> - vaddr = drm_client_buffer_vmap(helper->buffer);
> - if (IS_ERR(vaddr))
> + buf = drm_client_buffer_vmap(helper->buffer);
> + if (IS_ERR(buf))
> return;
> drm_fb_helper_dirty_blit_real(helper, &clip_copy);
> }
> @@ -2076,7 +2076,7 @@ static int drm_fb_helper_generic_probe(struct
> drm_fb_helper *fb_helper,
> struct drm_framebuffer *fb;
> struct fb_info *fbi;
> u32 format;
> - void *vaddr;
> + const struct drm_gem_membuf *membuf;
>
> drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
> sizes->surface_width, sizes->surface_height,
> @@ -2112,11 +2112,11 @@ static int drm_fb_helper_generic_probe(struct
> drm_fb_helper *fb_helper,
> fb_deferred_io_init(fbi);
> } else {
> /* buffer is mapped for HW framebuffer */
> - vaddr = drm_client_buffer_vmap(fb_helper->buffer);
> - if (IS_ERR(vaddr))
> - return PTR_ERR(vaddr);
> + membuf = drm_client_buffer_vmap(fb_helper->buffer);
> + if (IS_ERR(membuf))
> + return PTR_ERR(membuf);
>
> - fbi->screen_buffer = vaddr;
> + fbi->screen_buffer = membuf->vaddr;
> /* Shamelessly leak the physical address to user-space */
> #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
> if (drm_leak_fbdev_smem && fbi->fix.smem_start == 0)
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index 19d73868490e..36ded6a56fb2 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -1220,7 +1220,7 @@ void drm_gem_unpin(struct drm_gem_object *obj)
> obj->dev->driver->gem_prime_unpin(obj);
> }
>
> -void *drm_gem_vmap(struct drm_gem_object *obj)
> +int drm_gem_vmap(struct drm_gem_object *obj, struct drm_gem_membuf *buf)
> {
> void *vaddr;
>
> @@ -1229,23 +1229,26 @@ void *drm_gem_vmap(struct drm_gem_object *obj)
> else if (obj->dev->driver->gem_prime_vmap)
> vaddr = obj->dev->driver->gem_prime_vmap(obj);
> else
> - vaddr = ERR_PTR(-EOPNOTSUPP);
> + return -EOPNOTSUPP;
>
> if (!vaddr)
> - vaddr = ERR_PTR(-ENOMEM);
> + return -ENOMEM;
> +
> + buf->vaddr = vaddr;
> + buf->is_iomem = false;
>
> - return vaddr;
> + return 0;
> }
>
> -void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr)
> +void drm_gem_vunmap(struct drm_gem_object *obj, const struct drm_gem_membuf
> *buf)
> {
> - if (!vaddr)
> + if (!buf || !buf->vaddr)
> return;
>
> if (obj->funcs && obj->funcs->vunmap)
> - obj->funcs->vunmap(obj, vaddr);
> + obj->funcs->vunmap(obj, buf->vaddr);
> else if (obj->dev->driver->gem_prime_vunmap)
> - obj->dev->driver->gem_prime_vunmap(obj, vaddr);
> + obj->dev->driver->gem_prime_vunmap(obj, buf->vaddr);
> }
>
> /**
> diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
> index 8e01caaf95cc..201d71249954 100644
> --- a/drivers/gpu/drm/drm_internal.h
> +++ b/drivers/gpu/drm/drm_internal.h
> @@ -36,6 +36,7 @@ struct dma_buf;
> struct drm_connector;
> struct drm_crtc;
> struct drm_framebuffer;
> +struct drm_gem_membuf;
> struct drm_gem_object;
> struct drm_master;
> struct drm_minor;
> @@ -186,8 +187,8 @@ void drm_gem_print_info(struct drm_printer *p, unsigned
> int indent,
>
> int drm_gem_pin(struct drm_gem_object *obj);
> void drm_gem_unpin(struct drm_gem_object *obj);
> -void *drm_gem_vmap(struct drm_gem_object *obj);
> -void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr);
> +int drm_gem_vmap(struct drm_gem_object *obj, struct drm_gem_membuf *buf);
> +void drm_gem_vunmap(struct drm_gem_object *obj, const struct drm_gem_membuf
> *buf);
>
> /* drm_debugfs.c drm_debugfs_crc.c */
> #if defined(CONFIG_DEBUG_FS)
> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> index 1693aa7c14b5..d95a39030a93 100644
> --- a/drivers/gpu/drm/drm_prime.c
> +++ b/drivers/gpu/drm/drm_prime.c
> @@ -671,13 +671,14 @@ EXPORT_SYMBOL(drm_gem_unmap_dma_buf);
> void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> {
> struct drm_gem_object *obj = dma_buf->priv;
> - void *vaddr;
> + struct drm_gem_membuf buf;
> + int ret;
>
> - vaddr = drm_gem_vmap(obj);
> - if (IS_ERR(vaddr))
> - vaddr = NULL;
> + ret = drm_gem_vmap(obj, &buf);
> + if (ret)
> + buf.vaddr = NULL;
>
> - return vaddr;
> + return buf.vaddr;
> }
> EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
>
> @@ -692,8 +693,11 @@ EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
> void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
> {
> struct drm_gem_object *obj = dma_buf->priv;
> + struct drm_gem_membuf buf;
>
> - drm_gem_vunmap(obj, vaddr);
> + buf.vaddr = vaddr;
> + buf.is_iomem = false;
> + drm_gem_vunmap(obj, &buf);
> }
> EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
>
> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
> index 7aaea665bfc2..5ed73c390619 100644
> --- a/include/drm/drm_client.h
> +++ b/include/drm/drm_client.h
> @@ -14,6 +14,7 @@ struct drm_client_dev;
> struct drm_device;
> struct drm_file;
> struct drm_framebuffer;
> +struct drm_gem_membuf;
> struct drm_gem_object;
> struct drm_minor;
> struct module;
> @@ -141,9 +142,9 @@ struct drm_client_buffer {
> struct drm_gem_object *gem;
>
> /**
> - * @vaddr: Virtual address for the buffer
> + * @membuf: Virtual address for the buffer
> */
> - void *vaddr;
> + struct drm_gem_membuf membuf;
>
> /**
> * @fb: DRM framebuffer
> @@ -155,7 +156,7 @@ struct drm_client_buffer *
> drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32
> height, u32 format);
> void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
> int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct
> drm_rect *rect);
> -void *drm_client_buffer_vmap(struct drm_client_buffer *buffer);
> +const struct drm_gem_membuf *drm_client_buffer_vmap(struct drm_client_buffer
> *buffer);
> void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
>
> int drm_client_modeset_create(struct drm_client_dev *client);
> diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
> index 0988351d743c..6ecf03601c36 100644
> --- a/include/drm/drm_device.h
> +++ b/include/drm/drm_device.h
> @@ -381,4 +381,30 @@ struct drm_device {
> #endif
> };
>
> +/**
> + * struct drm_gem_membuf - GEM memory buffer
This isn't gem specific, and membuf feels a bit strange - it's not a
memory buffer, but more a buffer mapping. I'd call these struct
drm_bufmap.
> + */
> +struct drm_gem_membuf {
> + union {
> + /**
> + * @vaddr:
> + *
> + * The virtual address for the buffer in system memory.
> + */
> + void *vaddr;
> + /**
> + * @vaddr_iomem:
> + *
> + * The virtual address for the buffer in I/O memory.
> + */
> + void __iomem *vaddr_iomem;
> + };
> + /**
> + * @is_iomem:
> + *
> + * True if the memory is located in I/O memory, false otherwise.
> + */
> + bool is_iomem;
> +};
I think if we do this we should go all in, i.e. create a new header, and
then start to add all kinds of helper functions to it, like:
static inline drm_memcpy_to_bufmap(bufmap, ...)
{
if (bufmap->is_iomem)
memcpy_toio(bufmap->vaddr_iomem, ...);
else
memcpy(bufmap->vaddr_iomem, ...);
}
totally wrong code of course, but I think you get the idea. If we add
helpers like this I think a new header file is also warranted, so maybe
put it all in drm_bufmap.h and then wire up the kerneldoc.
Also I think cc: ttm people for an ack would be good, maybe long-term we
want to roll this out through ttm too.
Cheers, Daniel
> +
> #endif
> --
> 2.28.0
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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