On Thu, Aug 13, 2020 at 12:46 PM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:
>
> Hi
>
> Am 13.08.20 um 12:26 schrieb Daniel Vetter:
> > 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 <tzimmermann@xxxxxxx>
> >> ---
> >> 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.
>
> Yep, I didn't like the name either. struct drm_bufmap sounds good.
>
> As i mentioned on irc, I'd also want to propose this as an update to
> dma-buf's vmap. It's not that much more work and should fix the issue
> once and for all. If they are interested, struct dma_buf_addr might be a
> candidate.
Ah if that's the goal, I'd say call it dma_buf_map from the start and
have it under the dma-buf documentation section.
-Daniel
>
> >
> >> + */
> >> +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.
>
> Sure.
>
> Best regards
> Thomas
>
> >
> > Cheers, Daniel
> >
> >
> >> +
> >> #endif
> >> --
> >> 2.28.0
> >>
> >
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
> Geschäftsführer: Felix Imendörffer
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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