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.
>
>> + */
>> +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.
Just a note: while converting the fbdev blit code, I found it easier to
open-code the test for is_iomem and have two separate loops. Doing the
same with drm_memcpy_to_bufmap would also require helpers for pointer
arithmetics and array indexing to make it comfortable to use.
Best regards
Thomas
>
> 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
>>
>
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer
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