Re: [PATCH 2/2] drm/vkms: Add PRIME support by converting to Noralf's shmem helpers.
From: Daniel Vetter
Date: Tue Nov 27 2018 - 04:11:48 EST
On Mon, Nov 26, 2018 at 01:59:29PM -0800, Eric Anholt wrote:
> This cuts out a tremendous amount of boilerplate. I've used the PRIME
> support now to test V3D rendering on a STB development board with no
> KMS driver.
>
> Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
> ---
>
> This patch depends on https://patchwork.freedesktop.org/series/27184/
Nice stuff. Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx> on both.
>
> drivers/gpu/drm/Kconfig | 1 +
> drivers/gpu/drm/vkms/vkms_crc.c | 28 ++--
> drivers/gpu/drm/vkms/vkms_drv.c | 16 +--
> drivers/gpu/drm/vkms/vkms_drv.h | 22 ----
> drivers/gpu/drm/vkms/vkms_gem.c | 212 ++----------------------------
> drivers/gpu/drm/vkms/vkms_plane.c | 17 ++-
> 6 files changed, 42 insertions(+), 254 deletions(-)
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 0dedbc040c77..3bdd95f99feb 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -253,6 +253,7 @@ config DRM_VKMS
> tristate "Virtual KMS (EXPERIMENTAL)"
> depends on DRM
> select DRM_KMS_HELPER
> + select DRM_GEM_SHMEM_HELPER
> default n
> help
> Virtual Kernel Mode-Setting (VKMS) is used for testing or for
> diff --git a/drivers/gpu/drm/vkms/vkms_crc.c b/drivers/gpu/drm/vkms/vkms_crc.c
> index 9d9e8146db90..72d6422fb1a5 100644
> --- a/drivers/gpu/drm/vkms/vkms_crc.c
> +++ b/drivers/gpu/drm/vkms/vkms_crc.c
> @@ -4,6 +4,7 @@
> #include <drm/drm_atomic.h>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_gem_shmem_helper.h>
>
> /**
> * compute_crc - Compute CRC value on output frame
> @@ -91,21 +92,19 @@ static void compose_cursor(struct vkms_crc_data *cursor_crc,
> struct vkms_crc_data *primary_crc, void *vaddr_out)
> {
> struct drm_gem_object *cursor_obj;
> - struct vkms_gem_object *cursor_vkms_obj;
> + void *vaddr;
>
> cursor_obj = drm_gem_fb_get_obj(&cursor_crc->fb, 0);
> - cursor_vkms_obj = drm_gem_to_vkms_gem(cursor_obj);
> + vaddr = drm_gem_shmem_vmap(cursor_obj);
>
> - mutex_lock(&cursor_vkms_obj->pages_lock);
> - if (!cursor_vkms_obj->vaddr) {
> + if (IS_ERR(vaddr)) {
> DRM_WARN("cursor plane vaddr is NULL");
> - goto out;
> + return;
> }
>
> - blend(vaddr_out, cursor_vkms_obj->vaddr, primary_crc, cursor_crc);
> + blend(vaddr_out, vaddr, primary_crc, cursor_crc);
>
> -out:
> - mutex_unlock(&cursor_vkms_obj->pages_lock);
> + drm_gem_shmem_vunmap(cursor_obj, vaddr);
> }
>
> static uint32_t _vkms_get_crc(struct vkms_crc_data *primary_crc,
> @@ -113,8 +112,8 @@ static uint32_t _vkms_get_crc(struct vkms_crc_data *primary_crc,
> {
> struct drm_framebuffer *fb = &primary_crc->fb;
> struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0);
> - struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(gem_obj);
> - void *vaddr_out = kzalloc(vkms_obj->gem.size, GFP_KERNEL);
> + void *vaddr;
> + void *vaddr_out = kzalloc(gem_obj->size, GFP_KERNEL);
> u32 crc = 0;
>
> if (!vaddr_out) {
> @@ -122,21 +121,20 @@ static uint32_t _vkms_get_crc(struct vkms_crc_data *primary_crc,
> return 0;
> }
>
> - mutex_lock(&vkms_obj->pages_lock);
> - if (WARN_ON(!vkms_obj->vaddr)) {
> - mutex_unlock(&vkms_obj->pages_lock);
> + vaddr = drm_gem_shmem_vmap(gem_obj);
> + if (WARN_ON(IS_ERR(vaddr))) {
> kfree(vaddr_out);
> return crc;
> }
>
> - memcpy(vaddr_out, vkms_obj->vaddr, vkms_obj->gem.size);
> - mutex_unlock(&vkms_obj->pages_lock);
> + memcpy(vaddr_out, vaddr, gem_obj->size);
>
> if (cursor_crc)
> compose_cursor(cursor_crc, primary_crc, vaddr_out);
>
> crc = compute_crc(vaddr_out, primary_crc);
>
> + drm_gem_shmem_vunmap(gem_obj, vaddr);
> kfree(vaddr_out);
>
> return crc;
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
> index 83087877565c..fa26e2675028 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.c
> +++ b/drivers/gpu/drm/vkms/vkms_drv.c
> @@ -19,6 +19,7 @@
> #include <drm/drm_crtc_helper.h>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_gem_shmem_helper.h>
> #include <drm/drm_fb_helper.h>
> #include "vkms_drv.h"
>
> @@ -46,12 +47,6 @@ static const struct file_operations vkms_driver_fops = {
> .release = drm_release,
> };
>
> -static const struct vm_operations_struct vkms_gem_vm_ops = {
> - .fault = vkms_gem_fault,
> - .open = drm_gem_vm_open,
> - .close = drm_gem_vm_close,
> -};
> -
> static void vkms_release(struct drm_device *dev)
> {
> struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
> @@ -64,12 +59,13 @@ static void vkms_release(struct drm_device *dev)
> }
>
> static struct drm_driver vkms_driver = {
> - .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
> + .driver_features = (DRIVER_MODESET |
> + DRIVER_ATOMIC |
> + DRIVER_GEM |
> + DRIVER_PRIME),
> .release = vkms_release,
> .fops = &vkms_driver_fops,
> - .dumb_create = vkms_dumb_create,
> - .gem_vm_ops = &vkms_gem_vm_ops,
> - .gem_free_object_unlocked = vkms_gem_free_object,
> + DRM_GEM_SHMEM_DRIVER_OPS,
> .get_vblank_timestamp = vkms_get_vblank_timestamp,
>
> .name = DRIVER_NAME,
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> index e4469cd3d254..3faf49f43feb 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.h
> +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> @@ -80,23 +80,12 @@ struct vkms_device {
> struct vkms_output output;
> };
>
> -struct vkms_gem_object {
> - struct drm_gem_object gem;
> - struct mutex pages_lock; /* Page lock used in page fault handler */
> - struct page **pages;
> - unsigned int vmap_count;
> - void *vaddr;
> -};
> -
> #define drm_crtc_to_vkms_output(target) \
> container_of(target, struct vkms_output, crtc)
>
> #define drm_device_to_vkms_device(target) \
> container_of(target, struct vkms_device, drm)
>
> -#define drm_gem_to_vkms_gem(target)\
> - container_of(target, struct vkms_gem_object, gem)
> -
> #define to_vkms_crtc_state(target)\
> container_of(target, struct vkms_crtc_state, base)
>
> @@ -122,17 +111,6 @@ struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
> u32 *handle,
> u64 size);
>
> -vm_fault_t vkms_gem_fault(struct vm_fault *vmf);
> -
> -int vkms_dumb_create(struct drm_file *file, struct drm_device *dev,
> - struct drm_mode_create_dumb *args);
> -
> -void vkms_gem_free_object(struct drm_gem_object *obj);
> -
> -int vkms_gem_vmap(struct drm_gem_object *obj);
> -
> -void vkms_gem_vunmap(struct drm_gem_object *obj);
> -
> /* CRC Support */
> int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name);
> int vkms_verify_crc_source(struct drm_crtc *crtc, const char *source_name,
> diff --git a/drivers/gpu/drm/vkms/vkms_gem.c b/drivers/gpu/drm/vkms/vkms_gem.c
> index 80311daed47a..11f52aa4e732 100644
> --- a/drivers/gpu/drm/vkms/vkms_gem.c
> +++ b/drivers/gpu/drm/vkms/vkms_gem.c
> @@ -7,222 +7,34 @@
> */
>
> #include <linux/shmem_fs.h>
> +#include <drm/drm_gem_shmem_helper.h>
>
> #include "vkms_drv.h"
>
> -static struct vkms_gem_object *__vkms_gem_create(struct drm_device *dev,
> - u64 size)
> -{
> - struct vkms_gem_object *obj;
> - int ret;
> -
> - obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> - if (!obj)
> - return ERR_PTR(-ENOMEM);
> -
> - size = roundup(size, PAGE_SIZE);
> - ret = drm_gem_object_init(dev, &obj->gem, size);
> - if (ret) {
> - kfree(obj);
> - return ERR_PTR(ret);
> - }
> -
> - mutex_init(&obj->pages_lock);
> -
> - return obj;
> -}
> -
> -void vkms_gem_free_object(struct drm_gem_object *obj)
> -{
> - struct vkms_gem_object *gem = container_of(obj, struct vkms_gem_object,
> - gem);
> -
> - WARN_ON(gem->pages);
> - WARN_ON(gem->vaddr);
> -
> - mutex_destroy(&gem->pages_lock);
> - drm_gem_object_release(obj);
> - kfree(gem);
> -}
> -
> -vm_fault_t vkms_gem_fault(struct vm_fault *vmf)
> -{
> - struct vm_area_struct *vma = vmf->vma;
> - struct vkms_gem_object *obj = vma->vm_private_data;
> - unsigned long vaddr = vmf->address;
> - pgoff_t page_offset;
> - loff_t num_pages;
> - vm_fault_t ret = VM_FAULT_SIGBUS;
> -
> - page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
> - num_pages = DIV_ROUND_UP(obj->gem.size, PAGE_SIZE);
> -
> - if (page_offset > num_pages)
> - return VM_FAULT_SIGBUS;
> -
> - mutex_lock(&obj->pages_lock);
> - if (obj->pages) {
> - get_page(obj->pages[page_offset]);
> - vmf->page = obj->pages[page_offset];
> - ret = 0;
> - }
> - mutex_unlock(&obj->pages_lock);
> - if (ret) {
> - struct page *page;
> - struct address_space *mapping;
> -
> - mapping = file_inode(obj->gem.filp)->i_mapping;
> - page = shmem_read_mapping_page(mapping, page_offset);
> -
> - if (!IS_ERR(page)) {
> - vmf->page = page;
> - ret = 0;
> - } else {
> - switch (PTR_ERR(page)) {
> - case -ENOSPC:
> - case -ENOMEM:
> - ret = VM_FAULT_OOM;
> - break;
> - case -EBUSY:
> - ret = VM_FAULT_RETRY;
> - break;
> - case -EFAULT:
> - case -EINVAL:
> - ret = VM_FAULT_SIGBUS;
> - break;
> - default:
> - WARN_ON(PTR_ERR(page));
> - ret = VM_FAULT_SIGBUS;
> - break;
> - }
> - }
> - }
> - return ret;
> -}
> -
> struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
> struct drm_file *file,
> u32 *handle,
> u64 size)
> {
> - struct vkms_gem_object *obj;
> + struct drm_gem_shmem_object *obj;
> int ret;
>
> if (!file || !dev || !handle)
> return ERR_PTR(-EINVAL);
>
> - obj = __vkms_gem_create(dev, size);
> + obj = drm_gem_shmem_create(dev, size);
> if (IS_ERR(obj))
> return ERR_CAST(obj);
>
> - ret = drm_gem_handle_create(file, &obj->gem, handle);
> - drm_gem_object_put_unlocked(&obj->gem);
> - if (ret) {
> - drm_gem_object_release(&obj->gem);
> - kfree(obj);
> + /*
> + * Allocate an id of idr table where the obj is registered
> + * and handle has the id what user can see.
> + */
> + ret = drm_gem_handle_create(file, &obj->base, handle);
> + /* drop reference from allocate - handle holds it now. */
> + drm_gem_object_put_unlocked(&obj->base);
> + if (ret)
> return ERR_PTR(ret);
> - }
> -
> - return &obj->gem;
> -}
> -
> -int vkms_dumb_create(struct drm_file *file, struct drm_device *dev,
> - struct drm_mode_create_dumb *args)
> -{
> - struct drm_gem_object *gem_obj;
> - u64 pitch, size;
> -
> - if (!args || !dev || !file)
> - return -EINVAL;
> -
> - pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
> - size = pitch * args->height;
> -
> - if (!size)
> - return -EINVAL;
> -
> - gem_obj = vkms_gem_create(dev, file, &args->handle, size);
> - if (IS_ERR(gem_obj))
> - return PTR_ERR(gem_obj);
> -
> - args->size = gem_obj->size;
> - args->pitch = pitch;
> -
> - DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
> -
> - return 0;
> -}
> -
> -static struct page **_get_pages(struct vkms_gem_object *vkms_obj)
> -{
> - struct drm_gem_object *gem_obj = &vkms_obj->gem;
> -
> - if (!vkms_obj->pages) {
> - struct page **pages = drm_gem_get_pages(gem_obj);
> -
> - if (IS_ERR(pages))
> - return pages;
> -
> - if (cmpxchg(&vkms_obj->pages, NULL, pages))
> - drm_gem_put_pages(gem_obj, pages, false, true);
> - }
> -
> - return vkms_obj->pages;
> -}
> -
> -void vkms_gem_vunmap(struct drm_gem_object *obj)
> -{
> - struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(obj);
> -
> - mutex_lock(&vkms_obj->pages_lock);
> - if (vkms_obj->vmap_count < 1) {
> - WARN_ON(vkms_obj->vaddr);
> - WARN_ON(vkms_obj->pages);
> - mutex_unlock(&vkms_obj->pages_lock);
> - return;
> - }
> -
> - vkms_obj->vmap_count--;
> -
> - if (vkms_obj->vmap_count == 0) {
> - vunmap(vkms_obj->vaddr);
> - vkms_obj->vaddr = NULL;
> - drm_gem_put_pages(obj, vkms_obj->pages, false, true);
> - vkms_obj->pages = NULL;
> - }
> -
> - mutex_unlock(&vkms_obj->pages_lock);
> -}
> -
> -int vkms_gem_vmap(struct drm_gem_object *obj)
> -{
> - struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(obj);
> - int ret = 0;
> -
> - mutex_lock(&vkms_obj->pages_lock);
> -
> - if (!vkms_obj->vaddr) {
> - unsigned int n_pages = obj->size >> PAGE_SHIFT;
> - struct page **pages = _get_pages(vkms_obj);
> -
> - if (IS_ERR(pages)) {
> - ret = PTR_ERR(pages);
> - goto out;
> - }
> -
> - vkms_obj->vaddr = vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
> - if (!vkms_obj->vaddr)
> - goto err_vmap;
> - }
> -
> - vkms_obj->vmap_count++;
> - goto out;
>
> -err_vmap:
> - ret = -ENOMEM;
> - drm_gem_put_pages(obj, vkms_obj->pages, false, true);
> - vkms_obj->pages = NULL;
> -out:
> - mutex_unlock(&vkms_obj->pages_lock);
> - return ret;
> + return &obj->base;
> }
> diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
> index 7041007396ae..29e6e870d7ac 100644
> --- a/drivers/gpu/drm/vkms/vkms_plane.c
> +++ b/drivers/gpu/drm/vkms/vkms_plane.c
> @@ -11,6 +11,7 @@
> #include <drm/drm_atomic.h>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_gem_shmem_helper.h>
>
> static struct drm_plane_state *
> vkms_plane_duplicate_state(struct drm_plane *plane)
> @@ -138,17 +139,17 @@ static int vkms_prepare_fb(struct drm_plane *plane,
> struct drm_plane_state *state)
> {
> struct drm_gem_object *gem_obj;
> - struct vkms_gem_object *vkms_obj;
> - int ret;
> + void *map;
>
> if (!state->fb)
> return 0;
>
> gem_obj = drm_gem_fb_get_obj(state->fb, 0);
> - vkms_obj = drm_gem_to_vkms_gem(gem_obj);
> - ret = vkms_gem_vmap(gem_obj);
> - if (ret)
> - DRM_ERROR("vmap failed: %d\n", ret);
> + map = drm_gem_shmem_vmap(gem_obj);
> + if (IS_ERR(map)) {
> + DRM_ERROR("vmap failed: %ld\n", PTR_ERR(map));
> + return PTR_ERR(map);
> + }
>
> return drm_gem_fb_prepare_fb(plane, state);
> }
> @@ -157,12 +158,14 @@ static void vkms_cleanup_fb(struct drm_plane *plane,
> struct drm_plane_state *old_state)
> {
> struct drm_gem_object *gem_obj;
> + struct drm_gem_shmem_object *shmem_obj;
>
> if (!old_state->fb)
> return;
>
> gem_obj = drm_gem_fb_get_obj(old_state->fb, 0);
> - vkms_gem_vunmap(gem_obj);
> + shmem_obj = to_drm_gem_shmem_obj(gem_obj);
> + drm_gem_shmem_vunmap(gem_obj, shmem_obj->vaddr);
> }
>
> static const struct drm_plane_helper_funcs vkms_primary_helper_funcs = {
> --
> 2.20.0.rc1
>
> _______________________________________________
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> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch