[PATCH 2/3] drm/vkms: Switch to shmem helpers
Melissa Wen
melissa.srw at gmail.com
Mon Oct 12 12:41:18 UTC 2020
Hi Daniel,
Thanks for this patch.
It took me a while to understand the update.
I run some tests and it looks good to me.
On 10/10, Daniel Vetter wrote:
> Inspired by a patch by Chris Wilson for vgem. Plus this gives us vmap
> at the gem bo level, which we need for generic fbdev emulation.
>
> Luckily shmem also tracks ->vaddr, so we just need to adjust the code
> all over a bit to make this fit.
>
> Also wire up handle_to_fd, dunno why that was missing.
>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Maxime Ripard <mripard at kernel.org>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: David Airlie <airlied at linux.ie>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: Rodrigo Siqueira <rodrigosiqueiramelo at gmail.com>
> Cc: Melissa Wen <melissa.srw at gmail.com>
> Cc: Haneen Mohammed <hamohammed.sa at gmail.com>
> ---
> drivers/gpu/drm/Kconfig | 1 +
> drivers/gpu/drm/vkms/Makefile | 1 -
> drivers/gpu/drm/vkms/vkms_composer.c | 17 +-
> drivers/gpu/drm/vkms/vkms_drv.c | 19 +-
> drivers/gpu/drm/vkms/vkms_drv.h | 26 ---
> drivers/gpu/drm/vkms/vkms_gem.c | 261 --------------------------
> drivers/gpu/drm/vkms/vkms_plane.c | 13 +-
> drivers/gpu/drm/vkms/vkms_writeback.c | 17 +-
> 8 files changed, 32 insertions(+), 323 deletions(-)
> delete mode 100644 drivers/gpu/drm/vkms/vkms_gem.c
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 9efb82caaa87..b796c118fc3b 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -287,6 +287,7 @@ config DRM_VKMS
> tristate "Virtual KMS (EXPERIMENTAL)"
> depends on DRM
> select DRM_KMS_HELPER
> + select DRM_GEM_SHMEM_HELPER
> select CRC32
> default n
> help
> diff --git a/drivers/gpu/drm/vkms/Makefile b/drivers/gpu/drm/vkms/Makefile
> index 333d3cead0e3..72f779cbfedd 100644
> --- a/drivers/gpu/drm/vkms/Makefile
> +++ b/drivers/gpu/drm/vkms/Makefile
> @@ -4,7 +4,6 @@ vkms-y := \
> vkms_plane.o \
> vkms_output.o \
> vkms_crtc.o \
> - vkms_gem.o \
> vkms_composer.o \
> vkms_writeback.o
>
> diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
> index 33c031f27c2c..66c6842d70db 100644
> --- a/drivers/gpu/drm/vkms/vkms_composer.c
> +++ b/drivers/gpu/drm/vkms/vkms_composer.c
> @@ -5,6 +5,7 @@
> #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>
> #include <drm/drm_vblank.h>
>
> #include "vkms_drv.h"
> @@ -129,15 +130,15 @@ static void compose_cursor(struct vkms_composer *cursor_composer,
> void *vaddr_out)
> {
> struct drm_gem_object *cursor_obj;
> - struct vkms_gem_object *cursor_vkms_obj;
> + struct drm_gem_shmem_object *cursor_shmem_obj;
>
> cursor_obj = drm_gem_fb_get_obj(&cursor_composer->fb, 0);
> - cursor_vkms_obj = drm_gem_to_vkms_gem(cursor_obj);
> + cursor_shmem_obj = to_drm_gem_shmem_obj(cursor_obj);
>
> - if (WARN_ON(!cursor_vkms_obj->vaddr))
> + if (WARN_ON(!cursor_shmem_obj->vaddr))
> return;
>
> - blend(vaddr_out, cursor_vkms_obj->vaddr,
> + blend(vaddr_out, cursor_shmem_obj->vaddr,
> primary_composer, cursor_composer);
> }
>
> @@ -147,20 +148,20 @@ static int compose_planes(void **vaddr_out,
> {
> struct drm_framebuffer *fb = &primary_composer->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);
> + struct drm_gem_shmem_object *shmem_obj = to_drm_gem_shmem_obj(gem_obj);
>
> if (!*vaddr_out) {
> - *vaddr_out = kzalloc(vkms_obj->gem.size, GFP_KERNEL);
> + *vaddr_out = kzalloc(shmem_obj->base.size, GFP_KERNEL);
> if (!*vaddr_out) {
> DRM_ERROR("Cannot allocate memory for output frame.");
> return -ENOMEM;
> }
> }
>
> - if (WARN_ON(!vkms_obj->vaddr))
> + if (WARN_ON(!shmem_obj->vaddr))
> return -EINVAL;
>
> - memcpy(*vaddr_out, vkms_obj->vaddr, vkms_obj->gem.size);
> + memcpy(*vaddr_out, shmem_obj->vaddr, shmem_obj->base.size);
>
> if (cursor_composer)
> compose_cursor(cursor_composer, primary_composer, *vaddr_out);
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
> index eb4007443706..6221e5040264 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.c
> +++ b/drivers/gpu/drm/vkms/vkms_drv.c
> @@ -23,6 +23,7 @@
> #include <drm/drm_ioctl.h>
> #include <drm/drm_managed.h>
> #include <drm/drm_probe_helper.h>
> +#include <drm/drm_gem_shmem_helper.h>
> #include <drm/drm_vblank.h>
>
> #include "vkms_drv.h"
> @@ -39,17 +40,7 @@ bool enable_cursor = true;
> module_param_named(enable_cursor, enable_cursor, bool, 0444);
> MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
>
> -static const struct file_operations vkms_driver_fops = {
> - .owner = THIS_MODULE,
> - .open = drm_open,
> - .mmap = drm_gem_mmap,
> - .unlocked_ioctl = drm_ioctl,
> - .compat_ioctl = drm_compat_ioctl,
> - .poll = drm_poll,
> - .read = drm_read,
> - .llseek = no_llseek,
> - .release = drm_release,
> -};
> +DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
>
> static void vkms_release(struct drm_device *dev)
> {
> @@ -91,9 +82,11 @@ static struct drm_driver vkms_driver = {
> .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
> .release = vkms_release,
> .fops = &vkms_driver_fops,
> - .dumb_create = vkms_dumb_create,
> + .dumb_create = drm_gem_shmem_dumb_create,
> .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
> - .gem_prime_import_sg_table = vkms_prime_import_sg_table,
> + .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
> + .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table,
> + .gem_prime_mmap = drm_gem_prime_mmap,
>
> .name = DRIVER_NAME,
> .desc = DRIVER_DESC,
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> index 380a8f27e156..ef6482e3adea 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.h
> +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> @@ -88,14 +88,6 @@ 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;
> -};
> -
Around here, there is a "#define drm_gem_to_vkms_gem" that I think we
can also get rid of it.
> #define drm_crtc_to_vkms_output(target) \
> container_of(target, struct vkms_output, crtc)
>
> @@ -120,24 +112,6 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index);
> struct drm_plane *vkms_plane_init(struct vkms_device *vkmsdev,
> enum drm_plane_type type, int index);
>
> -/* Gem stuff */
> -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);
> -
> -/* Prime */
> -struct drm_gem_object *
> -vkms_prime_import_sg_table(struct drm_device *dev,
> - struct dma_buf_attachment *attach,
> - struct sg_table *sg);
> -
> /* CRC Support */
> const char *const *vkms_get_crc_sources(struct drm_crtc *crtc,
> size_t *count);
> diff --git a/drivers/gpu/drm/vkms/vkms_gem.c b/drivers/gpu/drm/vkms/vkms_gem.c
> deleted file mode 100644
> index 19a0e260a4df..000000000000
> --- a/drivers/gpu/drm/vkms/vkms_gem.c
> +++ /dev/null
> @@ -1,261 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0+
> -
> -#include <linux/dma-buf.h>
> -#include <linux/shmem_fs.h>
> -#include <linux/vmalloc.h>
> -#include <drm/drm_prime.h>
> -
> -#include "vkms_drv.h"
> -
> -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 const struct drm_gem_object_funcs vkms_gem_object_funcs = {
> - .free = vkms_gem_free_object,
> - .vm_ops = &vkms_gem_vm_ops,
> -};
> -
> -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);
> -
> - obj->gem.funcs = &vkms_gem_object_funcs;
> -
> - 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;
> -}
> -
> -static struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
> - struct drm_file *file,
> - u32 *handle,
> - u64 size)
> -{
> - struct vkms_gem_object *obj;
> - int ret;
> -
> - if (!file || !dev || !handle)
> - return ERR_PTR(-EINVAL);
> -
> - obj = __vkms_gem_create(dev, size);
> - if (IS_ERR(obj))
> - return ERR_CAST(obj);
> -
> - ret = drm_gem_handle_create(file, &obj->gem, handle);
> - 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_gem_object_put(gem_obj);
> -
> - 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;
> -}
> -
> -struct drm_gem_object *
> -vkms_prime_import_sg_table(struct drm_device *dev,
> - struct dma_buf_attachment *attach,
> - struct sg_table *sg)
> -{
> - struct vkms_gem_object *obj;
> - int npages;
> -
> - obj = __vkms_gem_create(dev, attach->dmabuf->size);
> - if (IS_ERR(obj))
> - return ERR_CAST(obj);
> -
> - npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
> - DRM_DEBUG_PRIME("Importing %d pages\n", npages);
> -
> - obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
> - if (!obj->pages) {
> - vkms_gem_free_object(&obj->gem);
> - return ERR_PTR(-ENOMEM);
> - }
> -
> - drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);
> - return &obj->gem;
> -}
> diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
> index 6d31265a2ab7..9890137bcb8d 100644
> --- a/drivers/gpu/drm/vkms/vkms_plane.c
> +++ b/drivers/gpu/drm/vkms/vkms_plane.c
> @@ -5,6 +5,7 @@
> #include <drm/drm_fourcc.h>
> #include <drm/drm_gem_framebuffer_helper.h>
> #include <drm/drm_plane_helper.h>
> +#include <drm/drm_gem_shmem_helper.h>
>
> #include "vkms_drv.h"
>
> @@ -145,15 +146,15 @@ static int vkms_prepare_fb(struct drm_plane *plane,
> struct drm_plane_state *state)
> {
> struct drm_gem_object *gem_obj;
> - int ret;
> + void *vaddr;
>
> if (!state->fb)
> return 0;
>
> gem_obj = drm_gem_fb_get_obj(state->fb, 0);
> - ret = vkms_gem_vmap(gem_obj);
> - if (ret)
> - DRM_ERROR("vmap failed: %d\n", ret);
> + vaddr = drm_gem_shmem_vmap(gem_obj);
> + if (IS_ERR(vaddr))
> + DRM_ERROR("vmap failed: %li\n", PTR_ERR(vaddr));
>
> return drm_gem_fb_prepare_fb(plane, state);
> }
> @@ -162,12 +163,14 @@ 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(drm_gem_fb_get_obj(old_state->fb, 0));
> + drm_gem_shmem_vunmap(gem_obj, shmem_obj->vaddr);
> }
>
> static const struct drm_plane_helper_funcs vkms_primary_helper_funcs = {
> diff --git a/drivers/gpu/drm/vkms/vkms_writeback.c b/drivers/gpu/drm/vkms/vkms_writeback.c
> index 094fa4aa061d..26b903926872 100644
> --- a/drivers/gpu/drm/vkms/vkms_writeback.c
> +++ b/drivers/gpu/drm/vkms/vkms_writeback.c
> @@ -6,6 +6,7 @@
> #include <drm/drm_probe_helper.h>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_gem_shmem_helper.h>
>
> static const u32 vkms_wb_formats[] = {
> DRM_FORMAT_XRGB8888,
> @@ -63,22 +64,20 @@ static int vkms_wb_connector_get_modes(struct drm_connector *connector)
> static int vkms_wb_prepare_job(struct drm_writeback_connector *wb_connector,
> struct drm_writeback_job *job)
> {
> - struct vkms_gem_object *vkms_obj;
> struct drm_gem_object *gem_obj;
> - int ret;
> + void *vaddr;
>
> if (!job->fb)
> return 0;
>
> gem_obj = drm_gem_fb_get_obj(job->fb, 0);
> - ret = vkms_gem_vmap(gem_obj);
> - if (ret) {
> - DRM_ERROR("vmap failed: %d\n", ret);
> - return ret;
> + vaddr = drm_gem_shmem_vmap(gem_obj);
> + if (IS_ERR(vaddr)) {
> + DRM_ERROR("vmap failed: %li\n", PTR_ERR(vaddr));
> + return PTR_ERR(vaddr);
> }
>
> - vkms_obj = drm_gem_to_vkms_gem(gem_obj);
> - job->priv = vkms_obj->vaddr;
> + job->priv = vaddr;
>
> return 0;
> }
> @@ -93,7 +92,7 @@ static void vkms_wb_cleanup_job(struct drm_writeback_connector *connector,
> return;
>
> gem_obj = drm_gem_fb_get_obj(job->fb, 0);
> - vkms_gem_vunmap(gem_obj);
> + drm_gem_shmem_vunmap(gem_obj, job->priv);
>
> vkmsdev = drm_device_to_vkms_device(gem_obj->dev);
> vkms_set_composer(&vkmsdev->output, false);
> --
> 2.28.0
>
Reviewed-by: Melissa Wen <melissa.srw at gmail.com>
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