Re: [PATCH 1/2] drm: add SimpleDRM driver

Noralf Trønnes
2016-08-04T17:05:29Z

Den 04.08.2016 16:03, skrev Noralf Trønnes:
> The SimpleDRM driver binds to simple-framebuffer devices and provides a
> DRM/KMS API. It provides only a single CRTC+encoder+connector combination
> plus one initial mode.
>
> Userspace can create dumb-buffers which can be blit into the real
> framebuffer similar to UDL. No access to the real framebuffer is allowed
> (compared to earlier version of this driver) to avoid security issues.
> Furthermore, this way we can support arbitrary modes as long as we have a
> conversion-helper.
>
> The driver was originally written by David Herrmann in 2014.
> My main contribution is to make use of drm_simple_kms_helper and
> rework the probe path to avoid use of the deprecated drm_platform_init()
> and drm_driver.{load,unload}().
>
> Cc: dh.herrmann@gmail.com
> Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
> ---

[snip]

> diff --git a/drivers/gpu/drm/simpledrm/Kconfig b/drivers/gpu/drm/simpledrm/Kconfig
> new file mode 100644
> index 0000000..f45b25d
> --- /dev/null
> +++ b/drivers/gpu/drm/simpledrm/Kconfig
> @@ -0,0 +1,19 @@
> +config DRM_SIMPLEDRM
> + tristate "Simple firmware framebuffer DRM driver"

FB_SIMPLE is bool, should we do the same here?

Another thing is that simplefb.c is registred at fs_initcall().
Should we do that?

Here's the commit message introducing it:

simplefb: Change simplefb_init from module_init to fs_initcall
One of the reasons for having the simplefb nodes in /chosen, and doing
explicit enumeration of the nodes there, is too allow enumerating them
sooner,
so that we get a console earlier on.

Doing this earlier then fs_initcall is not useful, since the fb only turns
into a console when fbcon intializes, which is a fs_initcall too.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Noralf.

> + depends on DRM
> + select DRM_KMS_HELPER
> + help
> + SimpleDRM can run on all systems with pre-initialized graphics
> + hardware. It uses a framebuffer that was initialized during
> + firmware boot. No page-flipping, modesetting or other advanced
> + features are available. However, other DRM drivers can be loaded
> + later and take over from SimpleDRM if they provide real hardware
> + support.
> +
> + SimpleDRM supports "simple-framebuffer" DeviceTree objects and
> + compatible platform framebuffers.
> +
> + If unsure, say Y.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called simpledrm.
> diff --git a/drivers/gpu/drm/simpledrm/Makefile b/drivers/gpu/drm/simpledrm/Makefile
> new file mode 100644
> index 0000000..f6a62dc
> --- /dev/null
> +++ b/drivers/gpu/drm/simpledrm/Makefile
> @@ -0,0 +1,4 @@
> +simpledrm-y := simpledrm_drv.o simpledrm_kms.o simpledrm_gem.o \
> + simpledrm_damage.o
> +
> +obj-$(CONFIG_DRM_SIMPLEDRM) := simpledrm.o
> diff --git a/drivers/gpu/drm/simpledrm/simpledrm.h b/drivers/gpu/drm/simpledrm/simpledrm.h
> new file mode 100644
> index 0000000..e841655
> --- /dev/null
> +++ b/drivers/gpu/drm/simpledrm/simpledrm.h
> @@ -0,0 +1,87 @@
> +/*
> + * SimpleDRM firmware framebuffer driver
> + * Copyright (c) 2012-2014 David Herrmann <dh.herrmann@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the Free
> + * Software Foundation; either version 2 of the License, or (at your option)
> + * any later version.
> + */
> +
> +#ifndef SDRM_DRV_H
> +#define SDRM_DRV_H
> +
> +#include <linux/errno.h>
> +#include <linux/fb.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/module.h>
> +#include <linux/platform_data/simplefb.h>
> +#include <linux/string.h>
> +#include <drm/drmP.h>
> +#include <drm/drm_gem.h>
> +#include <drm/drm_simple_kms_helper.h>
> +
> +struct sdrm_device;
> +struct sdrm_gem_object;
> +struct sdrm_framebuffer;
> +
> +struct sdrm_device {
> + struct drm_device *ddev;
> + struct drm_simple_display_pipe pipe;
> + struct drm_connector conn;
> +
> + /* framebuffer information */
> + const struct simplefb_format *fb_sformat;
> + u32 fb_format;
> + u32 fb_width;
> + u32 fb_height;
> + u32 fb_stride;
> + u32 fb_bpp;
> + unsigned long fb_base;
> + unsigned long fb_size;
> + void *fb_map;
> +};
> +
> +int sdrm_drm_modeset_init(struct sdrm_device *sdrm);
> +int sdrm_drm_mmap(struct file *filp, struct vm_area_struct *vma);
> +
> +int sdrm_dirty(struct drm_framebuffer *fb,
> + struct drm_file *file,
> + unsigned int flags, unsigned int color,
> + struct drm_clip_rect *clips,
> + unsigned int num_clips);
> +int sdrm_dirty_all_locked(struct sdrm_device *sdrm);
> +int sdrm_dirty_all_unlocked(struct sdrm_device *sdrm);
> +
> +struct sdrm_gem_object {
> + struct drm_gem_object base;
> + struct sg_table *sg;
> + struct page **pages;
> + void *vmapping;
> +};
> +
> +#define to_sdrm_bo(x) container_of(x, struct sdrm_gem_object, base)
> +
> +struct sdrm_gem_object *sdrm_gem_alloc_object(struct drm_device *ddev,
> + size_t size);
> +struct drm_gem_object *sdrm_gem_prime_import(struct drm_device *ddev,
> + struct dma_buf *dma_buf);
> +void sdrm_gem_free_object(struct drm_gem_object *obj);
> +int sdrm_gem_get_pages(struct sdrm_gem_object *obj);
> +
> +int sdrm_dumb_create(struct drm_file *file_priv, struct drm_device *ddev,
> + struct drm_mode_create_dumb *arg);
> +int sdrm_dumb_destroy(struct drm_file *file_priv, struct drm_device *ddev,
> + uint32_t handle);
> +int sdrm_dumb_map_offset(struct drm_file *file_priv, struct drm_device *ddev,
> + uint32_t handle, uint64_t *offset);
> +
> +struct sdrm_framebuffer {
> + struct drm_framebuffer base;
> + struct sdrm_gem_object *obj;
> +};
> +
> +#define to_sdrm_fb(x) container_of(x, struct sdrm_framebuffer, base)
> +
> +#endif /* SDRM_DRV_H */
> diff --git a/drivers/gpu/drm/simpledrm/simpledrm_damage.c b/drivers/gpu/drm/simpledrm/simpledrm_damage.c
> new file mode 100644
> index 0000000..e87dac7
> --- /dev/null
> +++ b/drivers/gpu/drm/simpledrm/simpledrm_damage.c
> @@ -0,0 +1,314 @@
> +/*
> + * SimpleDRM firmware framebuffer driver
> + * Copyright (c) 2012-2014 David Herrmann <dh.herrmann@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the Free
> + * Software Foundation; either version 2 of the License, or (at your option)
> + * any later version.
> + */
> +
> +#include <asm/unaligned.h>
> +#include <linux/dma-buf.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/module.h>
> +#include <linux/string.h>
> +#include <drm/drmP.h>
> +#include <drm/drm_crtc.h>
> +#include "simpledrm.h"
> +
> +static inline void sdrm_put(u8 *dst, u32 four_cc, u16 r, u16 g, u16 b)
> +{
> + switch (four_cc) {
> + case DRM_FORMAT_RGB565:
> + r >>= 11;
> + g >>= 10;
> + b >>= 11;
> + put_unaligned((u16)((r << 11) | (g << 5) | b), (u16 *)dst);
> + break;
> + case DRM_FORMAT_XRGB1555:
> + case DRM_FORMAT_ARGB1555:
> + r >>= 11;
> + g >>= 11;
> + b >>= 11;
> + put_unaligned((u16)((r << 10) | (g << 5) | b), (u16 *)dst);
> + break;
> + case DRM_FORMAT_RGB888:
> + r >>= 8;
> + g >>= 8;
> + b >>= 8;
> +#ifdef __LITTLE_ENDIAN
> + dst[2] = r;
> + dst[1] = g;
> + dst[0] = b;
> +#elif defined(__BIG_ENDIAN)
> + dst[0] = r;
> + dst[1] = g;
> + dst[2] = b;
> +#endif
> + break;
> + case DRM_FORMAT_XRGB8888:
> + case DRM_FORMAT_ARGB8888:
> + r >>= 8;
> + g >>= 8;
> + b >>= 8;
> + put_unaligned((u32)((r << 16) | (g << 8) | b), (u32 *)dst);
> + break;
> + case DRM_FORMAT_ABGR8888:
> + r >>= 8;
> + g >>= 8;
> + b >>= 8;
> + put_unaligned((u32)((b << 16) | (g << 8) | r), (u32 *)dst);
> + break;
> + case DRM_FORMAT_XRGB2101010:
> + case DRM_FORMAT_ARGB2101010:
> + r >>= 4;
> + g >>= 4;
> + b >>= 4;
> + put_unaligned((u32)((r << 20) | (g << 10) | b), (u32 *)dst);
> + break;
> + }
> +}
> +
> +static void sdrm_blit_from_xrgb8888(const u8 *src, u32 src_stride, u32 src_bpp,
> + u8 *dst, u32 dst_stride, u32 dst_bpp,
> + u32 dst_four_cc, u32 width, u32 height)
> +{
> + u32 val, i;
> +
> + while (height--) {
> + for (i = 0; i < width; ++i) {
> + val = get_unaligned((const u32 *)&src[i * src_bpp]);
> + sdrm_put(&dst[i * dst_bpp], dst_four_cc,
> + (val & 0x00ff0000U) >> 8,
> + (val & 0x0000ff00U),
> + (val & 0x000000ffU) << 8);
> + }
> +
> + src += src_stride;
> + dst += dst_stride;
> + }
> +}
> +
> +static void sdrm_blit_from_rgb565(const u8 *src, u32 src_stride, u32 src_bpp,
> + u8 *dst, u32 dst_stride, u32 dst_bpp,
> + u32 dst_four_cc, u32 width, u32 height)
> +{
> + u32 val, i;
> +
> + while (height--) {
> + for (i = 0; i < width; ++i) {
> + val = get_unaligned((const u16 *)&src[i * src_bpp]);
> + sdrm_put(&dst[i * dst_bpp], dst_four_cc,
> + (val & 0xf800),
> + (val & 0x07e0) << 5,
> + (val & 0x001f) << 11);
> + }
> +
> + src += src_stride;
> + dst += dst_stride;
> + }
> +}
> +
> +static void sdrm_blit_lines(const u8 *src, u32 src_stride,
> + u8 *dst, u32 dst_stride,
> + u32 bpp, u32 width, u32 height)
> +{
> + u32 len;
> +
> + len = width * bpp;
> +
> + while (height--) {
> + memcpy(dst, src, len);
> + src += src_stride;
> + dst += dst_stride;
> + }
> +}
> +
> +static void sdrm_blit(struct sdrm_framebuffer *sfb, u32 x, u32 y,
> + u32 width, u32 height)
> +{
> + struct drm_framebuffer *fb = &sfb->base;
> + struct drm_device *ddev = fb->dev;
> + struct sdrm_device *sdrm = ddev->dev_private;
> + u32 src_bpp, dst_bpp, xoff, yoff, x2, y2;
> + u8 *src, *dst;
> +
> + /* already unmapped; ongoing handover? */
> + if (!sdrm->fb_map)
> + return;
> +
> + /* empty dirty-region, nothing to do */
> + if (!width || !height)
> + return;
> + if (x >= fb->width || y >= fb->height)
> + return;
> +
> + /* sanity checks */
> + if (x + width < x)
> + width = fb->width - x;
> + if (y + height < y)
> + height = fb->height - y;
> +
> + /* get scanout offsets */
> + xoff = 0;
> + yoff = 0;
> + if (sdrm->pipe.plane.fb == fb) {
> + xoff = sdrm->pipe.crtc.x;
> + yoff = sdrm->pipe.crtc.y;
> + }
> +
> + /* get intersection of dirty region and scan-out region */
> + x2 = min(x + width, xoff + sdrm->fb_width);
> + y2 = min(y + height, yoff + sdrm->fb_height);
> + x = max(x, xoff);
> + y = max(y, yoff);
> + if (x2 <= x || y2 <= y)
> + return;
> + width = x2 - x;
> + height = y2 - y;
> +
> + /* get buffer offsets */
> + src = sfb->obj->vmapping;
> + dst = sdrm->fb_map;
> +
> + /* bo is guaranteed to be big enough; size checks not needed */
> + src_bpp = (fb->bits_per_pixel + 7) / 8;
> + src += fb->offsets[0] + y * fb->pitches[0] + x * src_bpp;
> +
> + dst_bpp = (sdrm->fb_bpp + 7) / 8;
> + dst += (y - yoff) * sdrm->fb_stride + (x - xoff) * dst_bpp;
> +
> + /* if formats are identical, do a line-by-line copy.. */
> + if (fb->pixel_format == sdrm->fb_format) {
> + sdrm_blit_lines(src, fb->pitches[0],
> + dst, sdrm->fb_stride,
> + src_bpp, width, height);
> + return;
> + }
> +
> + /* ..otherwise call slow blit-function */
> + switch (fb->pixel_format) {
> + case DRM_FORMAT_ARGB8888:
> + /* fallthrough */
> + case DRM_FORMAT_XRGB8888:
> + sdrm_blit_from_xrgb8888(src, fb->pitches[0], src_bpp,
> + dst, sdrm->fb_stride, dst_bpp,
> + sdrm->fb_format, width, height);
> + break;
> + case DRM_FORMAT_RGB565:
> + sdrm_blit_from_rgb565(src, fb->pitches[0], src_bpp,
> + dst, sdrm->fb_stride, dst_bpp,
> + sdrm->fb_format, width, height);
> + break;
> + }
> +}
> +
> +static int sdrm_begin_access(struct sdrm_framebuffer *sfb)
> +{
> + int r;
> +
> + r = sdrm_gem_get_pages(sfb->obj);
> + if (r)
> + return r;
> +
> + if (!sfb->obj->base.import_attach)
> + return 0;
> +
> + return dma_buf_begin_cpu_access(sfb->obj->base.import_attach->dmabuf,
> + DMA_FROM_DEVICE);
> +}
> +
> +static void sdrm_end_access(struct sdrm_framebuffer *sfb)
> +{
> + if (!sfb->obj->base.import_attach)
> + return;
> +
> + dma_buf_end_cpu_access(sfb->obj->base.import_attach->dmabuf,
> + DMA_FROM_DEVICE);
> +}
> +
> +int sdrm_dirty(struct drm_framebuffer *fb,
> + struct drm_file *file,
> + unsigned int flags, unsigned int color,
> + struct drm_clip_rect *clips,
> + unsigned int num_clips)
> +{
> + struct sdrm_framebuffer *sfb = to_sdrm_fb(fb);
> + struct drm_device *ddev = fb->dev;
> + struct sdrm_device *sdrm = ddev->dev_private;
> + struct drm_clip_rect full_clip;
> + unsigned int i;
> + int r;
> +
> + if (!clips || !num_clips) {
> + full_clip.x1 = 0;
> + full_clip.x2 = fb->width;
> + full_clip.y1 = 0;
> + full_clip.y2 = fb->height;
> + clips = &full_clip;
> + num_clips = 1;
> + }
> +
> + drm_modeset_lock_all(ddev);
> +
> + if (sdrm->pipe.plane.fb != fb) {
> + r = 0;
> + goto unlock;
> + }
> +
> + r = sdrm_begin_access(sfb);
> + if (r)
> + goto unlock;
> +
> + for (i = 0; i < num_clips; i++) {
> + if (clips[i].x2 <= clips[i].x1 ||
> + clips[i].y2 <= clips[i].y1)
> + continue;
> +
> + sdrm_blit(sfb, clips[i].x1, clips[i].y1,
> + clips[i].x2 - clips[i].x1,
> + clips[i].y2 - clips[i].y1);
> + }
> +
> + sdrm_end_access(sfb);
> +
> +unlock:
> + drm_modeset_unlock_all(ddev);
> + return 0;
> +}
> +
> +int sdrm_dirty_all_locked(struct sdrm_device *sdrm)
> +{
> + struct drm_framebuffer *fb;
> + struct sdrm_framebuffer *sfb;
> + int r;
> +
> + fb = sdrm->pipe.plane.fb;
> + if (!fb)
> + return 0;
> +
> + sfb = to_sdrm_fb(fb);
> + r = sdrm_begin_access(sfb);
> + if (r)
> + return r;
> +
> + sdrm_blit(sfb, 0, 0, fb->width, fb->height);
> +
> + sdrm_end_access(sfb);
> +
> + return 0;
> +}
> +
> +int sdrm_dirty_all_unlocked(struct sdrm_device *sdrm)
> +{
> + int r;
> +
> + drm_modeset_lock_all(sdrm->ddev);
> + r = sdrm_dirty_all_locked(sdrm);
> + drm_modeset_unlock_all(sdrm->ddev);
> +
> + return r;
> +}
> diff --git a/drivers/gpu/drm/simpledrm/simpledrm_drv.c b/drivers/gpu/drm/simpledrm/simpledrm_drv.c
> new file mode 100644
> index 0000000..26b4ca9
> --- /dev/null
> +++ b/drivers/gpu/drm/simpledrm/simpledrm_drv.c
> @@ -0,0 +1,295 @@
> +/*
> + * SimpleDRM firmware framebuffer driver
> + * Copyright (c) 2012-2014 David Herrmann <dh.herrmann@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the Free
> + * Software Foundation; either version 2 of the License, or (at your option)
> + * any later version.
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/module.h>
> +#include <linux/platform_data/simplefb.h>
> +#include <linux/string.h>
> +#include <drm/drmP.h>
> +#include "simpledrm.h"
> +
> +static const struct file_operations sdrm_drm_fops = {
> + .owner = THIS_MODULE,
> + .open = drm_open,
> + .mmap = sdrm_drm_mmap,
> + .poll = drm_poll,
> + .read = drm_read,
> + .unlocked_ioctl = drm_ioctl,
> + .release = drm_release,
> +#ifdef CONFIG_COMPAT
> + .compat_ioctl = drm_compat_ioctl,
> +#endif
> + .llseek = noop_llseek,
> +};
> +
> +static struct drm_driver sdrm_drm_driver = {
> + .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
> + DRIVER_ATOMIC,
> + .fops = &sdrm_drm_fops,
> +
> + .gem_free_object = sdrm_gem_free_object,
> + .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
> + .gem_prime_import = sdrm_gem_prime_import,
> +
> + .dumb_create = sdrm_dumb_create,
> + .dumb_map_offset = sdrm_dumb_map_offset,
> + .dumb_destroy = sdrm_dumb_destroy,
> +
> + .name = "simpledrm",
> + .desc = "Simple firmware framebuffer DRM driver",
> + .date = "20130601",
> + .major = 0,
> + .minor = 0,
> + .patchlevel = 1,
> +};
> +
> +static int parse_dt(struct platform_device *pdev,
> + struct simplefb_platform_data *mode)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + const char *format;
> + int ret;
> +
> + if (!np)
> + return -ENODEV;
> +
> + ret = of_property_read_u32(np, "width", &mode->width);
> + if (ret) {
> + dev_err(&pdev->dev, "Can't parse width property\n");
> + return ret;
> + }
> +
> + ret = of_property_read_u32(np, "height", &mode->height);
> + if (ret) {
> + dev_err(&pdev->dev, "Can't parse height property\n");
> + return ret;
> + }
> +
> + ret = of_property_read_u32(np, "stride", &mode->stride);
> + if (ret) {
> + dev_err(&pdev->dev, "Can't parse stride property\n");
> + return ret;
> + }
> +
> + ret = of_property_read_string(np, "format", &format);
> + if (ret) {
> + dev_err(&pdev->dev, "Can't parse format property\n");
> + return ret;
> + }
> + mode->format = format;
> +
> + return 0;
> +}
> +
> +static struct simplefb_format simplefb_formats[] = SIMPLEFB_FORMATS;
> +
> +int sdrm_pdev_init(struct sdrm_device *sdrm)
> +{
> + struct platform_device *pdev = sdrm->ddev->platformdev;
> + struct simplefb_platform_data *mode = pdev->dev.platform_data;
> + struct simplefb_platform_data pmode;
> + struct resource *mem;
> + unsigned int depth;
> + int ret, i, bpp;
> +
> + if (!mode) {
> + mode = &pmode;
> + ret = parse_dt(pdev, mode);
> + if (ret)
> + return ret;
> + }
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!mem) {
> + dev_err(sdrm->ddev->dev, "No memory resource\n");
> + return -ENODEV;
> + }
> +
> + for (i = 0; i < ARRAY_SIZE(simplefb_formats); ++i) {
> + if (strcmp(mode->format, simplefb_formats[i].name))
> + continue;
> +
> + sdrm->fb_sformat = &simplefb_formats[i];
> + sdrm->fb_format = simplefb_formats[i].fourcc;
> + sdrm->fb_width = mode->width;
> + sdrm->fb_height = mode->height;
> + sdrm->fb_stride = mode->stride;
> + sdrm->fb_base = mem->start;
> + sdrm->fb_size = resource_size(mem);
> + break;
> + }
> +
> + if (i >= ARRAY_SIZE(simplefb_formats)) {
> + dev_err(sdrm->ddev->dev, "Unknown format %s\n", mode->format);
> + return -ENODEV;
> + }
> +
> + switch (sdrm->fb_format) {
> + case DRM_FORMAT_RGB565:
> + case DRM_FORMAT_XRGB1555:
> + case DRM_FORMAT_ARGB1555:
> + case DRM_FORMAT_RGB888:
> + case DRM_FORMAT_XRGB8888:
> + case DRM_FORMAT_ARGB8888:
> + case DRM_FORMAT_ABGR8888:
> + case DRM_FORMAT_XRGB2101010:
> + case DRM_FORMAT_ARGB2101010:
> + /*
> + * You must adjust sdrm_put() whenever you add a new format
> + * here, otherwise, blitting operations will not work.
> + * Furthermore, include/linux/platform_data/simplefb.h needs
> + * to be adjusted so the platform-device actually allows this
> + * format.
> + */
> + break;
> + default:
> + dev_err(sdrm->ddev->dev, "Unsupported format %s\n",
> + mode->format);
> + return -ENODEV;
> + }
> +
> + drm_fb_get_bpp_depth(sdrm->fb_format, &depth, &bpp);
> + if (!bpp) {
> + dev_err(sdrm->ddev->dev, "Unknown format %s\n", mode->format);
> + return -ENODEV;
> + }
> +
> + if (sdrm->fb_size < sdrm->fb_stride * sdrm->fb_height) {
> + dev_err(sdrm->ddev->dev, "FB too small\n");
> + return -ENODEV;
> + } else if ((bpp + 7) / 8 * sdrm->fb_width > sdrm->fb_stride) {
> + dev_err(sdrm->ddev->dev, "Invalid stride\n");
> + return -ENODEV;
> + }
> +
> + sdrm->fb_bpp = bpp;
> +
> + sdrm->fb_map = ioremap_wc(sdrm->fb_base, sdrm->fb_size);
> + if (!sdrm->fb_map) {
> + dev_err(sdrm->ddev->dev, "cannot remap VMEM\n");
> + return -EIO;
> + }
> +
> + DRM_DEBUG_KMS("format: %s\n", drm_get_format_name(sdrm->fb_format));
> +
> + return 0;
> +}
> +
> +void sdrm_pdev_destroy(struct sdrm_device *sdrm)
> +{
> + if (sdrm->fb_map) {
> + iounmap(sdrm->fb_map);
> + sdrm->fb_map = NULL;
> + }
> +}
> +
> +static int sdrm_simplefb_probe(struct platform_device *pdev)
> +{
> + struct sdrm_device *sdrm;
> + struct drm_device *ddev;
> + int ret;
> +
> + ddev = drm_dev_alloc(&sdrm_drm_driver, &pdev->dev);
> + if (!ddev)
> + return -ENOMEM;
> +
> + sdrm = kzalloc(sizeof(*sdrm), GFP_KERNEL);
> + if (!sdrm)
> + goto err_free;
> +
> + ddev->platformdev = pdev;
> + ddev->dev_private = sdrm;
> + sdrm->ddev = ddev;
> +
> + ret = sdrm_pdev_init(sdrm);
> + if (ret)
> + goto err_free;
> +
> + ret = sdrm_drm_modeset_init(sdrm);
> + if (ret)
> + goto err_destroy;
> +
> + ret = drm_dev_register(ddev, 0);
> + if (ret)
> + goto err_cleanup;
> +
> + platform_set_drvdata(pdev, ddev);
> +
> + DRM_INFO("Initialized %s on minor %d\n", ddev->driver->name,
> + ddev->primary->index);
> +
> + return 0;
> +
> +err_cleanup:
> + drm_mode_config_cleanup(ddev);
> +err_destroy:
> + sdrm_pdev_destroy(sdrm);
> +err_free:
> + drm_dev_unref(ddev);
> + kfree(sdrm);
> +
> + return ret;
> +}
> +
> +static int sdrm_simplefb_remove(struct platform_device *pdev)
> +{
> + struct drm_device *ddev = platform_get_drvdata(pdev);
> + struct sdrm_device *sdrm = ddev->dev_private;
> +
> + drm_dev_unregister(ddev);
> + drm_mode_config_cleanup(ddev);
> +
> + /* protect fb_map removal against sdrm_blit() */
> + drm_modeset_lock_all(ddev);
> + sdrm_pdev_destroy(sdrm);
> + drm_modeset_unlock_all(ddev);
> +
> + drm_dev_unref(ddev);
> + kfree(sdrm);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id simplefb_of_match[] = {
> + { .compatible = "simple-framebuffer", },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, simplefb_of_match);
> +
> +static struct platform_driver sdrm_simplefb_driver = {
> + .probe = sdrm_simplefb_probe,
> + .remove = sdrm_simplefb_remove,
> + .driver = {
> + .name = "simple-framebuffer",
> + .mod_name = KBUILD_MODNAME,
> + .owner = THIS_MODULE,
> + .of_match_table = simplefb_of_match,
> + },
> +};
> +
> +static int __init sdrm_init(void)
> +{
> + return platform_driver_register(&sdrm_simplefb_driver);
> +}
> +
> +static void __exit sdrm_exit(void)
> +{
> + platform_driver_unregister(&sdrm_simplefb_driver);
> +}
> +
> +module_init(sdrm_init);
> +module_exit(sdrm_exit);
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>");
> +MODULE_DESCRIPTION("Simple firmware framebuffer DRM driver");
> +MODULE_ALIAS("platform:simple-framebuffer");
> diff --git a/drivers/gpu/drm/simpledrm/simpledrm_gem.c b/drivers/gpu/drm/simpledrm/simpledrm_gem.c
> new file mode 100644
> index 0000000..2d59632
> --- /dev/null
> +++ b/drivers/gpu/drm/simpledrm/simpledrm_gem.c
> @@ -0,0 +1,276 @@
> +/*
> + * SimpleDRM firmware framebuffer driver
> + * Copyright (c) 2012-2014 David Herrmann <dh.herrmann@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the Free
> + * Software Foundation; either version 2 of the License, or (at your option)
> + * any later version.
> + */
> +
> +#include <linux/dma-buf.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/module.h>
> +#include <linux/string.h>
> +#include <drm/drmP.h>
> +#include <drm/drm_legacy.h>
> +#include "simpledrm.h"
> +
> +int sdrm_gem_get_pages(struct sdrm_gem_object *obj)
> +{
> + size_t num, i;
> +
> + if (obj->vmapping)
> + return 0;
> +
> + if (obj->base.import_attach) {
> + obj->vmapping = dma_buf_vmap(obj->base.import_attach->dmabuf);
> + return !obj->vmapping ? -ENOMEM : 0;
> + }
> +
> + num = obj->base.size >> PAGE_SHIFT;
> + obj->pages = drm_malloc_ab(num, sizeof(*obj->pages));
> + if (!obj->pages)
> + return -ENOMEM;
> +
> + for (i = 0; i < num; ++i) {
> + obj->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
> + if (!obj->pages[i])
> + goto error;
> + }
> +
> + obj->vmapping = vmap(obj->pages, num, 0, PAGE_KERNEL);
> + if (!obj->vmapping)
> + goto error;
> +
> + return 0;
> +
> +error:
> + while (i > 0)
> + __free_pages(obj->pages[--i], 0);
> +
> + drm_free_large(obj->pages);
> + obj->pages = NULL;
> + return -ENOMEM;
> +}
> +
> +static void sdrm_gem_put_pages(struct sdrm_gem_object *obj)
> +{
> + size_t num, i;
> +
> + if (!obj->vmapping)
> + return;
> +
> + if (obj->base.import_attach) {
> + dma_buf_vunmap(obj->base.import_attach->dmabuf, obj->vmapping);
> + obj->vmapping = NULL;
> + return;
> + }
> +
> + vunmap(obj->vmapping);
> + obj->vmapping = NULL;
> +
> + num = obj->base.size >> PAGE_SHIFT;
> + for (i = 0; i < num; ++i)
> + __free_pages(obj->pages[i], 0);
> +
> + drm_free_large(obj->pages);
> + obj->pages = NULL;
> +}
> +
> +struct sdrm_gem_object *sdrm_gem_alloc_object(struct drm_device *ddev,
> + size_t size)
> +{
> + struct sdrm_gem_object *obj;
> +
> + WARN_ON(!size || (size & ~PAGE_MASK) != 0);
> +
> + obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> + if (!obj)
> + return NULL;
> +
> + drm_gem_private_object_init(ddev, &obj->base, size);
> + return obj;
> +}
> +
> +void sdrm_gem_free_object(struct drm_gem_object *gobj)
> +{
> + struct sdrm_gem_object *obj = to_sdrm_bo(gobj);
> + struct drm_device *ddev = gobj->dev;
> +
> + if (obj->pages) {
> + /* kill all user-space mappings */
> + drm_vma_node_unmap(&gobj->vma_node,
> + ddev->anon_inode->i_mapping);
> + sdrm_gem_put_pages(obj);
> + }
> +
> + if (gobj->import_attach)
> + drm_prime_gem_destroy(gobj, obj->sg);
> +
> + drm_gem_free_mmap_offset(gobj);
> + drm_gem_object_release(gobj);
> + kfree(obj);
> +}
> +
> +int sdrm_dumb_create(struct drm_file *dfile, struct drm_device *ddev,
> + struct drm_mode_create_dumb *args)
> +{
> + struct sdrm_gem_object *obj;
> + int r;
> +
> + if (args->flags)
> + return -EINVAL;
> +
> + /* overflow checks are done by DRM core */
> + args->pitch = (args->bpp + 7) / 8 * args->width;
> + args->size = PAGE_ALIGN(args->pitch * args->height);
> +
> + obj = sdrm_gem_alloc_object(ddev, args->size);
> + if (!obj)
> + return -ENOMEM;
> +
> + r = drm_gem_handle_create(dfile, &obj->base, &args->handle);
> + if (r) {
> + drm_gem_object_unreference_unlocked(&obj->base);
> + return r;
> + }
> +
> + /* handle owns a reference */
> + drm_gem_object_unreference_unlocked(&obj->base);
> + return 0;
> +}
> +
> +int sdrm_dumb_destroy(struct drm_file *dfile, struct drm_device *ddev,
> + uint32_t handle)
> +{
> + return drm_gem_handle_delete(dfile, handle);
> +}
> +
> +int sdrm_dumb_map_offset(struct drm_file *dfile, struct drm_device *ddev,
> + uint32_t handle, uint64_t *offset)
> +{
> + struct drm_gem_object *gobj;
> + int r;
> +
> + mutex_lock(&ddev->struct_mutex);
> +
> + gobj = drm_gem_object_lookup(dfile, handle);
> + if (!gobj) {
> + r = -ENOENT;
> + goto out_unlock;
> + }
> +
> + r = drm_gem_create_mmap_offset(gobj);
> + if (r)
> + goto out_unref;
> +
> + *offset = drm_vma_node_offset_addr(&gobj->vma_node);
> +
> +out_unref:
> + drm_gem_object_unreference(gobj);
> +out_unlock:
> + mutex_unlock(&ddev->struct_mutex);
> + return r;
> +}
> +
> +int sdrm_drm_mmap(struct file *filp, struct vm_area_struct *vma)
> +{
> + struct drm_file *priv = filp->private_data;
> + struct drm_device *dev = priv->minor->dev;
> + struct drm_vma_offset_node *node;
> + struct drm_gem_object *gobj;
> + struct sdrm_gem_object *obj;
> + size_t size, i, num;
> + int r;
> +
> + if (drm_device_is_unplugged(dev))
> + return -ENODEV;
> +
> + drm_vma_offset_lock_lookup(dev->vma_offset_manager);
> + node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
> + vma->vm_pgoff,
> + vma_pages(vma));
> + drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
> +
> + if (!node)
> + return drm_legacy_mmap(filp, vma);
> + else if (!drm_vma_node_is_allowed(node, filp))
> + return -EACCES;
> +
> + gobj = container_of(node, struct drm_gem_object, vma_node);
> + obj = to_sdrm_bo(gobj);
> + size = drm_vma_node_size(node) << PAGE_SHIFT;
> + if (size < vma->vm_end - vma->vm_start)
> + return r;
> +
> + r = sdrm_gem_get_pages(obj);
> + if (r < 0)
> + return r;
> +
> + /* prevent dmabuf-imported mmap to user-space */
> + if (!obj->pages)
> + return -EACCES;
> +
> + vma->vm_flags |= VM_DONTEXPAND;
> + vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
> +
> + num = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
> + for (i = 0; i < num; ++i) {
> + r = vm_insert_page(vma, vma->vm_start + i * PAGE_SIZE,
> + obj->pages[i]);
> + if (r < 0) {
> + if (i > 0)
> + zap_vma_ptes(vma, vma->vm_start, i * PAGE_SIZE);
> + return r;
> + }
> + }
> +
> + return 0;
> +}
> +
> +struct drm_gem_object *sdrm_gem_prime_import(struct drm_device *ddev,
> + struct dma_buf *dma_buf)
> +{
> + struct dma_buf_attachment *attach;
> + struct sdrm_gem_object *obj;
> + struct sg_table *sg;
> + int ret;
> +
> + /* need to attach */
> + attach = dma_buf_attach(dma_buf, ddev->dev);
> + if (IS_ERR(attach))
> + return ERR_CAST(attach);
> +
> + get_dma_buf(dma_buf);
> +
> + sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
> + if (IS_ERR(sg)) {
> + ret = PTR_ERR(sg);
> + goto fail_detach;
> + }
> +
> + /*
> + * dma_buf_vmap() gives us a page-aligned mapping, so lets bump the
> + * size of the dma-buf to the next page-boundary
> + */
> + obj = sdrm_gem_alloc_object(ddev, PAGE_ALIGN(dma_buf->size));
> + if (!obj) {
> + ret = -ENOMEM;
> + goto fail_unmap;
> + }
> +
> + obj->sg = sg;
> + obj->base.import_attach = attach;
> +
> + return &obj->base;
> +
> +fail_unmap:
> + dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
> +fail_detach:
> + dma_buf_detach(dma_buf, attach);
> + dma_buf_put(dma_buf);
> + return ERR_PTR(ret);
> +}
> diff --git a/drivers/gpu/drm/simpledrm/simpledrm_kms.c b/drivers/gpu/drm/simpledrm/simpledrm_kms.c
> new file mode 100644
> index 0000000..6295a9f
> --- /dev/null
> +++ b/drivers/gpu/drm/simpledrm/simpledrm_kms.c
> @@ -0,0 +1,276 @@
> +/*
> + * SimpleDRM firmware framebuffer driver
> + * Copyright (c) 2012-2014 David Herrmann <dh.herrmann@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the Free
> + * Software Foundation; either version 2 of the License, or (at your option)
> + * any later version.
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/module.h>
> +#include <linux/string.h>
> +#include <drm/drmP.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_crtc_helper.h>
> +#include "simpledrm.h"
> +
> +static const uint32_t sdrm_formats[] = {
> + DRM_FORMAT_RGB565,
> + DRM_FORMAT_ARGB8888,
> + DRM_FORMAT_XRGB8888,
> +};
> +
> +static int sdrm_conn_get_modes(struct drm_connector *conn)
> +{
> + struct sdrm_device *sdrm = conn->dev->dev_private;
> + struct drm_display_mode *mode;
> +
> + mode = drm_cvt_mode(sdrm->ddev, sdrm->fb_width, sdrm->fb_height,
> + 60, false, false, false);
> + if (!mode)
> + return 0;
> +
> + mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> + drm_mode_set_name(mode);
> + drm_mode_probed_add(conn, mode);
> +
> + return 1;
> +}
> +
> +static const struct drm_connector_helper_funcs sdrm_conn_hfuncs = {
> + .get_modes = sdrm_conn_get_modes,
> + .best_encoder = drm_atomic_helper_best_encoder,
> +};
> +
> +static enum drm_connector_status sdrm_conn_detect(struct drm_connector *conn,
> + bool force)
> +{
> + /*
> + * We simulate an always connected monitor. simple-fb doesn't
> + * provide any way to detect whether the connector is active. Hence,
> + * signal DRM core that it is always connected.
> + */
> +
> + return connector_status_connected;
> +}
> +
> +static const struct drm_connector_funcs sdrm_conn_ops = {
> + .dpms = drm_atomic_helper_connector_dpms,
> + .reset = drm_atomic_helper_connector_reset,
> + .detect = sdrm_conn_detect,
> + .fill_modes = drm_helper_probe_single_connector_modes,
> + .destroy = drm_connector_cleanup,
> + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static inline struct sdrm_device *
> +pipe_to_sdrm(struct drm_simple_display_pipe *pipe)
> +{
> + return container_of(pipe, struct sdrm_device, pipe);
> +}
> +
> +static int sdrm_display_pipe_check(struct drm_simple_display_pipe *pipe,
> + struct drm_plane_state *plane_state,
> + struct drm_crtc_state *crtc_state)
> +{
> + struct drm_display_mode *mode = &crtc_state->mode;
> + struct sdrm_device *sdrm = pipe_to_sdrm(pipe);
> + struct drm_framebuffer *fb = plane_state->fb;
> + u32 x = plane_state->src_x >> 16;
> + u32 y = plane_state->src_y >> 16;
> +
> + if (mode->hdisplay != sdrm->fb_width ||
> + mode->vdisplay != sdrm->fb_height)
> + return -EINVAL;
> + if (fb->width <= x || fb->height <= y ||
> + fb->width - x < sdrm->fb_width || fb->height - y < sdrm->fb_height)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +void sdrm_display_pipe_update(struct drm_simple_display_pipe *pipe,
> + struct drm_plane_state *plane_state)
> +{
> + struct drm_framebuffer *fb = pipe->plane.state->fb;
> + struct sdrm_device *sdrm = pipe_to_sdrm(pipe);
> +
> + if (fb)
> + sdrm_dirty_all_locked(sdrm);
> +}
> +
> +static void sdrm_crtc_send_vblank_event(struct drm_crtc *crtc)
> +{
> + if (crtc->state && crtc->state->event) {
> + spin_lock_irq(&crtc->dev->event_lock);
> + drm_crtc_send_vblank_event(crtc, crtc->state->event);
> + spin_unlock_irq(&crtc->dev->event_lock);
> + crtc->state->event = NULL;
> + }
> +}
> +
> +static void sdrm_display_pipe_enable(struct drm_simple_display_pipe *pipe,
> + struct drm_crtc_state *crtc_state)
> +{
> + sdrm_crtc_send_vblank_event(&pipe->crtc);
> +}
> +
> +static void sdrm_display_pipe_disable(struct drm_simple_display_pipe *pipe)
> +{
> + sdrm_crtc_send_vblank_event(&pipe->crtc);
> +}
> +
> +static const struct drm_simple_display_pipe_funcs sdrm_pipe_funcs = {
> + .check = sdrm_display_pipe_check,
> + .update = sdrm_display_pipe_update,
> + .enable = sdrm_display_pipe_enable,
> + .disable = sdrm_display_pipe_disable,
> +};
> +
> +static int sdrm_fb_create_handle(struct drm_framebuffer *fb,
> + struct drm_file *dfile,
> + unsigned int *handle)
> +{
> + struct sdrm_framebuffer *sfb = to_sdrm_fb(fb);
> +
> + return drm_gem_handle_create(dfile, &sfb->obj->base, handle);
> +}
> +
> +static void sdrm_fb_destroy(struct drm_framebuffer *fb)
> +{
> + struct sdrm_framebuffer *sfb = to_sdrm_fb(fb);
> +
> + drm_framebuffer_cleanup(fb);
> + drm_gem_object_unreference_unlocked(&sfb->obj->base);
> + kfree(sfb);
> +}
> +
> +static const struct drm_framebuffer_funcs sdrm_fb_ops = {
> + .create_handle = sdrm_fb_create_handle,
> + .dirty = sdrm_dirty,
> + .destroy = sdrm_fb_destroy,
> +};
> +
> +static struct drm_framebuffer *sdrm_fb_create(struct drm_device *ddev,
> + struct drm_file *dfile,
> + const struct drm_mode_fb_cmd2 *cmd)
> +{
> + struct sdrm_framebuffer *fb;
> + struct drm_gem_object *gobj;
> + u32 bpp, size;
> + int ret;
> + void *err;
> +
> + if (cmd->flags)
> + return ERR_PTR(-EINVAL);
> +
> + gobj = drm_gem_object_lookup(dfile, cmd->handles[0]);
> + if (!gobj)
> + return ERR_PTR(-EINVAL);
> +
> + fb = kzalloc(sizeof(*fb), GFP_KERNEL);
> + if (!fb) {
> + err = ERR_PTR(-ENOMEM);
> + goto err_unref;
> + }
> + fb->obj = to_sdrm_bo(gobj);
> +
> + fb->base.pitches[0] = cmd->pitches[0];
> + fb->base.offsets[0] = cmd->offsets[0];
> + fb->base.width = cmd->width;
> + fb->base.height = cmd->height;
> + fb->base.pixel_format = cmd->pixel_format;
> + drm_fb_get_bpp_depth(cmd->pixel_format, &fb->base.depth,
> + &fb->base.bits_per_pixel);
> +
> + /*
> + * width/height are already clamped into min/max_width/height range,
> + * so overflows are not possible
> + */
> +
> + bpp = (fb->base.bits_per_pixel + 7) / 8;
> + size = cmd->pitches[0] * cmd->height;
> + if (!bpp ||
> + bpp > 4 ||
> + cmd->pitches[0] < bpp * fb->base.width ||
> + cmd->pitches[0] > 0xffffU ||
> + size + fb->base.offsets[0] < size ||
> + size + fb->base.offsets[0] > fb->obj->base.size) {
> + err = ERR_PTR(-EINVAL);
> + goto err_free;
> + }
> +
> + ret = drm_framebuffer_init(ddev, &fb->base, &sdrm_fb_ops);
> + if (ret < 0) {
> + err = ERR_PTR(ret);
> + goto err_free;
> + }
> +
> + DRM_DEBUG_KMS("[FB:%d] pixel_format: %s\n", fb->base.base.id,
> + drm_get_format_name(fb->base.pixel_format));
> +
> + return &fb->base;
> +
> +err_free:
> + kfree(fb);
> +err_unref:
> + drm_gem_object_unreference_unlocked(gobj);
> +
> + return err;
> +}
> +
> +static const struct drm_mode_config_funcs sdrm_mode_config_ops = {
> + .fb_create = sdrm_fb_create,
> + .atomic_check = drm_atomic_helper_check,
> + .atomic_commit = drm_atomic_helper_commit,
> +};
> +
> +int sdrm_drm_modeset_init(struct sdrm_device *sdrm)
> +{
> + struct drm_connector *conn = &sdrm->conn;
> + struct drm_device *ddev = sdrm->ddev;
> + int ret;
> +
> + drm_mode_config_init(ddev);
> + ddev->mode_config.min_width = 1;
> + ddev->mode_config.min_height = 1;
> + ddev->mode_config.max_width = 8192;
> + ddev->mode_config.max_height = 8192;
> + ddev->mode_config.preferred_depth = sdrm->fb_bpp;
> + ddev->mode_config.funcs = &sdrm_mode_config_ops;
> +
> + drm_connector_helper_add(conn, &sdrm_conn_hfuncs);
> + ret = drm_connector_init(ddev, conn, &sdrm_conn_ops,
> + DRM_MODE_CONNECTOR_VIRTUAL);
> + if (ret)
> + goto err_cleanup;
> +
> + ret = drm_mode_create_dirty_info_property(ddev);
> + if (ret)
> + goto err_cleanup;
> +
> + drm_object_attach_property(&conn->base,
> + ddev->mode_config.dirty_info_property,
> + DRM_MODE_DIRTY_ON);
> +
> + ret = drm_simple_display_pipe_init(ddev, &sdrm->pipe, &sdrm_pipe_funcs,
> + sdrm_formats,
> + ARRAY_SIZE(sdrm_formats), conn);
> + if (ret)
> + goto err_cleanup;
> +
> + drm_mode_config_reset(ddev);
> +
> + return 0;
> +
> +err_cleanup:
> + drm_mode_config_cleanup(ddev);
> +
> + return ret;
> +}
> --
> 2.8.2
>