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fbdev: add FBIOCOPYAREA ioctl
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commit ba7d542d535059fe6e1a19c2a7cff811c01513c7 from
https://github.com/raspberrypi/linux.git rpi-6.6.y

Based on the patch authored by Ali Gholami Rudi at
    https://lkml.org/lkml/2009/7/13/153

Provide an ioctl for userspace applications, but only if this operation
is hardware accelerated (otherwide it does not make any sense).

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>

bcm2708_fb: Add ioctl for reading gpu memory through dma

video: bcm2708_fb: Add compat_ioctl support.

When using a 64 bit kernel with 32 bit userspace we need
compat ioctl handling for FBIODMACOPY as one of the
parameters is a pointer.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: Rajeshkumar Ramasamy <rajeshkumar.ramasamy@windriver.com>
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@ssvb @rajeshkumarwr
ssvb authored and rajeshkumarwr committed Aug 9, 2024
1 parent ac409fd commit 0084182
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Showing 3 changed files with 213 additions and 4 deletions.
170 changes: 166 additions & 4 deletions drivers/video/fbdev/bcm2708_fb.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,8 +32,10 @@
#include <linux/printk.h>
#include <linux/console.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/cred.h>
#include <soc/bcm2835/raspberrypi-firmware.h>
#include <linux/mutex.h>

Expand Down Expand Up @@ -184,9 +186,6 @@ static int bcm2708_fb_debugfs_init(struct bcm2708_fb *fb)

fb->debugfs_subdir = debugfs_create_dir(buf, fb->debugfs_dir);

debugfs_create_regset32("stats", 0444, fb->debugfs_dir,
&fb->stats.regset);

if (!fb->debugfs_subdir) {
dev_warn(fb->fb.dev, "%s: could not create debugfs entry %u\n",
__func__, fb->display_settings.display_num);
Expand Down Expand Up @@ -603,7 +602,110 @@ static int bcm2708_fb_pan_display(struct fb_var_screeninfo *var,
return result;
}

static int bcm2708_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
static void dma_memcpy(struct bcm2708_fb *fb, dma_addr_t dst, dma_addr_t src,
int size)
{
struct bcm2708_fb_dev *fbdev = fb->fbdev;
struct bcm2708_dma_cb *cb = fbdev->cb_base;
int burst_size = (fbdev->dma_chan == 0) ? 8 : 2;

cb->info = BCM2708_DMA_BURST(burst_size) | BCM2708_DMA_S_WIDTH |
BCM2708_DMA_S_INC | BCM2708_DMA_D_WIDTH |
BCM2708_DMA_D_INC;
cb->dst = dst;
cb->src = src;
cb->length = size;
cb->stride = 0;
cb->pad[0] = 0;
cb->pad[1] = 0;
cb->next = 0;

// Not sure what to do if this gets a signal whilst waiting
if (mutex_lock_interruptible(&fbdev->dma_mutex))
return;

if (size < dma_busy_wait_threshold) {
bcm_dma_start(fbdev->dma_chan_base, fbdev->cb_handle);
bcm_dma_wait_idle(fbdev->dma_chan_base);
} else {
void __iomem *local_dma_chan = fbdev->dma_chan_base;

cb->info |= BCM2708_DMA_INT_EN;
bcm_dma_start(fbdev->dma_chan_base, fbdev->cb_handle);
while (bcm_dma_is_busy(local_dma_chan)) {
wait_event_interruptible(fbdev->dma_waitq,
!bcm_dma_is_busy(local_dma_chan));
}
fbdev->dma_stats.dma_irqs++;
}
fbdev->dma_stats.dma_copies++;

mutex_unlock(&fbdev->dma_mutex);
}

/* address with no aliases */
#define INTALIAS_NORMAL(x) ((x) & ~0xc0000000)
/* cache coherent but non-allocating in L1 and L2 */
#define INTALIAS_L1L2_NONALLOCATING(x) (((x) & ~0xc0000000) | 0x80000000)

static long vc_mem_copy(struct bcm2708_fb *fb, struct fb_dmacopy *ioparam)
{
size_t size = PAGE_SIZE;
u32 *buf = NULL;
dma_addr_t bus_addr;
long rc = 0;
size_t offset;

/* restrict this to root user */
if (!uid_eq(current_euid(), GLOBAL_ROOT_UID)) {
rc = -EFAULT;
goto out;
}

if (!fb->gpu.base || !fb->gpu.length) {
pr_err("[%s]: Unable to determine gpu memory (%x,%x)\n",
__func__, fb->gpu.base, fb->gpu.length);
return -EFAULT;
}

if (INTALIAS_NORMAL(ioparam->src) < fb->gpu.base ||
INTALIAS_NORMAL(ioparam->src) >= fb->gpu.base + fb->gpu.length) {
pr_err("[%s]: Invalid memory access %x (%x-%x)", __func__,
INTALIAS_NORMAL(ioparam->src), fb->gpu.base,
fb->gpu.base + fb->gpu.length);
return -EFAULT;
}

buf = dma_alloc_coherent(fb->fb.device, PAGE_ALIGN(size), &bus_addr,
GFP_ATOMIC);
if (!buf) {
pr_err("[%s]: failed to dma_alloc_coherent(%zd)\n", __func__,
size);
rc = -ENOMEM;
goto out;
}

for (offset = 0; offset < ioparam->length; offset += size) {
size_t remaining = ioparam->length - offset;
size_t s = min(size, remaining);
u8 *p = (u8 *)((uintptr_t)ioparam->src + offset);
u8 *q = (u8 *)ioparam->dst + offset;

dma_memcpy(fb, bus_addr,
INTALIAS_L1L2_NONALLOCATING((dma_addr_t)p), size);
if (copy_to_user(q, buf, s) != 0) {
pr_err("[%s]: failed to copy-to-user\n", __func__);
rc = -EFAULT;
goto out;
}
}
out:
if (buf)
dma_free_coherent(fb->fb.device, PAGE_ALIGN(size), buf,
bus_addr);
return rc;
}

static int bcm2708_ioctl(struct fb_info *info, unsigned int cmd,
unsigned long arg)
{
Expand All @@ -619,6 +721,21 @@ static int bcm2708_ioctl(struct fb_info *info, unsigned int cmd,
RPI_FIRMWARE_FRAMEBUFFER_SET_VSYNC,
&dummy, sizeof(dummy));
break;

case FBIODMACOPY:
{
struct fb_dmacopy ioparam;
/* Get the parameter data.
*/
if (copy_from_user
(&ioparam, (void *)arg, sizeof(ioparam))) {
pr_err("[%s]: failed to copy-from-user\n", __func__);
ret = -EFAULT;
break;
}
ret = vc_mem_copy(fb, &ioparam);
break;
}
default:
dev_dbg(info->device, "Unknown ioctl 0x%x\n", cmd);
return -ENOTTY;
Expand All @@ -629,6 +746,48 @@ static int bcm2708_ioctl(struct fb_info *info, unsigned int cmd,

return ret;
}

#ifdef CONFIG_COMPAT
struct fb_dmacopy32 {
compat_uptr_t dst;
__u32 src;
__u32 length;
};

#define FBIODMACOPY32 _IOW('z', 0x22, struct fb_dmacopy32)

static int bcm2708_compat_ioctl(struct fb_info *info, unsigned int cmd,
unsigned long arg)
{
struct bcm2708_fb *fb = to_bcm2708(info);
int ret;

switch (cmd) {
case FBIODMACOPY32:
{
struct fb_dmacopy32 param32;
struct fb_dmacopy param;
/* Get the parameter data.
*/
if (copy_from_user(&param32, (void *)arg, sizeof(param32))) {
pr_err("[%s]: failed to copy-from-user\n", __func__);
ret = -EFAULT;
break;
}
param.dst = compat_ptr(param32.dst);
param.src = param32.src;
param.length = param32.length;
ret = vc_mem_copy(fb, &param);
break;
}
default:
ret = bcm2708_ioctl(info, cmd, arg);
break;
}
return ret;
}
#endif

static void bcm2708_fb_fillrect(struct fb_info *info,
const struct fb_fillrect *rect)
{
Expand Down Expand Up @@ -821,6 +980,9 @@ static struct fb_ops bcm2708_fb_ops = {
.fb_imageblit = bcm2708_fb_imageblit,
.fb_pan_display = bcm2708_fb_pan_display,
.fb_ioctl = bcm2708_ioctl,
#ifdef CONFIG_COMPAT
.fb_compat_ioctl = bcm2708_compat_ioctl,
#endif
};

static int bcm2708_fb_register(struct bcm2708_fb *fb)
Expand Down
35 changes: 35 additions & 0 deletions drivers/video/fbdev/core/fb_chrdev.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -59,6 +59,30 @@ static ssize_t fb_write(struct file *file, const char __user *buf, size_t count,
return fb_io_write(info, buf, count, ppos);
}

static int fb_copyarea_user(struct fb_info *info,
struct fb_copyarea *copy)
{
int ret = 0;
lock_fb_info(info);
if (copy->dx >= info->var.xres ||
copy->sx >= info->var.xres ||
copy->width > info->var.xres ||
copy->dy >= info->var.yres ||
copy->sy >= info->var.yres ||
copy->height > info->var.yres ||
copy->dx + copy->width > info->var.xres ||
copy->sx + copy->width > info->var.xres ||
copy->dy + copy->height > info->var.yres ||
copy->sy + copy->height > info->var.yres) {
ret = -EINVAL;
goto out;
}
info->fbops->fb_copyarea(info, copy);
out:
unlock_fb_info(info);
return ret;
}

static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
unsigned long arg)
{
Expand All @@ -67,6 +91,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
struct fb_fix_screeninfo fix;
struct fb_cmap cmap_from;
struct fb_cmap_user cmap;
struct fb_copyarea copy;
void __user *argp = (void __user *)arg;
long ret = 0;

Expand Down Expand Up @@ -148,6 +173,15 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
unlock_fb_info(info);
console_unlock();
break;
case FBIOCOPYAREA:
if (info->flags & FBINFO_HWACCEL_COPYAREA) {
/* only provide this ioctl if it is accelerated */
if (copy_from_user(&copy, argp, sizeof(copy)))
return -EFAULT;
ret = fb_copyarea_user(info, &copy);
break;
}
fallthrough;
default:
lock_fb_info(info);
fb = info->fbops;
Expand Down Expand Up @@ -287,6 +321,7 @@ static long fb_compat_ioctl(struct file *file, unsigned int cmd,
case FBIOPAN_DISPLAY:
case FBIOGET_CON2FBMAP:
case FBIOPUT_CON2FBMAP:
case FBIOCOPYAREA:
arg = (unsigned long) compat_ptr(arg);
fallthrough;
case FBIOBLANK:
Expand Down
12 changes: 12 additions & 0 deletions include/uapi/linux/fb.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,12 @@
#define FBIOPUT_MODEINFO 0x4617
#define FBIOGET_DISPINFO 0x4618
#define FBIO_WAITFORVSYNC _IOW('F', 0x20, __u32)
/*
* HACK: use 'z' in order not to clash with any other ioctl numbers which might
* be concurrently added to the mainline kernel
*/
#define FBIOCOPYAREA _IOW('z', 0x21, struct fb_copyarea)
#define FBIODMACOPY _IOW('z', 0x22, struct fb_dmacopy)

#define FB_TYPE_PACKED_PIXELS 0 /* Packed Pixels */
#define FB_TYPE_PLANES 1 /* Non interleaved planes */
Expand Down Expand Up @@ -348,6 +354,12 @@ struct fb_copyarea {
__u32 sy;
};

struct fb_dmacopy {
void *dst;
__u32 src;
__u32 length;
};

struct fb_fillrect {
__u32 dx; /* screen-relative */
__u32 dy;
Expand Down

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