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Subject[PATCH 1/3] au1100fb: fix DMA API abuse
Date
Virtual addresses return from dma(m)_alloc_coherent are opaque in what
backs then, and drivers must not poke into them. Switch the driver
to use the generic DMA API mmap helper to avoid these problems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
---
drivers/video/fbdev/au1100fb.c | 24 ++++--------------------
drivers/video/fbdev/au1100fb.h | 1 +
2 files changed, 5 insertions(+), 20 deletions(-)

diff --git a/drivers/video/fbdev/au1100fb.c b/drivers/video/fbdev/au1100fb.c
index 0adf0683cf08..99941ae1f3a1 100644
--- a/drivers/video/fbdev/au1100fb.c
+++ b/drivers/video/fbdev/au1100fb.c
@@ -340,14 +340,12 @@ int au1100fb_fb_pan_display(struct fb_var_screeninfo *var, struct fb_info *fbi)
*/
int au1100fb_fb_mmap(struct fb_info *fbi, struct vm_area_struct *vma)
{
- struct au1100fb_device *fbdev;
-
- fbdev = to_au1100fb_device(fbi);
+ struct au1100fb_device *fbdev = to_au1100fb_device(fbi);

- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
pgprot_val(vma->vm_page_prot) |= (6 << 9); //CCA=6

- return vm_iomap_memory(vma, fbdev->fb_phys, fbdev->fb_len);
+ return dma_mmap_coherent(fbdev->dev, vma, fbdev->fb_mem, fbdev->fb_phys,
+ fbdev->fb_len);
}

static struct fb_ops au1100fb_ops =
@@ -412,7 +410,6 @@ static int au1100fb_drv_probe(struct platform_device *dev)
{
struct au1100fb_device *fbdev;
struct resource *regs_res;
- unsigned long page;
struct clk *c;

/* Allocate new device private */
@@ -424,6 +421,7 @@ static int au1100fb_drv_probe(struct platform_device *dev)
goto failed;

platform_set_drvdata(dev, (void *)fbdev);
+ fbdev->dev = &dev->dev;

/* Allocate region for our registers and map them */
regs_res = platform_get_resource(dev, IORESOURCE_MEM, 0);
@@ -472,20 +470,6 @@ static int au1100fb_drv_probe(struct platform_device *dev)
au1100fb_fix.smem_start = fbdev->fb_phys;
au1100fb_fix.smem_len = fbdev->fb_len;

- /*
- * Set page reserved so that mmap will work. This is necessary
- * since we'll be remapping normal memory.
- */
- for (page = (unsigned long)fbdev->fb_mem;
- page < PAGE_ALIGN((unsigned long)fbdev->fb_mem + fbdev->fb_len);
- page += PAGE_SIZE) {
-#ifdef CONFIG_DMA_NONCOHERENT
- SetPageReserved(virt_to_page(CAC_ADDR((void *)page)));
-#else
- SetPageReserved(virt_to_page(page));
-#endif
- }
-
print_dbg("Framebuffer memory map at %p", fbdev->fb_mem);
print_dbg("phys=0x%08x, size=%dK", fbdev->fb_phys, fbdev->fb_len / 1024);

diff --git a/drivers/video/fbdev/au1100fb.h b/drivers/video/fbdev/au1100fb.h
index 9af19939a9c6..e7239bceefd3 100644
--- a/drivers/video/fbdev/au1100fb.h
+++ b/drivers/video/fbdev/au1100fb.h
@@ -110,6 +110,7 @@ struct au1100fb_device {
dma_addr_t fb_phys;
int panel_idx;
struct clk *lcdclk;
+ struct device *dev;
};

/********************************************************************/
--
2.20.1
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