camera: support PAT

PAT (Page Attribute Table) allows for different types of memory attributes.
We modified APIs about PAT from non-cached to write-combined.

Change-Id: Ifa15061098b58a3f305fe692ba244fec4e2604e6
Signed-off-by: sungmin ha <sungmin82.ha@samsung.com>
(cherry picked from commit e13e3c5ae5c7b0e9d10152375fc0551023e0b763)

diff --git a/drivers/maru/maru_camera.c b/drivers/maru/maru_camera.c
index 7323e40..483c036 100644 (file)
--- a/drivers/maru/maru_camera.c
+++ b/drivers/maru/maru_camera.c
@@ -288,7 +288,7 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
 
        pages = PAGE_ALIGN(vma->vm_end - vma->vm_start);
 
-       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+       vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
        retval = remap_pfn_range(vma, vma->vm_start,
                        (((struct marucam_device *)q->priv_data)->mem_base
                        + vma->vm_pgoff) >> PAGE_SHIFT,
@@ -1231,6 +1231,26 @@ static const struct pci_device_id marucam_pci_id_tbl[] = {
 };
 
 MODULE_DEVICE_TABLE(pci, marucam_pci_id_tbl);
+
+/* The following function already exist in the latest linux stable kernel.
+ * https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/
+ * commit/?id=c43996f4001de629af4a4d6713782e883677e5b9
+ * This should be removed if emulator-kernel is upgraded.
+ */
+static void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
+{
+       /*
+       * Make sure the BAR is actually a memory resource, not an IO resource
+       */
+       if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
+               WARN_ON(1);
+               return NULL;
+       }
+
+       return ioremap_wc(pci_resource_start(pdev, bar),
+                       pci_resource_len(pdev, bar));
+}
+
 static int marucam_pci_initdev(struct pci_dev *pdev,
                                const struct pci_device_id *id)
 {
@@ -1289,9 +1309,9 @@ static int marucam_pci_initdev(struct pci_dev *pdev,
                return -EBUSY;
        }
 
-       dev->args = pci_ioremap_bar(pdev, 1);
+       dev->args = pci_ioremap_wc_bar(pdev, 1);
        if (!dev->args) {
-               marucam_err("pci_ioremap_bar failed for 1 bar\n");
+               marucam_err("pci_ioremap_wc_bar failed for 1 bar\n");
                pci_release_region(pdev, 0);
                pci_release_region(pdev, 1);
                pci_release_region(pdev, 2);
@@ -1301,9 +1321,9 @@ static int marucam_pci_initdev(struct pci_dev *pdev,
        }
        dev->iomem_size = pci_resource_len(pdev, 1);
 
-       dev->mmregs = pci_ioremap_bar(pdev, 2);
+       dev->mmregs = pci_ioremap_wc_bar(pdev, 2);
        if (!dev->mmregs) {
-               marucam_err("pci_ioremap_bar failed for 2 bar\n");
+               marucam_err("pci_ioremap_wc_bar failed for 2 bar\n");
                iounmap(dev->args);
                pci_release_region(pdev, 0);
                pci_release_region(pdev, 1);