[PATCH 4/5] [resend] gxt4500: Use write-combining for framebuffer

[Ondrej Zary]

Use write-combining for framebuffer to greatly improve performance on x86.

Signed-off-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
---
 drivers/video/fbdev/gxt4500.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/gxt4500.c b/drivers/video/fbdev/gxt4500.c
index 442b07c..e0d1550 100644
--- a/drivers/video/fbdev/gxt4500.c
+++ b/drivers/video/fbdev/gxt4500.c
@@ -142,7 +142,7 @@ static const unsigned char watfmt[] = {
 
 struct gxt4500_par {
 	void __iomem *regs;
-
+	int wc_cookie;
 	int pixfmt;		/* pixel format, see DFA_PIX_* values */
 
 	/* PLL parameters */
@@ -663,7 +663,7 @@ static int gxt4500_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	info->fix.smem_start = fb_phys;
 	info->fix.smem_len = pci_resource_len(pdev, 1);
-	info->screen_base = pci_ioremap_bar(pdev, 1);
+	info->screen_base = ioremap_wc(fb_phys, info->fix.smem_len);
 	if (!info->screen_base) {
 		dev_err(&pdev->dev, "gxt4500: cannot map framebuffer\n");
 		goto err_unmap_regs;
@@ -671,6 +671,9 @@ static int gxt4500_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	pci_set_drvdata(pdev, info);
 
+	par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+					  info->fix.smem_len);
+
 #ifdef __BIG_ENDIAN
 	/* Set byte-swapping for DFA aperture for all pixel sizes */
 	pci_write_config_dword(pdev, CFG_ENDIAN0, 0x333300);
@@ -735,6 +738,7 @@ static void gxt4500_remove(struct pci_dev *pdev)
 		return;
 	par = info->par;
 	unregister_framebuffer(info);
+	arch_phys_wc_del(par->wc_cookie);
 	fb_dealloc_cmap(&info->cmap);
 	iounmap(par->regs);
 	iounmap(info->screen_base);
-- 
Ondrej Zary

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