From 4edcd2ab125506516c7de038f6e0a6d19dcc411d Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Mon, 24 Aug 2015 12:13:29 -0700 Subject: [PATCH] drivers/video/fbdev/s3fb: Use arch_phys_wc_add() and pci_iomap_wc() This driver uses the same area for MTRR as for the ioremap(). Convert the driver from using the x86-specific MTRR code to the architecture-agnostic arch_phys_wc_add(). It will avoid MTRRs if write-combining is available. In order to take advantage of that also ensure the ioremapped area is requested as write-combining. There are a few motivations for this: a) Take advantage of PAT when available. b) Help bury MTRR code away, MTRR is architecture-specific and on x86 it is being replaced by PAT. c) Help with the goal of eventually using _PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit de33c442e titled "x86 PAT: fix performance drop for glx, use UC minus for ioremap(), ioremap_nocache() and pci_mmap_page_range()"). The conversion done is expressed by the following Coccinelle SmPL patch, it additionally required manual intervention to address all the ifdeffery and removal of redundant things which arch_phys_wc_add() already addresses such as verbose message about when MTRR fails and doing nothing when we didn't get an MTRR. @ mtrr_found @ expression index, base, size; @@ -index = mtrr_add(base, size, MTRR_TYPE_WRCOMB, 1); +index = arch_phys_wc_add(base, size); @ mtrr_rm depends on mtrr_found @ expression mtrr_found.index, mtrr_found.base, mtrr_found.size; @@ -mtrr_del(index, base, size); +arch_phys_wc_del(index); @ mtrr_rm_zero_arg depends on mtrr_found @ expression mtrr_found.index; @@ -mtrr_del(index, 0, 0); +arch_phys_wc_del(index); @ mtrr_rm_fb_info depends on mtrr_found @ struct fb_info *info; expression mtrr_found.index; @@ -mtrr_del(index, info->fix.smem_start, info->fix.smem_len); +arch_phys_wc_del(index); @ ioremap_replace_nocache depends on mtrr_found @ struct fb_info *info; expression base, size; @@ -info->screen_base = ioremap_nocache(base, size); +info->screen_base = ioremap_wc(base, size); @ ioremap_replace_default depends on mtrr_found @ struct fb_info *info; expression base, size; @@ -info->screen_base = ioremap(base, size); +info->screen_base = ioremap_wc(base, size); Signed-off-by: Luis R. Rodriguez Signed-off-by: Borislav Petkov Acked-by: Tomi Valkeinen Cc: Andrew Morton Cc: Andy Lutomirski Cc: Antonino Daplas Cc: Arnd Bergmann Cc: Daniel Vetter Cc: Dave Airlie Cc: Geert Uytterhoeven Cc: H. Peter Anvin Cc: Jean-Christophe Plagniol-Villard Cc: Jingoo Han Cc: Juergen Gross Cc: Lad, Prabhakar Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rickard Strandqvist Cc: Suresh Siddha Cc: Thomas Gleixner Cc: airlied@linux.ie Cc: benh@kernel.crashing.org Cc: bhelgaas@google.com Cc: dan.j.williams@intel.com Cc: konrad.wilk@oracle.com Cc: linux-fbdev@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: mst@redhat.com Cc: toshi.kani@hp.com Cc: vinod.koul@intel.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1440443613-13696-8-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar --- drivers/video/fbdev/s3fb.c | 35 ++++++----------------------------- 1 file changed, 6 insertions(+), 29 deletions(-) diff --git a/drivers/video/fbdev/s3fb.c b/drivers/video/fbdev/s3fb.c index f0ae61a37f04..13b109073c63 100644 --- a/drivers/video/fbdev/s3fb.c +++ b/drivers/video/fbdev/s3fb.c @@ -28,13 +28,9 @@ #include #include -#ifdef CONFIG_MTRR -#include -#endif - struct s3fb_info { int chip, rev, mclk_freq; - int mtrr_reg; + int wc_cookie; struct vgastate state; struct mutex open_lock; unsigned int ref_count; @@ -154,11 +150,7 @@ static const struct svga_timing_regs s3_timing_regs = { static char *mode_option; - -#ifdef CONFIG_MTRR static int mtrr = 1; -#endif - static int fasttext = 1; @@ -170,11 +162,8 @@ module_param(mode_option, charp, 0444); MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)"); module_param_named(mode, mode_option, charp, 0444); MODULE_PARM_DESC(mode, "Default video mode ('640x480-8@60', etc) (deprecated)"); - -#ifdef CONFIG_MTRR module_param(mtrr, int, 0444); MODULE_PARM_DESC(mtrr, "Enable write-combining with MTRR (1=enable, 0=disable, default=1)"); -#endif module_param(fasttext, int, 0644); MODULE_PARM_DESC(fasttext, "Enable S3 fast text mode (1=enable, 0=disable, default=1)"); @@ -1168,7 +1157,7 @@ static int s3_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) info->fix.smem_len = pci_resource_len(dev, 0); /* Map physical IO memory address into kernel space */ - info->screen_base = pci_iomap(dev, 0, 0); + info->screen_base = pci_iomap_wc(dev, 0, 0); if (! info->screen_base) { rc = -ENOMEM; dev_err(info->device, "iomap for framebuffer failed\n"); @@ -1365,12 +1354,9 @@ static int s3_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) /* Record a reference to the driver data */ pci_set_drvdata(dev, info); -#ifdef CONFIG_MTRR - if (mtrr) { - par->mtrr_reg = -1; - par->mtrr_reg = mtrr_add(info->fix.smem_start, info->fix.smem_len, MTRR_TYPE_WRCOMB, 1); - } -#endif + if (mtrr) + par->wc_cookie = arch_phys_wc_add(info->fix.smem_start, + info->fix.smem_len); return 0; @@ -1405,14 +1391,7 @@ static void s3_pci_remove(struct pci_dev *dev) if (info) { par = info->par; - -#ifdef CONFIG_MTRR - if (par->mtrr_reg >= 0) { - mtrr_del(par->mtrr_reg, 0, 0); - par->mtrr_reg = -1; - } -#endif - + arch_phys_wc_del(par->wc_cookie); unregister_framebuffer(info); fb_dealloc_cmap(&info->cmap); @@ -1551,10 +1530,8 @@ static int __init s3fb_setup(char *options) if (!*opt) continue; -#ifdef CONFIG_MTRR else if (!strncmp(opt, "mtrr:", 5)) mtrr = simple_strtoul(opt + 5, NULL, 0); -#endif else if (!strncmp(opt, "fasttext:", 9)) fasttext = simple_strtoul(opt + 9, NULL, 0); else -- 2.39.2