From eacd2d542610e55cad0be445966ac8ae79124c6e Mon Sep 17 00:00:00 2001 From: Luis R. Rodriguez Date: Thu, 9 Jul 2015 18:24:56 -0700 Subject: drivers/video/fbdev/atyfb: Carve out framebuffer length fudging into a helper The size of the framebuffer to be used needs to be fudged to account for the different type of devices that are out there. This captures what is required to do well, we'll reuse this later. This has no functional changes. Signed-off-by: Luis R. Rodriguez Signed-off-by: Borislav Petkov Cc: H. Peter Anvin Cc: Jean-Christophe Plagniol-Villard Cc: Linus Torvalds Cc: Mathias Krause Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tomi Valkeinen Cc: airlied@redhat.com Cc: arnd@arndb.de Cc: benh@kernel.crashing.org Cc: dan.j.williams@intel.com Cc: geert@linux-m68k.org Cc: hch@lst.de Cc: hmh@hmh.eng.br Cc: jgross@suse.com Cc: linux-fbdev@vger.kernel.org Cc: linux-mm@kvack.org Cc: luto@amacapital.net Cc: mpe@ellerman.id.au Cc: mst@redhat.com Cc: ralf@linux-mips.org Cc: ross.zwisler@linux.intel.com Cc: stefan.bader@canonical.com Cc: syrjala@sci.fi Cc: tj@kernel.org Cc: toshi.kani@hp.com Cc: ville.syrjala@linux.intel.com Link: http://lkml.kernel.org/r/1435251019-32421-1-git-send-email-mcgrof@do-not-panic.com Link: http://lkml.kernel.org/r/1436491499-3289-2-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar --- drivers/video/fbdev/aty/atyfb_base.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'drivers/video') diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c index 8789e487b96e..16936bb1f865 100644 --- a/drivers/video/fbdev/aty/atyfb_base.c +++ b/drivers/video/fbdev/aty/atyfb_base.c @@ -427,6 +427,20 @@ static struct { #endif /* CONFIG_FB_ATY_CT */ }; +/* + * Last page of 8 MB (4 MB on ISA) aperture is MMIO, + * unless the auxiliary register aperture is used. + */ +static void aty_fudge_framebuffer_len(struct fb_info *info) +{ + struct atyfb_par *par = (struct atyfb_par *) info->par; + + if (!par->aux_start && + (info->fix.smem_len == 0x800000 || + (par->bus_type == ISA && info->fix.smem_len == 0x400000))) + info->fix.smem_len -= GUI_RESERVE; +} + static int correct_chipset(struct atyfb_par *par) { u8 rev; @@ -2603,14 +2617,7 @@ static int aty_init(struct fb_info *info) if (par->pll_ops->resume_pll) par->pll_ops->resume_pll(info, &par->pll); - /* - * Last page of 8 MB (4 MB on ISA) aperture is MMIO, - * unless the auxiliary register aperture is used. - */ - if (!par->aux_start && - (info->fix.smem_len == 0x800000 || - (par->bus_type == ISA && info->fix.smem_len == 0x400000))) - info->fix.smem_len -= GUI_RESERVE; + aty_fudge_framebuffer_len(info); /* * Disable register access through the linear aperture -- cgit v1.2.3-55-g7522 From f55de6ec375da89f89f1a76e1b998e5f14878c06 Mon Sep 17 00:00:00 2001 From: Luis R. Rodriguez Date: Thu, 9 Jul 2015 18:24:57 -0700 Subject: drivers/video/fbdev/atyfb: Clarify ioremap() base and length used Adjust the ioremap() call for the framebuffer to use the same values we later use for the framebuffer. This will make it easier to review the next change. The size of the framebuffer varies but since this is for PCI we *know* this defaults to 0x800000. atyfb_setup_generic() is *only* used on PCI probe. No functional change. Signed-off-by: Luis R. Rodriguez Signed-off-by: Borislav Petkov Cc: Andrew Morton Cc: Andrzej Hajda Cc: Andy Lutomirski Cc: Antonino Daplas Cc: Daniel Vetter Cc: Dave Airlie Cc: Davidlohr Bueso Cc: H. Peter Anvin Cc: Jean-Christophe Plagniol-Villard Cc: Juergen Gross Cc: Linus Torvalds Cc: Mathias Krause Cc: Mel Gorman Cc: Peter Zijlstra Cc: Rob Clark Cc: Suresh Siddha Cc: Thomas Gleixner Cc: Tomi Valkeinen Cc: Toshi Kani Cc: Ville Syrjälä Cc: Vlastimil Babka Cc: arnd@arndb.de Cc: benh@kernel.crashing.org Cc: dan.j.williams@intel.com Cc: geert@linux-m68k.org Cc: hch@lst.de Cc: hmh@hmh.eng.br Cc: linux-fbdev@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pci@vger.kernel.org Cc: mpe@ellerman.id.au Cc: mst@redhat.com Cc: ralf@linux-mips.org Cc: ross.zwisler@linux.intel.com Cc: stefan.bader@canonical.com Cc: tj@kernel.org Cc: ville.syrjala@linux.intel.com Link: http://lkml.kernel.org/r/1436491499-3289-3-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar --- drivers/video/fbdev/aty/atyfb_base.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'drivers/video') diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c index 16936bb1f865..de8f7e082c87 100644 --- a/drivers/video/fbdev/aty/atyfb_base.c +++ b/drivers/video/fbdev/aty/atyfb_base.c @@ -3489,7 +3489,21 @@ static int atyfb_setup_generic(struct pci_dev *pdev, struct fb_info *info, /* Map in frame buffer */ info->fix.smem_start = addr; - info->screen_base = ioremap(addr, 0x800000); + + /* + * The framebuffer is not always 8 MiB, that's just the size of the + * PCI BAR. We temporarily abuse smem_len here to store the size + * of the BAR. aty_init() will later correct it to match the actual + * framebuffer size. + * + * On devices that don't have the auxiliary register aperture, the + * registers are housed at the top end of the framebuffer PCI BAR. + * aty_fudge_framebuffer_len() is used to reduce smem_len to not + * overlap with the registers. + */ + info->fix.smem_len = 0x800000; + + info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len); if (info->screen_base == NULL) { ret = -ENOMEM; goto atyfb_setup_generic_fail; -- cgit v1.2.3-55-g7522 From 3cc2dac5be3f23414a4efdee0b26d79bed297cac Mon Sep 17 00:00:00 2001 From: Luis R. Rodriguez Date: Thu, 9 Jul 2015 18:24:58 -0700 Subject: drivers/video/fbdev/atyfb: Replace MTRR UC hole with strong UC Replace a WC MTRR call followed by a UC MTRR "hole" call with a single WC MTRR call and use strong UC to protect the MMIO region and account for the device's architecture and MTRR size requirements. The atyfb driver relies on two overlapping MTRRs. It does this to account for the fact that, on some devices, it has the MMIO region bundled together with the framebuffer on the same PCI BAR and the hardware requirement on MTRRs on both base and size to be powers of two. In the worst case, the PCI BAR is of 16 MiB while the MMIO region is on the last 4 KiB of the same PCI BAR. If we use just one MTRR for WC, we can only end up with an 8 MiB or 16 MiB framebuffer. Using a 16 MiB WC framebuffer area is unacceptable since we need the MMIO region to not be write-combined. An 8 MiB WC framebuffer option does not let use quite a bit of framebuffer space, it would reduce the resolution capability of the device considerably. An alternative is to use many MTRRs but on some systems that could mean not having enough MTRRs to cover the framebuffer. The current solution is to issue a 16 MiB WC MTRR followed by a 4 KiB UC MTRR on the last 4 KiB. Its worth mentioning and documenting that the current ioremap*() strategy as well: the first ioremap() is used only for the MMIO region, a second ioremap() call is used for the framebuffer *and* the MMIO region, the MMIO region then ends up mmapped twice. Two ioremap() calls are used since in some situations the framebuffer actually ends up on a separate auxiliary PCI BAR, but this is not always true. In the worst case, the PCI BAR is shared for both MMIO and the framebuffer. By allowing overlapping ioremap() calls, the driver enables two types of devices with one simple ioremap() strategy. See also: 2f9e897353fc ("x86/mm/mtrr, pat: Document Write Combining MTRR type effects on PAT / non-PAT pages") By default, Linux today defaults both pci_mmap_page_range() and ioremap_nocache() to use _PAGE_CACHE_MODE_UC_MINUS. On x86, ioremap() aliases ioremap_nocache(). The preferred value for Linux may soon change, however, the goal is to use _PAGE_CACHE_MODE_UC by default in the future. We can use ioremap_uc() to set PCD=1, PWT=1 on non-PAT systems and use a PAT value of UC for PAT systems. This will ensure the same settings are in place regardless of what Linux decides to use by default later and to not regress our MTRR strategy since the effective memory type will differ depending on the value used. Using a WC MTRR on such an area will be nullified. This technique can be used to protect the MMIO region in this driver's case and address the restrictions of the device's architecture as well as restrictions set upon us by powers of 2 when using MTRRs. This allows us to replace the two MTRR calls with a single 16 MiB WC MTRR and use page-attribute settings for non-PAT and PAT entry values for PAT systems to ensure the appropriate effective memory type won't have a write-combining effect on the MMIO region on both non-PAT and PAT systems. The framebuffer area will be sure to get the write-combined effective memory type by white-listing it with ioremap_wc(). We ensure the desired effective memory types are set by: 0) Using one ioremap_uc() for the MMIO region alone. This will set the page attribute settings for the MMIO region to PCD=1, PWT=1 for non-PAT systems while using a strong UC value on PAT systems. 1) Fixing the framebuffer ioremapped area to exclude the MMIO region and using ioremap_wc() instead to whitelist the area we want for write-combining. In both cases, an implementation defined (as per 2f9e897353fc) effective memory type of WC is used for the framebuffer for non-PAT systems. Signed-off-by: Luis R. Rodriguez Signed-off-by: Borislav Petkov Cc: Andrew Morton Cc: Andrzej Hajda Cc: Andy Lutomirski Cc: Antonino Daplas Cc: Daniel Vetter Cc: Dave Airlie Cc: Davidlohr Bueso Cc: H. Peter Anvin Cc: Jean-Christophe Plagniol-Villard Cc: Juergen Gross Cc: Linus Torvalds Cc: Mathias Krause Cc: Mel Gorman Cc: Peter Zijlstra Cc: Rob Clark Cc: Suresh Siddha Cc: Thomas Gleixner Cc: Tomi Valkeinen Cc: Toshi Kani Cc: Ville Syrjälä Cc: Vlastimil Babka Cc: arnd@arndb.de Cc: benh@kernel.crashing.org Cc: dan.j.williams@intel.com Cc: geert@linux-m68k.org Cc: hch@lst.de Cc: hmh@hmh.eng.br Cc: linux-fbdev@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pci@vger.kernel.org Cc: mpe@ellerman.id.au Cc: mst@redhat.com Cc: ralf@linux-mips.org Cc: ross.zwisler@linux.intel.com Cc: stefan.bader@canonical.com Cc: tj@kernel.org Cc: ville.syrjala@linux.intel.com Link: http://lkml.kernel.org/r/1435196060-27350-3-git-send-email-mcgrof@do-not-panic.com Link: http://lkml.kernel.org/r/1436491499-3289-4-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar --- drivers/video/fbdev/aty/atyfb.h | 1 - drivers/video/fbdev/aty/atyfb_base.c | 36 ++++++++++++++---------------------- 2 files changed, 14 insertions(+), 23 deletions(-) (limited to 'drivers/video') diff --git a/drivers/video/fbdev/aty/atyfb.h b/drivers/video/fbdev/aty/atyfb.h index 1f39a62f899b..89ec4398d201 100644 --- a/drivers/video/fbdev/aty/atyfb.h +++ b/drivers/video/fbdev/aty/atyfb.h @@ -184,7 +184,6 @@ struct atyfb_par { spinlock_t int_lock; #ifdef CONFIG_MTRR int mtrr_aper; - int mtrr_reg; #endif u32 mem_cntl; struct crtc saved_crtc; diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c index de8f7e082c87..7770a8485fb5 100644 --- a/drivers/video/fbdev/aty/atyfb_base.c +++ b/drivers/video/fbdev/aty/atyfb_base.c @@ -2630,21 +2630,13 @@ static int aty_init(struct fb_info *info) #ifdef CONFIG_MTRR par->mtrr_aper = -1; - par->mtrr_reg = -1; if (!nomtrr) { - /* Cover the whole resource. */ + /* + * Only the ioremap_wc()'d area will get WC here + * since ioremap_uc() was used on the entire PCI BAR. + */ par->mtrr_aper = mtrr_add(par->res_start, par->res_size, MTRR_TYPE_WRCOMB, 1); - if (par->mtrr_aper >= 0 && !par->aux_start) { - /* Make a hole for mmio. */ - par->mtrr_reg = mtrr_add(par->res_start + 0x800000 - - GUI_RESERVE, GUI_RESERVE, - MTRR_TYPE_UNCACHABLE, 1); - if (par->mtrr_reg < 0) { - mtrr_del(par->mtrr_aper, 0, 0); - par->mtrr_aper = -1; - } - } } #endif @@ -2776,10 +2768,6 @@ aty_init_exit: par->pll_ops->set_pll(info, &par->saved_pll); #ifdef CONFIG_MTRR - if (par->mtrr_reg >= 0) { - mtrr_del(par->mtrr_reg, 0, 0); - par->mtrr_reg = -1; - } if (par->mtrr_aper >= 0) { mtrr_del(par->mtrr_aper, 0, 0); par->mtrr_aper = -1; @@ -3466,7 +3454,11 @@ static int atyfb_setup_generic(struct pci_dev *pdev, struct fb_info *info, } info->fix.mmio_start = raddr; - par->ati_regbase = ioremap(info->fix.mmio_start, 0x1000); + /* + * By using strong UC we force the MTRR to never have an + * effect on the MMIO region on both non-PAT and PAT systems. + */ + par->ati_regbase = ioremap_uc(info->fix.mmio_start, 0x1000); if (par->ati_regbase == NULL) return -ENOMEM; @@ -3503,7 +3495,10 @@ static int atyfb_setup_generic(struct pci_dev *pdev, struct fb_info *info, */ info->fix.smem_len = 0x800000; - info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len); + aty_fudge_framebuffer_len(info); + + info->screen_base = ioremap_wc(info->fix.smem_start, + info->fix.smem_len); if (info->screen_base == NULL) { ret = -ENOMEM; goto atyfb_setup_generic_fail; @@ -3575,6 +3570,7 @@ static int atyfb_pci_probe(struct pci_dev *pdev, return -ENOMEM; } par = info->par; + par->bus_type = PCI; info->fix = atyfb_fix; info->device = &pdev->dev; par->pci_id = pdev->device; @@ -3744,10 +3740,6 @@ static void atyfb_remove(struct fb_info *info) #endif #ifdef CONFIG_MTRR - if (par->mtrr_reg >= 0) { - mtrr_del(par->mtrr_reg, 0, 0); - par->mtrr_reg = -1; - } if (par->mtrr_aper >= 0) { mtrr_del(par->mtrr_aper, 0, 0); par->mtrr_aper = -1; -- cgit v1.2.3-55-g7522 From 7d89a3cb159aecb1b363ea50cb14c967ff83b5a6 Mon Sep 17 00:00:00 2001 From: Luis R. Rodriguez Date: Thu, 9 Jul 2015 18:24:59 -0700 Subject: drivers/video/fbdev/atyfb: Use arch_phys_wc_add() and ioremap_wc() This driver uses strong UC for the MMIO region, and ioremap_wc() for the framebuffer to whitelist for the WC MTRR that can be changed to WC. On PAT systems we don't need the MTRR call so just use arch_phys_wc_add() there, this lets us remove all those ifdefs. Let's also be consistent and use ioremap_wc() for ATARI as well. 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 Cc: Andrew Morton Cc: Andrzej Hajda Cc: Andy Lutomirski Cc: Antonino Daplas Cc: Daniel Vetter Cc: Dave Airlie Cc: Davidlohr Bueso Cc: H. Peter Anvin Cc: Jean-Christophe Plagniol-Villard Cc: Juergen Gross Cc: Linus Torvalds Cc: Mathias Krause Cc: Mel Gorman Cc: Peter Zijlstra Cc: Rob Clark Cc: Suresh Siddha Cc: Thomas Gleixner Cc: Tomi Valkeinen Cc: Toshi Kani Cc: Ville Syrjälä Cc: Vlastimil Babka Cc: arnd@arndb.de Cc: benh@kernel.crashing.org Cc: dan.j.williams@intel.com Cc: geert@linux-m68k.org Cc: hch@lst.de Cc: hmh@hmh.eng.br Cc: linux-fbdev@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pci@vger.kernel.org Cc: mpe@ellerman.id.au Cc: mst@redhat.com Cc: ralf@linux-mips.org Cc: ross.zwisler@linux.intel.com Cc: stefan.bader@canonical.com Cc: tj@kernel.org Cc: ville.syrjala@linux.intel.com Link: http://lkml.kernel.org/r/1436491499-3289-5-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar --- drivers/video/fbdev/aty/atyfb.h | 4 +--- drivers/video/fbdev/aty/atyfb_base.c | 36 +++++++----------------------------- 2 files changed, 8 insertions(+), 32 deletions(-) (limited to 'drivers/video') diff --git a/drivers/video/fbdev/aty/atyfb.h b/drivers/video/fbdev/aty/atyfb.h index 89ec4398d201..63c4842eb224 100644 --- a/drivers/video/fbdev/aty/atyfb.h +++ b/drivers/video/fbdev/aty/atyfb.h @@ -182,9 +182,7 @@ struct atyfb_par { unsigned long irq_flags; unsigned int irq; spinlock_t int_lock; -#ifdef CONFIG_MTRR - int mtrr_aper; -#endif + int wc_cookie; u32 mem_cntl; struct crtc saved_crtc; union aty_pll saved_pll; diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c index 7770a8485fb5..f34ed47fcaf8 100644 --- a/drivers/video/fbdev/aty/atyfb_base.c +++ b/drivers/video/fbdev/aty/atyfb_base.c @@ -98,9 +98,6 @@ #ifdef CONFIG_PMAC_BACKLIGHT #include #endif -#ifdef CONFIG_MTRR -#include -#endif /* * Debug flags. @@ -303,9 +300,7 @@ static struct fb_ops atyfb_ops = { }; static bool noaccel; -#ifdef CONFIG_MTRR static bool nomtrr; -#endif static int vram; static int pll; static int mclk; @@ -2628,17 +2623,13 @@ static int aty_init(struct fb_info *info) aty_st_le32(BUS_CNTL, aty_ld_le32(BUS_CNTL, par) | BUS_APER_REG_DIS, par); -#ifdef CONFIG_MTRR - par->mtrr_aper = -1; - if (!nomtrr) { + if (!nomtrr) /* * Only the ioremap_wc()'d area will get WC here * since ioremap_uc() was used on the entire PCI BAR. */ - par->mtrr_aper = mtrr_add(par->res_start, par->res_size, - MTRR_TYPE_WRCOMB, 1); - } -#endif + par->wc_cookie = arch_phys_wc_add(par->res_start, + par->res_size); info->fbops = &atyfb_ops; info->pseudo_palette = par->pseudo_palette; @@ -2766,13 +2757,8 @@ aty_init_exit: /* restore video mode */ aty_set_crtc(par, &par->saved_crtc); par->pll_ops->set_pll(info, &par->saved_pll); + arch_phys_wc_del(par->wc_cookie); -#ifdef CONFIG_MTRR - if (par->mtrr_aper >= 0) { - mtrr_del(par->mtrr_aper, 0, 0); - par->mtrr_aper = -1; - } -#endif return ret; } @@ -3672,7 +3658,8 @@ static int __init atyfb_atari_probe(void) * Map the video memory (physical address given) * to somewhere in the kernel address space. */ - info->screen_base = ioremap(phys_vmembase[m64_num], phys_size[m64_num]); + info->screen_base = ioremap_wc(phys_vmembase[m64_num], + phys_size[m64_num]); info->fix.smem_start = (unsigned long)info->screen_base; /* Fake! */ par->ati_regbase = ioremap(phys_guiregbase[m64_num], 0x10000) + 0xFC00ul; @@ -3738,13 +3725,8 @@ static void atyfb_remove(struct fb_info *info) if (M64_HAS(MOBIL_BUS)) aty_bl_exit(info->bl_dev); #endif + arch_phys_wc_del(par->wc_cookie); -#ifdef CONFIG_MTRR - if (par->mtrr_aper >= 0) { - mtrr_del(par->mtrr_aper, 0, 0); - par->mtrr_aper = -1; - } -#endif #ifndef __sparc__ if (par->ati_regbase) iounmap(par->ati_regbase); @@ -3860,10 +3842,8 @@ static int __init atyfb_setup(char *options) while ((this_opt = strsep(&options, ",")) != NULL) { if (!strncmp(this_opt, "noaccel", 7)) { noaccel = 1; -#ifdef CONFIG_MTRR } else if (!strncmp(this_opt, "nomtrr", 6)) { nomtrr = 1; -#endif } else if (!strncmp(this_opt, "vram:", 5)) vram = simple_strtoul(this_opt + 5, NULL, 0); else if (!strncmp(this_opt, "pll:", 4)) @@ -4033,7 +4013,5 @@ module_param(comp_sync, int, 0); MODULE_PARM_DESC(comp_sync, "Set composite sync signal to low (0) or high (1)"); module_param(mode, charp, 0); MODULE_PARM_DESC(mode, "Specify resolution as \"x[-][@]\" "); -#ifdef CONFIG_MTRR module_param(nomtrr, bool, 0); MODULE_PARM_DESC(nomtrr, "bool: disable use of MTRR registers"); -#endif -- cgit v1.2.3-55-g7522 From c112709809b2ca1e8ff2841a1958503e548b81e4 Mon Sep 17 00:00:00 2001 From: Luis R. Rodriguez Date: Mon, 24 Aug 2015 12:13:24 -0700 Subject: drivers/video/fbdev/i740fb: Use arch_phys_wc_add() and pci_ioremap_wc_bar() Convert the driver from using the x86-specific MTRR code to the architecture-agnostic arch_phys_wc_add(). It will avoid MTRR 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: Benoit Taine Cc: Bjorn Helgaas 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: Linus Torvalds Cc: Peter Zijlstra Cc: Rob Clark Cc: Suresh Siddha Cc: Thomas Gleixner Cc: airlied@linux.ie Cc: benh@kernel.crashing.org 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/1440443613-13696-3-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar --- drivers/video/fbdev/i740fb.c | 35 ++++++----------------------------- 1 file changed, 6 insertions(+), 29 deletions(-) (limited to 'drivers/video') diff --git a/drivers/video/fbdev/i740fb.c b/drivers/video/fbdev/i740fb.c index a2b4204b42bb..452e1163ad02 100644 --- a/drivers/video/fbdev/i740fb.c +++ b/drivers/video/fbdev/i740fb.c @@ -27,24 +27,15 @@ #include #include