Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux…

…/kernel/git/tip/tip

Pull x86 mm updates from Ingo Molnar:
 "The dominant change in this cycle was the continued work to isolate
  kernel drivers from MTRR legacies: this tree gets rid of all kernel
  internal driver interfaces to MTRRs (mostly by rewriting it to proper
  PAT interfaces), the only access left is the /proc/mtrr ABI.

  This work was done by Luis R Rodriguez.

  There's also some related PCI interface additions for which I've
  Cc:-ed Bjorn"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  x86/mm/mtrr: Remove kernel internal MTRR interfaces: unexport mtrr_add() and mtrr_del()
  s390/io: Add pci_iomap_wc() and pci_iomap_wc_range()
  drivers/dma/iop-adma: Use dma_alloc_writecombine() kernel-style
  drivers/video/fbdev/vt8623fb: Use arch_phys_wc_add() and pci_iomap_wc()
  drivers/video/fbdev/s3fb: Use arch_phys_wc_add() and pci_iomap_wc()
  drivers/video/fbdev/arkfb.c: Use arch_phys_wc_add() and pci_iomap_wc()
  PCI: Add pci_iomap_wc() variants
  drivers/video/fbdev/gxt4500: Use pci_ioremap_wc_bar() to map framebuffer
  drivers/video/fbdev/kyrofb: Use arch_phys_wc_add() and pci_ioremap_wc_bar()
  drivers/video/fbdev/i740fb: Use arch_phys_wc_add() and pci_ioremap_wc_bar()
  PCI: Add pci_ioremap_wc_bar()
  x86/mm: Make kernel/check.c explicitly non-modular
  x86/mm/pat: Make mm/pageattr[-test].c explicitly non-modular
  x86/mm/pat: Add comments to cachemode translation tables
  arch/*/io.h: Add ioremap_uc() to all architectures
  drivers/video/fbdev/atyfb: Use arch_phys_wc_add() and ioremap_wc()
  drivers/video/fbdev/atyfb: Replace MTRR UC hole with strong UC
  drivers/video/fbdev/atyfb: Clarify ioremap() base and length used
  drivers/video/fbdev/atyfb: Carve out framebuffer length fudging into a helper
  x86/mm, asm-generic: Add IOMMU ioremap_uc() variant default
  ...

Documentation/x86/mtrr.txt

@@ -6,10 +6,22 @@ Luis R. Rodriguez <mcgrof@do-not-panic.com> - April 9, 2015
 ===============================================================================
 Phasing out MTRR use
 
-MTRR use is replaced on modern x86 hardware with PAT. Over time the only type
-of effective MTRR that is expected to be supported will be for write-combining.
-As MTRR use is phased out device drivers should use arch_phys_wc_add() to make
-MTRR effective on non-PAT systems while a no-op on PAT enabled systems.
+MTRR use is replaced on modern x86 hardware with PAT. Direct MTRR use by
+drivers on Linux is now completely phased out, device drivers should use
+arch_phys_wc_add() in combination with ioremap_wc() to make MTRR effective on
+non-PAT systems while a no-op but equally effective on PAT enabled systems.
+
+Even if Linux does not use MTRRs directly, some x86 platform firmware may still
+set up MTRRs early before booting the OS. They do this as some platform
+firmware may still have implemented access to MTRRs which would be controlled
+and handled by the platform firmware directly. An example of platform use of
+MTRRs is through the use of SMI handlers, one case could be for fan control,
+the platform code would need uncachable access to some of its fan control
+registers. Such platform access does not need any Operating System MTRR code in
+place other than mtrr_type_lookup() to ensure any OS specific mapping requests
+are aligned with platform MTRR setup. If MTRRs are only set up by the platform
+firmware code though and the OS does not make any specific MTRR mapping
+requests mtrr_type_lookup() should always return MTRR_TYPE_INVALID.
 
 For details refer to Documentation/x86/pat.txt.
 

arch/avr32/include/asm/io.h

@@ -297,6 +297,7 @@ extern void __iounmap(void __iomem *addr);
 
 #define ioremap_wc ioremap_nocache
 #define ioremap_wt ioremap_nocache
+#define ioremap_uc ioremap_nocache
 
 #define cached(addr) P1SEGADDR(addr)
 #define uncached(addr) P2SEGADDR(addr)

arch/frv/include/asm/io.h

@@ -278,6 +278,7 @@ static inline void __iomem *ioremap_fullcache(unsigned long physaddr, unsigned l
 }
 
 #define ioremap_wc ioremap_nocache
+#define ioremap_uc ioremap_nocache
 
 extern void iounmap(void volatile __iomem *addr);
 

arch/m32r/include/asm/io.h

@@ -69,6 +69,7 @@ extern void iounmap(volatile void __iomem *addr);
 #define ioremap_nocache(off,size) ioremap(off,size)
 #define ioremap_wc ioremap_nocache
 #define ioremap_wt ioremap_nocache
+#define ioremap_uc ioremap_nocache
 
 /*
  * IO bus memory addresses are also 1:1 with the physical address

arch/m68k/include/asm/io_mm.h

@@ -468,6 +468,7 @@ static inline void __iomem *ioremap_nocache(unsigned long physaddr, unsigned lon
 {
 	return __ioremap(physaddr, size, IOMAP_NOCACHE_SER);
 }
+#define ioremap_uc ioremap_nocache
 static inline void __iomem *ioremap_wt(unsigned long physaddr,
 					 unsigned long size)
 {

arch/mn10300/include/asm/io.h

@@ -283,6 +283,7 @@ static inline void __iomem *ioremap_nocache(unsigned long offset, unsigned long
 
 #define ioremap_wc ioremap_nocache
 #define ioremap_wt ioremap_nocache
+#define ioremap_uc ioremap_nocache
 
 static inline void iounmap(void __iomem *addr)
 {

arch/powerpc/include/asm/io.h

@@ -721,6 +721,7 @@ extern void __iomem *ioremap_prot(phys_addr_t address, unsigned long size,
 				  unsigned long flags);
 extern void __iomem *ioremap_wc(phys_addr_t address, unsigned long size);
 #define ioremap_nocache(addr, size)	ioremap((addr), (size))
+#define ioremap_uc(addr, size)		ioremap((addr), (size))
 
 extern void iounmap(volatile void __iomem *addr);
 

arch/s390/include/asm/io.h

@@ -57,6 +57,8 @@ static inline void ioport_unmap(void __iomem *p)
  */
 #define pci_iomap pci_iomap
 #define pci_iounmap pci_iounmap
+#define pci_iomap_wc pci_iomap
+#define pci_iomap_wc_range pci_iomap_range
 
 #define memcpy_fromio(dst, src, count)	zpci_memcpy_fromio(dst, src, count)
 #define memcpy_toio(dst, src, count)	zpci_memcpy_toio(dst, src, count)

arch/sh/include/asm/io.h

@@ -368,6 +368,7 @@ static inline int iounmap_fixed(void __iomem *addr) { return -EINVAL; }
 #endif
 
 #define ioremap_nocache	ioremap
+#define ioremap_uc	ioremap
 #define iounmap		__iounmap
 
 /*

arch/tile/include/asm/io.h

@@ -55,6 +55,7 @@ extern void iounmap(volatile void __iomem *addr);
 #define ioremap_nocache(physaddr, size)		ioremap(physaddr, size)
 #define ioremap_wc(physaddr, size)		ioremap(physaddr, size)
 #define ioremap_wt(physaddr, size)		ioremap(physaddr, size)
+#define ioremap_uc(physaddr, size)		ioremap(physaddr, size)
 #define ioremap_fullcache(physaddr, size)	ioremap(physaddr, size)
 
 #define mmiowb()

arch/x86/include/asm/io.h

@@ -180,6 +180,8 @@ static inline unsigned int isa_virt_to_bus(volatile void *address)
  */
 extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
 extern void __iomem *ioremap_uc(resource_size_t offset, unsigned long size);
+#define ioremap_uc ioremap_uc
+
 extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
 extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
 				unsigned long prot_val);

arch/x86/kernel/check.c

@@ -1,4 +1,4 @@
-#include <linux/module.h>
+#include <linux/init.h>
 #include <linux/sched.h>
 #include <linux/kthread.h>
 #include <linux/workqueue.h>
@@ -163,6 +163,5 @@ static int start_periodic_check_for_corruption(void)
 	schedule_delayed_work(&bios_check_work, 0);
 	return 0;
 }
-
-module_init(start_periodic_check_for_corruption);
+device_initcall(start_periodic_check_for_corruption);
 

arch/x86/kernel/cpu/mtrr/main.c

@@ -448,7 +448,6 @@ int mtrr_add(unsigned long base, unsigned long size, unsigned int type,
 	return mtrr_add_page(base >> PAGE_SHIFT, size >> PAGE_SHIFT, type,
 			     increment);
 }
-EXPORT_SYMBOL(mtrr_add);
 
 /**
  * mtrr_del_page - delete a memory type region
@@ -537,7 +536,6 @@ int mtrr_del(int reg, unsigned long base, unsigned long size)
 		return -EINVAL;
 	return mtrr_del_page(reg, base >> PAGE_SHIFT, size >> PAGE_SHIFT);
 }
-EXPORT_SYMBOL(mtrr_del);
 
 /**
  * arch_phys_wc_add - add a WC MTRR and handle errors if PAT is unavailable

arch/x86/mm/init.c

@@ -30,8 +30,11 @@
 /*
  * Tables translating between page_cache_type_t and pte encoding.
  *
- * Minimal supported modes are defined statically, they are modified
- * during bootup if more supported cache modes are available.
+ * The default values are defined statically as minimal supported mode;
+ * WC and WT fall back to UC-.  pat_init() updates these values to support
+ * more cache modes, WC and WT, when it is safe to do so.  See pat_init()
+ * for the details.  Note, __early_ioremap() used during early boot-time
+ * takes pgprot_t (pte encoding) and does not use these tables.
  *
  *   Index into __cachemode2pte_tbl[] is the cachemode.
  *

arch/x86/mm/init_32.c

@@ -137,6 +137,7 @@ page_table_range_init_count(unsigned long start, unsigned long end)
 
 	vaddr = start;
 	pgd_idx = pgd_index(vaddr);
+	pmd_idx = pmd_index(vaddr);
 
 	for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) {
 		for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);

arch/x86/mm/pageattr-test.c

@@ -8,6 +8,7 @@
 #include <linux/kthread.h>
 #include <linux/random.h>
 #include <linux/kernel.h>
+#include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
 
@@ -256,5 +257,4 @@ static int start_pageattr_test(void)
 
 	return 0;
 }
-
-module_init(start_pageattr_test);
+device_initcall(start_pageattr_test);

arch/x86/mm/pageattr.c

@@ -4,7 +4,6 @@
  */
 #include <linux/highmem.h>
 #include <linux/bootmem.h>
-#include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/interrupt.h>

drivers/dma/iop-adma.c

@@ -1300,10 +1300,11 @@ static int iop_adma_probe(struct platform_device *pdev)
 	 * note: writecombine gives slightly better performance, but
 	 * requires that we explicitly flush the writes
 	 */
-	if ((adev->dma_desc_pool_virt = dma_alloc_writecombine(&pdev->dev,
-					plat_data->pool_size,
-					&adev->dma_desc_pool,
-					GFP_KERNEL)) == NULL) {
+	adev->dma_desc_pool_virt = dma_alloc_writecombine(&pdev->dev,
+							  plat_data->pool_size,
+							  &adev->dma_desc_pool,
+							  GFP_KERNEL);
+	if (!adev->dma_desc_pool_virt) {
 		ret = -ENOMEM;
 		goto err_free_adev;
 	}

drivers/pci/pci.c

@@ -138,6 +138,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
 	return ioremap_nocache(res->start, resource_size(res));
 }
 EXPORT_SYMBOL_GPL(pci_ioremap_bar);
+
+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));
+}
+EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
 #endif
 
 

drivers/video/fbdev/arkfb.c

@@ -26,13 +26,9 @@
 #include <linux/console.h> /* Why should fb driver call console functions? because console_lock() */
 #include <video/vga.h>
 
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
-
 struct arkfb_info {
 	int mclk_freq;
-	int mtrr_reg;
+	int wc_cookie;
 
 	struct dac_info *dac;
 	struct vgastate state;
@@ -102,10 +98,6 @@ static const struct svga_timing_regs ark_timing_regs     = {
 
 static char *mode_option = "640x480-8@60";
 
-#ifdef CONFIG_MTRR
-static int mtrr = 1;
-#endif
-
 MODULE_AUTHOR("(c) 2007 Ondrej Zajicek <santiago@crfreenet.org>");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("fbdev driver for ARK 2000PV");
@@ -115,11 +107,6 @@ 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
-
 static int threshold = 4;
 
 module_param(threshold, int, 0644);
@@ -1002,7 +989,7 @@ static int ark_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");
@@ -1057,14 +1044,8 @@ static int ark_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
-
+	par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+					  info->fix.smem_len);
 	return 0;
 
 	/* Error handling */
@@ -1092,14 +1073,7 @@ static void ark_pci_remove(struct pci_dev *dev)
 
 	if (info) {
 		struct arkfb_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);
 		dac_release(par->dac);
 		unregister_framebuffer(info);
 		fb_dealloc_cmap(&info->cmap);

drivers/video/fbdev/aty/atyfb.h

@@ -182,10 +182,7 @@ struct atyfb_par {
 	unsigned long irq_flags;
 	unsigned int irq;
 	spinlock_t int_lock;
-#ifdef CONFIG_MTRR
-	int mtrr_aper;
-	int mtrr_reg;
-#endif
+	int wc_cookie;
 	u32 mem_cntl;
 	struct crtc saved_crtc;
 	union aty_pll saved_pll;