[PATCH v2 1/6] MIPS: Sync after cacheflush on BMIPS processors

[PATCH v2 1/6] MIPS: Sync after cacheflush on BMIPS processors

[Kevin Cernekee]

On BMIPS processors, cache writeback operations may complete before the
data has actually been written out to memory.  Subsequent uncached reads
(or I/O operations) may see stale data unless a sync instruction is
executed after the writeback loop.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---
 arch/mips/include/asm/hazards.h |   21 +++++++++++++++++++++
 arch/mips/mm/c-r4k.c            |    5 +++++
 2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/arch/mips/include/asm/hazards.h b/arch/mips/include/asm/hazards.h
index 4e33216..655da05 100644
--- a/arch/mips/include/asm/hazards.h
+++ b/arch/mips/include/asm/hazards.h
@@ -270,4 +270,25 @@ ASMMACRO(disable_fpu_hazard,
 )
 #endif
 
+/*
+ * Some processors will "pipeline" cache writeback operations, and need an
+ * extra sync instruction to ensure that they are actually flushed out to
+ * memory.  Performing an uncached read (or an I/O operation) without the
+ * flush may cause stale data to be fetched.
+ */
+
+#if defined(CONFIG_CPU_BMIPS3300) || defined(CONFIG_CPU_BMIPS4350) || \
+    defined(CONFIG_CPU_BMIPS4380) || defined(CONFIG_CPU_BMIPS5000)
+
+#define cacheflush_hazard()						\
+do {									\
+	__sync();							\
+} while (0)
+
+#else
+
+#define cacheflush_hazard() do { } while (0)
+
+#endif
+
 #endif /* _ASM_HAZARDS_H */
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index b4923a7..6c113cd 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -33,6 +33,7 @@
 #include <asm/mmu_context.h>
 #include <asm/war.h>
 #include <asm/cacheflush.h> /* for run_uncached() */
+#include <asm/hazards.h>
 
 
 /*
@@ -604,6 +605,7 @@ static void r4k_dma_cache_wback_inv(unsigned long addr, unsigned long size)
 			r4k_blast_scache();
 		else
 			blast_scache_range(addr, addr + size);
+		cacheflush_hazard();
 		return;
 	}
 
@@ -620,6 +622,7 @@ static void r4k_dma_cache_wback_inv(unsigned long addr, unsigned long size)
 	}
 
 	bc_wback_inv(addr, size);
+	cacheflush_hazard();
 }
 
 static void r4k_dma_cache_inv(unsigned long addr, unsigned long size)
@@ -647,6 +650,7 @@ static void r4k_dma_cache_inv(unsigned long addr, unsigned long size)
 				 (addr + size - 1) & almask);
 			blast_inv_scache_range(addr, addr + size);
 		}
+		cacheflush_hazard();
 		return;
 	}
 
@@ -663,6 +667,7 @@ static void r4k_dma_cache_inv(unsigned long addr, unsigned long size)
 	}
 
 	bc_inv(addr, size);
+	cacheflush_hazard();
 }
 #endif /* CONFIG_DMA_NONCOHERENT */
 
-- 
1.7.0.4

[PATCH v2 2/6] MIPS: pfn_valid() is broken on low memory HIGHMEM systems

[Kevin Cernekee]

pfn_valid() compares the PFN to max_mapnr:

        __pfn >= min_low_pfn && __pfn < max_mapnr;

On HIGHMEM kernels, highend_pfn is used to set the value of max_mapnr.
Unfortunately, highend_pfn is left at zero if the system does not
actually have enough RAM to reach into the HIGHMEM range.  This causes
pfn_valid() to always return false, and when debug checks are enabled
the kernel will fail catastrophically:

Memory: 22432k/32768k available (2249k kernel code, 10336k reserved, 653k data, 1352k init, 0k highmem)
NR_IRQS:128
kfree_debugcheck: out of range ptr 81c02900h.
Kernel bug detected[#1]:
Cpu 0
$ 0   : 00000000 10008400 00000034 00000000
$ 4   : 8003e160 802a0000 8003e160 00000000
$ 8   : 00000000 0000003e 00000747 00000747
...

On such a configuration, max_low_pfn should be used to set max_mapnr.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---
 arch/mips/mm/init.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 2efcbd2..45447cd 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -370,7 +370,7 @@ void __init mem_init(void)
 #ifdef CONFIG_DISCONTIGMEM
 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 #endif
-	max_mapnr = highend_pfn;
+	max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 #else
 	max_mapnr = max_low_pfn;
 #endif
-- 
1.7.0.4

[PATCH v2 RESEND 3/6] MIPS: Move FIXADDR_TOP into spaces.h

[Kevin Cernekee]

Memory maps and addressing quirks are normally defined in <spaces.h>.
There are already three targets that need to override FIXADDR_TOP, and
others exist.  This will be a cleaner approach than adding lots of
ifdefs in fixmap.h .

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---
 arch/mips/include/asm/fixmap.h              |   10 +---------
 arch/mips/include/asm/mach-bcm63xx/spaces.h |   17 +++++++++++++++++
 arch/mips/include/asm/mach-generic/spaces.h |    4 ++++
 arch/mips/include/asm/mach-tx39xx/spaces.h  |   17 +++++++++++++++++
 arch/mips/include/asm/mach-tx49xx/spaces.h  |   17 +++++++++++++++++
 5 files changed, 56 insertions(+), 9 deletions(-)
 create mode 100644 arch/mips/include/asm/mach-bcm63xx/spaces.h
 create mode 100644 arch/mips/include/asm/mach-tx39xx/spaces.h
 create mode 100644 arch/mips/include/asm/mach-tx49xx/spaces.h

diff --git a/arch/mips/include/asm/fixmap.h b/arch/mips/include/asm/fixmap.h
index 0b89b83..98bcc98 100644
--- a/arch/mips/include/asm/fixmap.h
+++ b/arch/mips/include/asm/fixmap.h
@@ -14,6 +14,7 @@
 #define _ASM_FIXMAP_H
 
 #include <asm/page.h>
+#include <spaces.h>
 #ifdef CONFIG_HIGHMEM
 #include <linux/threads.h>
 #include <asm/kmap_types.h>
@@ -67,15 +68,6 @@ enum fixed_addresses {
  * the start of the fixmap, and leave one page empty
  * at the top of mem..
  */
-#ifdef CONFIG_BCM63XX
-#define FIXADDR_TOP     ((unsigned long)(long)(int)0xff000000)
-#else
-#if defined(CONFIG_CPU_TX39XX) || defined(CONFIG_CPU_TX49XX)
-#define FIXADDR_TOP	((unsigned long)(long)(int)(0xff000000 - 0x20000))
-#else
-#define FIXADDR_TOP	((unsigned long)(long)(int)0xfffe0000)
-#endif
-#endif
 #define FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
 #define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
 
diff --git a/arch/mips/include/asm/mach-bcm63xx/spaces.h b/arch/mips/include/asm/mach-bcm63xx/spaces.h
new file mode 100644
index 0000000..61e750f
--- /dev/null
+++ b/arch/mips/include/asm/mach-bcm63xx/spaces.h
@@ -0,0 +1,17 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1994 - 1999, 2000, 03, 04 Ralf Baechle
+ * Copyright (C) 2000, 2002  Maciej W. Rozycki
+ * Copyright (C) 1990, 1999, 2000 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_BCM63XX_SPACES_H
+#define _ASM_BCM63XX_SPACES_H
+
+#define FIXADDR_TOP		((unsigned long)(long)(int)0xff000000)
+
+#include <asm/mach-generic/spaces.h>
+
+#endif /* __ASM_BCM63XX_SPACES_H */
diff --git a/arch/mips/include/asm/mach-generic/spaces.h b/arch/mips/include/asm/mach-generic/spaces.h
index c9fa4b1..d7a9efd 100644
--- a/arch/mips/include/asm/mach-generic/spaces.h
+++ b/arch/mips/include/asm/mach-generic/spaces.h
@@ -82,4 +82,8 @@
 #define PAGE_OFFSET		(CAC_BASE + PHYS_OFFSET)
 #endif
 
+#ifndef FIXADDR_TOP
+#define FIXADDR_TOP		((unsigned long)(long)(int)0xfffe0000)
+#endif
+
 #endif /* __ASM_MACH_GENERIC_SPACES_H */
diff --git a/arch/mips/include/asm/mach-tx39xx/spaces.h b/arch/mips/include/asm/mach-tx39xx/spaces.h
new file mode 100644
index 0000000..151fe7a
--- /dev/null
+++ b/arch/mips/include/asm/mach-tx39xx/spaces.h
@@ -0,0 +1,17 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1994 - 1999, 2000, 03, 04 Ralf Baechle
+ * Copyright (C) 2000, 2002  Maciej W. Rozycki
+ * Copyright (C) 1990, 1999, 2000 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_TX39XX_SPACES_H
+#define _ASM_TX39XX_SPACES_H
+
+#define FIXADDR_TOP		((unsigned long)(long)(int)0xfefe0000)
+
+#include <asm/mach-generic/spaces.h>
+
+#endif /* __ASM_TX39XX_SPACES_H */
diff --git a/arch/mips/include/asm/mach-tx49xx/spaces.h b/arch/mips/include/asm/mach-tx49xx/spaces.h
new file mode 100644
index 0000000..0cb10a6
--- /dev/null
+++ b/arch/mips/include/asm/mach-tx49xx/spaces.h
@@ -0,0 +1,17 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1994 - 1999, 2000, 03, 04 Ralf Baechle
+ * Copyright (C) 2000, 2002  Maciej W. Rozycki
+ * Copyright (C) 1990, 1999, 2000 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_TX49XX_SPACES_H
+#define _ASM_TX49XX_SPACES_H
+
+#define FIXADDR_TOP		((unsigned long)(long)(int)0xfefe0000)
+
+#include <asm/mach-generic/spaces.h>
+
+#endif /* __ASM_TX49XX_SPACES_H */
-- 
1.7.0.4

[PATCH v4 RESEND 4/6] MIPS: HIGHMEM DMA on noncoherent MIPS32 processors

[Kevin Cernekee]

The MIPS DMA coherency functions do not work properly (i.e. kernel oops)
when HIGHMEM pages are passed in as arguments.  Use kmap_atomic() to
temporarily map high pages for cache maintenance operations.

Tested on a 2.6.37-rc7 1GB HIGHMEM SMP no-alias system.

Signed-off-by: Dezhong Diao <dediao@cisco.com>
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---
 arch/mips/mm/dma-default.c |  114 ++++++++++++++++++++++++++------------------
 1 files changed, 68 insertions(+), 46 deletions(-)

diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index 21ea14e..4608491 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -15,18 +15,18 @@
 #include <linux/scatterlist.h>
 #include <linux/string.h>
 #include <linux/gfp.h>
+#include <linux/highmem.h>
 
 #include <asm/cache.h>
 #include <asm/io.h>
 
 #include <dma-coherence.h>
 
-static inline unsigned long dma_addr_to_virt(struct device *dev,
+static inline struct page *dma_addr_to_page(struct device *dev,
 	dma_addr_t dma_addr)
 {
-	unsigned long addr = plat_dma_addr_to_phys(dev, dma_addr);
-
-	return (unsigned long)phys_to_virt(addr);
+	return pfn_to_page(
+		plat_dma_addr_to_phys(dev, dma_addr) >> PAGE_SHIFT);
 }
 
 /*
@@ -148,20 +148,20 @@ static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 	free_pages(addr, get_order(size));
 }
 
-static inline void __dma_sync(unsigned long addr, size_t size,
+static inline void __dma_sync_virtual(void *addr, size_t size,
 	enum dma_data_direction direction)
 {
 	switch (direction) {
 	case DMA_TO_DEVICE:
-		dma_cache_wback(addr, size);
+		dma_cache_wback((unsigned long)addr, size);
 		break;
 
 	case DMA_FROM_DEVICE:
-		dma_cache_inv(addr, size);
+		dma_cache_inv((unsigned long)addr, size);
 		break;
 
 	case DMA_BIDIRECTIONAL:
-		dma_cache_wback_inv(addr, size);
+		dma_cache_wback_inv((unsigned long)addr, size);
 		break;
 
 	default:
@@ -169,12 +169,49 @@ static inline void __dma_sync(unsigned long addr, size_t size,
 	}
 }
 
+/*
+ * A single sg entry may refer to multiple physically contiguous
+ * pages. But we still need to process highmem pages individually.
+ * If highmem is not configured then the bulk of this loop gets
+ * optimized out.
+ */
+static inline void __dma_sync(struct page *page,
+	unsigned long offset, size_t size, enum dma_data_direction direction)
+{
+	size_t left = size;
+
+	do {
+		size_t len = left;
+
+		if (PageHighMem(page)) {
+			void *addr;
+
+			if (offset + len > PAGE_SIZE) {
+				if (offset >= PAGE_SIZE) {
+					page += offset >> PAGE_SHIFT;
+					offset &= ~PAGE_MASK;
+				}
+				len = PAGE_SIZE - offset;
+			}
+
+			addr = kmap_atomic(page);
+			__dma_sync_virtual(addr + offset, len, direction);
+			kunmap_atomic(addr);
+		} else
+			__dma_sync_virtual(page_address(page) + offset,
+					   size, direction);
+		offset = 0;
+		page++;
+		left -= len;
+	} while (left);
+}
+
 static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
 	size_t size, enum dma_data_direction direction, struct dma_attrs *attrs)
 {
 	if (cpu_is_noncoherent_r10000(dev))
-		__dma_sync(dma_addr_to_virt(dev, dma_addr), size,
-		           direction);
+		__dma_sync(dma_addr_to_page(dev, dma_addr),
+			   dma_addr & ~PAGE_MASK, size, direction);
 
 	plat_unmap_dma_mem(dev, dma_addr, size, direction);
 }
@@ -185,13 +222,11 @@ static int mips_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	int i;
 
 	for (i = 0; i < nents; i++, sg++) {
-		unsigned long addr;
-
-		addr = (unsigned long) sg_virt(sg);
-		if (!plat_device_is_coherent(dev) && addr)
-			__dma_sync(addr, sg->length, direction);
-		sg->dma_address = plat_map_dma_mem(dev,
-				                   (void *)addr, sg->length);
+		if (!plat_device_is_coherent(dev))
+			__dma_sync(sg_page(sg), sg->offset, sg->length,
+				   direction);
+		sg->dma_address = plat_map_dma_mem_page(dev, sg_page(sg)) +
+				  sg->offset;
 	}
 
 	return nents;
@@ -201,30 +236,23 @@ static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
 	unsigned long offset, size_t size, enum dma_data_direction direction,
 	struct dma_attrs *attrs)
 {
-	unsigned long addr;
-
-	addr = (unsigned long) page_address(page) + offset;
-
 	if (!plat_device_is_coherent(dev))
-		__dma_sync(addr, size, direction);
+		__dma_sync(page, offset, size, direction);
 
-	return plat_map_dma_mem(dev, (void *)addr, size);
+	return plat_map_dma_mem_page(dev, page) + offset;
 }
 
 static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 	int nhwentries, enum dma_data_direction direction,
 	struct dma_attrs *attrs)
 {
-	unsigned long addr;
 	int i;
 
 	for (i = 0; i < nhwentries; i++, sg++) {
 		if (!plat_device_is_coherent(dev) &&
-		    direction != DMA_TO_DEVICE) {
-			addr = (unsigned long) sg_virt(sg);
-			if (addr)
-				__dma_sync(addr, sg->length, direction);
-		}
+		    direction != DMA_TO_DEVICE)
+			__dma_sync(sg_page(sg), sg->offset, sg->length,
+				   direction);
 		plat_unmap_dma_mem(dev, sg->dma_address, sg->length, direction);
 	}
 }
@@ -232,24 +260,18 @@ static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 static void mips_dma_sync_single_for_cpu(struct device *dev,
 	dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 {
-	if (cpu_is_noncoherent_r10000(dev)) {
-		unsigned long addr;
-
-		addr = dma_addr_to_virt(dev, dma_handle);
-		__dma_sync(addr, size, direction);
-	}
+	if (cpu_is_noncoherent_r10000(dev))
+		__dma_sync(dma_addr_to_page(dev, dma_handle),
+			   dma_handle & ~PAGE_MASK, size, direction);
 }
 
 static void mips_dma_sync_single_for_device(struct device *dev,
 	dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 {
 	plat_extra_sync_for_device(dev);
-	if (!plat_device_is_coherent(dev)) {
-		unsigned long addr;
-
-		addr = dma_addr_to_virt(dev, dma_handle);
-		__dma_sync(addr, size, direction);
-	}
+	if (!plat_device_is_coherent(dev))
+		__dma_sync(dma_addr_to_page(dev, dma_handle),
+			   dma_handle & ~PAGE_MASK, size, direction);
 }
 
 static void mips_dma_sync_sg_for_cpu(struct device *dev,
@@ -260,8 +282,8 @@ static void mips_dma_sync_sg_for_cpu(struct device *dev,
 	/* Make sure that gcc doesn't leave the empty loop body.  */
 	for (i = 0; i < nelems; i++, sg++) {
 		if (cpu_is_noncoherent_r10000(dev))
-			__dma_sync((unsigned long)page_address(sg_page(sg)),
-			           sg->length, direction);
+			__dma_sync(sg_page(sg), sg->offset, sg->length,
+				   direction);
 	}
 }
 
@@ -273,8 +295,8 @@ static void mips_dma_sync_sg_for_device(struct device *dev,
 	/* Make sure that gcc doesn't leave the empty loop body.  */
 	for (i = 0; i < nelems; i++, sg++) {
 		if (!plat_device_is_coherent(dev))
-			__dma_sync((unsigned long)page_address(sg_page(sg)),
-			           sg->length, direction);
+			__dma_sync(sg_page(sg), sg->offset, sg->length,
+				   direction);
 	}
 }
 
@@ -295,7 +317,7 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 
 	plat_extra_sync_for_device(dev);
 	if (!plat_device_is_coherent(dev))
-		__dma_sync((unsigned long)vaddr, size, direction);
+		__dma_sync_virtual(vaddr, size, direction);
 }
 
 EXPORT_SYMBOL(dma_cache_sync);
-- 
1.7.0.4

[PATCH RESEND 5/6] MIPS: Install handlers for BMIPS software IRQs

[Kevin Cernekee]

BMIPS4350/4380/5000 CMT/SMT all use SW INT0/INT1 for inter-thread
signaling.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---
 arch/mips/kernel/irq_cpu.c |   14 ++++++--------
 1 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/arch/mips/kernel/irq_cpu.c b/arch/mips/kernel/irq_cpu.c
index 0262abe..70d4736 100644
--- a/arch/mips/kernel/irq_cpu.c
+++ b/arch/mips/kernel/irq_cpu.c
@@ -107,14 +107,12 @@ void __init mips_cpu_irq_init(void)
 	clear_c0_status(ST0_IM);
 	clear_c0_cause(CAUSEF_IP);
 
-	/*
-	 * Only MT is using the software interrupts currently, so we just
-	 * leave them uninitialized for other processors.
-	 */
-	if (cpu_has_mipsmt)
-		for (i = irq_base; i < irq_base + 2; i++)
-			set_irq_chip_and_handler(i, &mips_mt_cpu_irq_controller,
-						 handle_percpu_irq);
+	/* Software interrupts are used for MT/CMT IPI */
+	for (i = irq_base; i < irq_base + 2; i++)
+		set_irq_chip_and_handler(i, cpu_has_mipsmt ?
+					 &mips_mt_cpu_irq_controller :
+					 &mips_cpu_irq_controller,
+					 handle_percpu_irq);
 
 	for (i = irq_base + 2; i < irq_base + 8; i++)
 		set_irq_chip_and_handler(i, &mips_cpu_irq_controller,
-- 
1.7.0.4

[PATCH RESEND 6/6] MIPS: Limit fixrange_init() to the FIXMAP region

[Kevin Cernekee]

fixrange_init() allocates page tables for all addresses higher than
FIXADDR_TOP.  On processors that override the default FIXADDR_TOP
address of 0xfffe_0000, this can consume up to 4 pages (1 page per 4MB)
for pgd's that are never used.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---
 arch/mips/mm/init.c       |    6 +++---
 arch/mips/mm/pgtable-32.c |    2 +-
 arch/mips/mm/pgtable-64.c |    2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 45447cd..14a89bd 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -279,11 +279,11 @@ void __init fixrange_init(unsigned long start, unsigned long end,
 	k = __pmd_offset(vaddr);
 	pgd = pgd_base + i;
 
-	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
+	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 		pud = (pud_t *)pgd;
-		for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
+		for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 			pmd = (pmd_t *)pud;
-			for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
+			for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 				if (pmd_none(*pmd)) {
 					pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 					set_pmd(pmd, __pmd((unsigned long)pte));
diff --git a/arch/mips/mm/pgtable-32.c b/arch/mips/mm/pgtable-32.c
index 575e401..adc6911 100644
--- a/arch/mips/mm/pgtable-32.c
+++ b/arch/mips/mm/pgtable-32.c
@@ -52,7 +52,7 @@ void __init pagetable_init(void)
 	 * Fixed mappings:
 	 */
 	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
-	fixrange_init(vaddr, 0, pgd_base);
+	fixrange_init(vaddr, vaddr + FIXADDR_SIZE, pgd_base);
 
 #ifdef CONFIG_HIGHMEM
 	/*
diff --git a/arch/mips/mm/pgtable-64.c b/arch/mips/mm/pgtable-64.c
index 78eaa4f..cda4e30 100644
--- a/arch/mips/mm/pgtable-64.c
+++ b/arch/mips/mm/pgtable-64.c
@@ -76,5 +76,5 @@ void __init pagetable_init(void)
 	 * Fixed mappings:
 	 */
 	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
-	fixrange_init(vaddr, 0, pgd_base);
+	fixrange_init(vaddr, vaddr + FIXADDR_SIZE, pgd_base);
 }
-- 
1.7.0.4