MIPS: Add support files for hugetlbfs.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 216 insertions, 0 deletions

diff --git a/arch/mips/include/asm/hugetlb.h b/arch/mips/include/asm/hugetlb.h
new file mode 100644
index 000000000000..f5e856015329
--- /dev/null
+++ b/arch/mips/include/asm/hugetlb.h
@@ -0,0 +1,114 @@
+/*
+ * 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) 2008, 2009 Cavium Networks, Inc.
+ */
+
+#ifndef __ASM_HUGETLB_H
+#define __ASM_HUGETLB_H
+
+#include <asm/page.h>
+
+
+static inline int is_hugepage_only_range(struct mm_struct *mm,
+                                         unsigned long addr,
+                                         unsigned long len)
+{
+        return 0;
+}
+
+static inline int prepare_hugepage_range(struct file *file,
+                                         unsigned long addr,
+                                         unsigned long len)
+{
+        unsigned long task_size = STACK_TOP;
+        struct hstate *h = hstate_file(file);
+
+        if (len & ~huge_page_mask(h))
+                return -EINVAL;
+        if (addr & ~huge_page_mask(h))
+                return -EINVAL;
+        if (len > task_size)
+                return -ENOMEM;
+        if (task_size - len < addr)
+                return -EINVAL;
+        return 0;
+}
+
+static inline void hugetlb_prefault_arch_hook(struct mm_struct *mm)
+{
+}
+
+static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
+                                          unsigned long addr,
+                                          unsigned long end,
+                                          unsigned long floor,
+                                          unsigned long ceiling)
+{
+        free_pgd_range(tlb, addr, end, floor, ceiling);
+}
+
+static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+                                   pte_t *ptep, pte_t pte)
+{
+        set_pte_at(mm, addr, ptep, pte);
+}
+
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+                                            unsigned long addr, pte_t *ptep)
+{
+        pte_t clear;
+        pte_t pte = *ptep;
+
+        pte_val(clear) = (unsigned long)invalid_pte_table;
+        set_pte_at(mm, addr, ptep, clear);
+        return pte;
+}
+
+static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
+                                         unsigned long addr, pte_t *ptep)
+{
+}
+
+static inline int huge_pte_none(pte_t pte)
+{
+        unsigned long val = pte_val(pte) & ~_PAGE_GLOBAL;
+        return !val || (val == (unsigned long)invalid_pte_table);
+}
+
+static inline pte_t huge_pte_wrprotect(pte_t pte)
+{
+        return pte_wrprotect(pte);
+}
+
+static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
+                                           unsigned long addr, pte_t *ptep)
+{
+        ptep_set_wrprotect(mm, addr, ptep);
+}
+
+static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+                                             unsigned long addr,
+                                             pte_t *ptep, pte_t pte,
+                                             int dirty)
+{
+        return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
+}
+
+static inline pte_t huge_ptep_get(pte_t *ptep)
+{
+        return *ptep;
+}
+
+static inline int arch_prepare_hugepage(struct page *page)
+{
+        return 0;
+}
+
+static inline void arch_release_hugepage(struct page *page)
+{
+}
+
+#endif /* __ASM_HUGETLB_H */
diff --git a/arch/mips/mm/Makefile b/arch/mips/mm/Makefile
index d7ec95522292..f0e435599707 100644
--- a/arch/mips/mm/Makefile
+++ b/arch/mips/mm/Makefile
@@ -8,6 +8,7 @@ obj-y				+= cache.o dma-default.o extable.o fault.o \
 obj-$(CONFIG_32BIT)             += ioremap.o pgtable-32.o
 obj-$(CONFIG_64BIT)             += pgtable-64.o
 obj-$(CONFIG_HIGHMEM)           += highmem.o
+obj-$(CONFIG_HUGETLB_PAGE)      += hugetlbpage.o
 
 obj-$(CONFIG_CPU_LOONGSON2)     += c-r4k.o cex-gen.o tlb-r4k.o
 obj-$(CONFIG_CPU_MIPS32)        += c-r4k.o cex-gen.o tlb-r4k.o
diff --git a/arch/mips/mm/hugetlbpage.c b/arch/mips/mm/hugetlbpage.c
new file mode 100644
index 000000000000..471c09aa1614
--- /dev/null
+++ b/arch/mips/mm/hugetlbpage.c
@@ -0,0 +1,101 @@
+/*
+ * MIPS Huge TLB Page Support for Kernel.
+ *
+ * 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) 2002, Rohit Seth <rohit.seth@intel.com>
+ * Copyright 2005, Embedded Alley Solutions, Inc.
+ * Matt Porter <mporter@embeddedalley.com>
+ * Copyright (C) 2008, 2009 Cavium Networks, Inc.
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.h>
+#include <linux/smp_lock.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/sysctl.h>
+#include <asm/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr,
+                      unsigned long sz)
+{
+        pgd_t *pgd;
+        pud_t *pud;
+        pte_t *pte = NULL;
+
+        pgd = pgd_offset(mm, addr);
+        pud = pud_alloc(mm, pgd, addr);
+        if (pud)
+                pte = (pte_t *)pmd_alloc(mm, pud, addr);
+
+        return pte;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+        pgd_t *pgd;
+        pud_t *pud;
+        pmd_t *pmd = NULL;
+
+        pgd = pgd_offset(mm, addr);
+        if (pgd_present(*pgd)) {
+                pud = pud_offset(pgd, addr);
+                if (pud_present(*pud))
+                        pmd = pmd_offset(pud, addr);
+        }
+        return (pte_t *) pmd;
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+        return 0;
+}
+
+/*
+ * This function checks for proper alignment of input addr and len parameters.
+ */
+int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
+{
+        if (len & ~HPAGE_MASK)
+                return -EINVAL;
+        if (addr & ~HPAGE_MASK)
+                return -EINVAL;
+        return 0;
+}
+
+struct page *
+follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
+{
+        return ERR_PTR(-EINVAL);
+}
+
+int pmd_huge(pmd_t pmd)
+{
+        return (pmd_val(pmd) & _PAGE_HUGE) != 0;
+}
+
+int pud_huge(pud_t pud)
+{
+        return (pud_val(pud) & _PAGE_HUGE) != 0;
+}
+
+struct page *
+follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+                pmd_t *pmd, int write)
+{
+        struct page *page;
+
+        page = pte_page(*(pte_t *)pmd);
+        if (page)
+                page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
+        return page;
+}
+