[PATCH mm-unstable 12/17] mm: sparc32: Introduce arch_mmap_hint()

[Kalesh Singh]

Introduce sparc32 arch_mmap_hint() and define HAVE_ARCH_MMAP_HINT.

If a sufficiently sized hole doesn't exist at the hint address,
fallback to searching the entire valid VA space instead of only
the VA space above the hint address.

Signed-off-by: Kalesh Singh <kaleshsi...@google.com>
---
 arch/sparc/include/asm/pgtable_32.h |  1 +
 arch/sparc/kernel/sys_sparc_32.c    | 21 ++++++++++++++++++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/arch/sparc/include/asm/pgtable_32.h 
b/arch/sparc/include/asm/pgtable_32.h
index 62bcafe38b1f..95084c4d0b01 100644
--- a/arch/sparc/include/asm/pgtable_32.h
+++ b/arch/sparc/include/asm/pgtable_32.h
@@ -437,6 +437,7 @@ static inline int io_remap_pfn_range(struct vm_area_struct 
*vma,
 
 /* We provide our own get_unmapped_area to cope with VA holes for userland */
 #define HAVE_ARCH_UNMAPPED_AREA
+#define HAVE_ARCH_MMAP_HINT
 
 #define pmd_pgtable(pmd)       ((pgtable_t)__pmd_page(pmd))
 
diff --git a/arch/sparc/kernel/sys_sparc_32.c b/arch/sparc/kernel/sys_sparc_32.c
index fb31bc0c5b48..2d5065ee1a94 100644
--- a/arch/sparc/kernel/sys_sparc_32.c
+++ b/arch/sparc/kernel/sys_sparc_32.c
@@ -40,6 +40,19 @@ SYSCALL_DEFINE0(getpagesize)
        return PAGE_SIZE; /* Possibly older binaries want 8192 on sun4's? */
 }
 
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+                            unsigned long len, unsigned long pgoff,
+                            unsigned long flags)
+{
+       if (!addr)
+               return 0;
+
+       if (len > TASK_SIZE - PAGE_SIZE)
+               return 0;
+
+       return generic_mmap_hint(filp, addr, len, pgoff, flags);
+}
+
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, 
unsigned long len, unsigned long pgoff, unsigned long flags, vm_flags_t 
vm_flags)
 {
        struct vm_unmapped_area_info info = {};
@@ -61,11 +74,13 @@ unsigned long arch_get_unmapped_area(struct file *filp, 
unsigned long addr, unsi
        /* See asm-sparc/uaccess.h */
        if (len > TASK_SIZE - PAGE_SIZE)
                return -ENOMEM;
-       if (!addr)
-               addr = TASK_UNMAPPED_BASE;
+
+       addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+       if (addr)
+               return addr;
 
        info.length = len;
-       info.low_limit = addr;
+       info.low_limit = TASK_UNMAPPED_BASE;
        info.high_limit = TASK_SIZE;
        if (!file_hugepage) {
                info.align_mask = (flags & MAP_SHARED) ?
-- 
2.47.0.338.g60cca15819-goog


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