s390/mm: simplify arch_get_unmapped_area[_topdown]
With TASK_SIZE now reflecting the maximum size of the address space for
a process the code for arch_get_unmapped_area[_topdown] can be simplified.
Just let the logic pick a suitable address and deal with the page table
upgrade after the address has been selected.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index eed233c..b017dae 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -89,32 +89,43 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
struct vm_unmapped_area_info info;
+ int rc;
- if (len > mm->context.asce_limit - mmap_min_addr)
+ if (len > TASK_SIZE - mmap_min_addr)
return -ENOMEM;
if (flags & MAP_FIXED)
- return addr;
+ goto check_asce_limit;
if (addr) {
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
- if (mm->context.asce_limit - len >= addr &&
- addr >= mmap_min_addr &&
+ if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
(!vma || addr + len <= vma->vm_start))
- return addr;
+ goto check_asce_limit;
}
info.flags = 0;
info.length = len;
info.low_limit = mm->mmap_base;
- info.high_limit = mm->context.asce_limit;
+ info.high_limit = TASK_SIZE;
if (filp || (flags & MAP_SHARED))
info.align_mask = MMAP_ALIGN_MASK << PAGE_SHIFT;
else
info.align_mask = 0;
info.align_offset = pgoff << PAGE_SHIFT;
- return vm_unmapped_area(&info);
+ addr = vm_unmapped_area(&info);
+ if (addr & ~PAGE_MASK)
+ return addr;
+
+check_asce_limit:
+ if (addr + len > current->mm->context.asce_limit) {
+ rc = crst_table_upgrade(mm);
+ if (rc)
+ return (unsigned long) rc;
+ }
+
+ return addr;
}
unsigned long
@@ -126,22 +137,22 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
struct vm_unmapped_area_info info;
+ int rc;
/* requested length too big for entire address space */
- if (len > mm->context.asce_limit - mmap_min_addr)
+ if (len > TASK_SIZE - mmap_min_addr)
return -ENOMEM;
if (flags & MAP_FIXED)
- return addr;
+ goto check_asce_limit;
/* requesting a specific address */
if (addr) {
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
- if (mm->context.asce_limit - len >= addr &&
- addr >= mmap_min_addr &&
+ if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
(!vma || addr + len <= vma->vm_start))
- return addr;
+ goto check_asce_limit;
}
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
@@ -165,58 +176,22 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
VM_BUG_ON(addr != -ENOMEM);
info.flags = 0;
info.low_limit = TASK_UNMAPPED_BASE;
- info.high_limit = mm->context.asce_limit;
+ info.high_limit = TASK_SIZE;
addr = vm_unmapped_area(&info);
+ if (addr & ~PAGE_MASK)
+ return addr;
+ }
+
+check_asce_limit:
+ if (addr + len > current->mm->context.asce_limit) {
+ rc = crst_table_upgrade(mm);
+ if (rc)
+ return (unsigned long) rc;
}
return addr;
}
-static unsigned long
-s390_get_unmapped_area(struct file *filp, unsigned long addr,
- unsigned long len, unsigned long pgoff, unsigned long flags)
-{
- struct mm_struct *mm = current->mm;
- unsigned long area;
- int rc;
-
- area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
- if (!(area & ~PAGE_MASK))
- return area;
- if (area == -ENOMEM && !is_compat_task() &&
- current->mm->context.asce_limit < TASK_SIZE_MAX) {
- /* Upgrade the page table to 4 levels and retry. */
- rc = crst_table_upgrade(mm);
- if (rc)
- return (unsigned long) rc;
- area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
- }
- return area;
-}
-
-static unsigned long
-s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
- const unsigned long len, const unsigned long pgoff,
- const unsigned long flags)
-{
- struct mm_struct *mm = current->mm;
- unsigned long area;
- int rc;
-
- area = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
- if (!(area & ~PAGE_MASK))
- return area;
- if (area == -ENOMEM && !is_compat_task() &&
- current->mm->context.asce_limit < TASK_SIZE_MAX) {
- /* Upgrade the page table to 4 levels and retry. */
- rc = crst_table_upgrade(mm);
- if (rc)
- return (unsigned long) rc;
- area = arch_get_unmapped_area_topdown(filp, addr, len,
- pgoff, flags);
- }
- return area;
-}
/*
* This function, called very early during the creation of a new
* process VM image, sets up which VM layout function to use:
@@ -234,9 +209,9 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
*/
if (mmap_is_legacy()) {
mm->mmap_base = mmap_base_legacy(random_factor);
- mm->get_unmapped_area = s390_get_unmapped_area;
+ mm->get_unmapped_area = arch_get_unmapped_area;
} else {
mm->mmap_base = mmap_base(random_factor);
- mm->get_unmapped_area = s390_get_unmapped_area_topdown;
+ mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
}