From: Hugh Dickins <hugh@veritas.com>
Convert i386 ioremap pagetable walkers to loops using p?d_addr_end.
Rename internal levels ioremap_p??_range. Don't cheat, give it a real
(but inlined) ioremap_pud_range; uninline lowest level to help debug.
Replace "page already exists" printk and BUG by BUG_ON.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/i386/mm/ioremap.c | 112 +++++++++++++++++++----------------------
1 files changed, 53 insertions(+), 59 deletions(-)
diff -puN arch/i386/mm/ioremap.c~ptwalk-ioremap_page_range arch/i386/mm/ioremap.c
--- 25/arch/i386/mm/ioremap.c~ptwalk-ioremap_page_range 2005-03-09 16:34:09.000000000 -0800
+++ 25-akpm/arch/i386/mm/ioremap.c 2005-03-09 16:34:09.000000000 -0800
@@ -20,89 +20,82 @@
#define ISA_START_ADDRESS 0xa0000
#define ISA_END_ADDRESS 0x100000
-static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
- unsigned long phys_addr, unsigned long flags)
+static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, unsigned long phys_addr, unsigned long flags)
{
- unsigned long end;
+ pte_t *pte;
unsigned long pfn;
- address &= ~PMD_MASK;
- end = address + size;
- if (end > PMD_SIZE)
- end = PMD_SIZE;
- if (address >= end)
- BUG();
pfn = phys_addr >> PAGE_SHIFT;
+ pte = pte_alloc_kernel(&init_mm, pmd, addr);
+ if (!pte)
+ return -ENOMEM;
do {
- if (!pte_none(*pte)) {
- printk("remap_area_pte: page already exists\n");
- BUG();
- }
+ BUG_ON(!pte_none(*pte));
set_pte(pte, pfn_pte(pfn, __pgprot(_PAGE_PRESENT | _PAGE_RW |
_PAGE_DIRTY | _PAGE_ACCESSED | flags)));
- address += PAGE_SIZE;
pfn++;
- pte++;
- } while (address && (address < end));
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ return 0;
}
-static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
- unsigned long phys_addr, unsigned long flags)
+static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
+ unsigned long end, unsigned long phys_addr, unsigned long flags)
{
- unsigned long end;
+ pmd_t *pmd;
+ unsigned long next;
- address &= ~PGDIR_MASK;
- end = address + size;
- if (end > PGDIR_SIZE)
- end = PGDIR_SIZE;
- phys_addr -= address;
- if (address >= end)
- BUG();
+ phys_addr -= addr;
+ pmd = pmd_alloc(&init_mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
do {
- pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
- if (!pte)
+ next = pmd_addr_end(addr, end);
+ if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, flags))
return -ENOMEM;
- remap_area_pte(pte, address, end - address, address + phys_addr, flags);
- address = (address + PMD_SIZE) & PMD_MASK;
- pmd++;
- } while (address && (address < end));
+ } while (pmd++, addr = next, addr != end);
return 0;
}
-static int remap_area_pages(unsigned long address, unsigned long phys_addr,
- unsigned long size, unsigned long flags)
+static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
+ unsigned long end, unsigned long phys_addr, unsigned long flags)
{
- int error;
- pgd_t * dir;
- unsigned long end = address + size;
+ pud_t *pud;
+ unsigned long next;
- phys_addr -= address;
- dir = pgd_offset(&init_mm, address);
+ phys_addr -= addr;
+ pud = pud_alloc(&init_mm, pgd, addr);
+ if (!pud)
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+ if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, flags))
+ return -ENOMEM;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+static int ioremap_page_range(unsigned long addr,
+ unsigned long end, unsigned long phys_addr, unsigned long flags)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ int err;
+
+ BUG_ON(addr >= end);
flush_cache_all();
- if (address >= end)
- BUG();
+ phys_addr -= addr;
+ pgd = pgd_offset_k(addr);
spin_lock(&init_mm.page_table_lock);
do {
- pud_t *pud;
- pmd_t *pmd;
-
- error = -ENOMEM;
- pud = pud_alloc(&init_mm, dir, address);
- if (!pud)
- break;
- pmd = pmd_alloc(&init_mm, pud, address);
- if (!pmd)
- break;
- if (remap_area_pmd(pmd, address, end - address,
- phys_addr + address, flags))
+ next = pgd_addr_end(addr, end);
+ err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, flags);
+ if (err)
break;
- error = 0;
- address = (address + PGDIR_SIZE) & PGDIR_MASK;
- dir++;
- } while (address && (address < end));
+ } while (pgd++, addr = next, addr != end);
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
- return error;
+ return err;
}
/*
@@ -165,7 +158,8 @@ void __iomem * __ioremap(unsigned long p
return NULL;
area->phys_addr = phys_addr;
addr = (void __iomem *) area->addr;
- if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
+ if (ioremap_page_range((unsigned long) addr,
+ (unsigned long) addr + size, phys_addr, flags)) {
vunmap((void __force *) addr);
return NULL;
}
_