On Fri, 14 Jul 2006 08:48:43 -0700
Dave Hansen <[EMAIL PROTECTED]> wrote:
> It would also be nice to see a _couple_ of patches that perhaps
> abstract a thing or two into generic code. I know that new
> architectures usually begin with a 'cp -r', but it would be nice to
> see a wee bit of code refactoring as a small price of admission.
> Some of the ioremap and other pagetable code looked pretty generic to
> me.
Ok, here's a first try.
This patch moves the i386 implementation of ioremap_page_range() into
lib/ioremap.c for use by other architectures.
There's one difference between the generic ioremap_page_range and the
i386 version: it takes a pgprot_t argument instead of unsigned long
flags, meaning that the arch-specific ioremap() implementation must
set all pte flags before calling ioremap_page_range() instead of
in the lowest-level page remapping function.
If you think this looks like a good idea, I'll split out the i386
modifications in a separate patch and submit patches for several other
architectures as well.
To get the review started, here are a couple of questions:
* Wouldn't it make more sense to call flush_cache_vmap() instead of
flush_cache_all()?
* Why do we need to call flush_tlb_all()? I thought you only needed
to do that when changing/removing existing mappings...
Haavard
---
arch/i386/mm/ioremap.c | 88 ++++--------------------------------------------
include/linux/io.h | 3 ++
lib/Makefile | 2 +
lib/ioremap.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 99 insertions(+), 81 deletions(-)
diff --git a/arch/i386/mm/ioremap.c b/arch/i386/mm/ioremap.c
index 247fde7..df8427d 100644
--- a/arch/i386/mm/ioremap.c
+++ b/arch/i386/mm/ioremap.c
@@ -12,7 +12,7 @@ #include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
-#include <asm/io.h>
+#include <linux/io.h>
#include <asm/fixmap.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
@@ -21,82 +21,6 @@ #include <asm/pgtable.h>
#define ISA_START_ADDRESS 0xa0000
#define ISA_END_ADDRESS 0x100000
-static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
- unsigned long end, unsigned long phys_addr, unsigned long flags)
-{
- pte_t *pte;
- unsigned long pfn;
-
- pfn = phys_addr >> PAGE_SHIFT;
- pte = pte_alloc_kernel(pmd, addr);
- if (!pte)
- return -ENOMEM;
- do {
- BUG_ON(!pte_none(*pte));
- set_pte(pte, pfn_pte(pfn, __pgprot(_PAGE_PRESENT | _PAGE_RW |
- _PAGE_DIRTY | _PAGE_ACCESSED | flags)));
- pfn++;
- } while (pte++, addr += PAGE_SIZE, addr != end);
- return 0;
-}
-
-static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
- unsigned long end, unsigned long phys_addr, unsigned long flags)
-{
- pmd_t *pmd;
- unsigned long next;
-
- phys_addr -= addr;
- pmd = pmd_alloc(&init_mm, pud, addr);
- if (!pmd)
- return -ENOMEM;
- do {
- next = pmd_addr_end(addr, end);
- if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, flags))
- return -ENOMEM;
- } while (pmd++, addr = next, addr != end);
- return 0;
-}
-
-static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
- unsigned long end, unsigned long phys_addr, unsigned long flags)
-{
- pud_t *pud;
- unsigned long next;
-
- 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();
- phys_addr -= addr;
- pgd = pgd_offset_k(addr);
- do {
- next = pgd_addr_end(addr, end);
- err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, flags);
- if (err)
- break;
- } while (pgd++, addr = next, addr != end);
- flush_tlb_all();
- return err;
-}
-
/*
* Generic mapping function (not visible outside):
*/
@@ -112,9 +36,10 @@ static int ioremap_page_range(unsigned l
*/
void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned
long flags)
{
- void __iomem * addr;
- struct vm_struct * area;
+ void __iomem *addr;
+ struct vm_struct *area;
unsigned long offset, last_addr;
+ pgprot_t prot;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
@@ -142,6 +67,9 @@ void __iomem * __ioremap(unsigned long p
return NULL;
}
+ prot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY
+ | _PAGE_ACCESSED | flags);
+
/*
* Mappings have to be page-aligned
*/
@@ -158,7 +86,7 @@ void __iomem * __ioremap(unsigned long p
area->phys_addr = phys_addr;
addr = (void __iomem *) area->addr;
if (ioremap_page_range((unsigned long) addr,
- (unsigned long) addr + size, phys_addr, flags)) {
+ (unsigned long) addr + size, phys_addr, prot)) {
vunmap((void __force *) addr);
return NULL;
}
diff --git a/include/linux/io.h b/include/linux/io.h
index 420e2fd..d9d45be 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -23,4 +23,7 @@ #include <asm/io.h>
void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
+int ioremap_page_range(unsigned long addr, unsigned long end,
+ unsigned long phys_addr, pgprot_t prot);
+
#endif /* _LINUX_IO_H */
diff --git a/lib/Makefile b/lib/Makefile
index be9719a..a4dcb07 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -5,7 +5,7 @@ #
lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \
bust_spinlocks.o rbtree.o radix-tree.o dump_stack.o \
idr.o div64.o int_sqrt.o bitmap.o extable.o prio_tree.o \
- sha1.o
+ sha1.o ioremap.o
lib-$(CONFIG_SMP) += cpumask.o
diff --git a/lib/ioremap.c b/lib/ioremap.c
new file mode 100644
index 0000000..d3e1bfd
--- /dev/null
+++ b/lib/ioremap.c
@@ -0,0 +1,87 @@
+/*
+ * Re-map IO memory to kernel address space so that we can access it.
+ * This is needed for high PCI addresses that aren't mapped in the
+ * 640k-1MB IO memory area on PC's
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ */
+#include <linux/io.h>
+#include <linux/vmalloc.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/pgtable.h>
+
+static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+ pte_t *pte;
+ unsigned long pfn;
+
+ pfn = phys_addr >> PAGE_SHIFT;
+ pte = pte_alloc_kernel(pmd, addr);
+ if (!pte)
+ return -ENOMEM;
+ do {
+ BUG_ON(!pte_none(*pte));
+ set_pte(pte, pfn_pte(pfn, prot));
+ pfn++;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ return 0;
+}
+
+static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
+ unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ phys_addr -= addr;
+ pmd = pmd_alloc(&init_mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
+ do {
+ next = pmd_addr_end(addr, end);
+ if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
+ return -ENOMEM;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
+ unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ 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, prot))
+ return -ENOMEM;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+int ioremap_page_range(unsigned long addr,
+ unsigned long end, unsigned long phys_addr, pgprot_t
prot)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ int err;
+
+ BUG_ON(addr >= end);
+ flush_cache_all();
+ phys_addr -= addr;
+ pgd = pgd_offset_k(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
+ if (err)
+ break;
+ } while (pgd++, addr = next, addr != end);
+ flush_tlb_all();
+ return err;
+}
--
1.4.0
-
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