[patch 048/198] ppc64: Fix semantics of __ioremap

From: akpm
Date: Tue Apr 12 2005 - 19:58:56 EST



From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>

This patch fixes ppc64 __ioremap() so that it stops adding implicitely
_PAGE_GUARDED when the cache is not writeback, and instead, let the callers
provide the flag they want here. This allows things like framebuffers to
explicitely request a non-cacheable and non-guarded mapping which is more
efficient for that type of memory without side effects. The patch also
fixes all current callers to add _PAGE_GUARDED except btext, which is fine
without it.

Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---

25-akpm/arch/ppc64/kernel/maple_setup.c | 2 +-
25-akpm/arch/ppc64/kernel/pSeries_setup.c | 2 +-
25-akpm/arch/ppc64/kernel/pci.c | 12 +++++++-----
25-akpm/arch/ppc64/mm/init.c | 18 +++++++++---------
4 files changed, 18 insertions(+), 16 deletions(-)

diff -puN arch/ppc64/kernel/maple_setup.c~ppc64-fix-semantics-of-__ioremap arch/ppc64/kernel/maple_setup.c
--- 25/arch/ppc64/kernel/maple_setup.c~ppc64-fix-semantics-of-__ioremap 2005-04-12 03:21:15.021853232 -0700
+++ 25-akpm/arch/ppc64/kernel/maple_setup.c 2005-04-12 03:21:15.028852168 -0700
@@ -142,7 +142,7 @@ static void __init maple_init_early(void
if (physport) {
void *comport;
/* Map the uart for udbg. */
- comport = (void *)__ioremap(physport, 16, _PAGE_NO_CACHE);
+ comport = (void *)ioremap(physport, 16);
udbg_init_uart(comport, default_speed);

ppc_md.udbg_putc = udbg_putc;
diff -puN arch/ppc64/kernel/pci.c~ppc64-fix-semantics-of-__ioremap arch/ppc64/kernel/pci.c
--- 25/arch/ppc64/kernel/pci.c~ppc64-fix-semantics-of-__ioremap 2005-04-12 03:21:15.022853080 -0700
+++ 25-akpm/arch/ppc64/kernel/pci.c 2005-04-12 03:21:15.029852016 -0700
@@ -547,8 +547,9 @@ static void __devinit pci_process_ISA_OF
if (range == NULL || (rlen < sizeof(struct isa_range))) {
printk(KERN_ERR "no ISA ranges or unexpected isa range size,"
"mapping 64k\n");
- __ioremap_explicit(phb_io_base_phys, (unsigned long)phb_io_base_virt,
- 0x10000, _PAGE_NO_CACHE);
+ __ioremap_explicit(phb_io_base_phys,
+ (unsigned long)phb_io_base_virt,
+ 0x10000, _PAGE_NO_CACHE | _PAGE_GUARDED);
return;
}

@@ -576,7 +577,7 @@ static void __devinit pci_process_ISA_OF

__ioremap_explicit(phb_io_base_phys,
(unsigned long) phb_io_base_virt,
- size, _PAGE_NO_CACHE);
+ size, _PAGE_NO_CACHE | _PAGE_GUARDED);
}
}

@@ -692,7 +693,7 @@ void __devinit pci_setup_phb_io_dynamic(
struct resource *res;

hose->io_base_virt = __ioremap(hose->io_base_phys, size,
- _PAGE_NO_CACHE);
+ _PAGE_NO_CACHE | _PAGE_GUARDED);
DBG("phb%d io_base_phys 0x%lx io_base_virt 0x%lx\n",
hose->global_number, hose->io_base_phys,
(unsigned long) hose->io_base_virt);
@@ -780,7 +781,8 @@ int remap_bus_range(struct pci_bus *bus)
if (get_bus_io_range(bus, &start_phys, &start_virt, &size))
return 1;
printk("mapping IO %lx -> %lx, size: %lx\n", start_phys, start_virt, size);
- if (__ioremap_explicit(start_phys, start_virt, size, _PAGE_NO_CACHE))
+ if (__ioremap_explicit(start_phys, start_virt, size,
+ _PAGE_NO_CACHE | _PAGE_GUARDED))
return 1;

return 0;
diff -puN arch/ppc64/kernel/pSeries_setup.c~ppc64-fix-semantics-of-__ioremap arch/ppc64/kernel/pSeries_setup.c
--- 25/arch/ppc64/kernel/pSeries_setup.c~ppc64-fix-semantics-of-__ioremap 2005-04-12 03:21:15.024852776 -0700
+++ 25-akpm/arch/ppc64/kernel/pSeries_setup.c 2005-04-12 03:21:15.030851864 -0700
@@ -363,7 +363,7 @@ static void __init pSeries_init_early(vo
find_udbg_vterm();
else if (physport) {
/* Map the uart for udbg. */
- comport = (void *)__ioremap(physport, 16, _PAGE_NO_CACHE);
+ comport = (void *)ioremap(physport, 16);
udbg_init_uart(comport, default_speed);

ppc_md.udbg_putc = udbg_putc;
diff -puN arch/ppc64/mm/init.c~ppc64-fix-semantics-of-__ioremap arch/ppc64/mm/init.c
--- 25/arch/ppc64/mm/init.c~ppc64-fix-semantics-of-__ioremap 2005-04-12 03:21:15.025852624 -0700
+++ 25-akpm/arch/ppc64/mm/init.c 2005-04-12 03:21:15.031851712 -0700
@@ -155,7 +155,8 @@ static void map_io_page(unsigned long ea
ptep = pte_alloc_kernel(&ioremap_mm, pmdp, ea);

pa = abs_to_phys(pa);
- set_pte_at(&ioremap_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags)));
+ set_pte_at(&ioremap_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
+ __pgprot(flags)));
spin_unlock(&ioremap_mm.page_table_lock);
} else {
unsigned long va, vpn, hash, hpteg;
@@ -191,12 +192,9 @@ static void __iomem * __ioremap_com(unsi

if ((flags & _PAGE_PRESENT) == 0)
flags |= pgprot_val(PAGE_KERNEL);
- if (flags & (_PAGE_NO_CACHE | _PAGE_WRITETHRU))
- flags |= _PAGE_GUARDED;

- for (i = 0; i < size; i += PAGE_SIZE) {
+ for (i = 0; i < size; i += PAGE_SIZE)
map_io_page(ea+i, pa+i, flags);
- }

return (void __iomem *) (ea + (addr & ~PAGE_MASK));
}
@@ -205,7 +203,7 @@ static void __iomem * __ioremap_com(unsi
void __iomem *
ioremap(unsigned long addr, unsigned long size)
{
- return __ioremap(addr, size, _PAGE_NO_CACHE);
+ return __ioremap(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED);
}

void __iomem *
@@ -272,7 +270,8 @@ int __ioremap_explicit(unsigned long pa,
return 1;
}
if (ea != (unsigned long) area->addr) {
- printk(KERN_ERR "unexpected addr return from im_get_area\n");
+ printk(KERN_ERR "unexpected addr return from "
+ "im_get_area\n");
return 1;
}
}
@@ -315,7 +314,8 @@ static void unmap_im_area_pte(pmd_t *pmd
continue;
if (pte_present(page))
continue;
- printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
+ printk(KERN_CRIT "Whee.. Swapped out page in kernel page"
+ " table\n");
} while (address < end);
}

@@ -352,7 +352,7 @@ static void unmap_im_area_pmd(pgd_t *dir
* Access to IO memory should be serialized by driver.
* This code is modeled after vmalloc code - unmap_vm_area()
*
- * XXX what about calls before mem_init_done (ie python_countermeasures())
+ * XXX what about calls before mem_init_done (ie python_countermeasures())
*/
void iounmap(volatile void __iomem *token)
{
_
-
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