[PATCH] ppc64: Fix semantics of __ioremap

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@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 9 insertions, 7 deletions

diff --git a/arch/ppc64/kernel/maple_setup.c b/arch/ppc64/kernel/maple_setup.c
index 1db6ea0f336..8cf95a27178 100644
--- a/arch/ppc64/kernel/maple_setup.c
+++ b/arch/ppc64/kernel/maple_setup.c
@@ -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 --git a/arch/ppc64/kernel/pSeries_setup.c b/arch/ppc64/kernel/pSeries_setup.c
index 06536de5125..6c0d1d58a55 100644
--- a/arch/ppc64/kernel/pSeries_setup.c
+++ b/arch/ppc64/kernel/pSeries_setup.c
@@ -363,7 +363,7 @@ static void __init pSeries_init_early(void)
 		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 --git a/arch/ppc64/kernel/pci.c b/arch/ppc64/kernel/pci.c
index fdd8f7869a6..be3cc387c1e 100644
--- a/arch/ppc64/kernel/pci.c
+++ b/arch/ppc64/kernel/pci.c
@@ -547,8 +547,9 @@ static void __devinit pci_process_ISA_OF_ranges(struct device_node *isa_node,
 	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_ranges(struct device_node *isa_node,
 
 		__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 pci_controller *hose,
 	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;