[PATCH] sh: I/O routine cleanups and ioremap() overhaul

This introduces a few changes in the way that the I/O routines are defined on
SH, specifically so that things like the iomap API properly wrap through the
machvec for board-specific quirks.

In addition to this, the old p3_ioremap() work is converted to a more generic
__ioremap() that will map through the PMB if it's available, or fall back on
page tables for everything else.

An alpha-like IO_CONCAT is also added so we can start to clean up the
board-specific io.h mess, which will be handled in board update patches..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 81 insertions, 18 deletions

diff --git a/arch/sh/mm/ioremap.c b/arch/sh/mm/ioremap.c
index e794e27a72f1..96fa4a999e2a 100644
--- a/arch/sh/mm/ioremap.c
+++ b/arch/sh/mm/ioremap.c
@@ -6,13 +6,19 @@
  * 640k-1MB IO memory area on PC's
  *
  * (C) Copyright 1995 1996 Linus Torvalds
+ * (C) Copyright 2005, 2006 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
  */
-
 #include <linux/vmalloc.h>
+#include <linux/module.h>
 #include <linux/mm.h>
 #include <asm/io.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
+#include <asm/addrspace.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
@@ -80,9 +86,15 @@ int remap_area_pages(unsigned long address, unsigned long phys_addr,
         if (address >= end)
                 BUG();
         do {
+                pud_t *pud;
                 pmd_t *pmd;
-                pmd = pmd_alloc(&init_mm, dir, address);
+
                 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,
@@ -97,10 +109,6 @@ int remap_area_pages(unsigned long address, unsigned long phys_addr,
 }
 
 /*
- * Generic mapping function (not visible outside):
- */
-
-/*
  * Remap an arbitrary physical address space into the kernel virtual
  * address space. Needed when the kernel wants to access high addresses
  * directly.
@@ -109,11 +117,11 @@ int remap_area_pages(unsigned long address, unsigned long phys_addr,
  * have to convert them into an offset in a page-aligned mapping, but the
  * caller shouldn't need to know that small detail.
  */
-void * p3_ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
+void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
+                        unsigned long flags)
 {
-        void * addr;
         struct vm_struct * area;
-        unsigned long offset, last_addr;
+        unsigned long offset, last_addr, addr, orig_addr;
 
         /* Don't allow wraparound or zero size */
         last_addr = phys_addr + size - 1;
@@ -124,7 +132,7 @@ void * p3_ioremap(unsigned long phys_addr, unsigned long size, unsigned long fla
          * Don't remap the low PCI/ISA area, it's always mapped..
          */
         if (phys_addr >= 0xA0000 && last_addr < 0x100000)
-                return phys_to_virt(phys_addr);
+                return (void __iomem *)phys_to_virt(phys_addr);
 
         /*
          * Don't allow anybody to remap normal RAM that we're using..
@@ -146,16 +154,71 @@ void * p3_ioremap(unsigned long phys_addr, unsigned long size, unsigned long fla
         if (!area)
                 return NULL;
         area->phys_addr = phys_addr;
-        addr = area->addr;
-        if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
-                vunmap(addr);
-                return NULL;
+        orig_addr = addr = (unsigned long)area->addr;
+
+#ifdef CONFIG_32BIT
+        /*
+         * First try to remap through the PMB once a valid VMA has been
+         * established. Smaller allocations (or the rest of the size
+         * remaining after a PMB mapping due to the size not being
+         * perfectly aligned on a PMB size boundary) are then mapped
+         * through the UTLB using conventional page tables.
+         *
+         * PMB entries are all pre-faulted.
+         */
+        if (unlikely(size >= 0x1000000)) {
+                unsigned long mapped = pmb_remap(addr, phys_addr, size, flags);
+
+                if (likely(mapped)) {
+                        addr            += mapped;
+                        phys_addr       += mapped;
+                        size            -= mapped;
+                }
         }
-        return (void *) (offset + (char *)addr);
+#endif
+
+        if (likely(size))
+                if (remap_area_pages(addr, phys_addr, size, flags)) {
+                        vunmap((void *)orig_addr);
+                        return NULL;
+                }
+
+        return (void __iomem *)(offset + (char *)orig_addr);
 }
+EXPORT_SYMBOL(__ioremap);
 
-void p3_iounmap(void *addr)
+void __iounmap(void __iomem *addr)
 {
-        if (addr > high_memory)
-                vfree((void *)(PAGE_MASK & (unsigned long)addr));
+        unsigned long vaddr = (unsigned long __force)addr;
+        struct vm_struct *p;
+
+        if (PXSEG(vaddr) < P3SEG)
+                return;
+
+#ifdef CONFIG_32BIT
+        /*
+         * Purge any PMB entries that may have been established for this
+         * mapping, then proceed with conventional VMA teardown.
+         *
+         * XXX: Note that due to the way that remove_vm_area() does
+         * matching of the resultant VMA, we aren't able to fast-forward
+         * the address past the PMB space until the end of the VMA where
+         * the page tables reside. As such, unmap_vm_area() will be
+         * forced to linearly scan over the area until it finds the page
+         * tables where PTEs that need to be unmapped actually reside,
+         * which is far from optimal. Perhaps we need to use a separate
+         * VMA for the PMB mappings?
+         *                                      -- PFM.
+         */
+        pmb_unmap(vaddr);
+#endif
+
+        p = remove_vm_area((void *)(vaddr & PAGE_MASK));
+        if (!p) {
+                printk(KERN_ERR "%s: bad address %p\n", __FUNCTION__, addr);
+                return;
+        }
+
+        kfree(p);
 }
+EXPORT_SYMBOL(__iounmap);