x86, 64-bit: unify early_ioremap

The 32-bit early_ioremap will work equally well for 64-bit, so just use it.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/mm/init_64.c

@@ -257,58 +257,6 @@ static __meminit void unmap_low_page(void *adr)
 	early_iounmap(adr, PAGE_SIZE);
 }
 
-/* Must run before zap_low_mappings */
-__meminit void *early_ioremap(unsigned long addr, unsigned long size)
-{
-	pmd_t *pmd, *last_pmd;
-	unsigned long vaddr;
-	int i, pmds;
-
-	pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
-	vaddr = __START_KERNEL_map;
-	pmd = level2_kernel_pgt;
-	last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
-
-	for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
-		for (i = 0; i < pmds; i++) {
-			if (pmd_present(pmd[i]))
-				goto continue_outer_loop;
-		}
-		vaddr += addr & ~PMD_MASK;
-		addr &= PMD_MASK;
-
-		for (i = 0; i < pmds; i++, addr += PMD_SIZE)
-			set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
-		__flush_tlb_all();
-
-		return (void *)vaddr;
-continue_outer_loop:
-		;
-	}
-	printk(KERN_ERR "early_ioremap(0x%lx, %lu) failed\n", addr, size);
-
-	return NULL;
-}
-
-/*
- * To avoid virtual aliases later:
- */
-__meminit void early_iounmap(void *addr, unsigned long size)
-{
-	unsigned long vaddr;
-	pmd_t *pmd;
-	int i, pmds;
-
-	vaddr = (unsigned long)addr;
-	pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
-	pmd = level2_kernel_pgt + pmd_index(vaddr);
-
-	for (i = 0; i < pmds; i++)
-		pmd_clear(pmd + i);
-
-	__flush_tlb_all();
-}
-
 static unsigned long __meminit
 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
 {

arch/x86/mm/ioremap.c

@@ -381,8 +381,6 @@ void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
 	return;
 }
 
-#ifdef CONFIG_X86_32
-
 int __initdata early_ioremap_debug;
 
 static int __init early_ioremap_debug_setup(char *str)
@@ -483,6 +481,7 @@ static void __init __early_set_fixmap(enum fixed_addresses idx,
 		return;
 	}
 	pte = early_ioremap_pte(addr);
+
 	if (pgprot_val(flags))
 		set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
 	else
@@ -624,5 +623,3 @@ void __this_fixmap_does_not_exist(void)
 {
 	WARN_ON(1);
 }
-
-#endif /* CONFIG_X86_32 */

include/asm-x86/fixmap_64.h

@@ -49,6 +49,19 @@ enum fixed_addresses {
 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
 	FIX_OHCI1394_BASE,
 #endif
+	__end_of_permanent_fixed_addresses,
+	/*
+	 * 256 temporary boot-time mappings, used by early_ioremap(),
+	 * before ioremap() is functional.
+	 *
+	 * We round it up to the next 512 pages boundary so that we
+	 * can have a single pgd entry and a single pte table:
+	 */
+#define NR_FIX_BTMAPS		64
+#define FIX_BTMAPS_NESTING	4
+	FIX_BTMAP_END = __end_of_permanent_fixed_addresses + 512 -
+			(__end_of_permanent_fixed_addresses & 511),
+	FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_NESTING - 1,
 	__end_of_fixed_addresses
 };
 

include/asm-x86/io.h

@@ -72,4 +72,17 @@ extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 				unsigned long prot_val);
 extern void __iomem *ioremap_wc(unsigned long offset, unsigned long size);
 
+/*
+ * early_ioremap() and early_iounmap() are for temporary early boot-time
+ * mappings, before the real ioremap() is functional.
+ * A boot-time mapping is currently limited to at most 16 pages.
+ */
+extern void early_ioremap_init(void);
+extern void early_ioremap_clear(void);
+extern void early_ioremap_reset(void);
+extern void *early_ioremap(unsigned long offset, unsigned long size);
+extern void early_iounmap(void *addr, unsigned long size);
+extern void __iomem *fix_ioremap(unsigned idx, unsigned long phys);
+
+
 #endif /* _ASM_X86_IO_H */

include/asm-x86/io_32.h

@@ -121,18 +121,6 @@ static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
 
 extern void iounmap(volatile void __iomem *addr);
 
-/*
- * early_ioremap() and early_iounmap() are for temporary early boot-time
- * mappings, before the real ioremap() is functional.
- * A boot-time mapping is currently limited to at most 16 pages.
- */
-extern void early_ioremap_init(void);
-extern void early_ioremap_clear(void);
-extern void early_ioremap_reset(void);
-extern void *early_ioremap(unsigned long offset, unsigned long size);
-extern void early_iounmap(void *addr, unsigned long size);
-extern void __iomem *fix_ioremap(unsigned idx, unsigned long phys);
-
 /*
  * ISA I/O bus memory addresses are 1:1 with the physical address.
  */