[IA64] Rationalise Region Definitions

Currently, region numbers are defined in several files, with several 
names.  For example, we have REGION_KERNEL in asm/page.h and 
RGN_KERNEL in pgtable.h 
 
We also have address definitions that should depend on the 
RGN_XXX macros, but are currently just long constants. 
 
The following patch reorganises all the definitions so that they have 
the same form (RGN_XXX), are in one place, and that addresses that 
depend on RGN_XXX are derived from them. 

(This is a necessary but not sufficient patch to allow UML-like 
operation on IA64). 

Thanks to David Mosberger for catching the change I missed in mmu_context.h.
 
Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au> 
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/sys_ia64.c

@@ -35,7 +35,7 @@ arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len
 		return -ENOMEM;
 
 #ifdef CONFIG_HUGETLB_PAGE
-	if (REGION_NUMBER(addr) == REGION_HPAGE)
+	if (REGION_NUMBER(addr) == RGN_HPAGE)
 		addr = 0;
 #endif
 	if (!addr)

arch/ia64/mm/hugetlbpage.c

@@ -76,7 +76,7 @@ int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
 		return -EINVAL;
 	if (addr & ~HPAGE_MASK)
 		return -EINVAL;
-	if (REGION_NUMBER(addr) != REGION_HPAGE)
+	if (REGION_NUMBER(addr) != RGN_HPAGE)
 		return -EINVAL;
 
 	return 0;
@@ -87,7 +87,7 @@ struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int writ
 	struct page *page;
 	pte_t *ptep;
 
-	if (REGION_NUMBER(addr) != REGION_HPAGE)
+	if (REGION_NUMBER(addr) != RGN_HPAGE)
 		return ERR_PTR(-EINVAL);
 
 	ptep = huge_pte_offset(mm, addr);
@@ -142,8 +142,8 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, u
 		return -ENOMEM;
 	if (len & ~HPAGE_MASK)
 		return -EINVAL;
-	/* This code assumes that REGION_HPAGE != 0. */
-	if ((REGION_NUMBER(addr) != REGION_HPAGE) || (addr & (HPAGE_SIZE - 1)))
+	/* This code assumes that RGN_HPAGE != 0. */
+	if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
 		addr = HPAGE_REGION_BASE;
 	else
 		addr = ALIGN(addr, HPAGE_SIZE);

include/asm-ia64/io.h

@@ -23,7 +23,7 @@
 #define __SLOW_DOWN_IO	do { } while (0)
 #define SLOW_DOWN_IO	do { } while (0)
 
-#define __IA64_UNCACHED_OFFSET	0xc000000000000000UL	/* region 6 */
+#define __IA64_UNCACHED_OFFSET	RGN_BASE(RGN_UNCACHED)
 
 /*
  * The legacy I/O space defined by the ia64 architecture supports only 65536 ports, but

include/asm-ia64/mmu_context.h

@@ -19,6 +19,7 @@
 
 #define ia64_rid(ctx,addr)	(((ctx) << 3) | (addr >> 61))
 
+# include <asm/page.h>
 # ifndef __ASSEMBLY__
 
 #include <linux/compiler.h>
@@ -110,7 +111,7 @@ reload_context (mm_context_t context)
 	unsigned long rid_incr = 0;
 	unsigned long rr0, rr1, rr2, rr3, rr4, old_rr4;
 
-	old_rr4 = ia64_get_rr(0x8000000000000000UL);
+	old_rr4 = ia64_get_rr(RGN_BASE(RGN_HPAGE));
 	rid = context << 3;	/* make space for encoding the region number */
 	rid_incr = 1 << 8;
 
@@ -122,6 +123,10 @@ reload_context (mm_context_t context)
 	rr4 = rr0 + 4*rid_incr;
 #ifdef  CONFIG_HUGETLB_PAGE
 	rr4 = (rr4 & (~(0xfcUL))) | (old_rr4 & 0xfc);
+
+#  if RGN_HPAGE != 4
+#    error "reload_context assumes RGN_HPAGE is 4"
+#  endif
 #endif
 
 	ia64_set_rr(0x0000000000000000UL, rr0);

include/asm-ia64/page.h

@@ -12,6 +12,19 @@
 #include <asm/intrinsics.h>
 #include <asm/types.h>
 
+/*
+ * The top three bits of an IA64 address are its Region Number.
+ * Different regions are assigned to different purposes.
+ */
+#define RGN_SHIFT	(61)
+#define RGN_BASE(r)  (__IA64_UL_CONST(r)<<RGN_SHIFT)
+
+#define KHIGH -1	/* high three bits of Kernel virtual address */
+#define RGN_KERNEL	7	/* Identity mapped region */
+#define RGN_UNCACHED    6	/* Identity mapped I/O region */
+#define RGN_GATE	5	/* Gate page, Kernel text, etc */
+#define RGN_HPAGE	4	/* For Huge TLB pages */
+
 /*
  * PAGE_SHIFT determines the actual kernel page size.
  */
@@ -36,10 +49,9 @@
 
 #define RGN_MAP_LIMIT	((1UL << (4*PAGE_SHIFT - 12)) - PAGE_SIZE)	/* per region addr limit */
 
+
 #ifdef CONFIG_HUGETLB_PAGE
-# define REGION_HPAGE		(4UL)	/* note: this is hardcoded in reload_context()!*/
-# define REGION_SHIFT		61
-# define HPAGE_REGION_BASE	(REGION_HPAGE << REGION_SHIFT)
+# define HPAGE_REGION_BASE	RGN_BASE(RGN_HPAGE)
 # define HPAGE_SHIFT		hpage_shift
 # define HPAGE_SHIFT_DEFAULT	28	/* check ia64 SDM for architecture supported size */
 # define HPAGE_SIZE		(__IA64_UL_CONST(1) << HPAGE_SHIFT)
@@ -130,16 +142,13 @@ typedef union ia64_va {
 #define REGION_NUMBER(x)	({ia64_va _v; _v.l = (long) (x); _v.f.reg;})
 #define REGION_OFFSET(x)	({ia64_va _v; _v.l = (long) (x); _v.f.off;})
 
-#define REGION_SIZE		REGION_NUMBER(1)
-#define REGION_KERNEL		7
-
 #ifdef CONFIG_HUGETLB_PAGE
 # define htlbpage_to_page(x)	(((unsigned long) REGION_NUMBER(x) << 61)			\
 				 | (REGION_OFFSET(x) >> (HPAGE_SHIFT-PAGE_SHIFT)))
 # define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
 # define is_hugepage_only_range(mm, addr, len)		\
-	 (REGION_NUMBER(addr) == REGION_HPAGE &&	\
-	  REGION_NUMBER((addr)+(len)-1) == REGION_HPAGE)
+	 (REGION_NUMBER(addr) == RGN_HPAGE &&	\
+	  REGION_NUMBER((addr)+(len)-1) == RGN_HPAGE)
 extern unsigned int hpage_shift;
 #endif
 
@@ -197,7 +206,7 @@ get_order (unsigned long size)
 # define __pgprot(x)	(x)
 #endif /* !STRICT_MM_TYPECHECKS */
 
-#define PAGE_OFFSET			__IA64_UL_CONST(0xe000000000000000)
+#define PAGE_OFFSET			RGN_BASE(RGN_KERNEL)
 
 #define VM_DATA_DEFAULT_FLAGS		(VM_READ | VM_WRITE |					\
 					 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC |		\

include/asm-ia64/pgtable.h

@@ -204,21 +204,18 @@ ia64_phys_addr_valid (unsigned long addr)
 #define set_pte(ptep, pteval)	(*(ptep) = (pteval))
 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 
-#define RGN_SIZE	(1UL << 61)
-#define RGN_KERNEL	7
-
-#define VMALLOC_START		0xa000000200000000UL
+#define VMALLOC_START		(RGN_BASE(RGN_GATE) + 0x200000000UL)
 #ifdef CONFIG_VIRTUAL_MEM_MAP
-# define VMALLOC_END_INIT	(0xa000000000000000UL + (1UL << (4*PAGE_SHIFT - 9)))
+# define VMALLOC_END_INIT	(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
 # define VMALLOC_END		vmalloc_end
   extern unsigned long vmalloc_end;
 #else
-# define VMALLOC_END		(0xa000000000000000UL + (1UL << (4*PAGE_SHIFT - 9)))
+# define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
 #endif
 
 /* fs/proc/kcore.c */
-#define	kc_vaddr_to_offset(v) ((v) - 0xa000000000000000UL)
-#define	kc_offset_to_vaddr(o) ((o) + 0xa000000000000000UL)
+#define	kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
+#define	kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))
 
 /*
  * Conversion functions: convert page frame number (pfn) and a protection value to a page

include/asm-ia64/system.h

@@ -19,12 +19,13 @@
 #include <asm/pal.h>
 #include <asm/percpu.h>
 
-#define GATE_ADDR		__IA64_UL_CONST(0xa000000000000000)
+#define GATE_ADDR		RGN_BASE(RGN_GATE)
+
 /*
  * 0xa000000000000000+2*PERCPU_PAGE_SIZE
  * - 0xa000000000000000+3*PERCPU_PAGE_SIZE remain unmapped (guard page)
  */
-#define KERNEL_START		 __IA64_UL_CONST(0xa000000100000000)
+#define KERNEL_START		 (GATE_ADDR+0x100000000)
 #define PERCPU_ADDR		(-PERCPU_PAGE_SIZE)
 
 #ifndef __ASSEMBLY__