[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>

7 files changed, 38 insertions, 26 deletions

diff --git a/arch/ia64/kernel/sys_ia64.c b/arch/ia64/kernel/sys_ia64.c
index 770fab37928e..f2dbcd1db0d4 100644
--- a/arch/ia64/kernel/sys_ia64.c
+++ b/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)
diff --git a/arch/ia64/mm/hugetlbpage.c b/arch/ia64/mm/hugetlbpage.c
index e0a776a3044c..2d13889d0a99 100644
--- a/arch/ia64/mm/hugetlbpage.c
+++ b/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);
diff --git a/include/asm-ia64/io.h b/include/asm-ia64/io.h
index 54e7637a326c..3c28eeb0b009 100644
--- a/include/asm-ia64/io.h
+++ b/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
diff --git a/include/asm-ia64/mmu_context.h b/include/asm-ia64/mmu_context.h
index e3e5fededb04..ab60a6a26911 100644
--- a/include/asm-ia64/mmu_context.h
+++ b/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);
diff --git a/include/asm-ia64/page.h b/include/asm-ia64/page.h
index 08894f73abf0..ec17f9e9da75 100644
--- a/include/asm-ia64/page.h
+++ b/include/asm-ia64/page.h
@@ -13,6 +13,19 @@
 #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.
  */
 #if defined(CONFIG_IA64_PAGE_SIZE_4KB)
@@ -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 |                \
diff --git a/include/asm-ia64/pgtable.h b/include/asm-ia64/pgtable.h
index 48586e08f432..2e34c06e6777 100644
--- a/include/asm-ia64/pgtable.h
+++ b/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
diff --git a/include/asm-ia64/system.h b/include/asm-ia64/system.h
index cd2cf76b2db1..33256db4a7cf 100644
--- a/include/asm-ia64/system.h
+++ b/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__