[linuxsh-dev] Swap is buggy

[NIIBE Y. <gn...@ch...>]

I tried swap, and soon found problem.  The implementation was quite
buggy.  Here is the fix.  I'll commit this change and the fix of
handle_vmalloc_fault.

2000-05-18  NIIBE Yutaka  <gn...@m1...>
 
	* include/asm-sh/pgtable.h (mk_pte_phys): Bug fix.  Added
	__MEMORY_START.

	Bug fixes for swap entry encoding and pte encoding.
	(_PAGE_FLAGS_HARDWARE_MASK): Mask V-bit.
	(_PAGE_FLAGS_HARDWARE_DEFAULT): Enable V-bit.
	Make _PAGE_PRESENT as software flag, and let it be the b0-bit.

Index: include/asm-sh/pgtable.h
===================================================================
RCS file: /cvsroot/linuxsh/kernel/include/asm-sh/pgtable.h,v
retrieving revision 1.2
diff -u -r1.2 pgtable.h
--- include/asm-sh/pgtable.h	2000/04/30 00:50:23	1.2
+++ include/asm-sh/pgtable.h	2000/05/18 07:52:35
@@ -89,26 +89,26 @@
 #define VMALLOC_VMADDR(x) ((unsigned long)(x))
 #define VMALLOC_END	P4SEG
 
-#define _PAGE_READ 	0x001  /* software: read access allowed */
+#define _PAGE_PRESENT	0x001  /* software: page is present */
 #define _PAGE_ACCESSED	0x002  /* software: page referenced */
 #define _PAGE_DIRTY	0x004  /* D-bit   : page changed */
 #define _PAGE_CACHABLE	0x008  /* C-bit   : cachable */
-/*		 	0x010  */
+/*		 	0x010     SZ-bit  : size of page */
 #define _PAGE_RW	0x020  /* PR0-bit : write access allowed */
 #define _PAGE_USER	0x040  /* PR1-bit : user space access allowed */
 #define _PAGE_PROTNONE	0x080  /* software: if not present */
-#define _PAGE_PRESENT	0x100  /* V-bit   : page is valid */
+/*			0x100     V-bit   : page is valid */
 
 #if defined(__sh3__)
 /* Mask which drop software flags */
-#define _PAGE_FLAGS_HARDWARE_MASK	0x1ffff16c
+#define _PAGE_FLAGS_HARDWARE_MASK	0x1ffff06c
 /* Flags defalult: SZ=1 (4k-byte), C=0 (non-cachable), SH=0 (not shared) */
-#define _PAGE_FLAGS_HARDWARE_DEFAULT	0x00000010
+#define _PAGE_FLAGS_HARDWARE_DEFAULT	0x00000110
 #elif defined(__SH4__)
 /* Mask which drops software flags */
-#define _PAGE_FLAGS_HARDWARE_MASK	0x1ffff16c
+#define _PAGE_FLAGS_HARDWARE_MASK	0x1ffff06c
 /* Flags defalult: SZ=01 (4k-byte), C=0 (non-cachable), SH=0 (not shared), WT=0 */
-#define _PAGE_FLAGS_HARDWARE_DEFAULT	0x00000010
+#define _PAGE_FLAGS_HARDWARE_DEFAULT	0x00000110
 #endif
 
 #define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
@@ -208,7 +208,7 @@
 
 /* This takes a physical page address that is used by the remapping functions */
 #define mk_pte_phys(physpage, pgprot) \
-({ pte_t __pte; set_pte(&__pte, __pte(physpage + pgprot_val(pgprot))); __pte; })
+({ pte_t __pte; set_pte(&__pte, __pte(physpage + pgprot_val(pgprot) + __MEMORY_START)); __pte; })
 
 extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 { set_pte(&pte, __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot))); return pte; }