[linuxsh-dev] BUG fix for VMALLOC-ed page

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Sugioka-san pointed me that there's a problem using lsmod, and it caused
by vmalloced page.  Here's the patch.  Basically, we set "SH" bit on PTE
for the vmalloced pages.

Besides, here's the list of TODO, which is the result of the meeting
in Japan (Kaz, Toshinobu, Toshiharu, Takashi & Takeshi).

------- TODO 2000-09-03
* Implement shutdown, reboot
  ---> BIOS call? Jump to 0xa0000000?

* Implement profile functionality: arch/sh/time.c

* Implement /dev/rtc with SH's RTC

* Merge of floppy driver

* Kernel PGD optimization

* kernel math emulation
* x86 emulation
* SH emulation by x86
* freeze/snapshot feature ---> dump .data & .bss, reload, kick the driver...
* MTD device enhancement, optimize flash write
* PCMCIA(SH-4) TLB wiring, conservative TLB initialization
* boot from CDROM
* boot from net (TFTP?)
* toolchain + glibc once again with standard GNU
* USB
* PCI
------------

----------------------
2000-09-03  NIIBE Yutaka  <gn...@m1...>

	* include/asm-sh/pgtable.h (_PAGE_PRESENT): Use hardware V-bit.
	(_PAGE_U0_SHARED): New macro to implement user space shared page.
	(_PAGE_HW_SHARED): We need this hardware setting.
	(_PAGE_FLAGS_HARDWARE_DEFAULT): Removed.
	(_PAGE_FLAGS_HARDWARE_MASK): Include SZ-bit, SH-bit and WT-bit.
	(_PAGE_FLAGS_HARD): Hardware PTE flags setting (for SZ=4KB).
	(_PAGE_SHARED): Use U0_SHARED for SH-4, HW_SHARED for SH-3, because 
	there's alias issue on SH-4.
	(PAGE_NONE, PAGE_SHARED, PAGE_COPY, PAGE_READONLY, PAGE_KERNEL,
	PAGE_KERNEL_RO): Includd _PAGE_FLAGS_HARD.

	(PAGE_KERNEL, PAGE_KERNEL_RO): Include _PAGE_HW_SHARED.

	(_PAGE_ACCESSED, _PAGE_PROTNONE): Layout changed.
	(SWP_TYPE, SWP_OFFSET, SWP_ENTRY): Likewise.

	* arch/sh/mm/fault.c (update_mmu_cache): Don't OR the hardware value
	to PTE.  It's now already included.

Index: arch/sh/mm/fault.c
===================================================================
RCS file: /cvsroot/linuxsh/kernel/arch/sh/mm/fault.c,v
retrieving revision 1.20
diff -u -r1.20 fault.c

--- arch/sh/mm/fault.c	2000/09/01 01:11:25	1.20
+++ arch/sh/mm/fault.c	2000/09/03 03:04:40
@@ -326,7 +326,6 @@
 	/* Set PTEL register */
 	pteval = pte_val(pte);
 	pteval &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
-	pteval |= _PAGE_FLAGS_HARDWARE_DEFAULT; /* add default flags */
 	ctrl_outl(pteval, MMU_PTEL);
 
 	/* Load the TLB */
Index: include/asm-sh/pgtable.h
===================================================================
RCS file: /cvsroot/linuxsh/kernel/include/asm-sh/pgtable.h,v
retrieving revision 1.9
diff -u -r1.9 pgtable.h
--- include/asm-sh/pgtable.h	2000/09/01 01:11:25	1.9
+++ include/asm-sh/pgtable.h	2000/09/03 03:04:41
@@ -92,41 +92,40 @@
 #define VMALLOC_VMADDR(x) ((unsigned long)(x))
 #define VMALLOC_END	P4SEG
 
-#define _PAGE_PRESENT	0x001  /* software: page is present */
-#define _PAGE_ACCESSED	0x002  /* software: page referenced */
+/*			0x001     WT-bit on SH-4, 0 on SH-3 */
+#define _PAGE_HW_SHARED	0x002  /* SH-bit  : page is shared among processes */
 #define _PAGE_DIRTY	0x004  /* D-bit   : page changed */
 #define _PAGE_CACHABLE	0x008  /* C-bit   : cachable */
-/*		 	0x010     SZ-bit  : size of page */
+/*			0x010     SZ0-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 */
-/*			0x100     V-bit   : page is valid */
-#define _PAGE_SHARED    0x200  /* software: page is shared */
-/*			0x400     can be used as software flag */
-/*			0x800     can be used as software flag */
+/*			0x080     SZ1-bit : Size of page (on SH-4) */
+#define _PAGE_PRESENT	0x100  /* V-bit   : page is valid */
+#define _PAGE_PROTNONE	0x200  /* software: if not present  */
+#define _PAGE_ACCESSED 	0x400  /* software: page referenced */
+#define _PAGE_U0_SHARED 0x800  /* software: page is shared in user space */
 
-#if defined(__sh3__)
 /* Mask which drop software flags */
-#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	0x00000110
+#define _PAGE_FLAGS_HARDWARE_MASK	0x1ffff1ff
+/* Hardware flags: SZ=1 (4k-byte) */
+#define _PAGE_FLAGS_HARD		0x00000010
+
+#if defined(__sh3__)
+#define _PAGE_SHARED	_PAGE_HW_SHARED
 #elif defined(__SH4__)
-/* Mask which drops software flags */
-#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	0x00000110
+#define _PAGE_SHARED	_PAGE_U0_SHARED
 #endif
 
 #define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
 #define _KERNPG_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
 #define _PAGE_CHG_MASK	(PTE_MASK | _PAGE_ACCESSED | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_SHARED)
 
-#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_CACHABLE |_PAGE_ACCESSED)
-#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_CACHABLE |_PAGE_ACCESSED | _PAGE_SHARED)
-#define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | _PAGE_ACCESSED)
-#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | _PAGE_ACCESSED)
-#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_ACCESSED)
-#define PAGE_KERNEL_RO	__pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_ACCESSED)
+#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_CACHABLE |_PAGE_ACCESSED | _PAGE_FLAGS_HARD)
+#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_CACHABLE |_PAGE_ACCESSED | _PAGE_SHARED | _PAGE_FLAGS_HARD)
+#define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | _PAGE_ACCESSED | _PAGE_FLAGS_HARD)
+#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | _PAGE_ACCESSED | _PAGE_FLAGS_HARD)
+#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HW_SHARED | _PAGE_FLAGS_HARD)
+#define PAGE_KERNEL_RO	__pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HW_SHARED | _PAGE_FLAGS_HARD)
 
 /*
  * As i386 and MIPS, SuperH can't do page protection for execute, and
@@ -245,11 +244,15 @@
 			     unsigned long address, pte_t pte);
 
 /* Encode and de-code a swap entry */
-#define SWP_TYPE(x)			(((x).val >> 1) & 0x3f)
-#define SWP_OFFSET(x)			((x).val >> 8)
-#define SWP_ENTRY(type, offset)		((swp_entry_t) { ((type) << 1) | ((offset) << 8) })
-#define pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
-#define swp_entry_to_pte(x)		((pte_t) { (x).val })
+/*
+ * NOTE: We should set ZEROs at the position of _PAGE_PRESENT
+ *       and _PAGE_PROTONOE bits
+ */
+#define SWP_TYPE(x)		((x).val & 0xff)
+#define SWP_OFFSET(x)		((x).val >> 10)
+#define SWP_ENTRY(type, offset)	((swp_entry_t) { (type) | ((offset) << 10) })
+#define pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
+#define swp_entry_to_pte(x)	((pte_t) { (x).val })
 
 #define module_map      vmalloc
 #define module_unmap    vfree

