[PATCH] powerpc/mm: Merge various PTE bits and accessors definitions

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4 messages, 2 authors, 2009-03-02 · open the first message on its own page

[PATCH] powerpc/mm: Merge various PTE bits and accessors definitions

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2009-03-02 06:22:51

Now that they are almost identical, we can merge some of the definitions
related to the PTE format into common files.

This creates a new pte-common.h which is included by both 32 and 64-bit
right after the CPU specific pte-*.h file, and which defines some
bits to "default" values if they haven't been defined already, and
then provides a generic definition of most of the bit combinations
based on these and exposed to the rest of the kernel.

I also moved to the common pgtable.h most of the "small" accessors to the
PTE bits and modification helpers (pte_mk*). The actual accessors remain
in their separate files.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

 arch/powerpc/include/asm/pgtable-ppc32.h |  124 ---------------------
 arch/powerpc/include/asm/pgtable-ppc64.h |  130 ----------------------
 arch/powerpc/include/asm/pgtable.h       |   53 ++++++++-
 arch/powerpc/include/asm/pte-common.h    |  177 +++++++++++++++++++++++++++++++
 4 files changed, 229 insertions(+), 255 deletions(-)
--- linux-work.orig/arch/powerpc/include/asm/pgtable-ppc32.h	2009-03-02 16:11:50.000000000 +1100
+++ linux-work/arch/powerpc/include/asm/pgtable-ppc32.h	2009-03-02 16:12:50.000000000 +1100
@@ -97,94 +97,11 @@ extern int icache_44x_need_flush;
 #include <asm/pte-hash32.h>
 #endif
 
-/* If _PAGE_SPECIAL is defined, then we advertise our support for it */
-#ifdef _PAGE_SPECIAL
-#define __HAVE_ARCH_PTE_SPECIAL
-#endif
-
-/*
- * We define 2 sets of base prot bits, one for basic pages (ie,
- * cacheable kernel and user pages) and one for non cacheable
- * pages. We always set _PAGE_COHERENT when SMP is enabled or
- * the processor might need it for DMA coherency.
- */
-#if defined(CONFIG_SMP) || defined(CONFIG_PPC_STD_MMU)
-#define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_COHERENT)
-#else
-#define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED)
-#endif
-#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED)
-
-/* Permission masks used for kernel mappings */
-#define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
-#define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
-				 _PAGE_NO_CACHE)
-#define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
-				 _PAGE_NO_CACHE | _PAGE_GUARDED)
-#define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW | _PAGE_EXEC)
-#define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
-#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO | _PAGE_EXEC)
-
-#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
-	defined(CONFIG_KPROBES)
-/* We want the debuggers to be able to set breakpoints anywhere, so
- * don't write protect the kernel text */
-#define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
-#else
-#define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
-#endif
-
-#define PAGE_NONE	__pgprot(_PAGE_BASE)
-#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
-#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
-#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-
-/*
- * The PowerPC can only do execute protection on a segment (256MB) basis,
- * not on a page basis.  So we consider execute permission the same as read.
- * Also, write permissions imply read permissions.
- * This is the closest we can get..
- */
-#define __P000	PAGE_NONE
-#define __P001	PAGE_READONLY_X
-#define __P010	PAGE_COPY
-#define __P011	PAGE_COPY_X
-#define __P100	PAGE_READONLY
-#define __P101	PAGE_READONLY_X
-#define __P110	PAGE_COPY
-#define __P111	PAGE_COPY_X
-
-#define __S000	PAGE_NONE
-#define __S001	PAGE_READONLY_X
-#define __S010	PAGE_SHARED
-#define __S011	PAGE_SHARED_X
-#define __S100	PAGE_READONLY
-#define __S101	PAGE_READONLY_X
-#define __S110	PAGE_SHARED
-#define __S111	PAGE_SHARED_X
+/* And here we include common definitions */
+#include <asm/pte-common.h>
 
 #ifndef __ASSEMBLY__
-/* Make sure we get a link error if PMD_PAGE_SIZE is ever called on a
- * kernel without large page PMD support */
-extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
 
-/*
- * Conversions between PTE values and page frame numbers.
- */
-
-#define pte_pfn(x)		(pte_val(x) >> PTE_RPN_SHIFT)
-#define pte_page(x)		pfn_to_page(pte_pfn(x))
-
-#define pfn_pte(pfn, prot)	__pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |\
-					pgprot_val(prot))
-#define mk_pte(page, prot)	pfn_pte(page_to_pfn(page), prot)
-#endif /* __ASSEMBLY__ */
-
-#define pte_none(pte)		((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
-#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
 #define pte_clear(mm, addr, ptep) \
 	do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)
 
@@ -193,43 +110,6 @@ extern unsigned long bad_call_to_PMD_PAG
 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
 #define	pmd_clear(pmdp)		do { pmd_val(*(pmdp)) = 0; } while (0)
 
-#ifndef __ASSEMBLY__
-/*
- * The following only work if pte_present() is true.
- * Undefined behaviour if not..
- */
-static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_RW; }
-static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
-static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
-static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }
-static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
-
-static inline pte_t pte_wrprotect(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_RW | _PAGE_HWWRITE); return pte; }
-static inline pte_t pte_mkclean(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HWWRITE); return pte; }
-static inline pte_t pte_mkold(pte_t pte) {
-	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
-
-static inline pte_t pte_mkwrite(pte_t pte) {
-	pte_val(pte) |= _PAGE_RW; return pte; }
-static inline pte_t pte_mkdirty(pte_t pte) {
-	pte_val(pte) |= _PAGE_DIRTY; return pte; }
-static inline pte_t pte_mkyoung(pte_t pte) {
-	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
-static inline pte_t pte_mkspecial(pte_t pte) {
-	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
-static inline pgprot_t pte_pgprot(pte_t pte)
-{
-	return __pgprot(pte_val(pte) & PAGE_PROT_BITS);
-}
-
-static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
-{
-	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
-	return pte;
-}
-
 /*
  * When flushing the tlb entry for a page, we also need to flush the hash
  * table entry.  flush_hash_pages is assembler (for speed) in hashtable.S.
Index: linux-work/arch/powerpc/include/asm/pgtable-ppc64.h
===================================================================
--- linux-work.orig/arch/powerpc/include/asm/pgtable-ppc64.h	2009-03-02 16:11:50.000000000 +1100
+++ linux-work/arch/powerpc/include/asm/pgtable-ppc64.h	2009-03-02 16:12:50.000000000 +1100
@@ -80,80 +80,8 @@
  * Include the PTE bits definitions
  */
 #include <asm/pte-hash64.h>
+#include <asm/pte-common.h>
 
-/* Some other useful definitions */
-#define PTE_RPN_MAX	(1UL << (64 - PTE_RPN_SHIFT))
-#define PTE_RPN_MASK	(~((1UL<<PTE_RPN_SHIFT)-1))
-
-/* _PAGE_CHG_MASK masks of bits that are to be preserved accross
- * pgprot changes
- */
-#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
-                         _PAGE_ACCESSED | _PAGE_SPECIAL)
-
-#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE)
-#define _PAGE_BASE	(_PAGE_BASE_NC | _PAGE_COHERENT)
-
-
-/* Permission masks used to generate the __P and __S table,
- *
- * Note:__pgprot is defined in arch/powerpc/include/asm/page.h
- */
-#define PAGE_NONE	__pgprot(_PAGE_BASE)
-#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
-#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
-#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-
-/* Permission masks used for kernel mappings */
-#define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
-#define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
-				 _PAGE_NO_CACHE)
-#define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
-				 _PAGE_NO_CACHE | _PAGE_GUARDED)
-#define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW | _PAGE_EXEC)
-#define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
-#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO | _PAGE_EXEC)
-
-/* Protection bits for use by pte_pgprot() */
-#define PAGE_PROT_BITS	(_PAGE_GUARDED | _PAGE_COHERENT | \
-			 _PAGE_NO_CACHE | _PAGE_WRITETHRU |		\
-			 _PAGE_4K_PFN | _PAGE_USER | _PAGE_RW |		\
-			 _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_EXEC)
-
-
-/* We always have _PAGE_SPECIAL on 64 bit */
-#define __HAVE_ARCH_PTE_SPECIAL
-
-
-/*
- * POWER4 and newer have per page execute protection, older chips can only
- * do this on a segment (256MB) basis.
- *
- * Also, write permissions imply read permissions.
- * This is the closest we can get..
- *
- * Note due to the way vm flags are laid out, the bits are XWR
- */
-#define __P000	PAGE_NONE
-#define __P001	PAGE_READONLY
-#define __P010	PAGE_COPY
-#define __P011	PAGE_COPY
-#define __P100	PAGE_READONLY_X
-#define __P101	PAGE_READONLY_X
-#define __P110	PAGE_COPY_X
-#define __P111	PAGE_COPY_X
-
-#define __S000	PAGE_NONE
-#define __S001	PAGE_READONLY
-#define __S010	PAGE_SHARED
-#define __S011	PAGE_SHARED
-#define __S100	PAGE_READONLY_X
-#define __S101	PAGE_READONLY_X
-#define __S110	PAGE_SHARED_X
-#define __S111	PAGE_SHARED_X
 
 #ifdef CONFIG_PPC_MM_SLICES
 #define HAVE_ARCH_UNMAPPED_AREA
@@ -194,34 +122,8 @@
 #endif /* __real_pte */
 
 
-/*
- * Conversion functions: convert a page and protection to a page entry,
- * and a page entry and page directory to the page they refer to.
- *
- * mk_pte takes a (struct page *) as input
- */
-#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
-
-static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
-{
-	pte_t pte;
-
-
-	pte_val(pte) = (pfn << PTE_RPN_SHIFT) | pgprot_val(pgprot);
-	return pte;
-}
-
-#define pte_modify(_pte, newprot) \
-  (__pte((pte_val(_pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)))
-
-#define pte_none(pte)		((pte_val(pte) & ~_PAGE_HPTEFLAGS) == 0)
-#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
-
 /* pte_clear moved to later in this file */
 
-#define pte_pfn(x)		((unsigned long)((pte_val(x)>>PTE_RPN_SHIFT)))
-#define pte_page(x)		pfn_to_page(pte_pfn(x))
-
 #define PMD_BAD_BITS		(PTE_TABLE_SIZE-1)
 #define PUD_BAD_BITS		(PMD_TABLE_SIZE-1)
 
@@ -269,36 +171,6 @@ static inline pte_t pfn_pte(unsigned lon
 /* This now only contains the vmalloc pages */
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
-/*
- * The following only work if pte_present() is true.
- * Undefined behaviour if not..
- */
-static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW;}
-static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY;}
-static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED;}
-static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE;}
-static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
-
-static inline pte_t pte_wrprotect(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_RW); return pte; }
-static inline pte_t pte_mkclean(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_DIRTY); return pte; }
-static inline pte_t pte_mkold(pte_t pte) {
-	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
-static inline pte_t pte_mkwrite(pte_t pte) {
-	pte_val(pte) |= _PAGE_RW; return pte; }
-static inline pte_t pte_mkdirty(pte_t pte) {
-	pte_val(pte) |= _PAGE_DIRTY; return pte; }
-static inline pte_t pte_mkyoung(pte_t pte) {
-	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
-static inline pte_t pte_mkhuge(pte_t pte) {
-	return pte; }
-static inline pte_t pte_mkspecial(pte_t pte) {
-	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
-static inline pgprot_t pte_pgprot(pte_t pte)
-{
-	return __pgprot(pte_val(pte) & PAGE_PROT_BITS);
-}
 
 /* Atomic PTE updates */
 static inline unsigned long pte_update(struct mm_struct *mm,
Index: linux-work/arch/powerpc/include/asm/pgtable.h
===================================================================
--- linux-work.orig/arch/powerpc/include/asm/pgtable.h	2009-03-02 16:11:50.000000000 +1100
+++ linux-work/arch/powerpc/include/asm/pgtable.h	2009-03-02 16:17:52.000000000 +1100
@@ -25,12 +25,57 @@ static inline void assert_pte_locked(str
 #  include <asm/pgtable-ppc32.h>
 #endif
 
-/* Special mapping for AGP */
-#define PAGE_AGP	(PAGE_KERNEL_NC)
-#define HAVE_PAGE_AGP
-
 #ifndef __ASSEMBLY__
 
+/* Generic accessors to PTE bits */
+static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_RW; }
+static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
+static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
+static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }
+static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
+static inline int pte_present(pte_t pte)	{ return pte_val(pte) & _PAGE_PRESENT; }
+static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
+static inline pgprot_t pte_pgprot(pte_t pte)	{ return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }
+
+/* Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ *
+ * Even if PTEs can be unsigned long long, a PFN is always an unsigned
+ * long for now.
+ */
+static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) {
+	return __pte((pfn << PTE_RPN_SHIFT) | pgprot_val(pgprot)); }
+static inline unsigned long pte_pfn(pte_t pte)	{
+	return pte_val(pte) >> PTE_RPN_SHIFT; }
+
+/* Keep these as a macros to avoid include dependency mess */
+#define pte_page(x)		pfn_to_page(pte_pfn(x))
+#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
+
+/* Generic modifiers for PTE bits */
+static inline pte_t pte_wrprotect(pte_t pte) {
+	pte_val(pte) &= ~(_PAGE_RW | _PAGE_HWWRITE); return pte; }
+static inline pte_t pte_mkclean(pte_t pte) {
+	pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HWWRITE); return pte; }
+static inline pte_t pte_mkold(pte_t pte) {
+	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
+static inline pte_t pte_mkwrite(pte_t pte) {
+	pte_val(pte) |= _PAGE_RW; return pte; }
+static inline pte_t pte_mkdirty(pte_t pte) {
+	pte_val(pte) |= _PAGE_DIRTY; return pte; }
+static inline pte_t pte_mkyoung(pte_t pte) {
+	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
+static inline pte_t pte_mkspecial(pte_t pte) {
+	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
+static inline pte_t pte_mkhuge(pte_t pte) {
+	return pte; }
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
+	return pte;
+}
+
+
 /* Insert a PTE, top-level function is out of line. It uses an inline
  * low level function in the respective pgtable-* files
  */
Index: linux-work/arch/powerpc/include/asm/pte-common.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-work/arch/powerpc/include/asm/pte-common.h	2009-03-02 16:20:02.000000000 +1100
@@ -0,0 +1,177 @@
+/* Included from asm/pgtable-*.h only ! */
+
+/*
+ * Some bits are only used on some cpu families... Make sure that all
+ * the undefined gets a sensible default
+ */
+#ifndef _PAGE_HASHPTE
+#define _PAGE_HASHPTE	0
+#endif
+#ifndef _PAGE_SHARED
+#define _PAGE_SHARED	0
+#endif
+#ifndef _PAGE_HWWRITE
+#define _PAGE_HWWRITE	0
+#endif
+#ifndef _PAGE_HWEXEC
+#define _PAGE_HWEXEC	0
+#endif
+#ifndef _PAGE_EXEC
+#define _PAGE_EXEC	0
+#endif
+#ifndef _PAGE_ENDIAN
+#define _PAGE_ENDIAN	0
+#endif
+#ifndef _PAGE_COHERENT
+#define _PAGE_COHERENT	0
+#endif
+#ifndef _PAGE_WRITETHRU
+#define _PAGE_WRITETHRU	0
+#endif
+#ifndef _PAGE_SPECIAL
+#define _PAGE_SPECIAL	0
+#endif
+#ifndef _PAGE_4K_PFN
+#define _PAGE_4K_PFN		0
+#endif
+#ifndef _PAGE_PSIZE
+#define _PAGE_PSIZE		0
+#endif
+#ifndef _PMD_PRESENT_MASK
+#define _PMD_PRESENT_MASK	_PMD_PRESENT
+#endif
+#ifndef _PMD_SIZE
+#define _PMD_SIZE	0
+#define PMD_PAGE_SIZE(pmd)	bad_call_to_PMD_PAGE_SIZE()
+#endif
+#ifndef _PAGE_KERNEL_RO
+#define _PAGE_KERNEL_RO	0
+#endif
+#ifndef _PAGE_KERNEL_RW
+#define _PAGE_KERNEL_RW	(_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE)
+#endif
+#ifndef _PAGE_HPTEFLAGS
+#define _PAGE_HPTEFLAGS _PAGE_HASHPTE
+#endif
+#ifndef _PTE_NONE_MASK
+#define _PTE_NONE_MASK	_PAGE_HPTEFLAGS
+#endif
+
+/* Make sure we get a link error if PMD_PAGE_SIZE is ever called on a
+ * kernel without large page PMD support
+ */
+#ifndef __ASSEMBLY__
+extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
+#endif /* __ASSEMBLY__ */
+
+/* Location of the PFN in the PTE. Most 32-bit platforms use the same
+ * as _PAGE_SHIFT here (ie, naturally aligned).
+ * Platform who don't just pre-define the value so we don't override it here
+ */
+#ifndef PTE_RPN_SHIFT
+#define PTE_RPN_SHIFT	(PAGE_SHIFT)
+#endif
+
+/* The mask convered by the RPN must be a ULL on 32-bit platforms with
+ * 64-bit PTEs
+ */
+#if defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT)
+#define PTE_RPN_MAX	(1ULL << (64 - PTE_RPN_SHIFT))
+#define PTE_RPN_MASK	(~((1ULL<<PTE_RPN_SHIFT)-1))
+#else
+#define PTE_RPN_MAX	(1UL << (32 - PTE_RPN_SHIFT))
+#define PTE_RPN_MASK	(~((1UL<<PTE_RPN_SHIFT)-1))
+#endif
+
+/* _PAGE_CHG_MASK masks of bits that are to be preserved accross
+ * pgprot changes
+ */
+#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
+                         _PAGE_ACCESSED | _PAGE_SPECIAL)
+
+/* Mask of bits returned by pte_pgprot() */
+#define PAGE_PROT_BITS	(_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \
+			 _PAGE_WRITETHRU | _PAGE_ENDIAN | _PAGE_4K_PFN | \
+			 _PAGE_USER | _PAGE_ACCESSED | \
+			 _PAGE_RW | _PAGE_HWWRITE | _PAGE_DIRTY | \
+			 _PAGE_EXEC | _PAGE_HWEXEC)
+
+/*
+ * We define 2 sets of base prot bits, one for basic pages (ie,
+ * cacheable kernel and user pages) and one for non cacheable
+ * pages. We always set _PAGE_COHERENT when SMP is enabled or
+ * the processor might need it for DMA coherency.
+ */
+#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE)
+#if defined(CONFIG_SMP) || defined(CONFIG_PPC_STD_MMU)
+#define _PAGE_BASE	(_PAGE_BASE_NC | _PAGE_COHERENT)
+#else
+#define _PAGE_BASE	(_PAGE_BASE_NC)
+#endif
+
+/* Permission masks used to generate the __P and __S table,
+ *
+ * Note:__pgprot is defined in arch/powerpc/include/asm/page.h
+ *
+ * Write permissions imply read permissions for now (we could make write-only
+ * pages on BookE but we don't bother for now). Execute permission control is
+ * possible on platforms that define _PAGE_EXEC
+ *
+ * Note due to the way vm flags are laid out, the bits are XWR
+ */
+#define PAGE_NONE	__pgprot(_PAGE_BASE)
+#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
+#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
+#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
+#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
+#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
+#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
+
+#define __P000	PAGE_NONE
+#define __P001	PAGE_READONLY
+#define __P010	PAGE_COPY
+#define __P011	PAGE_COPY
+#define __P100	PAGE_READONLY_X
+#define __P101	PAGE_READONLY_X
+#define __P110	PAGE_COPY_X
+#define __P111	PAGE_COPY_X
+
+#define __S000	PAGE_NONE
+#define __S001	PAGE_READONLY
+#define __S010	PAGE_SHARED
+#define __S011	PAGE_SHARED
+#define __S100	PAGE_READONLY_X
+#define __S101	PAGE_READONLY_X
+#define __S110	PAGE_SHARED_X
+#define __S111	PAGE_SHARED_X
+
+/* Permission masks used for kernel mappings */
+#define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
+#define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
+				 _PAGE_NO_CACHE)
+#define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
+				 _PAGE_NO_CACHE | _PAGE_GUARDED)
+#define PAGE_KERNEL_X	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW | _PAGE_EXEC)
+#define PAGE_KERNEL_RO	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
+#define PAGE_KERNEL_ROX	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RO | _PAGE_EXEC)
+
+/* Protection used for kernel text. We want the debuggers to be able to
+ * set breakpoints anywhere, so don't write protect the kernel text
+ * on platforms where such control is possible.
+ */
+#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
+	defined(CONFIG_KPROBES)
+#define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
+#else
+#define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
+#endif
+
+/* Advertise special mapping type for AGP */
+#define PAGE_AGP	(PAGE_KERNEL_NC)
+#define HAVE_PAGE_AGP
+
+/* Advertise support for _PAGE_SPECIAL */
+#ifdef _PAGE_SPECIAL
+#define __HAVE_ARCH_PTE_SPECIAL
+#endif
+

Re: [PATCH] powerpc/mm: Merge various PTE bits and accessors definitions

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2009-03-02 06:27:21

On Mon, 2009-03-02 at 17:22 +1100, Benjamin Herrenschmidt wrote:
Now that they are almost identical, we can merge some of the definitions
related to the PTE format into common files.
Hrm... some of the last 2 patches got mangled with each other ...
applying both works fine but don't try to build with only one of them.

I'll try to fix that up tomorrow.

Ben.
quoted hunk
This creates a new pte-common.h which is included by both 32 and 64-bit
right after the CPU specific pte-*.h file, and which defines some
bits to "default" values if they haven't been defined already, and
then provides a generic definition of most of the bit combinations
based on these and exposed to the rest of the kernel.

I also moved to the common pgtable.h most of the "small" accessors to the
PTE bits and modification helpers (pte_mk*). The actual accessors remain
in their separate files.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

 arch/powerpc/include/asm/pgtable-ppc32.h |  124 ---------------------
 arch/powerpc/include/asm/pgtable-ppc64.h |  130 ----------------------
 arch/powerpc/include/asm/pgtable.h       |   53 ++++++++-
 arch/powerpc/include/asm/pte-common.h    |  177 +++++++++++++++++++++++++++++++
 4 files changed, 229 insertions(+), 255 deletions(-)
--- linux-work.orig/arch/powerpc/include/asm/pgtable-ppc32.h	2009-03-02 16:11:50.000000000 +1100
+++ linux-work/arch/powerpc/include/asm/pgtable-ppc32.h	2009-03-02 16:12:50.000000000 +1100
@@ -97,94 +97,11 @@ extern int icache_44x_need_flush;
 #include <asm/pte-hash32.h>
 #endif
 
-/* If _PAGE_SPECIAL is defined, then we advertise our support for it */
-#ifdef _PAGE_SPECIAL
-#define __HAVE_ARCH_PTE_SPECIAL
-#endif
-
-/*
- * We define 2 sets of base prot bits, one for basic pages (ie,
- * cacheable kernel and user pages) and one for non cacheable
- * pages. We always set _PAGE_COHERENT when SMP is enabled or
- * the processor might need it for DMA coherency.
- */
-#if defined(CONFIG_SMP) || defined(CONFIG_PPC_STD_MMU)
-#define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_COHERENT)
-#else
-#define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED)
-#endif
-#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED)
-
-/* Permission masks used for kernel mappings */
-#define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
-#define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
-				 _PAGE_NO_CACHE)
-#define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
-				 _PAGE_NO_CACHE | _PAGE_GUARDED)
-#define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW | _PAGE_EXEC)
-#define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
-#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO | _PAGE_EXEC)
-
-#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
-	defined(CONFIG_KPROBES)
-/* We want the debuggers to be able to set breakpoints anywhere, so
- * don't write protect the kernel text */
-#define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
-#else
-#define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
-#endif
-
-#define PAGE_NONE	__pgprot(_PAGE_BASE)
-#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
-#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
-#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-
-/*
- * The PowerPC can only do execute protection on a segment (256MB) basis,
- * not on a page basis.  So we consider execute permission the same as read.
- * Also, write permissions imply read permissions.
- * This is the closest we can get..
- */
-#define __P000	PAGE_NONE
-#define __P001	PAGE_READONLY_X
-#define __P010	PAGE_COPY
-#define __P011	PAGE_COPY_X
-#define __P100	PAGE_READONLY
-#define __P101	PAGE_READONLY_X
-#define __P110	PAGE_COPY
-#define __P111	PAGE_COPY_X
-
-#define __S000	PAGE_NONE
-#define __S001	PAGE_READONLY_X
-#define __S010	PAGE_SHARED
-#define __S011	PAGE_SHARED_X
-#define __S100	PAGE_READONLY
-#define __S101	PAGE_READONLY_X
-#define __S110	PAGE_SHARED
-#define __S111	PAGE_SHARED_X
+/* And here we include common definitions */
+#include <asm/pte-common.h>
 
 #ifndef __ASSEMBLY__
-/* Make sure we get a link error if PMD_PAGE_SIZE is ever called on a
- * kernel without large page PMD support */
-extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
 
-/*
- * Conversions between PTE values and page frame numbers.
- */
-
-#define pte_pfn(x)		(pte_val(x) >> PTE_RPN_SHIFT)
-#define pte_page(x)		pfn_to_page(pte_pfn(x))
-
-#define pfn_pte(pfn, prot)	__pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |\
-					pgprot_val(prot))
-#define mk_pte(page, prot)	pfn_pte(page_to_pfn(page), prot)
-#endif /* __ASSEMBLY__ */
-
-#define pte_none(pte)		((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
-#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
 #define pte_clear(mm, addr, ptep) \
 	do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)
 
@@ -193,43 +110,6 @@ extern unsigned long bad_call_to_PMD_PAG
 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
 #define	pmd_clear(pmdp)		do { pmd_val(*(pmdp)) = 0; } while (0)
 
-#ifndef __ASSEMBLY__
-/*
- * The following only work if pte_present() is true.
- * Undefined behaviour if not..
- */
-static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_RW; }
-static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
-static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
-static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }
-static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
-
-static inline pte_t pte_wrprotect(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_RW | _PAGE_HWWRITE); return pte; }
-static inline pte_t pte_mkclean(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HWWRITE); return pte; }
-static inline pte_t pte_mkold(pte_t pte) {
-	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
-
-static inline pte_t pte_mkwrite(pte_t pte) {
-	pte_val(pte) |= _PAGE_RW; return pte; }
-static inline pte_t pte_mkdirty(pte_t pte) {
-	pte_val(pte) |= _PAGE_DIRTY; return pte; }
-static inline pte_t pte_mkyoung(pte_t pte) {
-	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
-static inline pte_t pte_mkspecial(pte_t pte) {
-	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
-static inline pgprot_t pte_pgprot(pte_t pte)
-{
-	return __pgprot(pte_val(pte) & PAGE_PROT_BITS);
-}
-
-static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
-{
-	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
-	return pte;
-}
-
 /*
  * When flushing the tlb entry for a page, we also need to flush the hash
  * table entry.  flush_hash_pages is assembler (for speed) in hashtable.S.
Index: linux-work/arch/powerpc/include/asm/pgtable-ppc64.h
===================================================================
--- linux-work.orig/arch/powerpc/include/asm/pgtable-ppc64.h	2009-03-02 16:11:50.000000000 +1100
+++ linux-work/arch/powerpc/include/asm/pgtable-ppc64.h	2009-03-02 16:12:50.000000000 +1100
@@ -80,80 +80,8 @@
  * Include the PTE bits definitions
  */
 #include <asm/pte-hash64.h>
+#include <asm/pte-common.h>
 
-/* Some other useful definitions */
-#define PTE_RPN_MAX	(1UL << (64 - PTE_RPN_SHIFT))
-#define PTE_RPN_MASK	(~((1UL<<PTE_RPN_SHIFT)-1))
-
-/* _PAGE_CHG_MASK masks of bits that are to be preserved accross
- * pgprot changes
- */
-#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
-                         _PAGE_ACCESSED | _PAGE_SPECIAL)
-
-#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE)
-#define _PAGE_BASE	(_PAGE_BASE_NC | _PAGE_COHERENT)
-
-
-/* Permission masks used to generate the __P and __S table,
- *
- * Note:__pgprot is defined in arch/powerpc/include/asm/page.h
- */
-#define PAGE_NONE	__pgprot(_PAGE_BASE)
-#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
-#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
-#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-
-/* Permission masks used for kernel mappings */
-#define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
-#define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
-				 _PAGE_NO_CACHE)
-#define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
-				 _PAGE_NO_CACHE | _PAGE_GUARDED)
-#define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW | _PAGE_EXEC)
-#define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
-#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO | _PAGE_EXEC)
-
-/* Protection bits for use by pte_pgprot() */
-#define PAGE_PROT_BITS	(_PAGE_GUARDED | _PAGE_COHERENT | \
-			 _PAGE_NO_CACHE | _PAGE_WRITETHRU |		\
-			 _PAGE_4K_PFN | _PAGE_USER | _PAGE_RW |		\
-			 _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_EXEC)
-
-
-/* We always have _PAGE_SPECIAL on 64 bit */
-#define __HAVE_ARCH_PTE_SPECIAL
-
-
-/*
- * POWER4 and newer have per page execute protection, older chips can only
- * do this on a segment (256MB) basis.
- *
- * Also, write permissions imply read permissions.
- * This is the closest we can get..
- *
- * Note due to the way vm flags are laid out, the bits are XWR
- */
-#define __P000	PAGE_NONE
-#define __P001	PAGE_READONLY
-#define __P010	PAGE_COPY
-#define __P011	PAGE_COPY
-#define __P100	PAGE_READONLY_X
-#define __P101	PAGE_READONLY_X
-#define __P110	PAGE_COPY_X
-#define __P111	PAGE_COPY_X
-
-#define __S000	PAGE_NONE
-#define __S001	PAGE_READONLY
-#define __S010	PAGE_SHARED
-#define __S011	PAGE_SHARED
-#define __S100	PAGE_READONLY_X
-#define __S101	PAGE_READONLY_X
-#define __S110	PAGE_SHARED_X
-#define __S111	PAGE_SHARED_X
 
 #ifdef CONFIG_PPC_MM_SLICES
 #define HAVE_ARCH_UNMAPPED_AREA
@@ -194,34 +122,8 @@
 #endif /* __real_pte */
 

-/*
- * Conversion functions: convert a page and protection to a page entry,
- * and a page entry and page directory to the page they refer to.
- *
- * mk_pte takes a (struct page *) as input
- */
-#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
-
-static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
-{
-	pte_t pte;
-
-
-	pte_val(pte) = (pfn << PTE_RPN_SHIFT) | pgprot_val(pgprot);
-	return pte;
-}
-
-#define pte_modify(_pte, newprot) \
-  (__pte((pte_val(_pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)))
-
-#define pte_none(pte)		((pte_val(pte) & ~_PAGE_HPTEFLAGS) == 0)
-#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
-
 /* pte_clear moved to later in this file */
 
-#define pte_pfn(x)		((unsigned long)((pte_val(x)>>PTE_RPN_SHIFT)))
-#define pte_page(x)		pfn_to_page(pte_pfn(x))
-
 #define PMD_BAD_BITS		(PTE_TABLE_SIZE-1)
 #define PUD_BAD_BITS		(PMD_TABLE_SIZE-1)
 
@@ -269,36 +171,6 @@ static inline pte_t pfn_pte(unsigned lon
 /* This now only contains the vmalloc pages */
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
-/*
- * The following only work if pte_present() is true.
- * Undefined behaviour if not..
- */
-static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW;}
-static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY;}
-static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED;}
-static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE;}
-static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
-
-static inline pte_t pte_wrprotect(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_RW); return pte; }
-static inline pte_t pte_mkclean(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_DIRTY); return pte; }
-static inline pte_t pte_mkold(pte_t pte) {
-	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
-static inline pte_t pte_mkwrite(pte_t pte) {
-	pte_val(pte) |= _PAGE_RW; return pte; }
-static inline pte_t pte_mkdirty(pte_t pte) {
-	pte_val(pte) |= _PAGE_DIRTY; return pte; }
-static inline pte_t pte_mkyoung(pte_t pte) {
-	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
-static inline pte_t pte_mkhuge(pte_t pte) {
-	return pte; }
-static inline pte_t pte_mkspecial(pte_t pte) {
-	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
-static inline pgprot_t pte_pgprot(pte_t pte)
-{
-	return __pgprot(pte_val(pte) & PAGE_PROT_BITS);
-}
 
 /* Atomic PTE updates */
 static inline unsigned long pte_update(struct mm_struct *mm,
Index: linux-work/arch/powerpc/include/asm/pgtable.h
===================================================================
--- linux-work.orig/arch/powerpc/include/asm/pgtable.h	2009-03-02 16:11:50.000000000 +1100
+++ linux-work/arch/powerpc/include/asm/pgtable.h	2009-03-02 16:17:52.000000000 +1100
@@ -25,12 +25,57 @@ static inline void assert_pte_locked(str
 #  include <asm/pgtable-ppc32.h>
 #endif
 
-/* Special mapping for AGP */
-#define PAGE_AGP	(PAGE_KERNEL_NC)
-#define HAVE_PAGE_AGP
-
 #ifndef __ASSEMBLY__
 
+/* Generic accessors to PTE bits */
+static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_RW; }
+static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
+static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
+static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }
+static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
+static inline int pte_present(pte_t pte)	{ return pte_val(pte) & _PAGE_PRESENT; }
+static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
+static inline pgprot_t pte_pgprot(pte_t pte)	{ return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }
+
+/* Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ *
+ * Even if PTEs can be unsigned long long, a PFN is always an unsigned
+ * long for now.
+ */
+static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) {
+	return __pte((pfn << PTE_RPN_SHIFT) | pgprot_val(pgprot)); }
+static inline unsigned long pte_pfn(pte_t pte)	{
+	return pte_val(pte) >> PTE_RPN_SHIFT; }
+
+/* Keep these as a macros to avoid include dependency mess */
+#define pte_page(x)		pfn_to_page(pte_pfn(x))
+#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
+
+/* Generic modifiers for PTE bits */
+static inline pte_t pte_wrprotect(pte_t pte) {
+	pte_val(pte) &= ~(_PAGE_RW | _PAGE_HWWRITE); return pte; }
+static inline pte_t pte_mkclean(pte_t pte) {
+	pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HWWRITE); return pte; }
+static inline pte_t pte_mkold(pte_t pte) {
+	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
+static inline pte_t pte_mkwrite(pte_t pte) {
+	pte_val(pte) |= _PAGE_RW; return pte; }
+static inline pte_t pte_mkdirty(pte_t pte) {
+	pte_val(pte) |= _PAGE_DIRTY; return pte; }
+static inline pte_t pte_mkyoung(pte_t pte) {
+	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
+static inline pte_t pte_mkspecial(pte_t pte) {
+	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
+static inline pte_t pte_mkhuge(pte_t pte) {
+	return pte; }
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
+	return pte;
+}
+
+
 /* Insert a PTE, top-level function is out of line. It uses an inline
  * low level function in the respective pgtable-* files
  */
Index: linux-work/arch/powerpc/include/asm/pte-common.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-work/arch/powerpc/include/asm/pte-common.h	2009-03-02 16:20:02.000000000 +1100
@@ -0,0 +1,177 @@
+/* Included from asm/pgtable-*.h only ! */
+
+/*
+ * Some bits are only used on some cpu families... Make sure that all
+ * the undefined gets a sensible default
+ */
+#ifndef _PAGE_HASHPTE
+#define _PAGE_HASHPTE	0
+#endif
+#ifndef _PAGE_SHARED
+#define _PAGE_SHARED	0
+#endif
+#ifndef _PAGE_HWWRITE
+#define _PAGE_HWWRITE	0
+#endif
+#ifndef _PAGE_HWEXEC
+#define _PAGE_HWEXEC	0
+#endif
+#ifndef _PAGE_EXEC
+#define _PAGE_EXEC	0
+#endif
+#ifndef _PAGE_ENDIAN
+#define _PAGE_ENDIAN	0
+#endif
+#ifndef _PAGE_COHERENT
+#define _PAGE_COHERENT	0
+#endif
+#ifndef _PAGE_WRITETHRU
+#define _PAGE_WRITETHRU	0
+#endif
+#ifndef _PAGE_SPECIAL
+#define _PAGE_SPECIAL	0
+#endif
+#ifndef _PAGE_4K_PFN
+#define _PAGE_4K_PFN		0
+#endif
+#ifndef _PAGE_PSIZE
+#define _PAGE_PSIZE		0
+#endif
+#ifndef _PMD_PRESENT_MASK
+#define _PMD_PRESENT_MASK	_PMD_PRESENT
+#endif
+#ifndef _PMD_SIZE
+#define _PMD_SIZE	0
+#define PMD_PAGE_SIZE(pmd)	bad_call_to_PMD_PAGE_SIZE()
+#endif
+#ifndef _PAGE_KERNEL_RO
+#define _PAGE_KERNEL_RO	0
+#endif
+#ifndef _PAGE_KERNEL_RW
+#define _PAGE_KERNEL_RW	(_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE)
+#endif
+#ifndef _PAGE_HPTEFLAGS
+#define _PAGE_HPTEFLAGS _PAGE_HASHPTE
+#endif
+#ifndef _PTE_NONE_MASK
+#define _PTE_NONE_MASK	_PAGE_HPTEFLAGS
+#endif
+
+/* Make sure we get a link error if PMD_PAGE_SIZE is ever called on a
+ * kernel without large page PMD support
+ */
+#ifndef __ASSEMBLY__
+extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
+#endif /* __ASSEMBLY__ */
+
+/* Location of the PFN in the PTE. Most 32-bit platforms use the same
+ * as _PAGE_SHIFT here (ie, naturally aligned).
+ * Platform who don't just pre-define the value so we don't override it here
+ */
+#ifndef PTE_RPN_SHIFT
+#define PTE_RPN_SHIFT	(PAGE_SHIFT)
+#endif
+
+/* The mask convered by the RPN must be a ULL on 32-bit platforms with
+ * 64-bit PTEs
+ */
+#if defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT)
+#define PTE_RPN_MAX	(1ULL << (64 - PTE_RPN_SHIFT))
+#define PTE_RPN_MASK	(~((1ULL<<PTE_RPN_SHIFT)-1))
+#else
+#define PTE_RPN_MAX	(1UL << (32 - PTE_RPN_SHIFT))
+#define PTE_RPN_MASK	(~((1UL<<PTE_RPN_SHIFT)-1))
+#endif
+
+/* _PAGE_CHG_MASK masks of bits that are to be preserved accross
+ * pgprot changes
+ */
+#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
+                         _PAGE_ACCESSED | _PAGE_SPECIAL)
+
+/* Mask of bits returned by pte_pgprot() */
+#define PAGE_PROT_BITS	(_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \
+			 _PAGE_WRITETHRU | _PAGE_ENDIAN | _PAGE_4K_PFN | \
+			 _PAGE_USER | _PAGE_ACCESSED | \
+			 _PAGE_RW | _PAGE_HWWRITE | _PAGE_DIRTY | \
+			 _PAGE_EXEC | _PAGE_HWEXEC)
+
+/*
+ * We define 2 sets of base prot bits, one for basic pages (ie,
+ * cacheable kernel and user pages) and one for non cacheable
+ * pages. We always set _PAGE_COHERENT when SMP is enabled or
+ * the processor might need it for DMA coherency.
+ */
+#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE)
+#if defined(CONFIG_SMP) || defined(CONFIG_PPC_STD_MMU)
+#define _PAGE_BASE	(_PAGE_BASE_NC | _PAGE_COHERENT)
+#else
+#define _PAGE_BASE	(_PAGE_BASE_NC)
+#endif
+
+/* Permission masks used to generate the __P and __S table,
+ *
+ * Note:__pgprot is defined in arch/powerpc/include/asm/page.h
+ *
+ * Write permissions imply read permissions for now (we could make write-only
+ * pages on BookE but we don't bother for now). Execute permission control is
+ * possible on platforms that define _PAGE_EXEC
+ *
+ * Note due to the way vm flags are laid out, the bits are XWR
+ */
+#define PAGE_NONE	__pgprot(_PAGE_BASE)
+#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
+#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
+#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
+#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
+#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
+#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
+
+#define __P000	PAGE_NONE
+#define __P001	PAGE_READONLY
+#define __P010	PAGE_COPY
+#define __P011	PAGE_COPY
+#define __P100	PAGE_READONLY_X
+#define __P101	PAGE_READONLY_X
+#define __P110	PAGE_COPY_X
+#define __P111	PAGE_COPY_X
+
+#define __S000	PAGE_NONE
+#define __S001	PAGE_READONLY
+#define __S010	PAGE_SHARED
+#define __S011	PAGE_SHARED
+#define __S100	PAGE_READONLY_X
+#define __S101	PAGE_READONLY_X
+#define __S110	PAGE_SHARED_X
+#define __S111	PAGE_SHARED_X
+
+/* Permission masks used for kernel mappings */
+#define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
+#define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
+				 _PAGE_NO_CACHE)
+#define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
+				 _PAGE_NO_CACHE | _PAGE_GUARDED)
+#define PAGE_KERNEL_X	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW | _PAGE_EXEC)
+#define PAGE_KERNEL_RO	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
+#define PAGE_KERNEL_ROX	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RO | _PAGE_EXEC)
+
+/* Protection used for kernel text. We want the debuggers to be able to
+ * set breakpoints anywhere, so don't write protect the kernel text
+ * on platforms where such control is possible.
+ */
+#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
+	defined(CONFIG_KPROBES)
+#define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
+#else
+#define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
+#endif
+
+/* Advertise special mapping type for AGP */
+#define PAGE_AGP	(PAGE_KERNEL_NC)
+#define HAVE_PAGE_AGP
+
+/* Advertise support for _PAGE_SPECIAL */
+#ifdef _PAGE_SPECIAL
+#define __HAVE_ARCH_PTE_SPECIAL
+#endif
+
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Re: [PATCH] powerpc/mm: Merge various PTE bits and accessors definitions

From: Michael Ellerman <hidden>
Date: 2009-03-02 07:38:01

On Mon, 2009-03-02 at 17:22 +1100, Benjamin Herrenschmidt wrote:
Now that they are almost identical, we can merge some of the definitions
related to the PTE format into common files.
<snip>
+/* Protection used for kernel text. We want the debuggers to be able to
+ * set breakpoints anywhere, so don't write protect the kernel text
+ * on platforms where such control is possible.
+ */
+#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
+	defined(CONFIG_KPROBES)
+#define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
+#else
+#define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
+#endif
What about FTRACE? ∞TRACE etc.

cheers

-- 
Michael Ellerman
OzLabs, IBM Australia Development Lab

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person

Re: [PATCH] powerpc/mm: Merge various PTE bits and accessors definitions

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2009-03-02 07:58:02

On Mon, 2009-03-02 at 18:38 +1100, Michael Ellerman wrote:
On Mon, 2009-03-02 at 17:22 +1100, Benjamin Herrenschmidt wrote:
quoted
Now that they are almost identical, we can merge some of the definitions
related to the PTE format into common files.
<snip>
quoted
+/* Protection used for kernel text. We want the debuggers to be able to
+ * set breakpoints anywhere, so don't write protect the kernel text
+ * on platforms where such control is possible.
+ */
+#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
+	defined(CONFIG_KPROBES)
+#define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
+#else
+#define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
+#endif
What about FTRACE? ∞TRACE etc.
Well, I'm just moving those bits around from pgtable-ppc32.h (ie, only
ppc32 uses PAGE_KERNEL_TEXT for now anyway).

Note also that as it is, with ppc32 hash, we don't honor the read-only
restriction on the BAT mapping anyway.

So yes, there's room for fixing things but that isn't what this patch
does.

Cheers,
Ben.
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