[SPARC32]: Make PAGE_SHARED a read-mostly variable.

same scheme as for sparc64, same rationale
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/mm/init.c

@@ -308,6 +308,9 @@ extern void sun4c_paging_init(void);
 extern void srmmu_paging_init(void);
 extern void device_scan(void);
 
+pgprot_t PAGE_SHARED __read_mostly;
+EXPORT_SYMBOL(PAGE_SHARED);
+
 void __init paging_init(void)
 {
 	switch(sparc_cpu_model) {

arch/sparc/mm/srmmu.c

@@ -2154,7 +2154,7 @@ void __init ld_mmu_srmmu(void)
 	BTFIXUPSET_SIMM13(ptrs_per_pgd, SRMMU_PTRS_PER_PGD);
 
 	BTFIXUPSET_INT(page_none, pgprot_val(SRMMU_PAGE_NONE));
-	BTFIXUPSET_INT(page_shared, pgprot_val(SRMMU_PAGE_SHARED));
+	PAGE_SHARED = pgprot_val(SRMMU_PAGE_SHARED);
 	BTFIXUPSET_INT(page_copy, pgprot_val(SRMMU_PAGE_COPY));
 	BTFIXUPSET_INT(page_readonly, pgprot_val(SRMMU_PAGE_RDONLY));
 	BTFIXUPSET_INT(page_kernel, pgprot_val(SRMMU_PAGE_KERNEL));

arch/sparc/mm/sun4c.c

@@ -2155,7 +2155,7 @@ void __init ld_mmu_sun4c(void)
 	BTFIXUPSET_SIMM13(user_ptrs_per_pgd, KERNBASE / SUN4C_PGDIR_SIZE);
 
 	BTFIXUPSET_INT(page_none, pgprot_val(SUN4C_PAGE_NONE));
-	BTFIXUPSET_INT(page_shared, pgprot_val(SUN4C_PAGE_SHARED));
+	PAGE_SHARED = pgprot_val(SUN4C_PAGE_SHARED);
 	BTFIXUPSET_INT(page_copy, pgprot_val(SUN4C_PAGE_COPY));
 	BTFIXUPSET_INT(page_readonly, pgprot_val(SUN4C_PAGE_READONLY));
 	BTFIXUPSET_INT(page_kernel, pgprot_val(SUN4C_PAGE_KERNEL));

include/asm-sparc/pgtable.h

@@ -46,7 +46,6 @@ BTFIXUPDEF_SIMM13(user_ptrs_per_pgd)
 #define pgd_ERROR(e)   __builtin_trap()
 
 BTFIXUPDEF_INT(page_none)
-BTFIXUPDEF_INT(page_shared)
 BTFIXUPDEF_INT(page_copy)
 BTFIXUPDEF_INT(page_readonly)
 BTFIXUPDEF_INT(page_kernel)
@@ -66,7 +65,7 @@ BTFIXUPDEF_INT(page_kernel)
 #define PTE_SIZE		(PTRS_PER_PTE*4)
 
 #define PAGE_NONE      __pgprot(BTFIXUP_INT(page_none))
-#define PAGE_SHARED    __pgprot(BTFIXUP_INT(page_shared))
+extern pgprot_t PAGE_SHARED;
 #define PAGE_COPY      __pgprot(BTFIXUP_INT(page_copy))
 #define PAGE_READONLY  __pgprot(BTFIXUP_INT(page_readonly))