Revert pmd/pgd slabification. wli will fix it properly

Cset exclude: akpm@digeo.com|ChangeSet|20030204165956|06074
Cset exclude: akpm@digeo.com|ChangeSet|20030204165949|06077

arch/i386/mm/init.c

@@ -505,36 +505,20 @@ void __init mem_init(void)
 #endif
 }
 
-#include <linux/slab.h>
-
-kmem_cache_t *pmd_cache;
-kmem_cache_t *pgd_cache;
-
-void pmd_ctor(void *, kmem_cache_t *, unsigned long);
-void pgd_ctor(void *, kmem_cache_t *, unsigned long);
+#if CONFIG_X86_PAE
+struct kmem_cache_s *pae_pgd_cachep;
 
 void __init pgtable_cache_init(void)
 {
-	if (PTRS_PER_PMD > 1) {
-		pmd_cache = kmem_cache_create("pae_pmd",
-						PTRS_PER_PMD*sizeof(pmd_t),
-						0,
-						SLAB_HWCACHE_ALIGN | SLAB_MUST_HWCACHE_ALIGN,
-						pmd_ctor,
-						NULL);
-
-		if (!pmd_cache)
-			panic("pgtable_cache_init(): cannot create pmd cache");
-	}
-
         /*
          * PAE pgds must be 16-byte aligned:
          */
-        pgd_cache = kmem_cache_create("pgd", PTRS_PER_PGD*sizeof(pgd_t), 0,
-                SLAB_HWCACHE_ALIGN | SLAB_MUST_HWCACHE_ALIGN, pgd_ctor, NULL);
-        if (!pgd_cache)
-                panic("pgtable_cache_init(): Cannot create pgd cache");
+        pae_pgd_cachep = kmem_cache_create("pae_pgd", 32, 0,
+                SLAB_HWCACHE_ALIGN | SLAB_MUST_HWCACHE_ALIGN, NULL, NULL);
+        if (!pae_pgd_cachep)
+                panic("init_pae(): Cannot alloc pae_pgd SLAB cache");
 }
+#endif
 
 /*
  * This function cannot be __init, since exceptions don't work in that

arch/i386/mm/pgtable.c

@@ -151,47 +151,30 @@ struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 	return pte;
 }
 
-extern kmem_cache_t *pmd_cache;
-extern kmem_cache_t *pgd_cache;
-
-void pmd_ctor(void *__pmd, kmem_cache_t *pmd_cache, unsigned long flags)
-{
-	clear_page(__pmd);
-}
-
-void pgd_ctor(void *__pgd, kmem_cache_t *pgd_cache, unsigned long flags)
-{
-	pgd_t *pgd = __pgd;
-
-	if (PTRS_PER_PMD == 1)
-		memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
-	memcpy(pgd + USER_PTRS_PER_PGD,
-		swapper_pg_dir + USER_PTRS_PER_PGD,
-		(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
-}
+#if CONFIG_X86_PAE
 
 pgd_t *pgd_alloc(struct mm_struct *mm)
 {
 	int i;
-	pgd_t *pgd = kmem_cache_alloc(pgd_cache, SLAB_KERNEL);
+	pgd_t *pgd = kmem_cache_alloc(pae_pgd_cachep, GFP_KERNEL);
 
-	if (PTRS_PER_PMD == 1)
-		return pgd;
-	else if (!pgd)
-		return NULL;
-
-	for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
-		pmd_t *pmd = kmem_cache_alloc(pmd_cache, SLAB_KERNEL);
+	if (pgd) {
+		for (i = 0; i < USER_PTRS_PER_PGD; i++) {
+			unsigned long pmd = __get_free_page(GFP_KERNEL);
 			if (!pmd)
 				goto out_oom;
-		set_pgd(pgd + i, __pgd(1 + __pa((unsigned long long)((unsigned long)pmd))));
+			clear_page(pmd);
+			set_pgd(pgd + i, __pgd(1 + __pa(pmd)));
+		}
+		memcpy(pgd + USER_PTRS_PER_PGD,
+			swapper_pg_dir + USER_PTRS_PER_PGD,
+			(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
 	}
 	return pgd;
-
 out_oom:
-	for (i--; i >= 0; --i)
-		kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
-	kmem_cache_free(pgd_cache, (void *)pgd);
+	for (i--; i >= 0; i--)
+		free_page((unsigned long)__va(pgd_val(pgd[i])-1));
+	kmem_cache_free(pae_pgd_cachep, pgd);
 	return NULL;
 }
 
@@ -199,12 +182,30 @@ void pgd_free(pgd_t *pgd)
 {
 	int i;
 
-	if (PTRS_PER_PMD > 1) {
-		for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
-			kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
-			set_pgd(pgd + i, __pgd(0));
-		}
+	for (i = 0; i < USER_PTRS_PER_PGD; i++)
+		free_page((unsigned long)__va(pgd_val(pgd[i])-1));
+	kmem_cache_free(pae_pgd_cachep, pgd);
+}
+
+#else
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+	pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
+
+	if (pgd) {
+		memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
+		memcpy(pgd + USER_PTRS_PER_PGD,
+			swapper_pg_dir + USER_PTRS_PER_PGD,
+			(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
 	}
+	return pgd;
+}
 
-	kmem_cache_free(pgd_cache, (void *)pgd);
+void pgd_free(pgd_t *pgd)
+{
+	free_page((unsigned long)pgd);
 }
+
+#endif /* CONFIG_X86_PAE */
+

include/asm-i386/pgalloc.h

@@ -20,11 +20,11 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *p
  * Allocate and free page tables.
  */
 
-pgd_t *pgd_alloc(struct mm_struct *);
-void pgd_free(pgd_t *pgd);
+extern pgd_t *pgd_alloc(struct mm_struct *);
+extern void pgd_free(pgd_t *pgd);
 
-pte_t *pte_alloc_one_kernel(struct mm_struct *, unsigned long);
-struct page *pte_alloc_one(struct mm_struct *, unsigned long);
+extern pte_t *pte_alloc_one_kernel(struct mm_struct *, unsigned long);
+extern struct page *pte_alloc_one(struct mm_struct *, unsigned long);
 
 static inline void pte_free_kernel(pte_t *pte)
 {

include/asm-i386/pgtable-3level.h

@@ -123,4 +123,6 @@ static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
 #define pgoff_to_pte(off) ((pte_t) { _PAGE_FILE, (off) })
 #define PTE_FILE_MAX_BITS       32
 
+extern struct kmem_cache_s *pae_pgd_cachep;
+
 #endif /* _I386_PGTABLE_3LEVEL_H */

include/asm-i386/pgtable.h

@@ -41,12 +41,21 @@ extern unsigned long empty_zero_page[1024];
 #ifndef __ASSEMBLY__
 #ifdef CONFIG_X86_PAE
 # include <asm/pgtable-3level.h>
+
+/*
+ * Need to initialise the X86 PAE caches
+ */
+extern void pgtable_cache_init(void);
+
 #else
 # include <asm/pgtable-2level.h>
-#endif
 
-void pgtable_cache_init(void);
+/*
+ * No page table caches to initialise
+ */
+#define pgtable_cache_init()	do { } while (0)
 
+#endif
 #endif
 
 #define PMD_SIZE	(1UL << PMD_SHIFT)