sparc64: kill page table quicklists

With the recent mmu_gather changes that included generic RCU freeing of
page-tables, it is now quite straightforward to implement gup_fast() on
sparc64.

This patch:

Remove the page table quicklists.  They are pointless and make it harder
to use RCU page table freeing and share code with other architectures.

BTW, this is the second time this has happened, see commit 3c93646524
("[SPARC64]: Kill pgtable quicklists and use SLAB.")

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/sparc/Kconfig

@@ -81,10 +81,6 @@ config IOMMU_HELPER
 	bool
 	default y if SPARC64
 
-config QUICKLIST
-	bool
-	default y if SPARC64
-
 config STACKTRACE_SUPPORT
 	bool
 	default y if SPARC64

arch/sparc/include/asm/pgalloc_64.h

@@ -5,7 +5,6 @@
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
-#include <linux/quicklist.h>
 
 #include <asm/spitfire.h>
 #include <asm/cpudata.h>
@@ -14,69 +13,68 @@
 
 /* Page table allocation/freeing. */
 
+extern struct kmem_cache *pgtable_cache;
+
 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 {
-	return quicklist_alloc(0, GFP_KERNEL, NULL);
+	return kmem_cache_alloc(pgtable_cache, GFP_KERNEL);
 }
 
 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 {
-	quicklist_free(0, NULL, pgd);
+	kmem_cache_free(pgtable_cache, pgd);
 }
 
 #define pud_populate(MM, PUD, PMD)	pud_set(PUD, PMD)
 
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	return quicklist_alloc(0, GFP_KERNEL, NULL);
+	return kmem_cache_alloc(pgtable_cache,
+				GFP_KERNEL|__GFP_REPEAT);
 }
 
 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 {
-	quicklist_free(0, NULL, pmd);
+	kmem_cache_free(pgtable_cache, pmd);
 }
 
 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 					  unsigned long address)
 {
-	return quicklist_alloc(0, GFP_KERNEL, NULL);
+	return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO);
 }
 
 static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
 					unsigned long address)
 {
 	struct page *page;
-	void *pg;
+	pte_t *pte;
 
-	pg = quicklist_alloc(0, GFP_KERNEL, NULL);
-	if (!pg)
+	pte = pte_alloc_one_kernel(mm, address);
+	if (!pte)
 		return NULL;
-	page = virt_to_page(pg);
+	page = virt_to_page(pte);
 	pgtable_page_ctor(page);
 	return page;
 }
 
 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 {
-	quicklist_free(0, NULL, pte);
+	free_page((unsigned long)pte);
 }
 
 static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
 {
 	pgtable_page_dtor(ptepage);
-	quicklist_free_page(0, NULL, ptepage);
+	__free_page(ptepage);
 }
 
-
 #define pmd_populate_kernel(MM, PMD, PTE)	pmd_set(PMD, PTE)
 #define pmd_populate(MM,PMD,PTE_PAGE)		\
 	pmd_populate_kernel(MM,PMD,page_address(PTE_PAGE))
 #define pmd_pgtable(pmd) pmd_page(pmd)
 
-static inline void check_pgt_cache(void)
-{
-	quicklist_trim(0, NULL, 25, 16);
-}
+#define check_pgt_cache()	do { } while (0)
 
 #define __pte_free_tlb(tlb, pte, addr)	pte_free((tlb)->mm, pte)
 #define __pmd_free_tlb(tlb, pmd, addr)	pmd_free((tlb)->mm, pmd)

arch/sparc/mm/tsb.c

@@ -236,6 +236,8 @@ static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_idx, unsign
 	}
 }
 
+struct kmem_cache *pgtable_cache __read_mostly;
+
 static struct kmem_cache *tsb_caches[8] __read_mostly;
 
 static const char *tsb_cache_names[8] = {
@@ -253,6 +255,15 @@ void __init pgtable_cache_init(void)
 {
 	unsigned long i;
 
+	pgtable_cache = kmem_cache_create("pgtable_cache",
+					  PAGE_SIZE, PAGE_SIZE,
+					  0,
+					  _clear_page);
+	if (!pgtable_cache) {
+		prom_printf("pgtable_cache_init(): Could not create!\n");
+		prom_halt();
+	}
+
 	for (i = 0; i < 8; i++) {
 		unsigned long size = 8192 << i;
 		const char *name = tsb_cache_names[i];