powerpc: fix pgtable pmd cache init

Commit 9b081e10805cd ("powerpc: port 64 bits pgtable_cache to 32 bits") mixed up PMD_INDEX_SIZE and PMD_CACHE_INDEX a couple of times. This resulted in 64s/hash/4k configs to panic at boot with a false positive error check.

Fix that and simplify error handling by moving the check to the caller.

Fixes 9b081e10805cd ("powerpc: port 64 bits pgtable_cache to 32 bits")

Cc Christophe Leroy <[email protected]>

Cc Aneesh Kumar K.V <[email protected]>

Cc Scott Wood <[email protected]>

Cc [email protected]

Signed-off-by Nicholas Piggin <[email protected]>

---
 arch/powerpc/mm/hugetlbpage.c |  6 +-----
 arch/powerpc/mm/init-common.c | 11 +++--------
 2 files changed, 4 insertions(+), 13 deletions(-)

arch/powerpc/mm/hugetlbpage.c +1 -5

index 289df38fb7e0..f21f6b907d99 100644
@@ -810,12 +810,8 @@ static int __init hugetlbpage_init(void)
 		 * if we have pdshift and shift value same, we don't
 		 * use pgt cache for hugepd.
 		 */
-		if (pdshift > shift) {
+		if (pdshift > shift)
 			pgtable_cache_add(pdshift - shift, NULL);
-			if (!PGT_CACHE(pdshift - shift))
-				panic("hugetlbpage_init(): could not create "
-				      "pgtable cache for %d bit pagesize\n", shift);
-		}
 #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
 		else if (!hugepte_cache) {
 			/*

arch/powerpc/mm/init-common.c +3 -8

index a175cd82ae8c..1a3be5ae1d07 100644
@@ -80,6 +80,8 @@ void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
 	new = kmem_cache_create(name, table_size, align, 0, ctor);
 	kfree(name);
 	pgtable_cache[shift - 1] = new;
+	if (!new)
+		panic("Could not allocate pgtable cache for order %d", shift);
 	pr_debug("Allocated pgtable cache for order %d\n", shift);
 }
 

@@ -88,7 +90,7 @@ void pgtable_cache_init(void)
 {
 	pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
 
-	if (PMD_INDEX_SIZE && !PGT_CACHE(PMD_INDEX_SIZE))
+	if (PMD_CACHE_INDEX && !PGT_CACHE(PMD_CACHE_INDEX))
 		pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor);
 	/*
 	 * In all current configs, when the PUD index exists it's the

@@ -97,11 +99,4 @@ void pgtable_cache_init(void)
 	 */
 	if (PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE))
 		pgtable_cache_add(PUD_INDEX_SIZE, pud_ctor);
-
-	if (!PGT_CACHE(PGD_INDEX_SIZE))
-		panic("Couldn't allocate pgd cache");
-	if (PMD_INDEX_SIZE && !PGT_CACHE(PMD_INDEX_SIZE))
-		panic("Couldn't allocate pmd pgtable caches");
-	if (PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE))
-		panic("Couldn't allocate pud pgtable caches");
 }

Signature · 1 line

2.11.0

Quoted 5 lines · Nicholas Piggin

Commit 9b081e10805cd ("powerpc: port 64 bits pgtable_cache to 32 bits") mixed up PMD_INDEX_SIZE and PMD_CACHE_INDEX a couple of times. This resulted in 64s/hash/4k configs to panic at boot with a false positive error check.

Quoted 8 lines

Fix that and simplify error handling by moving the check to the caller.

Fixes 9b081e10805cd ("powerpc: port 64 bits pgtable_cache to 32 bits")

Cc Christophe Leroy <[email protected]>

Cc Aneesh Kumar K.V <[email protected]>

Cc Scott Wood <[email protected]>

Cc [email protected]

Signed-off-by Nicholas Piggin <[email protected]>

I did another fix here.

https://lkml.kernel.org/r/[email protected]

But this patch makes it much simpler. Hence.

Reviewed-by Aneesh Kumar K.V <[email protected]>

There is this hunk in the patch I did.

arch/powerpc/include/asm/book3s/64/hash.h +2 -2

@@ -33,9 +33,9 @@
 				 H_PUD_INDEX_SIZE + H_PGD_INDEX_SIZE + PAGE_SHIFT)
 #define H_PGTABLE_RANGE		(ASM_CONST(1) << H_PGTABLE_EADDR_SIZE)
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) &&  defined(CONFIG_PPC_64K_PAGES)
 /*
- * only with hash we need to use the second half of pmd page table
+ * only with hash 64k we need to use the second half of pmd page table
  * to store pointer to deposited pgtable_t
  */
 #define H_PMD_CACHE_INDEX	(H_PMD_INDEX_SIZE + 1)

Quoted 22 lines · On Wed, 04 Jan 2017 07:34:41 +0530 "Aneesh Kumar K.V"…

Quoted 5 lines · Nicholas Piggin

Commit 9b081e10805cd ("powerpc: port 64 bits pgtable_cache to 32 bits") mixed up PMD_INDEX_SIZE and PMD_CACHE_INDEX a couple of times. This resulted in 64s/hash/4k configs to panic at boot with a false positive error check.

Quoted 8 lines

Fix that and simplify error handling by moving the check to the caller.

Fixes 9b081e10805cd ("powerpc: port 64 bits pgtable_cache to 32 bits")

Cc Christophe Leroy <[email protected]>

Cc Aneesh Kumar K.V <[email protected]>

Cc Scott Wood <[email protected]>

Cc [email protected]

Signed-off-by Nicholas Piggin <[email protected]>

I did another fix here.

https://lkml.kernel.org/r/[email protected]

But this patch makes it much simpler. Hence.

Quoted 3 lines

Reviewed-by Aneesh Kumar K.V <[email protected]>

There is this hunk in the patch I did.

Ah, I missed that. My patch just fixes the 9b081e10805cd bug, but this hunk looks like it should still go in as another patch. Will you resend it?

Commit 9b081e10805cd ("powerpc: port 64 bits pgtable_cache to 32 bits") mixed up PMD_INDEX_SIZE and PMD_CACHE_INDEX a couple of times. This resulted in 64s/hash/4k configs to panic at boot with a false positive error check.

Fix that and simplify error handling by moving the check to the caller.

Fixes 9b081e10805cd ("powerpc: port 64 bits pgtable_cache to 32 bits")

Cc Christophe Leroy <[email protected]>

Cc Aneesh Kumar K.V <[email protected]>

Cc Scott Wood <[email protected]>

Cc [email protected]

Signed-off-by Nicholas Piggin <[email protected]>