Nicholas Piggin <npig...@gmail.com> writes:
> 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 <christophe.le...@c-s.fr>
> Cc: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
> Cc: Scott Wood <o...@buserror.net>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
I did another fix here.
https://lkml.kernel.org/r/20161214043349.23677-1-aneesh.ku...@linux.vnet.ibm.com
But this patch makes it much simpler. Hence.
Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
There is this hunk in the patch I did.
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -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)
> ---
> arch/powerpc/mm/hugetlbpage.c | 6 +-----
> arch/powerpc/mm/init-common.c | 11 +++--------
> 2 files changed, 4 insertions(+), 13 deletions(-)
>
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index 289df38fb7e0..f21f6b907d99 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -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) {
> /*
> diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
> index a175cd82ae8c..1a3be5ae1d07 100644
> --- a/arch/powerpc/mm/init-common.c
> +++ b/arch/powerpc/mm/init-common.c
> @@ -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");
> }
> --
> 2.11.0
