[PATCH v8 17/20] powerpc/8xx: Enable 512k hugepage support with HW assistance

From: Christophe Leroy
Date: Thu Nov 29 2018 - 03:10:44 EST


For using 512k pages with hardware assistance, the PTEs have to be spread
every 128 bytes in the L2 table.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/include/asm/hugetlb.h | 4 +++-
arch/powerpc/mm/hugetlbpage.c | 10 +++++++++-
arch/powerpc/mm/tlb_nohash.c | 3 +++
3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index dfb8bf236586..62a0ca02ca7d 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -74,7 +74,9 @@ static inline pte_t *hugepte_offset(hugepd_t hpd, unsigned long addr,
unsigned long idx = 0;

pte_t *dir = hugepd_page(hpd);
-#ifndef CONFIG_PPC_FSL_BOOK3E
+#ifdef CONFIG_PPC_8xx
+ idx = (addr & ((1UL << pdshift) - 1)) >> PAGE_SHIFT;
+#elif !defined(CONFIG_PPC_FSL_BOOK3E)
idx = (addr & ((1UL << pdshift) - 1)) >> hugepd_shift(hpd);
#endif

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index bc97874d7c74..5f22f1d399b3 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -65,6 +65,9 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
if (pshift >= pdshift) {
cachep = PGT_CACHE(PTE_T_ORDER);
num_hugepd = 1 << (pshift - pdshift);
+ } else if (IS_ENABLED(CONFIG_PPC_8xx)) {
+ cachep = PGT_CACHE(PTE_SHIFT);
+ num_hugepd = 1;
} else {
cachep = PGT_CACHE(pdshift - pshift);
num_hugepd = 1;
@@ -331,6 +334,9 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif

if (shift >= pdshift)
hugepd_free(tlb, hugepte);
+ else if (IS_ENABLED(CONFIG_PPC_8xx))
+ pgtable_free_tlb(tlb, hugepte,
+ get_hugepd_cache_index(PTE_SHIFT));
else
pgtable_free_tlb(tlb, hugepte,
get_hugepd_cache_index(pdshift - shift));
@@ -700,7 +706,9 @@ 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 && IS_ENABLED(CONFIG_PPC_8xx))
+ pgtable_cache_add(PTE_SHIFT);
+ else if (pdshift > shift)
pgtable_cache_add(pdshift - shift);
#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
else
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index 8ad7aab150b7..ae5d568e267f 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -97,6 +97,9 @@ struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
.shift = 14,
},
#endif
+ [MMU_PAGE_512K] = {
+ .shift = 19,
+ },
[MMU_PAGE_8M] = {
.shift = 23,
},
--
2.13.3