[PATCH v6 12/20] powerpc/mm: Enable 512k hugepage support with HW assistance on the 8xx

From: Christophe Leroy
Date: Fri Oct 19 2018 - 02:55:21 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 | 13 +++++++++++++
arch/powerpc/mm/tlb_nohash.c | 3 +++
3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index e13843556414..b22f164216ad 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -75,7 +75,9 @@ 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 d56d92783295..75856a5b476b 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -67,7 +67,11 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
cachep = PGT_CACHE(PTE_T_ORDER);
num_hugepd = 1 << (pshift - pdshift);
} else {
+#ifdef CONFIG_PPC_8xx
+ cachep = PGT_CACHE(PTE_SHIFT);
+#else
cachep = PGT_CACHE(pdshift - pshift);
+#endif
num_hugepd = 1;
}

@@ -333,8 +337,13 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif
if (shift >= pdshift)
hugepd_free(tlb, hugepte);
else
+#ifdef 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));
+#endif
}

static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
@@ -702,7 +711,11 @@ static int __init hugetlbpage_init(void)
* use pgt cache for hugepd.
*/
if (pdshift > shift)
+#ifdef CONFIG_PPC_8xx
+ pgtable_cache_add(PTE_SHIFT);
+#else
pgtable_cache_add(pdshift - shift);
+#endif
#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
else
pgtable_cache_add(PTE_T_ORDER);
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