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authorGerald Schaefer <gerald.schaefer@de.ibm.com>2016-07-04 14:47:01 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2016-07-06 08:46:43 +0200
commitd08de8e2d86744f91d9d5d57c56ca2b6e33bf6ec (patch)
tree2bcf0bcb5ec30e48eb82fbc7e3a216cab8671f04 /arch/s390/mm/hugetlbpage.c
parents390: have unique symbol for __switch_to address (diff)
downloadlinux-dev-d08de8e2d86744f91d9d5d57c56ca2b6e33bf6ec.tar.xz
linux-dev-d08de8e2d86744f91d9d5d57c56ca2b6e33bf6ec.zip
s390/mm: add support for 2GB hugepages
This adds support for 2GB hugetlbfs pages on s390. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm/hugetlbpage.c')
-rw-r--r--arch/s390/mm/hugetlbpage.c129
1 files changed, 90 insertions, 39 deletions
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index 1b5e8983f4f3..e19d853883be 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -1,19 +1,22 @@
/*
* IBM System z Huge TLB Page Support for Kernel.
*
- * Copyright IBM Corp. 2007
+ * Copyright IBM Corp. 2007,2016
* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
*/
+#define KMSG_COMPONENT "hugetlb"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
#include <linux/mm.h>
#include <linux/hugetlb.h>
-static inline pmd_t __pte_to_pmd(pte_t pte)
+static inline unsigned long __pte_to_rste(pte_t pte)
{
- pmd_t pmd;
+ unsigned long rste;
/*
- * Convert encoding pte bits pmd bits
+ * Convert encoding pte bits pmd / pud bits
* lIR.uswrdy.p dy..R...I...wr
* empty 010.000000.0 -> 00..0...1...00
* prot-none, clean, old 111.000000.1 -> 00..1...1...00
@@ -33,25 +36,31 @@ static inline pmd_t __pte_to_pmd(pte_t pte)
* u unused, l large
*/
if (pte_present(pte)) {
- pmd_val(pmd) = pte_val(pte) & PAGE_MASK;
- pmd_val(pmd) |= (pte_val(pte) & _PAGE_READ) >> 4;
- pmd_val(pmd) |= (pte_val(pte) & _PAGE_WRITE) >> 4;
- pmd_val(pmd) |= (pte_val(pte) & _PAGE_INVALID) >> 5;
- pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT);
- pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10;
- pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10;
- pmd_val(pmd) |= (pte_val(pte) & _PAGE_SOFT_DIRTY) << 13;
+ rste = pte_val(pte) & PAGE_MASK;
+ rste |= (pte_val(pte) & _PAGE_READ) >> 4;
+ rste |= (pte_val(pte) & _PAGE_WRITE) >> 4;
+ rste |= (pte_val(pte) & _PAGE_INVALID) >> 5;
+ rste |= (pte_val(pte) & _PAGE_PROTECT);
+ rste |= (pte_val(pte) & _PAGE_DIRTY) << 10;
+ rste |= (pte_val(pte) & _PAGE_YOUNG) << 10;
+ rste |= (pte_val(pte) & _PAGE_SOFT_DIRTY) << 13;
} else
- pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;
- return pmd;
+ rste = _SEGMENT_ENTRY_INVALID;
+ return rste;
}
-static inline pte_t __pmd_to_pte(pmd_t pmd)
+static inline pte_t __rste_to_pte(unsigned long rste)
{
+ int present;
pte_t pte;
+ if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
+ present = pud_present(__pud(rste));
+ else
+ present = pmd_present(__pmd(rste));
+
/*
- * Convert encoding pmd bits pte bits
+ * Convert encoding pmd / pud bits pte bits
* dy..R...I...wr lIR.uswrdy.p
* empty 00..0...1...00 -> 010.000000.0
* prot-none, clean, old 00..1...1...00 -> 111.000000.1
@@ -70,16 +79,16 @@ static inline pte_t __pmd_to_pte(pmd_t pmd)
* SW-bits: p present, y young, d dirty, r read, w write, s special,
* u unused, l large
*/
- if (pmd_present(pmd)) {
- pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE;
+ if (present) {
+ pte_val(pte) = rste & _SEGMENT_ENTRY_ORIGIN_LARGE;
pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
- pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4;
- pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4;
- pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5;
- pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT);
- pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) >> 10;
- pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) >> 10;
- pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_SOFT_DIRTY) >> 13;
+ pte_val(pte) |= (rste & _SEGMENT_ENTRY_READ) << 4;
+ pte_val(pte) |= (rste & _SEGMENT_ENTRY_WRITE) << 4;
+ pte_val(pte) |= (rste & _SEGMENT_ENTRY_INVALID) << 5;
+ pte_val(pte) |= (rste & _SEGMENT_ENTRY_PROTECT);
+ pte_val(pte) |= (rste & _SEGMENT_ENTRY_DIRTY) >> 10;
+ pte_val(pte) |= (rste & _SEGMENT_ENTRY_YOUNG) >> 10;
+ pte_val(pte) |= (rste & _SEGMENT_ENTRY_SOFT_DIRTY) >> 13;
} else
pte_val(pte) = _PAGE_INVALID;
return pte;
@@ -88,27 +97,33 @@ static inline pte_t __pmd_to_pte(pmd_t pmd)
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
- pmd_t pmd = __pte_to_pmd(pte);
-
- pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
- *(pmd_t *) ptep = pmd;
+ unsigned long rste = __pte_to_rste(pte);
+
+ /* Set correct table type for 2G hugepages */
+ if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
+ rste |= _REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE;
+ else
+ rste |= _SEGMENT_ENTRY_LARGE;
+ pte_val(*ptep) = rste;
}
pte_t huge_ptep_get(pte_t *ptep)
{
- pmd_t pmd = *(pmd_t *) ptep;
-
- return __pmd_to_pte(pmd);
+ return __rste_to_pte(pte_val(*ptep));
}
pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
+ pte_t pte = huge_ptep_get(ptep);
pmd_t *pmdp = (pmd_t *) ptep;
- pmd_t old;
+ pud_t *pudp = (pud_t *) ptep;
- old = pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
- return __pmd_to_pte(old);
+ if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
+ pudp_xchg_direct(mm, addr, pudp, __pud(_REGION3_ENTRY_EMPTY));
+ else
+ pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
+ return pte;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
@@ -120,8 +135,12 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
pgdp = pgd_offset(mm, addr);
pudp = pud_alloc(mm, pgdp, addr);
- if (pudp)
- pmdp = pmd_alloc(mm, pudp, addr);
+ if (pudp) {
+ if (sz == PUD_SIZE)
+ return (pte_t *) pudp;
+ else if (sz == PMD_SIZE)
+ pmdp = pmd_alloc(mm, pudp, addr);
+ }
return (pte_t *) pmdp;
}
@@ -134,8 +153,11 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
pgdp = pgd_offset(mm, addr);
if (pgd_present(*pgdp)) {
pudp = pud_offset(pgdp, addr);
- if (pud_present(*pudp))
+ if (pud_present(*pudp)) {
+ if (pud_large(*pudp))
+ return (pte_t *) pudp;
pmdp = pmd_offset(pudp, addr);
+ }
}
return (pte_t *) pmdp;
}
@@ -147,5 +169,34 @@ int pmd_huge(pmd_t pmd)
int pud_huge(pud_t pud)
{
- return 0;
+ return pud_large(pud);
+}
+
+struct page *
+follow_huge_pud(struct mm_struct *mm, unsigned long address,
+ pud_t *pud, int flags)
+{
+ if (flags & FOLL_GET)
+ return NULL;
+
+ return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
+}
+
+static __init int setup_hugepagesz(char *opt)
+{
+ unsigned long size;
+ char *string = opt;
+
+ size = memparse(opt, &opt);
+ if (MACHINE_HAS_EDAT1 && size == PMD_SIZE) {
+ hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
+ } else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE) {
+ hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+ } else {
+ pr_err("hugepagesz= specifies an unsupported page size %s\n",
+ string);
+ return 0;
+ }
+ return 1;
}
+__setup("hugepagesz=", setup_hugepagesz);