[PATCH v3 1/4] sparc64: Add 16GB hugepage support

From: Nitin Gupta
Date: Mon Jun 19 2017 - 21:54:17 EST

Adds support for 16GB hugepage size. To use this page size
use kernel parameters as:

default_hugepagesz=16G hugepagesz=16G hugepages=10

Testing:

Tested with the stream benchmark which allocates 48G of
arrays backed by 16G hugepages and does RW operation on
them in parallel.

Orabug: 25362942

Signed-off-by: Nitin Gupta <nitin.m.gupta@xxxxxxxxxx>
---
Changelog v3 vs v2:
- Fixed email headers so the subject shows up correctly

Changelog v2 vs v1:
- Remove redundant brgez,pn (Bob Picco)
- Remove unncessary label rename from 700 to 701 (Rob Gardner)
- Add patch description (Paul)
- Add 16G case to get_user_pages()

arch/sparc/include/asm/page_64.h | 3 +-
arch/sparc/include/asm/pgtable_64.h | 5 +++
arch/sparc/include/asm/tsb.h | 30 +++++++++++++++
arch/sparc/kernel/tsb.S | 2 +-
arch/sparc/mm/hugetlbpage.c | 74 ++++++++++++++++++++++++++-----------
arch/sparc/mm/init_64.c | 41 ++++++++++++++++----
6 files changed, 125 insertions(+), 30 deletions(-)

diff --git a/arch/sparc/include/asm/page_64.h b/arch/sparc/include/asm/page_64.h
index 5961b2d..8ee1f97 100644
--- a/arch/sparc/include/asm/page_64.h
+++ b/arch/sparc/include/asm/page_64.h
@@ -17,6 +17,7 @@

#define HPAGE_SHIFT 23
#define REAL_HPAGE_SHIFT 22
+#define HPAGE_16GB_SHIFT 34
#define HPAGE_2GB_SHIFT 31
#define HPAGE_256MB_SHIFT 28
#define HPAGE_64K_SHIFT 16
@@ -28,7 +29,7 @@
#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
#define REAL_HPAGE_PER_HPAGE (_AC(1,UL) << (HPAGE_SHIFT - REAL_HPAGE_SHIFT))
-#define HUGE_MAX_HSTATE 4
+#define HUGE_MAX_HSTATE 5
#endif

#ifndef __ASSEMBLY__
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 6fbd931..2444b02 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -414,6 +414,11 @@ static inline bool is_hugetlb_pmd(pmd_t pmd)
return !!(pmd_val(pmd) & _PAGE_PMD_HUGE);
}

+static inline bool is_hugetlb_pud(pud_t pud)
+{
+ return !!(pud_val(pud) & _PAGE_PUD_HUGE);
+}
+
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline pmd_t pmd_mkhuge(pmd_t pmd)
{
diff --git a/arch/sparc/include/asm/tsb.h b/arch/sparc/include/asm/tsb.h
index 32258e0..7b240a3 100644
--- a/arch/sparc/include/asm/tsb.h
+++ b/arch/sparc/include/asm/tsb.h
@@ -195,6 +195,35 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
nop; \
699:

+ /* PUD has been loaded into REG1, interpret the value, seeing
+ * if it is a HUGE PUD or a normal one. If it is not valid
+ * then jump to FAIL_LABEL. If it is a HUGE PUD, and it
+ * translates to a valid PTE, branch to PTE_LABEL.
+ *
+ * We have to propagate bits [32:22] from the virtual address
+ * to resolve at 4M granularity.
+ */
+#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
+#define USER_PGTABLE_CHECK_PUD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
+ brz,pn REG1, FAIL_LABEL; \
+ sethi %uhi(_PAGE_PUD_HUGE), REG2; \
+ sllx REG2, 32, REG2; \
+ andcc REG1, REG2, %g0; \
+ be,pt %xcc, 700f; \
+ sethi %hi(0x1ffc0000), REG2; \
+ sllx REG2, 1, REG2; \
+ brgez,pn REG1, FAIL_LABEL; \
+ andn REG1, REG2, REG1; \
+ and VADDR, REG2, REG2; \
+ brlz,pt REG1, PTE_LABEL; \
+ or REG1, REG2, REG1; \
+700:
+#else
+#define USER_PGTABLE_CHECK_PUD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
+ brz,pn REG1, FAIL_LABEL; \
+ nop;
+#endif
+
/* PMD has been loaded into REG1, interpret the value, seeing
* if it is a HUGE PMD or a normal one. If it is not valid
* then jump to FAIL_LABEL. If it is a HUGE PMD, and it
@@ -242,6 +271,7 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
srlx REG2, 64 - PAGE_SHIFT, REG2; \
andn REG2, 0x7, REG2; \
ldxa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
+ USER_PGTABLE_CHECK_PUD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, 800f) \
brz,pn REG1, FAIL_LABEL; \
sllx VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
srlx REG2, 64 - PAGE_SHIFT, REG2; \
diff --git a/arch/sparc/kernel/tsb.S b/arch/sparc/kernel/tsb.S
index 07c0df9..5f42ac0 100644
--- a/arch/sparc/kernel/tsb.S
+++ b/arch/sparc/kernel/tsb.S
@@ -117,7 +117,7 @@ tsb_miss_page_table_walk_sun4v_fastpath:
/* Valid PTE is now in %g5. */

#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
- sethi %uhi(_PAGE_PMD_HUGE), %g7
+ sethi %uhi(_PAGE_PMD_HUGE | _PAGE_PUD_HUGE), %g7
sllx %g7, 32, %g7

andcc %g5, %g7, %g0
diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index 88855e3..f0bb42d 100644
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -143,6 +143,10 @@ static pte_t sun4v_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
pte_val(entry) = pte_val(entry) & ~_PAGE_SZALL_4V;

switch (shift) {
+ case HPAGE_16GB_SHIFT:
+ hugepage_size = _PAGE_SZ16GB_4V;
+ pte_val(entry) |= _PAGE_PUD_HUGE;
+ break;
case HPAGE_2GB_SHIFT:
hugepage_size = _PAGE_SZ2GB_4V;
pte_val(entry) |= _PAGE_PMD_HUGE;
@@ -187,6 +191,9 @@ static unsigned int sun4v_huge_tte_to_shift(pte_t entry)
unsigned int shift;

switch (tte_szbits) {
+ case _PAGE_SZ16GB_4V:
+ shift = HPAGE_16GB_SHIFT;
+ break;
case _PAGE_SZ2GB_4V:
shift = HPAGE_2GB_SHIFT;
break;
@@ -263,7 +270,12 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,

pgd = pgd_offset(mm, addr);
pud = pud_alloc(mm, pgd, addr);
- if (pud) {
+ if (!pud)
+ return NULL;
+
+ if (sz >= PUD_SIZE)
+ pte = (pte_t *)pud;
+ else {
pmd = pmd_alloc(mm, pud, addr);
if (!pmd)
return NULL;
@@ -288,12 +300,16 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
if (!pgd_none(*pgd)) {
pud = pud_offset(pgd, addr);
if (!pud_none(*pud)) {
- pmd = pmd_offset(pud, addr);
- if (!pmd_none(*pmd)) {
- if (is_hugetlb_pmd(*pmd))
- pte = (pte_t *)pmd;
- else
- pte = pte_offset_map(pmd, addr);
+ if (is_hugetlb_pud(*pud))
+ pte = (pte_t *)pud;
+ else {
+ pmd = pmd_offset(pud, addr);
+ if (!pmd_none(*pmd)) {
+ if (is_hugetlb_pmd(*pmd))
+ pte = (pte_t *)pmd;
+ else
+ pte = pte_offset_map(pmd, addr);
+ }
}
}
}
@@ -304,12 +320,20 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t entry)
{
- unsigned int i, nptes, orig_shift, shift;
- unsigned long size;
+ unsigned int nptes, orig_shift, shift;
+ unsigned long i, size;
pte_t orig;

size = huge_tte_to_size(entry);
- shift = size >= HPAGE_SIZE ? PMD_SHIFT : PAGE_SHIFT;
+
+ shift = PAGE_SHIFT;
+ if (size >= PUD_SIZE)
+ shift = PUD_SHIFT;
+ else if (size >= PMD_SIZE)
+ shift = PMD_SHIFT;
+ else
+ shift = PAGE_SHIFT;
+
nptes = size >> shift;

if (!pte_present(*ptep) && pte_present(entry))
@@ -332,19 +356,23 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
- unsigned int i, nptes, hugepage_shift;
+ unsigned int i, nptes, orig_shift, shift;
unsigned long size;
pte_t entry;

entry = *ptep;
size = huge_tte_to_size(entry);
- if (size >= HPAGE_SIZE)
- nptes = size >> PMD_SHIFT;
+
+ shift = PAGE_SHIFT;
+ if (size >= PUD_SIZE)
+ shift = PUD_SHIFT;
+ else if (size >= PMD_SIZE)
+ shift = PMD_SHIFT;
else
- nptes = size >> PAGE_SHIFT;
+ shift = PAGE_SHIFT;

- hugepage_shift = pte_none(entry) ? PAGE_SHIFT :
- huge_tte_to_shift(entry);
+ nptes = size >> shift;
+ orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry);

if (pte_present(entry))
mm->context.hugetlb_pte_count -= nptes;
@@ -353,11 +381,11 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
for (i = 0; i < nptes; i++)
ptep[i] = __pte(0UL);

- maybe_tlb_batch_add(mm, addr, ptep, entry, 0, hugepage_shift);
+ maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift);
/* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
if (size == HPAGE_SIZE)
maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0,
- hugepage_shift);
+ orig_shift);

return entry;
}
@@ -370,7 +398,8 @@ int pmd_huge(pmd_t pmd)

int pud_huge(pud_t pud)
{
- return 0;
+ return !pud_none(pud) &&
+ (pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID;
}

static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
@@ -434,8 +463,11 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
continue;
- hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
- ceiling);
+ if (is_hugetlb_pud(*pud))
+ pud_clear(pud);
+ else
+ hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
+ ceiling);
} while (pud++, addr = next, addr != end);

start &= PGDIR_MASK;
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 3c40ebd..cc8d0d4 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -337,6 +337,10 @@ static int __init setup_hugepagesz(char *string)
hugepage_shift = ilog2(hugepage_size);

switch (hugepage_shift) {
+ case HPAGE_16GB_SHIFT:
+ hv_pgsz_mask = HV_PGSZ_MASK_16GB;
+ hv_pgsz_idx = HV_PGSZ_IDX_16GB;
+ break;
case HPAGE_2GB_SHIFT:
hv_pgsz_mask = HV_PGSZ_MASK_2GB;
hv_pgsz_idx = HV_PGSZ_IDX_2GB;
@@ -377,6 +381,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *
{
struct mm_struct *mm;
unsigned long flags;
+ bool is_huge_tsb;
pte_t pte = *ptep;

if (tlb_type != hypervisor) {
@@ -394,15 +399,37 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *

spin_lock_irqsave(&mm->context.lock, flags);

+ is_huge_tsb = false;
#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
- if ((mm->context.hugetlb_pte_count || mm->context.thp_pte_count) &&
- is_hugetlb_pmd(__pmd(pte_val(pte)))) {
- /* We are fabricating 8MB pages using 4MB real hw pages. */
- pte_val(pte) |= (address & (1UL << REAL_HPAGE_SHIFT));
- __update_mmu_tsb_insert(mm, MM_TSB_HUGE, REAL_HPAGE_SHIFT,
- address, pte_val(pte));
- } else
+ if (mm->context.hugetlb_pte_count || mm->context.thp_pte_count) {
+ unsigned long hugepage_size = PAGE_SIZE;
+
+ if (is_vm_hugetlb_page(vma))
+ hugepage_size = huge_page_size(hstate_vma(vma));
+
+ if (hugepage_size >= PUD_SIZE) {
+ unsigned long mask = 0x1ffc00000UL;
+
+ /* Transfer bits [32:22] from address to resolve
+ * at 4M granularity.
+ */
+ pte_val(pte) &= ~mask;
+ pte_val(pte) |= (address & mask);
+ } else if (hugepage_size >= PMD_SIZE) {
+ /* We are fabricating 8MB pages using 4MB
+ * real hw pages.
+ */
+ pte_val(pte) |= (address & (1UL << REAL_HPAGE_SHIFT));
+ }
+
+ if (hugepage_size >= PMD_SIZE) {
+ __update_mmu_tsb_insert(mm, MM_TSB_HUGE,
+ REAL_HPAGE_SHIFT, address, pte_val(pte));
+ is_huge_tsb = true;
+ }
+ }
#endif
+ if (!is_huge_tsb)
__update_mmu_tsb_insert(mm, MM_TSB_BASE, PAGE_SHIFT,
address, pte_val(pte));

--
2.9.2