sparc64: Add 16GB hugepage support

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

Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: Nitin Gupta <nitin.m.gupta@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 47 insertions, 7 deletions

diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index afa0099f3748..b2ba410b26f4 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -348,6 +348,18 @@ static int __init hugetlbpage_init(void)
 
 arch_initcall(hugetlbpage_init);
 
+static void __init pud_huge_patch(void)
+{
+	struct pud_huge_patch_entry *p;
+	unsigned long addr;
+
+	p = &__pud_huge_patch;
+	addr = p->addr;
+	*(unsigned int *)addr = p->insn;
+
+	__asm__ __volatile__("flush %0" : : "r" (addr));
+}
+
 static int __init setup_hugepagesz(char *string)
 {
 	unsigned long long hugepage_size;
@@ -360,6 +372,11 @@ 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;
+		pud_huge_patch();
+		break;
 	case HPAGE_2GB_SHIFT:
 		hv_pgsz_mask = HV_PGSZ_MASK_2GB;
 		hv_pgsz_idx = HV_PGSZ_IDX_2GB;
@@ -400,6 +417,7 @@ 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) {
@@ -417,15 +435,37 @@ 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));