sparc64: Multi-page size support

Add support for using multiple hugepage sizes simultaneously
on mainline. Currently, support for 256M has been added which
can be used along with 8M pages.

Page tables are set like this (e.g. for 256M page):
    VA + (8M * x) -> PA + (8M * x) (sz bit = 256M) where x in [0, 31]

and TSB is set similarly:
    VA + (4M * x) -> PA + (4M * x) (sz bit = 256M) where x in [0, 63]

- Testing

Tested on Sonoma (which supports 256M pages) by running stream
benchmark instances in parallel: one instance uses 8M pages and
another uses 256M pages, consuming 48G each.

Boot params used:

default_hugepagesz=256M hugepagesz=256M hugepages=300 hugepagesz=8M
hugepages=10000

Signed-off-by: Nitin Gupta <nitin.m.gupta@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 9 deletions

diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index c56a195c9071..afda3bbf7854 100644
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c
@@ -67,7 +67,7 @@ void arch_leave_lazy_mmu_mode(void)
 }
 
 static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
-			      bool exec, bool huge)
+			      bool exec, unsigned int hugepage_shift)
 {
 	struct tlb_batch *tb = &get_cpu_var(tlb_batch);
 	unsigned long nr;
@@ -84,19 +84,19 @@ static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
 	}
 
 	if (!tb->active) {
-		flush_tsb_user_page(mm, vaddr, huge);
+		flush_tsb_user_page(mm, vaddr, hugepage_shift);
 		global_flush_tlb_page(mm, vaddr);
 		goto out;
 	}
 
 	if (nr == 0) {
 		tb->mm = mm;
-		tb->huge = huge;
+		tb->hugepage_shift = hugepage_shift;
 	}
 
-	if (tb->huge != huge) {
+	if (tb->hugepage_shift != hugepage_shift) {
 		flush_tlb_pending();
-		tb->huge = huge;
+		tb->hugepage_shift = hugepage_shift;
 		nr = 0;
 	}
 
@@ -110,10 +110,9 @@ out:
 }
 
 void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
-		   pte_t *ptep, pte_t orig, int fullmm)
+		   pte_t *ptep, pte_t orig, int fullmm,
+		   unsigned int hugepage_shift)
 {
-	bool huge = is_hugetlb_pte(orig);
-
 	if (tlb_type != hypervisor &&
 	    pte_dirty(orig)) {
 		unsigned long paddr, pfn = pte_pfn(orig);
@@ -139,7 +138,7 @@ void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
 
 no_cache_flush:
 	if (!fullmm)
-		tlb_batch_add_one(mm, vaddr, pte_exec(orig), huge);
+		tlb_batch_add_one(mm, vaddr, pte_exec(orig), hugepage_shift);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE