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, 37 insertions, 7 deletions

diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c
index e20fbbafb0b0..4ccca32bd1e1 100644
--- a/arch/sparc/mm/tsb.c
+++ b/arch/sparc/mm/tsb.c
@@ -86,6 +86,33 @@ static void __flush_tsb_one(struct tlb_batch *tb, unsigned long hash_shift,
 		__flush_tsb_one_entry(tsb, tb->vaddrs[i], hash_shift, nentries);
 }
 
+#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
+static void __flush_huge_tsb_one_entry(unsigned long tsb, unsigned long v,
+				       unsigned long hash_shift,
+				       unsigned long nentries,
+				       unsigned int hugepage_shift)
+{
+	unsigned int hpage_entries;
+	unsigned int i;
+
+	hpage_entries = 1 << (hugepage_shift - hash_shift);
+	for (i = 0; i < hpage_entries; i++)
+		__flush_tsb_one_entry(tsb, v + (i << hash_shift), hash_shift,
+				      nentries);
+}
+
+static void __flush_huge_tsb_one(struct tlb_batch *tb, unsigned long hash_shift,
+				 unsigned long tsb, unsigned long nentries,
+				 unsigned int hugepage_shift)
+{
+	unsigned long i;
+
+	for (i = 0; i < tb->tlb_nr; i++)
+		__flush_huge_tsb_one_entry(tsb, tb->vaddrs[i], hash_shift,
+					   nentries, hugepage_shift);
+}
+#endif
+
 void flush_tsb_user(struct tlb_batch *tb)
 {
 	struct mm_struct *mm = tb->mm;
@@ -93,7 +120,7 @@ void flush_tsb_user(struct tlb_batch *tb)
 
 	spin_lock_irqsave(&mm->context.lock, flags);
 
-	if (!tb->huge) {
+	if (tb->hugepage_shift == PAGE_SHIFT) {
 		base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
 		nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
 		if (tlb_type == cheetah_plus || tlb_type == hypervisor)
@@ -101,24 +128,26 @@ void flush_tsb_user(struct tlb_batch *tb)
 		__flush_tsb_one(tb, PAGE_SHIFT, base, nentries);
 	}
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-	if (tb->huge && mm->context.tsb_block[MM_TSB_HUGE].tsb) {
+	else if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
 		base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
 		nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
 		if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 			base = __pa(base);
-		__flush_tsb_one(tb, REAL_HPAGE_SHIFT, base, nentries);
+		__flush_huge_tsb_one(tb, REAL_HPAGE_SHIFT, base, nentries,
+				     tb->hugepage_shift);
 	}
 #endif
 	spin_unlock_irqrestore(&mm->context.lock, flags);
 }
 
-void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr, bool huge)
+void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr,
+			 unsigned int hugepage_shift)
 {
 	unsigned long nentries, base, flags;
 
 	spin_lock_irqsave(&mm->context.lock, flags);
 
-	if (!huge) {
+	if (hugepage_shift == PAGE_SHIFT) {
 		base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
 		nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
 		if (tlb_type == cheetah_plus || tlb_type == hypervisor)
@@ -126,12 +155,13 @@ void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr, bool huge)
 		__flush_tsb_one_entry(base, vaddr, PAGE_SHIFT, nentries);
 	}
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-	if (huge && mm->context.tsb_block[MM_TSB_HUGE].tsb) {
+	else if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
 		base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
 		nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
 		if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 			base = __pa(base);
-		__flush_tsb_one_entry(base, vaddr, REAL_HPAGE_SHIFT, nentries);
+		__flush_huge_tsb_one_entry(base, vaddr, REAL_HPAGE_SHIFT,
+					   nentries, hugepage_shift);
 	}
 #endif
 	spin_unlock_irqrestore(&mm->context.lock, flags);