From ce33fdc52ad50043eef07d11473bc51e225565bd Mon Sep 17 00:00:00 2001
From: David S. Miller
Date: Thu, 6 Sep 2012 19:01:25 -0700
Subject: sparc64: Probe cpu page size support more portably.

On sun4v, interrogate the machine description.  This code is extremely
defensive in nature, and a lot of the checks can probably be removed.

On sun4u things are a lot simpler.  There are the page sizes all chips
support, and then Panther adds 32MB and 256MB pages.

Report the probed value in /proc/cpuinfo

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 arch/sparc/mm/init_64.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

(limited to 'arch/sparc/mm')

diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index c0fc25be0c51..445369132e03 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -83,6 +83,8 @@ unsigned long kpte_linear_bitmap[KPTE_BITMAP_BYTES / sizeof(unsigned long)];
 extern struct tsb swapper_4m_tsb[KERNEL_TSB4M_NENTRIES];
 #endif
 
+static unsigned long cpu_pgsz_mask;
+
 #define MAX_BANKS	32
 
 static struct linux_prom64_registers pavail[MAX_BANKS] __devinitdata;
@@ -419,6 +421,12 @@ EXPORT_SYMBOL(flush_icache_range);
 
 void mmu_info(struct seq_file *m)
 {
+	static const char *pgsz_strings[] = {
+		"8K", "64K", "512K", "4MB", "32MB",
+		"256MB", "2GB", "16GB",
+	};
+	int i, printed;
+
 	if (tlb_type == cheetah)
 		seq_printf(m, "MMU Type\t: Cheetah\n");
 	else if (tlb_type == cheetah_plus)
@@ -430,6 +438,17 @@ void mmu_info(struct seq_file *m)
 	else
 		seq_printf(m, "MMU Type\t: ???\n");
 
+	seq_printf(m, "MMU PGSZs\t: ");
+	printed = 0;
+	for (i = 0; i < ARRAY_SIZE(pgsz_strings); i++) {
+		if (cpu_pgsz_mask & (1UL << i)) {
+			seq_printf(m, "%s%s",
+				   printed ? "," : "", pgsz_strings[i]);
+			printed++;
+		}
+	}
+	seq_putc(m, '\n');
+
 #ifdef CONFIG_DEBUG_DCFLUSH
 	seq_printf(m, "DCPageFlushes\t: %d\n",
 		   atomic_read(&dcpage_flushes));
@@ -1803,6 +1822,18 @@ void __init paging_init(void)
 #ifndef CONFIG_SMP
 		mdesc_fill_in_cpu_data(cpu_all_mask);
 #endif
+		mdesc_get_page_sizes(cpu_all_mask, &cpu_pgsz_mask);
+	} else {
+		unsigned long impl, ver;
+
+		cpu_pgsz_mask = (HV_PGSZ_MASK_8K | HV_PGSZ_MASK_64K |
+				 HV_PGSZ_MASK_512K | HV_PGSZ_MASK_4MB);
+
+		__asm__ __volatile__("rdpr %%ver, %0" : "=r" (ver));
+		impl = ((ver >> 32) & 0xffff);
+		if (impl == PANTHER_IMPL)
+			cpu_pgsz_mask |= (HV_PGSZ_MASK_32MB |
+					  HV_PGSZ_MASK_256MB);
 	}
 
 	/* Setup bootmem... */
-- 
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