[Cbe-oss-dev] [PATCH 2/3] Allocate the hash table under 1G on cell

[Michael Ellerman]

In order to support our IOMMU performance trick, we need the hash table to be
inside the DMA window. This is usually 2G, but let's make sure the hash table
is under 1G as that will satisfy the IOMMU requirements and also means the
hash table will be on node 0.

Signed-off-by: Michael Ellerman <michael at ellerman.id.au>
---
 arch/powerpc/mm/hash_utils_64.c |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 9326a69..487c5e2 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -471,7 +471,7 @@ void __init htab_initialize(void)
 	unsigned long table;
 	unsigned long pteg_count;
 	unsigned long mode_rw;
-	unsigned long base = 0, size = 0;
+	unsigned long base = 0, size = 0, limit;
 	int i;
 
 	extern unsigned long tce_alloc_start, tce_alloc_end;
@@ -505,9 +505,15 @@ void __init htab_initialize(void)
 		_SDR1 = 0; 
 	} else {
 		/* Find storage for the HPT.  Must be contiguous in
-		 * the absolute address space.
+		 * the absolute address space. On cell we want it to be
+		 * in the first 1 Gig.
 		 */
-		table = lmb_alloc(htab_size_bytes, htab_size_bytes);
+		if (machine_is(cell))
+			limit = 0x40000000;
+		else
+			limit = 0;
+
+		table = lmb_alloc_base(htab_size_bytes, htab_size_bytes, limit);
 
 		DBG("Hash table allocated at %lx, size: %lx\n", table,
 		    htab_size_bytes);
-- 
1.5.2.rc1.1884.g59b20