From: Michael Ellerman <michael@ellerman.id.au>
Date: Wed, 12 Mar 2008 07:03:24 +0000 (+1100)
Subject: [POWERPC] Fix large hash table allocation on Cell blades
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=31bf111944e31b64a7b692f9d660f71c5ff3d419;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

[POWERPC] Fix large hash table allocation on Cell blades

My recent hack to allocate the hash table under 1GB on cell was poorly
tested, *cough*. It turns out on blades with large amounts of memory we
fail to allocate the hash table at all. This is because RTAS has been
instantiated just below 768MB, and 0-x MB are used by the kernel,
leaving no areas that are both large enough and also naturally-aligned.

For the cell IOMMU hack the page tables must be under 2GB, so use that
as the limit instead. This has been tested on real hardware and boots
happily.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 32f416175db..590f1f67c87 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -506,10 +506,10 @@ void __init htab_initialize(void)
 	} else {
 		/* Find storage for the HPT.  Must be contiguous in
 		 * the absolute address space. On cell we want it to be
-		 * in the first 1 Gig.
+		 * in the first 2 Gig so we can use it for IOMMU hacks.
 		 */
 		if (machine_is(cell))
-			limit = 0x40000000;
+			limit = 0x80000000;
 		else
 			limit = 0;