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Diffstat (limited to 'arch/powerpc/mm/hash_utils_64.c')
-rw-r--r--arch/powerpc/mm/hash_utils_64.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 35dd93eeaf4..6e9e05cce02 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -155,6 +155,27 @@ static inline void create_pte_mapping(unsigned long start, unsigned long end,
}
}
+static unsigned long get_hashtable_size(void)
+{
+ unsigned long rnd_mem_size, pteg_count;
+
+ /* If hash size wasn't obtained in prom.c, we calculate it now based on
+ * the total RAM size
+ */
+ if (ppc64_pft_size)
+ return 1UL << ppc64_pft_size;
+
+ /* round mem_size up to next power of 2 */
+ rnd_mem_size = 1UL << __ilog2(systemcfg->physicalMemorySize);
+ if (rnd_mem_size < systemcfg->physicalMemorySize)
+ rnd_mem_size <<= 1;
+
+ /* # pages / 2 */
+ pteg_count = max(rnd_mem_size >> (12 + 1), 1UL << 11);
+
+ return pteg_count << 7;
+}
+
void __init htab_initialize(void)
{
unsigned long table, htab_size_bytes;
@@ -170,7 +191,7 @@ void __init htab_initialize(void)
* Calculate the required size of the htab. We want the number of
* PTEGs to equal one half the number of real pages.
*/
- htab_size_bytes = 1UL << ppc64_pft_size;
+ htab_size_bytes = get_hashtable_size();
pteg_count = htab_size_bytes >> 7;
/* For debug, make the HTAB 1/8 as big as it normally would be. */