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authorPaul Mackerras <paulus@samba.org>2005-10-12 16:58:53 +1000
committerPaul Mackerras <paulus@samba.org>2005-10-12 16:58:53 +1000
commit3eac8c69d1ac1266327f4e29deb23716a12c6d30 (patch)
tree0f79bf41c9f7e9e72d7f2827c1810d3815d6f2af /arch/powerpc/mm
parentb6ec995a21a9428aef620b5adf46d047a18d88b8 (diff)
powerpc: Move default hash table size calculation to hash_utils_64.c
We weren't computing the size of the hash table correctly on iSeries because the relevant code in prom.c was #ifdef CONFIG_PPC_PSERIES. This moves the code to hash_utils_64.c, makes it unconditional, and cleans it up a bit. Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/mm')
-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 35dd93eeaf4b..6e9e05cce02c 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. */