powerpc: support multiple hugepage sizes

Instead of using the variable mmu_huge_psize to keep track of the huge
page size we use an array of MMU_PAGE_* values.  For each supported huge
page size we need to know the hugepte_shift value and have a
pgtable_cache.  The hstate or an mmu_huge_psizes index is passed to
functions so that they know which huge page size they should use.

The hugepage sizes 16M and 64K are setup(if available on the hardware) so
that they don't have to be set on the boot cmd line in order to use them.
The number of 16G pages have to be specified at boot-time though (e.g.
hugepagesz=16G hugepages=5).

Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 5 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 30278e9e5211..01a2992b5754 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -776,11 +776,11 @@ and is between 256 and 4096 characters. It is defined in the file
 
         hugepages=      [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
         hugepagesz=     [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
-                        On x86 this option can be specified multiple times
-                        interleaved with hugepages= to reserve huge pages
-                        of different sizes. Valid pages sizes on x86-64
-                        are 2M (when the CPU supports "pse") and 1G (when the
-                        CPU supports the "pdpe1gb" cpuinfo flag)
+                        On x86-64 and powerpc, this option can be specified
+                        multiple times interleaved with hugepages= to reserve
+                        huge pages of different sizes. Valid pages sizes on
+                        x86-64 are 2M (when the CPU supports "pse") and 1G
+                        (when the CPU supports the "pdpe1gb" cpuinfo flag)
                         Note that 1GB pages can only be allocated at boot time
                         using hugepages= and not freed afterwards.
         default_hugepagesz=