Enable hugepages on Freescale BookE processors. This allows the kernel to
use huge TLB entries to map pages, which can greatly reduce the number of
TLB misses and the amount of TLB thrashing experienced by applications with
large memory footprints. Care should be taken when using this on FSL
processors, as the number of large TLB entries supported by the core is low
(16-64) on current processors.
The supported set of hugepage sizes include 4m, 16m, 64m, 256m, and 1g.
Page sizes larger than the max zone size are called "gigantic" pages and
must be allocated on the command line (and cannot be deallocated).
This is currently only fully implemented for Freescale 32-bit BookE
processors, but there is some infrastructure in the code for
64-bit BooKE.
Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
slb0_limit() wasn't a very descriptive name. This changes it along with
a comment explaining what it's used for, and provides a 64-bit BookE
implementation.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When we set up the TLB for ourselves on Book3E, we need to flush out any
old mappings established by the firmware or bootloader. At present we
attempt this with a tlbilx to flush everything, but this will leave behind
any entries with the IPROT bit set.
There are several good reason firmware might establish mappings with IPROT,
and in fact ePAPR compliant firmwares are required to establish their
initial mapped area with IPROT.
This patch, therefore adds more complex code to scan through the TLB upon
entry and flush away any entries that are not our own.
Signed-off-by: Jack Miller <jack@codezen.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Update setup_page_sizes() to support for a MMU v1.0 FSL style MMU
implementation. In such a processor, we don't have TLB0PS or EPTCFG
registers (and access to these registers may cause exceptions). We need
to parse the older format of TLBnCFG for page size support. Additionaly,
assume since we are an FSL implementation that we have 2 TLB arrays and
the second array contains the variable size pages.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Use the MMU config registers to scan for available direct and
indirect page sizes and print out the result. Will be needed
for future hugetlbfs implementation.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The MMUCSR is now defined as part of the Book-3E architecture so we
can move it into mmu-book3e.h and add some of the additional bits
defined by the architecture specs.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
The base TLB support didn't include support for SPARSEMEM_VMEMMAP, though
we did carve out some virtual space for it, the necessary support code
wasn't there. This implements it by using 16M pages for now, though the
page size could easily be changed at runtime if necessary.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds the PTE and pgtable format definitions, along with changes
to the kernel memory map and other definitions related to implementing
support for 64-bit Book3E. This also shields some asm-offset bits that
are currently only relevant on 32-bit
We also move the definition of the "linux" page size constants to
the common mmu.h file and add a few sizes that are relevant to
embedded processors.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds various additional bit definitions for various MMU related
SPRs used on Book3E.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The Power ISA 2.06 spec introduces a standard MMU programming model that
is based on the Freescale Book-E MMU programing model. The Freescale
version is pretty backwards compatiable with the ISA 2.06 definition so
we are starting to refactor some of the Freescale code so it can be
easily shared.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
