This patch convert different functions to take virtual page number
instead of virtual address. Virtual page number is virtual address
shifted right by VPN_SHIFT (12) bits. This enable us to have an
address range of upto 76 bits.
Reviewed-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

abs_to_virt() is just a wrapper around __va(), call __va() directly.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Disintegrate asm/system.h for PowerPC.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
cc: linuxppc-dev@lists.ozlabs.org

This is no longer selectable, so just remove all the dependent code.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On 2012-02-20 11:02:51 Mon, Paul Mackerras wrote:
> On Thu, Feb 16, 2012 at 04:44:30PM +0530, Mahesh J Salgaonkar wrote:
>
> If I have read the code correctly, we are going to get this printk on
> non-pSeries machines or on older pSeries machines, even if the user
> has not put the fadump=on option on the kernel command line.  The
> printk will be annoying since there is no actual error condition.  It
> seems to me that the condition for the printk should include
> fw_dump.fadump_enabled.  In other words you should probably add
>
> 	if (!fw_dump.fadump_enabled)
> 		return 0;
>
> at the beginning of the function.

Hi Paul,

Thanks for pointing it out. Please find the updated patch below.

The existing patches above this (4/10 through 10/10) cleanly applies
on this update.

Thanks,
-Mahesh.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

With module.h being implicitly everywhere via device.h, the absence
of explicitly including something for EXPORT_SYMBOL went unnoticed.
Since we are heading to fix things up and clean module.h from the
device.h file, we need to explicitly include these files now.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

If we echo an address the hypervisor doesn't like to
/sys/devices/system/memory/probe we oops the box:

# echo 0x10000000000 > /sys/devices/system/memory/probe

kernel BUG at arch/powerpc/mm/hash_utils_64.c:541!

The backtrace is:

create_section_mapping
arch_add_memory
add_memory
memory_probe_store
sysdev_class_store
sysfs_write_file
vfs_write
SyS_write

In create_section_mapping we BUG if htab_bolt_mapping returned
an error. A better approach is to return an error which will
propagate back to userspace.

Rerunning the test with this patch applied:

# echo 0x10000000000 > /sys/devices/system/memory/probe
-bash: echo: write error: Invalid argument
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

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: NBecky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Some of the 64bit PPC CPU features are MMU-related, so this patch moves
them to MMU_FTR_ bits.  All cpu_has_feature()-style tests are moved to
mmu_has_feature(), and seven feature bits are freed as a result.
Signed-off-by: NMatt Evans <matt@ozlabs.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There are a few places we patch instructions without using
patch_instruction and patch_branch, probably because they
predated it. Fix it.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Change pgdir from a void to real type.  Having this as a void is
stupid and has already caused 1 bug.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

In:
  powerpc/mm: Fix pgtable cache cleanup with CONFIG_PPC_SUBPAGE_PROT
  commit d28513bc
  Author: David Gibson <david@gibson.dropbear.id.au>

subpage_protection() was changed to to take an mm rather a pgdir but it
didn't change calling site in hashpage_preload().  The change wasn't
noticed at compile time since hashpage_preload() used a void* as the
parameter to subpage_protection().

This is obviously wrong and can trigger the following crash when
CONFIG_SLAB, CONFIG_DEBUG_SLAB, CONFIG_PPC_64K_PAGES
CONFIG_PPC_SUBPAGE_PROT are enabled.

Freeing unused kernel memory: 704k freed
Unable to handle kernel paging request for data at address 0x6b6b6b6b6b6c49b7
Faulting instruction address: 0xc0000000000410f4
cpu 0x2: Vector: 300 (Data Access) at [c00000004233f590]
    pc: c0000000000410f4: .hash_preload+0x258/0x338
    lr: c000000000041054: .hash_preload+0x1b8/0x338
    sp: c00000004233f810
   msr: 8000000000009032
   dar: 6b6b6b6b6b6c49b7
 dsisr: 40000000
  current = 0xc00000007e2c0070
  paca    = 0xc000000007fe0500
    pid   = 1, comm = init
enter ? for help
[c00000004233f810] c000000000041020 .hash_preload+0x184/0x338 (unreliable)
[c00000004233f8f0] c00000000003ed98 .update_mmu_cache+0xb0/0xd0
[c00000004233f990] c000000000157754 .__do_fault+0x48c/0x5dc
[c00000004233faa0] c000000000158fd0 .handle_mm_fault+0x508/0xa8c
[c00000004233fb90] c0000000006acdd4 .do_page_fault+0x428/0x6ac
[c00000004233fe30] c000000000005260 handle_page_fault+0x20/0x74
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The RMA (RMO is a misnomer) is a concept specific to ppc64 (in fact
server ppc64 though I hijack it on embedded ppc64 for similar purposes)
and represents the area of memory that can be accessed in real mode
(aka with MMU off), or on embedded, from the exception vectors (which
is bolted in the TLB) which pretty much boils down to the same thing.

We take that out of the generic MEMBLOCK data structure and move it into
arch/powerpc where it belongs, renaming it to "RMA" while at it.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This introduce memblock.current_limit which is used to limit allocations
from memblock_alloc() or memblock_alloc_base(..., MEMBLOCK_ALLOC_ACCESSIBLE).

The old MEMBLOCK_ALLOC_ANYWHERE changes value from 0 to ~(u64)0 and can still
be used with memblock_alloc_base() to allocate really anywhere.

It is -no-longer- cropped to MEMBLOCK_REAL_LIMIT which disappears.

Note to archs: I'm leaving the default limit to MEMBLOCK_ALLOC_ANYWHERE. I
strongly recommend that you ensure that you set an appropriate limit
during boot in order to guarantee that an memblock_alloc() at any time
results in something that is accessible with a simple __va().

The reason is that a subsequent patch will introduce the ability for
the array to resize itself by reallocating itself. The MEMBLOCK core will
honor the current limit when performing those allocations.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This adds some debug output to our MMU hash code to print out some
useful debug data if the hypervisor refuses the insertion (which
should normally never happen).
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
---

Instead of adding _PAGE_PRESENT to the access permission mask
in each low level routine independently, we add it once from
hash_page().

We also move the preliminary access check (the racy one before
the PTE is locked) up so it applies to the huge page case. This
duplicates code in __hash_page_huge() which we'll remove in a
subsequent patch to fix a race in there.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

via following scripts

      FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

      sed -i \
        -e 's/lmb/memblock/g' \
        -e 's/LMB/MEMBLOCK/g' \
        $FILES

      for N in $(find . -name lmb.[ch]); do
        M=$(echo $N | sed 's/lmb/memblock/g')
        mv $N $M
      done

and remove some wrong change like lmbench and dlmb etc.

also move memblock.c from lib/ to mm/
Suggested-by: NIngo Molnar <mingo@elte.hu>
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Commit d28513bc ("Fix bug in pagetable
cache cleanup with CONFIG_PPC_SUBPAGE_PROT"), itself a fix for
breakage caused by an earlier clean up patch of mine, contains a
stupid bug.  I changed the parameters of the subpage_protection()
function, but failed to update one of the callers.

This patch fixes it, and replaces a void * with a typed pointer so
that the compiler will warn on such an error in future.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This time without the funny characters.

Fix following build errors generated with DEBUG=1

cc1: warnings being treated as errors
arch/powerpc/mm/hash_utils_64.c: In function 'htab_dt_scan_page_sizes':
arch/powerpc/mm/hash_utils_64.c:343: error: format '%04x' expects type 'unsigned int', but argument 4 has type 'long unsigned int'
arch/powerpc/mm/hash_utils_64.c:343: error: format '%08x' expects type 'unsigned int', but argument 5 has type 'long unsigned int'
arch/powerpc/mm/hash_utils_64.c: In function 'htab_initialize':
arch/powerpc/mm/hash_utils_64.c:666: error: format '%x' expects type 'unsigned int', but argument 4 has type 'long unsigned int'
... SNIP ...
Signed-off-by: NSachin Sant <sachinp@in.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Commit a0668cdc cleans up the handling
of kmem_caches for allocating various levels of pagetables.
Unfortunately, it conflicts badly with CONFIG_PPC_SUBPAGE_PROT, due to
the latter's cleverly hidden technique of adding some extra allocation
space to the top level page directory to store the extra information
it needs.

Since that extra allocation really doesn't fit into the cleaned up
page directory allocating scheme, this patch alters
CONFIG_PPC_SUBPAGE_PROT to instead allocate its struct
subpage_prot_table as part of the mm_context_t.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This reverts commit c045256d.

It breaks build when CONFIG_PPC_SUBPAGE_PROT is not set. I will
commit a fixed version separately
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Commit a0668cdc cleans up the handling
of kmem_caches for allocating various levels of pagetables.
Unfortunately, it conflicts badly with CONFIG_PPC_SUBPAGE_PROT, due to
the latter's cleverly hidden technique of adding some extra allocation
space to the top level page directory to store the extra information
it needs.

Since that extra allocation really doesn't fit into the cleaned up
page directory allocating scheme, this patch alters
CONFIG_PPC_SUBPAGE_PROT to instead allocate its struct
subpage_prot_table as part of the mm_context_t.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We want to be able to build KVM as a module. To enable us doing so, we
need some more exports from core Linux parts.

This patch exports all functions and variables that are required for KVM.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The hugepage arch code provides a number of hook functions/macros
which mirror the functionality of various normal page pte access
functions.  Various changes in the normal page accessors (in
particular BenH's recent changes to the handling of lazy icache
flushing and PAGE_EXEC) have caused the hugepage versions to get out
of sync with the originals.  In some cases, this is a bug, at least on
some MMU types.

One of the reasons that some hooks were not identical to the normal
page versions, is that the fact we're dealing with a hugepage needed
to be passed down do use the correct dcache-icache flush function.
This patch makes the main flush_dcache_icache_page() function hugepage
aware (by checking for the PageCompound flag).  That in turn means we
can make set_huge_pte_at() just a call to set_pte_at() bringing it
back into sync.  As a bonus, this lets us remove the
hash_huge_page_do_lazy_icache() function, replacing it with a call to
the hash_page_do_lazy_icache() function it was based on.

Some other hugepage pte access hooks - huge_ptep_get_and_clear() and
huge_ptep_clear_flush() - are not so easily unified, but this patch at
least brings them back into sync with the current versions of the
corresponding normal page functions.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch simplifies the logic used to initialize hugepages on
powerpc.  The somewhat oddly named set_huge_psize() is renamed to
add_huge_page_size() and now does all necessary verification of
whether it's given a valid hugepage sizes (instead of just some) and
instantiates the generic hstate structure (but no more).

hugetlbpage_init() now steps through the available pagesizes, checks
if they're valid for hugepages by calling add_huge_page_size() and
initializes the kmem_caches for the hugepage pagetables.  This means
we can now eliminate the mmu_huge_psizes array, since we no longer
need to pass the sizing information for the pagetable caches from
set_huge_psize() into hugetlbpage_init()

Determination of the default huge page size is also moved from the
hash code into the general hugepage code.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently each available hugepage size uses a slightly different
pagetable layout: that is, the bottem level table of pointers to
hugepages is a different size, and may branch off from the normal page
tables at a different level.  Every hugepage aware path that needs to
walk the pagetables must therefore look up the hugepage size from the
slice info first, and work out the correct way to walk the pagetables
accordingly.  Future hardware is likely to add more possible hugepage
sizes, more layout options and more mess.

This patch, therefore reworks the handling of hugepage pagetables to
reduce this complexity.  In the new scheme, instead of having to
consult the slice mask, pagetable walking code can check a flag in the
PGD/PUD/PMD entries to see where to branch off to hugepage pagetables,
and the entry also contains the information (eseentially hugepage
shift) necessary to then interpret that table without recourse to the
slice mask.  This scheme can be extended neatly to handle multiple
levels of self-describing "special" hugepage pagetables, although for
now we assume only one level exists.

This approach means that only the pagetable allocation path needs to
know how the pagetables should be set out.  All other (hugepage)
pagetable walking paths can just interpret the structure as they go.

There already was a flag bit in PGD/PUD/PMD entries for hugepage
directory pointers, but it was only used for debug.  We alter that
flag bit to instead be a 0 in the MSB to indicate a hugepage pagetable
pointer (normally it would be 1 since the pointer lies in the linear
mapping).  This means that asm pagetable walking can test for (and
punt on) hugepage pointers with the same test that checks for
unpopulated page directory entries (beq becomes bge), since hugepage
pointers will always be positive, and normal pointers always negative.

While we're at it, we get rid of the confusing (and grep defeating)
#defining of hugepte_shift to be the same thing as mmu_huge_psizes.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

early_init_mmu_secondary() is called at CPU hotplug time, so it
must be marked as __cpuinit, not __init.

Caused by 757c74d2 ("powerpc/mm: Introduce early_init_mmu() on 64-bit").
Tested-by: NSachin Sant <sachinp@in.ibm.com>
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This moves some MMU related init code out of setup_64.c into hash_utils_64.c
and calls it early_init_mmu() and early_init_mmu_secondary(). This will
make it easier to plug in a new MMU type.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Makes code futureproof against the impending change to mm->cpu_vm_mask.

It's also a chance to use the new cpumask_ ops which take a pointer
(the older ones are deprecated, but there's no hurry for arch code).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

At the moment we size the hashtable based on 4kB pages / 2, even on a
64kB kernel. This results in a hashtable that is much larger than it
needs to be.

Grab the real page size and size the hashtable based on that

Note: This only has effect on non hypervisor machines.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

If mem= is used on the boot command line to limit memory then the memory block where a 16G page resides may not be available.

Thanks to Michael Ellerman for finding the problem.
Signed-off-by: NJon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The typesafe version of the powerpc pagetable handling (with
USE_STRICT_MM_TYPECHECKS defined) has bitrotted again.  This patch
makes a bunch of small fixes to get it back to building status.

It's still not enabled by default as gcc still generates worse
code with it for some reason.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This implements CONFIG_RELOCATABLE for 64-bit by making the kernel as
a position-independent executable (PIE) when it is set.  This involves
processing the dynamic relocations in the image in the early stages of
booting, even if the kernel is being run at the address it is linked at,
since the linker does not necessarily fill in words in the image for
which there are dynamic relocations.  (In fact the linker does fill in
such words for 64-bit executables, though not for 32-bit executables,
so in principle we could avoid calling relocate() entirely when we're
running a 64-bit kernel at the linked address.)

The dynamic relocations are processed by a new function relocate(addr),
where the addr parameter is the virtual address where the image will be
run.  In fact we call it twice; once before calling prom_init, and again
when starting the main kernel.  This means that reloc_offset() returns
0 in prom_init (since it has been relocated to the address it is running
at), which necessitated a few adjustments.

This also changes __va and __pa to use an equivalent definition that is
simpler.  With the relocatable kernel, PAGE_OFFSET and MEMORY_START are
constants (for 64-bit) whereas PHYSICAL_START is a variable (and
KERNELBASE ideally should be too, but isn't yet).

With this, relocatable kernels still copy themselves down to physical
address 0 and run there.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Commit bc033b63 ("powerpc/mm: Fix
attribute confusion with htab_bolt_mapping()") moved the check for
whether we should make pages of the linear mapping executable from
htab_bolt_mapping into its callers, including htab_initialize.
A side-effect of this is that the decision is now made once for
each contiguous section in the LMB array rather than for each page
individually.  This can often mean that the whole of the linear
mapping ends up being executable.

This reverts to the previous behaviour, where individual pages are
checked for being part of the kernel text or not, by moving the check
back down into htab_bolt_mapping.
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

htab_dt_scan_hugepage_blocks is only used when CONFIG_HUGETLB_PAGE is
defined, so guard the declaration likewise.
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The function htab_bolt_mapping() is used to create permanent
mappings in the MMU hash table, for example, in order to create
the linear mapping of vmemmap.  It's also used by early boot
ioremap (before mem_init_done).

However, the way ioremap uses it is incorrect as it passes it the
protection flags in the "linux PTE" form while htab_bolt_mapping()
expects them in the hash table format.  This is made more confusing by
the fact that some of those flags are actually in the same position in
both cases.

This fixes it all by making htab_bolt_mapping() take normal linux
protection flags instead, and use a little helper to convert them to
htab flags. Callers can now use the usual PAGE_* definitions safely.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

 arch/powerpc/include/asm/mmu-hash64.h |    2 -
 arch/powerpc/mm/hash_utils_64.c       |   65 ++++++++++++++++++++--------------
 arch/powerpc/mm/init_64.c             |    9 +---
 3 files changed, 44 insertions(+), 32 deletions(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>