linux-toradex.git/arch/powerpc/include/asm/pgtable.h, branch v3.14.8

mm: Use ptep/pmdp_set_numa() for updating _PAGE_NUMA bit

2014-02-17T00:19:36+00:00

Archs like ppc64 doesn't do tlb flush in set_pte/pmd functions when using
a hash table MMU for various reasons (the flush is handled as part of
the PTE modification when necessary).

ppc64 thus doesn't implement flush_tlb_range for hash based MMUs.

Additionally ppc64 require the tlb flushing to be batched within ptl locks.

The reason to do that is to ensure that the hash page table is in sync with
linux page table.

We track the hpte index in linux pte and if we clear them without flushing
hash and drop the ptl lock, we can have another cpu update the pte and can
end up with duplicate entry in the hash table, which is fatal.

We also want to keep set_pte_at simpler by not requiring them to do hash
flush for performance reason. We do that by assuming that set_pte_at() is
never *ever* called on a PTE that is already valid.

This was the case until the NUMA code went in which broke that assumption.

Fix that by introducing a new pair of helpers to set _PAGE_NUMA in a
way similar to ptep/pmdp_set_wrprotect(), with a generic implementation
using set_pte_at() and a powerpc specific one using the appropriate
mechanism needed to keep the hash table in sync.

Acked-by: Mel Gorman 
Reviewed-by: Rik van Riel 
Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Benjamin Herrenschmidt

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2014-01-31T16:37:32+00:00

Pull more KVM updates from Paolo Bonzini:
 "Second batch of KVM updates.  Some minor x86 fixes, two s390 guest
  features that need some handling in the host, and all the PPC changes.

  The PPC changes include support for little-endian guests and
  enablement for new POWER8 features"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (45 commits)
  x86, kvm: correctly access the KVM_CPUID_FEATURES leaf at 0x40000101
  x86, kvm: cache the base of the KVM cpuid leaves
  kvm: x86: move KVM_CAP_HYPERV_TIME outside #ifdef
  KVM: PPC: Book3S PR: Cope with doorbell interrupts
  KVM: PPC: Book3S HV: Add software abort codes for transactional memory
  KVM: PPC: Book3S HV: Add new state for transactional memory
  powerpc/Kconfig: Make TM select VSX and VMX
  KVM: PPC: Book3S HV: Basic little-endian guest support
  KVM: PPC: Book3S HV: Add support for DABRX register on POWER7
  KVM: PPC: Book3S HV: Prepare for host using hypervisor doorbells
  KVM: PPC: Book3S HV: Handle new LPCR bits on POWER8
  KVM: PPC: Book3S HV: Handle guest using doorbells for IPIs
  KVM: PPC: Book3S HV: Consolidate code that checks reason for wake from nap
  KVM: PPC: Book3S HV: Implement architecture compatibility modes for POWER8
  KVM: PPC: Book3S HV: Add handler for HV facility unavailable
  KVM: PPC: Book3S HV: Flush the correct number of TLB sets on POWER8
  KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs
  KVM: PPC: Book3S HV: Align physical and virtual CPU thread numbers
  KVM: PPC: Book3S HV: Don't set DABR on POWER8
  kvm/ppc: IRQ disabling cleanup
  ...

kvm: powerpc: define a linux pte lookup function

2014-01-09T09:15:07+00:00

We need to search linux "pte" to get "pte" attributes for setting TLB in KVM.
This patch defines a lookup_linux_ptep() function which returns pte pointer.

Signed-off-by: Bharat Bhushan 
Reviewed-by: Scott Wood 
Signed-off-by: Alexander Graf

powerpc/mm: Enable _PAGE_NUMA for book3s

2013-12-09T00:40:30+00:00

We steal the _PAGE_COHERENCE bit and use that for indicating NUMA ptes.

Signed-off-by: Aneesh Kumar K.V 
Acked-by: Paul Mackerras 
Signed-off-by: Benjamin Herrenschmidt

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2013-07-04T17:29:23+00:00

Pull powerpc updates from Ben Herrenschmidt:
 "This is the powerpc changes for the 3.11 merge window.  In addition to
  the usual bug fixes and small updates, the main highlights are:

   - Support for transparent huge pages by Aneesh Kumar for 64-bit
     server processors.  This allows the use of 16M pages as transparent
     huge pages on kernels compiled with a 64K base page size.

   - Base VFIO support for KVM on power by Alexey Kardashevskiy

   - Wiring up of our nvram to the pstore infrastructure, including
     putting compressed oopses in there by Aruna Balakrishnaiah

   - Move, rework and improve our "EEH" (basically PCI error handling
     and recovery) infrastructure.  It is no longer specific to pseries
     but is now usable by the new "powernv" platform as well (no
     hypervisor) by Gavin Shan.

   - I fixed some bugs in our math-emu instruction decoding and made it
     usable to emulate some optional FP instructions on processors with
     hard FP that lack them (such as fsqrt on Freescale embedded
     processors).

   - Support for Power8 "Event Based Branch" facility by Michael
     Ellerman.  This facility allows what is basically "userspace
     interrupts" for performance monitor events.

   - A bunch of Transactional Memory vs.  Signals bug fixes and HW
     breakpoint/watchpoint fixes by Michael Neuling.

  And more ...  I appologize in advance if I've failed to highlight
  something that somebody deemed worth it."

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits)
  pstore: Add hsize argument in write_buf call of pstore_ftrace_call
  powerpc/fsl: add MPIC timer wakeup support
  powerpc/mpic: create mpic subsystem object
  powerpc/mpic: add global timer support
  powerpc/mpic: add irq_set_wake support
  powerpc/85xx: enable coreint for all the 64bit boards
  powerpc/8xx: Erroneous double irq_eoi() on CPM IRQ in MPC8xx
  powerpc/fsl: Enable CONFIG_E1000E in mpc85xx_smp_defconfig
  powerpc/mpic: Add get_version API both for internal and external use
  powerpc: Handle both new style and old style reserve maps
  powerpc/hw_brk: Fix off by one error when validating DAWR region end
  powerpc/pseries: Support compression of oops text via pstore
  powerpc/pseries: Re-organise the oops compression code
  pstore: Pass header size in the pstore write callback
  powerpc/powernv: Fix iommu initialization again
  powerpc/pseries: Inform the hypervisor we are using EBB regs
  powerpc/perf: Add power8 EBB support
  powerpc/perf: Core EBB support for 64-bit book3s
  powerpc/perf: Drop MMCRA from thread_struct
  powerpc/perf: Don't enable if we have zero events
  ...

consolidate io_remap_pfn_range definitions

2013-06-29T08:46:35+00:00

Signed-off-by: Al Viro

powerpc: move find_linux_pte_or_hugepte and gup_hugepte to common code

2013-06-21T06:01:54+00:00

We will use this in the later patch for handling THP pages

Reviewed-by: David Gibson 
Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Benjamin Herrenschmidt

powerpc/THP: Implement transparent hugepages for ppc64

2013-06-21T06:01:53+00:00

We now have pmd entries covering 16MB range and the PMD table double its original size.
We use the second half of the PMD table to deposit the pgtable (PTE page).
The depoisted PTE page is further used to track the HPTE information. The information
include [ secondary group | 3 bit hidx | valid ]. We use one byte per each HPTE entry.
With 16MB hugepage and 64K HPTE we need 256 entries and with 4K HPTE we need
4096 entries. Both will fit in a 4K PTE page. On hugepage invalidate we need to walk
the PTE page and invalidate all valid HPTEs.

This patch implements necessary arch specific functions for THP support and also
hugepage invalidate logic. These PMD related functions are intentionally kept
similar to their PTE counter-part.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format

2013-04-30T05:59:56+00:00

We will be switching PMD_SHIFT to 24 bits to facilitate THP impmenetation.
With PMD_SHIFT set to 24, we now have 16MB huge pages allocated at PGD level.
That means with 32 bit process we cannot allocate normal pages at
all, because we cover the entire address space with one pgd entry. Fix this
by switching to a new page table format for hugepages. With the new page table
format for 16GB and 16MB hugepages we won't allocate hugepage directory. Instead
we encode the PTE information directly at the directory level. This forces 16MB
hugepage at PMD level. This will also make the page take walk much simpler later
when we add the THP support.

With the new table format we have 4 cases for pgds and pmds:
(1) invalid (all zeroes)
(2) pointer to next table, as normal; bottom 6 bits == 0
(3) leaf pte for huge page, bottom two bits != 00
(4) hugepd pointer, bottom two bits == 00, next 4 bits indicate size of table

Signed-off-by: Aneesh Kumar K.V 
Acked-by: Paul Mackerras 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Don't hard code the size of pte page

2013-04-30T05:59:46+00:00

USE PTRS_PER_PTE to indicate the size of pte page. To support THP,
later patches will be changing PTRS_PER_PTE value.

Acked-by: Paul Mackerras 
Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Benjamin Herrenschmidt