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  1. 10 7月, 2008 2 次提交
  3. 03 7月, 2008 3 次提交
  5. 01 7月, 2008 2 次提交
  7. 30 6月, 2008 3 次提交
  9. 18 6月, 2008 1 次提交
    • P
      [POWERPC] Clear sub-page HPTE present bits when demoting page size · 65ba6cdc
      由 Paul Mackerras 提交于 
      When we demote a slice from 64k to 4k, and we are about to insert an
HPTE for a 4k subpage and we notice that there is an existing 64k
HPTE, we first invalidate that HPTE before inserting the new 4k
subpage HPTE.  Since the bits that encode which hash bucket the old
HPTE was in overlap with the bits that encode which of the 16 subpages
have HPTEs, we need to clear out the subpage HPTE-present bits before
starting to insert HPTEs for the 4k subpages.  If we don't do that, we
can erroneously think that a subpage already has an HPTE when it
doesn't.

That in itself wouldn't be such a problem except that when we go to
update the HPTE that we think is present on machines with a
hypervisor, the hypervisor can tell us that the HPTE we think is there
is actually there even though it isn't, which can lead to a process
getting stuck in a loop, continually faulting.  The reason for the
confusion is that the AVPN (abbreviated virtual page number) we are
looking for in the HPTE for a 4k subpage can actually match the AVPN
in a stale HPTE for another 64k page.  For example, the HPTE for
the 4k subpage at 0x84000f000 will be in the same hash bucket and have
the same AVPN as the HPTE for the 64k page at 0x8400f0000.

This fixes the code to clear out the subpage HPTE-present bits.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      65ba6cdc
  11. 09 6月, 2008 1 次提交
  13. 23 5月, 2008 1 次提交
  15. 20 5月, 2008 1 次提交
  17. 15 5月, 2008 1 次提交
    • B
      [POWERPC] vmemmap fixes to use smaller pages · cec08e7a
      由 Benjamin Herrenschmidt 提交于 
      This changes vmemmap to use a different region (region 0xf) of the
address space, and to configure the page size of that region
dynamically at boot.

The problem with the current approach of always using 16M pages is that
it's not well suited to machines that have small amounts of memory such
as small partitions on pseries, or PS3's.

In fact, on the PS3, failure to allocate the 16M page backing vmmemmap
tends to prevent hotplugging the HV's "additional" memory, thus limiting
the available memory even more, from my experience down to something
like 80M total, which makes it really not very useable.

The logic used by my match to choose the vmemmap page size is:

 - If 16M pages are available and there's 1G or more RAM at boot,
   use that size.
 - Else if 64K pages are available, use that
 - Else use 4K pages

I've tested on a POWER6 (16M pages) and on an iSeries POWER3 (4K pages)
and it seems to work fine.

Note that I intend to change the way we organize the kernel regions &
SLBs so the actual region will change from 0xf back to something else at
one point, as I simplify the SLB miss handler, but that will be for a
later patch.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      cec08e7a
  19. 14 5月, 2008 4 次提交
  21. 02 5月, 2008 2 次提交
    • P
      [POWERPC] Bolt in SLB entry for kernel stack on secondary cpus · 3b575064
      由 Paul Mackerras 提交于 
      This fixes a regression reported by Kamalesh Bulabel where a POWER4
machine would crash because of an SLB miss at a point where the SLB
miss exception was unrecoverable.  This regression is tracked at:

http://bugzilla.kernel.org/show_bug.cgi?id=10082

SLB misses at such points shouldn't happen because the kernel stack is
the only memory accessed other than things in the first segment of the
linear mapping (which is mapped at all times by entry 0 of the SLB).
The context switch code ensures that SLB entry 2 covers the kernel
stack, if it is not already covered by entry 0.  None of entries 0
to 2 are ever replaced by the SLB miss handler.

Where this went wrong is that the context switch code assumes it
doesn't have to write to SLB entry 2 if the new kernel stack is in the
same segment as the old kernel stack, since entry 2 should already be
correct.  However, when we start up a secondary cpu, it calls
slb_initialize, which doesn't set up entry 2.  This is correct for
the boot cpu, where we will be using a stack in the kernel BSS at this
point (i.e. init_thread_union), but not necessarily for secondary
cpus, whose initial stack can be allocated anywhere.  This doesn't
cause any immediate problem since the SLB miss handler will just
create an SLB entry somewhere else to cover the initial stack.

In fact it's possible for the cpu to go quite a long time without SLB
entry 2 being valid.  Eventually, though, the entry created by the SLB
miss handler will get overwritten by some other entry, and if the next
access to the stack is at an unrecoverable point, we get the crash.

This fixes the problem by making slb_initialize create a suitable
entry for the kernel stack, if we are on a secondary cpu and the stack
isn't covered by SLB entry 0.  This requires initializing the
get_paca()->kstack field earlier, so I do that in smp_create_idle
where the current field is initialized.  This also abstracts a bit of
the computation that mk_esid_data in slb.c does so that it can be used
in slb_initialize.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      3b575064
    • G
      [POWERPC] Fix slb.c compile warnings · bbea3460
      由 Geoff Levand 提交于 
      Arrange for a syntax check to always be done on the powerpc/mm/slb.c
DBG() macro by defining it to pr_debug() for non-debug builds.

Also, fix these related compile warnings:

  slb.c:273: warning: format '%04x' expects type 'unsigned int', but argument 2 has type 'long unsigned int
  slb.c:274: warning: format '%04x' expects type 'unsigned int', but argument 2 has type 'long unsigned int'
Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      bbea3460
  23. 29 4月, 2008 1 次提交
  25. 28 4月, 2008 1 次提交
  27. 24 4月, 2008 4 次提交
    • K
      [POWERPC] Clean up access to thread_info in assembly · f608600e
      由 Kumar Gala 提交于 
      Use (31-THREAD_SHIFT) to get to thread_info from stack pointer.  This makes
the code a bit easier to read and more robust if we ever change THREAD_SHIFT.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      f608600e
    • K
      [POWERPC] Port fixmap from x86 and use for kmap_atomic · 2c419bde
      由 Kumar Gala 提交于 
      The fixmap code from x86 allows us to have compile time virtual addresses
that we change the physical addresses of at run time.

This is useful for applications like kmap_atomic, PCI config that is done
via direct memory map, kexec/kdump.

We got ride of CONFIG_HIGHMEM_START as we can now determine a more optimal
location for PKMAP_BASE based on where the fixmap addresses start and
working back from there.

Additionally, the kmap code in asm-powerpc/highmem.h always had debug
enabled.  Moved to using CONFIG_DEBUG_HIGHMEM to determine if we should
have the extra debug checking.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      2c419bde
    • K
      [POWERPC] 85xx: Add support for relocatable kernel (and booting at non-zero) · 37dd2bad
      由 Kumar Gala 提交于 
      Added support to allow an 85xx kernel to be run from a non-zero physical
address (useful for cooperative asymmetric multiprocessing situations and
kdump).  The support can be configured at compile time by setting
CONFIG_PAGE_OFFSET, CONFIG_KERNEL_START, and CONFIG_PHYSICAL_START as
desired.

Alternatively, the kernel build can set CONFIG_RELOCATABLE.  Setting this
config option causes the kernel to determine at runtime the physical
addresses of CONFIG_PAGE_OFFSET and CONFIG_KERNEL_START.  If
CONFIG_RELOCATABLE is set, then CONFIG_PHYSICAL_START has no meaning.
However, CONFIG_PHYSICAL_START will always be used to set the LOAD program
header physical address field in the resulting ELF image.

Currently we are limited to running at a physical address that is a
multiple of 256M.  This is due to how we map TLBs to cover
lowmem.  This should be fixed to allow 64M or maybe even 16M alignment
in the future.  It is considered an error to try and run a kernel at a
non-aligned physical address.

All the magic for this support is accomplished by proper initialization
of the kernel memory subsystem and use of ARCH_PFN_OFFSET.

The use of ARCH_PFN_OFFSET only affects normal memory and not IO mappings.
ioremap uses map_page and isn't affected by ARCH_PFN_OFFSET.

/dev/mem continues to allow access to any physical address in the system
regardless of how CONFIG_PHYSICAL_START is set.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      37dd2bad
    • M
      [POWERPC] Add include of linux/of.h to numa.c · 6df1646e
      由 Michael Ellerman 提交于 
      numa.c requires routines declared in linux/of.h, so should include it.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      6df1646e
  29. 18 4月, 2008 1 次提交
  31. 17 4月, 2008 5 次提交
  33. 07 4月, 2008 1 次提交
  35. 03 4月, 2008 1 次提交
  37. 01 4月, 2008 4 次提交
  39. 24 3月, 2008 1 次提交
    • P
      [POWERPC] Don't use 64k pages for ioremap on pSeries · cfe666b1
      由 Paul Mackerras 提交于 
      On pSeries, the hypervisor doesn't let us map in the eHEA ethernet
adapter using 64k pages, and thus the ehea driver will fail if 64k
pages are configured.  This works around the problem by always
using 4k pages for ioremap on pSeries (but not on other platforms).
A better fix would be to check whether the partition could ever
have an eHEA adapter, and only force 4k pages if it could, but this
will do for 2.6.25.

This is based on an earlier patch by Tony Breeds.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      cfe666b1