Commit Graph

14 Commits

Author SHA1 Message Date
Nathan Whitehorn
83c01b8cf6 Close a race involving the OEA64 scratchpage. When the scratch page's
physical address is changed, there is a brief window during which its PTE
is invalid. Since moea64_set_scratchpage_pa() does not and cannot hold
the page table lock, it was possible for another CPU to insert a new PTE
into the scratch page's PTEG slot during this interval, corrupting both
mappings.

Solve this by creating a new flag, LPTE_LOCKED, such that
moea64_pte_insert will avoid claiming locked PTEG slots even if they
are invalid. This change also incorporates some additional paranoia
added to solve things I thought might be this bug.

Reported by:	linimon
2010-02-24 00:54:37 +00:00
Nathan Whitehorn
ab73970649 Reduce KVA pressure on OEA64 systems running in bridge mode by mapping
UMA segments at their physical addresses instead of into KVA. This emulates
the direct mapping behavior of OEA32 in an ad-hoc way. To make this work
properly required sharing the entire kernel PMAP with Open Firmware, so
ofw_pmap is transformed into a stub on 64-bit CPUs.

Also implement some more tweaks to get more mileage out of our limited
amount of KVA, principally by extending KVA into segment 16 until the
beginning of the first OFW mapping.

Reported by:	linimon
2010-02-20 16:23:29 +00:00
Nathan Whitehorn
062c8f4c86 Fix a bug where pages being removed from memory entirely no longer have
PVOs, and so the modified state of the page can no longer be communicated
to the VM layer, causing pages not to be flushed to swap when needed, in
turn causing memory corruption. Also make several correctness adjustments
to I-Cache synchronization and TLB invalidation for 64-bit Book-S CPUs.

Obtained from:	projects/ppc64
Discussed with:	grehan
MFC after:	2 weeks
2010-02-18 15:00:43 +00:00
Martin Blapp
c2ede4b379 Remove extraneous semicolons, no functional changes.
Submitted by:	Marc Balmer <marc@msys.ch>
MFC after:	1 week
2010-01-07 21:01:37 +00:00
Nathan Whitehorn
4603558264 Provide a real fix to the too-many-translations problem when booting
from CD on 64-bit hardware to replace existing band-aids. This occurred
when the preloaded mdroot required too many mappings for the static
buffer.

Since we only use the translations buffer once, allocate a dynamic
buffer on the stack. This early in the boot process, the call chain
is quite short and we can be assured of having sufficient stack space.

Reviewed by:	grehan
2009-11-12 15:19:09 +00:00
Nathan Whitehorn
c10d3c2cd8 Spell sz correctly.
Pointed out by:	jmallett
2009-11-09 21:12:28 +00:00
Nathan Whitehorn
f90550c2d2 Increase the size of the OFW translations buffer to handle G5 systems
that use many translation regions in firmware, and add bounds checking
to prevent buffer overflows in case even the new value is exceeded.

Reported by:	Jacob Lambert
MFC after:	3 days
2009-11-09 14:26:23 +00:00
Nathan Whitehorn
e2ee8728ee Do not map the trap vectors into the kernel's address space. They are
only used in real mode and keeping them mapped only serves to make NULL
a valid address, which results in silent NULL pointer deferences.

Suggested by:   Patrick Kerharo
Obtained from:	projects/ppc64
2009-10-23 14:27:40 +00:00
Nathan Whitehorn
999987e51a Add SMP support on U3-based G5 systems. This does not yet work perfectly:
at least on my Xserve, getting the decrementer and timebase on APs to tick
requires setting up a clock chip over I2C, which is not yet done.

While here, correct the 64-bit tlbie function to set the CPU to 64-bit
mode correctly.

Hardware donated by:	grehan
2009-10-23 03:17:02 +00:00
Marcel Moolenaar
1a4fcaebe3 o Introduce vm_sync_icache() for making the I-cache coherent with
the memory or D-cache, depending on the semantics of the platform.
    vm_sync_icache() is basically a wrapper around pmap_sync_icache(),
    that translates the vm_map_t argumument to pmap_t.
o   Introduce pmap_sync_icache() to all PMAP implementation. For powerpc
    it replaces the pmap_page_executable() function, added to solve
    the I-cache problem in uiomove_fromphys().
o   In proc_rwmem() call vm_sync_icache() when writing to a page that
    has execute permissions. This assures that when breakpoints are
    written, the I-cache will be coherent and the process will actually
    hit the breakpoint.
o   This also fixes the Book-E PMAP implementation that was missing
    necessary locking while trying to deal with the I-cache coherency
    in pmap_enter() (read: mmu_booke_enter_locked).

The key property of this change is that the I-cache is made coherent
*after* writes have been done. Doing it in the PMAP layer when adding
or changing a mapping means that the I-cache is made coherent *before*
any writes happen. The difference is key when the I-cache prefetches.
2009-10-21 18:38:02 +00:00
Nathan Whitehorn
f136543e41 Increase the size of the page table on 64-bit PowerPC machines as a
bandaid to prevent exhaustion of the primary and secondary hash groups
in the event of extreme stress on the PMAP layer (e.g. a forkbomb). This
wastes memory, and should be revised to properly handle PTEG spills instead.

Suggested by:	grehan
Approved by:	re (kensmith)
2009-07-12 04:07:52 +00:00
Jeff Roberson
50c202c592 Implement a facility for dynamic per-cpu variables.
- Modules and kernel code alike may use DPCPU_DEFINE(),
   DPCPU_GET(), DPCPU_SET(), etc. akin to the statically defined
   PCPU_*.  Requires only one extra instruction more than PCPU_* and is
   virtually the same as __thread for builtin and much faster for shared
   objects.  DPCPU variables can be initialized when defined.
 - Modules are supported by relocating the module's per-cpu linker set
   over space reserved in the kernel.  Modules may fail to load if there
   is insufficient space available.
 - Track space available for modules with a one-off extent allocator.
   Free may block for memory to allocate space for an extent.

Reviewed by:    jhb, rwatson, kan, sam, grehan, marius, marcel, stas
2009-06-23 22:42:39 +00:00
Nathan Whitehorn
b40ce02a2f Factor out platform dependent things unrelated to device drivers into a
new platform module. These are probed in early boot, and have the
responsibility of determining the layout of physical memory, determining
the CPU timebase frequency, and handling the zoo of SMP mechanisms
found on PowerPC.

Reviewed by:	marcel, raj
Book-E parts by: raj
2009-05-14 00:34:26 +00:00
Nathan Whitehorn
1c96bdd146 Add support for 64-bit PowerPC CPUs operating in the 64-bit bridge mode
provided, for example, on the PowerPC 970 (G5), as well as on related CPUs
like the POWER3 and POWER4.

This also adds support for various built-in hardware found on Apple G5
hardware (e.g. the IBM CPC925 northbridge).

Reviewed by:    grehan
2009-04-04 00:22:44 +00:00