instead of a PCPU field for curthread. This averts a race on SMP systems
with a high interrupt rate where the thread looking up the value of
curthread could be preempted and migrated between obtaining the PCPU
pointer and reading the value of pc_curthread, resulting in curthread being
observed to be the current thread on the thread's original CPU. This played
merry havoc with the system, in particular with mutexes. Many thanks to
jhb for helping me work this one out.
Note that Book-E is in principle susceptible to the same problem, but has
not been modified yet due to lack of Book-E hardware.
MFC after: 2 weeks
some interesting bugs (mostly on SMP systems) with atomic operations
silently failing in interrupt heavy situations, especially when using
overflow pages.
pmap_sync_icache() to sync random (possibly uncached or nonexisting!)
memory, causing kernel page faults or machine checks, most easily
triggered by using GDB. While here, add an additional safeguard to only
sync cacheable memory.
MFC after: 2 days
Renovate and improve the AIM Open Firmware support:
- Add RTAS (Run-Time Abstraction Services) support, found on all IBM systems
and some Apple ones
- Improve support for 32-bit real mode Open Firmware systems
- Pull some more OF bits over from the AIM directory
- Fix memory detection on IBM LPARs and systems with more than one /memory
node (by andreast@)
sf buf allocation, use wakeup() instead of wakeup_one() to notify sf
buffer waiters about free buffer.
sf_buf_alloc() calls msleep(PCATCH) when SFB_CATCH flag was given,
and for simultaneous wakeup and signal delivery, msleep() returns
EINTR/ERESTART despite the thread was selected for wakeup_one(). As
result, we loose a wakeup, and some other waiter will not be woken up.
Reported and tested by: az
Reviewed by: alc, jhb
MFC after: 1 week
table. The 'locked' attribute is used to circumvent the regular page table
locking for some special pages, with the result that including locked pages
here causes races when updating the stats.
logic to support modifying the page table through a hypervisor. This
uses KOBJ inheritance to provide subclasses of the base 64-bit AIM MMU
class with additional methods for page table manipulation.
Many thanks to Peter Grehan for suggesting this design and implementing
the MMU KOBJ inheritance mechanism.
DPCPU_DEFINE and VNET_DEFINE macros, as these cause problems for various
people working on the affected files. A better long-term solution is
still being considered. This reversal may give some modules empty
set_pcpu or set_vnet sections, but these are harmless.
Changes reverted:
------------------------------------------------------------------------
r215318 | dim | 2010-11-14 21:40:55 +0100 (Sun, 14 Nov 2010) | 4 lines
Instead of unconditionally emitting .globl's for the __start_set_xxx and
__stop_set_xxx symbols, only emit them when the set_vnet or set_pcpu
sections are actually defined.
------------------------------------------------------------------------
r215317 | dim | 2010-11-14 21:38:11 +0100 (Sun, 14 Nov 2010) | 3 lines
Apply the STATIC_VNET_DEFINE and STATIC_DPCPU_DEFINE macros throughout
the tree.
------------------------------------------------------------------------
r215316 | dim | 2010-11-14 21:23:02 +0100 (Sun, 14 Nov 2010) | 2 lines
Add macros to define static instances of VNET_DEFINE and DPCPU_DEFINE.
that causes AP bringup to fail if some of the Cell HID-register code
is anywhere in the instruction stream. Pending a better solution, cache
performance on SMP Cell systems running without a hypervisor will be
suboptimal.
mappings need to end up in the kernel anyway since the kernel begins
executing in OF context. Separating them adds needless complexity,
especially since the powerpc64 and mmu_oea64 code gave up on it a long
time ago.
As a side effect, the PPC ofw_machdep code is no longer AIM-specific,
so move it to powerpc/ofw.
hypervisor infrastructure support:
- Fix coexistence of multiple platform modules in the same kernel
- Allow platform modules to provide an SMP topology
- PowerPC hypervisors limit the amount of memory accessible in real mode.
Allow the platform modules to specify the maximum real-mode address,
and modify the bits of the kernel that need to allocate
real-mode-accessible buffers to respect this limits.
work properly with single-stepping in a kernel debugger. Specifically,
these routines have always disabled interrupts before increasing the nesting
count and restored the prior state of interrupts after decreasing the nesting
count to avoid problems with a nested interrupt not disabling interrupts
when acquiring a spin lock. However, trap interrupts for single-stepping
can still occur even when interrupts are disabled. Now the saved state of
interrupts is not saved in the thread until after interrupts have been
disabled and the nesting count has been increased. Similarly, the saved
state from the thread cannot be read once the nesting count has been
decreased to zero. To fix this, use temporary variables to store interrupt
state and shuffle it between the thread's MD area and the appropriate
registers.
In cooperation with: bde
MFC after: 1 month
only, and should be protected with an ifdef, and the no-execute bit in
32-bit set_user_sr() should be set before the comparison, not after, or
it will never match.
set_user_sr() itself caches the user segment VSID, there is no need for
cpu_switch() to do it again. This change also unifies the 32 and 64-bit
code paths for kernel faults on user pages and remaps the user SLB slot
on 64-bit systems when taking a syscall to avoid some unnecessary segment
exception traps.
