kernel.git/arch/powerpc/include, branch linux-2.6.34.y

powerpc/kexec: Fix race in kexec shutdown

2011-06-26T16:47:10Z

commit 1fc711f7ffb01089efc58042cfdbac8573d1b59a upstream. In kexec_prepare_cpus, the primary CPU IPIs the secondary CPUs to kexec_smp_down(). kexec_smp_down() calls kexec_smp_wait() which sets the hw_cpu_id() to -1. The primary does this while leaving IRQs on which means the primary can take a timer interrupt which can lead to the IPIing one of the secondary CPUs (say, for a scheduler re-balance) but since the secondary CPU now has a hw_cpu_id = -1, we IPI CPU -1... Kaboom! We are hitting this case regularly on POWER7 machines. There is also a second race, where the primary will tear down the MMU mappings before knowing the secondaries have entered real mode. Also, the secondaries are clearing out any pending IPIs before guaranteeing that no more will be received. This changes kexec_prepare_cpus() so that we turn off IRQs in the primary CPU much earlier. It adds a paca flag to say that the secondaries have entered the kexec_smp_down() IPI and turned off IRQs, rather than overloading hw_cpu_id with -1. This new paca flag is again used to in indicate when the secondaries has entered real mode. It also ensures that all CPUs have their IRQs off before we clear out any pending IPI requests (in kexec_cpu_down()) to ensure there are no trailing IPIs left unacknowledged. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker

perf, powerpc: Handle events that raise an exception without overflowing

2011-06-26T16:47:07Z

commit 0837e3242c73566fc1c0196b4ec61779c25ffc93 upstream. Events on POWER7 can roll back if a speculative event doesn't eventually complete. Unfortunately in some rare cases they will raise a performance monitor exception. We need to catch this to ensure we reset the PMC. In all cases the PMC will be 256 or less cycles from overflow. Signed-off-by: Anton Blanchard Signed-off-by: Peter Zijlstra LKML-Reference: <20110309143842.6c22845e@kryten> Signed-off-by: Ingo Molnar Signed-off-by: Paul Gortmaker

powerpc/pseries: Add hcall to read 4 ptes at a time in real mode

2011-06-26T16:46:58Z

commit f90ece28c1f5b3ec13fe481406857fe92f4bc7d1 upstream. This adds plpar_pte_read_4_raw() which can be used read 4 PTEs from PHYP at a time, while in real mode. It also creates a new hcall9 which can be used in real mode. It's the same as plpar_hcall9 but minus the tracing hcall statistics which may require variables outside the RMO. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker

compat: Make compat_alloc_user_space() incorporate the access_ok()

2011-01-06T23:07:49Z

commit c41d68a513c71e35a14f66d71782d27a79a81ea6 upstream. compat_alloc_user_space() expects the caller to independently call access_ok() to verify the returned area. A missing call could introduce problems on some architectures. This patch incorporates the access_ok() check into compat_alloc_user_space() and also adds a sanity check on the length. The existing compat_alloc_user_space() implementations are renamed arch_compat_alloc_user_space() and are used as part of the implementation of the new global function. This patch assumes NULL will cause __get_user()/__put_user() to either fail or access userspace on all architectures. This should be followed by checking the return value of compat_access_user_space() for NULL in the callers, at which time the access_ok() in the callers can also be removed. Reported-by: Ben Hawkes Signed-off-by: H. Peter Anvin Acked-by: Benjamin Herrenschmidt Acked-by: Chris Metcalf Acked-by: David S. Miller Acked-by: Ingo Molnar Acked-by: Thomas Gleixner Acked-by: Tony Luck Cc: Andrew Morton Cc: Arnd Bergmann Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Heiko Carstens Cc: Helge Deller Cc: James Bottomley Cc: Kyle McMartin Cc: Martin Schwidefsky Cc: Paul Mackerras Cc: Ralf Baechle Signed-off-by: Paul Gortmaker

powerpc/cpm: Reintroduce global spi_pram struct (fixes build issue)

2010-08-02T17:29:50Z

commit 56825c88ff438f4dbb51a44591cc29e707fe783a upstream. spi_t was removed in commit 644b2a680ccc51a9ec4d6beb12e9d47d2dee98e2 ("powerpc/cpm: Remove SPI defines and spi structs"), the commit assumed that spi_t isn't used anywhere outside of the spi_mpc8xxx driver. But it appears that the struct is needed for micropatch code. So, let's reintroduce the struct. Fixes the following build issue: CC arch/powerpc/sysdev/micropatch.o micropatch.c: In function 'cpm_load_patch': micropatch.c:629: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token micropatch.c:629: error: 'spp' undeclared (first use in this function) micropatch.c:629: error: (Each undeclared identifier is reported only once micropatch.c:629: error: for each function it appears in.) Reported-by: LEROY Christophe Reported-by: Tony Breeds Signed-off-by: Anton Vorontsov Signed-off-by: Kumar Gala Signed-off-by: Greg Kroah-Hartman

powerpc/perf_event: Fix oops due to perf_event_do_pending call

2010-05-12T04:34:00Z

Anton Blanchard found that large POWER systems would occasionally crash in the exception exit path when profiling with perf_events. The symptom was that an interrupt would occur late in the exit path when the MSR[RI] (recoverable interrupt) bit was clear. Interrupts should be hard-disabled at this point but they were enabled. Because the interrupt was not recoverable the system panicked. The reason is that the exception exit path was calling perf_event_do_pending after hard-disabling interrupts, and perf_event_do_pending will re-enable interrupts. The simplest and cleanest fix for this is to use the same mechanism that 32-bit powerpc does, namely to cause a self-IPI by setting the decrementer to 1. This means we can remove the tests in the exception exit path and raw_local_irq_restore. This also makes sure that the call to perf_event_do_pending from timer_interrupt() happens within irq_enter/irq_exit. (Note that calling perf_event_do_pending from timer_interrupt does not mean that there is a possible 1/HZ latency; setting the decrementer to 1 ensures that the timer interrupt will happen immediately, i.e. within one timebase tick, which is a few nanoseconds or 10s of nanoseconds.) Signed-off-by: Paul Mackerras Cc: stable@kernel.org Signed-off-by: Benjamin Herrenschmidt

powerpc/fsl-booke: Fix CONFIG_RELOCATABLE support on FSL Book-E ppc32

2010-04-26T22:54:15Z

The following commit broke CONFIG_RELOCATABLE support on FSL Book-E parts: commit 549e8152de8039506f69c677a4546e5427aa6ae7 Author: Paul Mackerras Date: Sat Aug 30 11:43:47 2008 +1000 powerpc: Make the 64-bit kernel as a position-independent executable The change to __va and __pa to use PAGE_OFFSET & MEMORY_START causes problems on the Book-E parts because we don't know MEMORY_START until after we parse the device tree. We need __va to work properly to even parse the device tree so we have a chicken an egg. So go back to using he other definition of __va/__pa on CONFIG_BOOKE and use the PAGE_OFFSET/MEMORY_START version on "Classic" PPC64. Also updated casts to handle phys_addr_t being a different size from unsigned long (ie 36-bit physical on PPC32). Signed-off-by: Kumar Gala

Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2010-03-26T22:09:33Z

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: powerpc/perf_events: Fix call-graph recording, add perf_arch_fetch_caller_regs perf top: Add missing initialization to zero perf probe: Use original address instead of CU-based address perf probe: Fix offset to allow signed value perf top: Improve the autosizing of column lenghts perf probe: Fix need_dwarf flag if lazy matching is used perf probe: Fix probe_point buffer overrun

powerpc: Use correct ccr bit for syscall error status

2010-03-19T05:38:16Z

The powerpc implementations of syscall_get_error and syscall_set_return_value should use CCR0:S0 (0x10000000) for testing and setting syscall error status. Fortunately these APIs don't seem to be used at the moment. Signed-off-by: Nathan Lynch Signed-off-by: Benjamin Herrenschmidt

Merge commit 'kumar/merge' into merge

2010-03-19T05:23:55Z