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

powerpc/pci: Check devices status property when scanning OF tree

2012-08-17T19:35:11Z

commit 5b339bdf164d8aee394609768f7e2e4415b0252a upstream. We ran into an issue where it looks like we're not properly ignoring a pci device with a non-good status property when we walk the device tree and instanciate the Linux side PCI devices. However, the EEH init code does look for the property and disables EEH on these devices. This leaves us in an inconsistent where we are poking at a supposedly bad piece of hardware and RTAS will block our config cycles because EEH isn't enabled anyway. Signed-of-by: Sonny Rao Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker

powerpc: Fix device tree claim code

2012-05-17T15:21:28Z

commit 966728dd88b4026ec58fee169ccceaeaf56ef120 upstream. I have a box that fails in OF during boot with: DEFAULT CATCH!, exception-handler=fff00400 at %SRR0: 49424d2c4c6f6768 %SRR1: 800000004000b002 ie "IBM,Logh". OF got corrupted with a device tree string. Looking at make_room and alloc_up, we claim the first chunk (1 MB) but we never claim any more. mem_end is always set to alloc_top which is the top of our available address space, guaranteeing we will never call alloc_up and claim more memory. Also alloc_up wasn't setting alloc_bottom to the bottom of the available address space. This doesn't help the box to boot, but we at least fail with an obvious error. We could relocate the device tree in a future patch. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker

powerpc/kdump: Fix timeout in crash_kexec_wait_realmode

2012-05-17T15:21:19Z

commit 63f21a56f1cc0b800a4c00349c59448f82473d19 upstream. The existing code it pretty ugly. How about we clean it up even more like this? From: Anton Blanchard We check for timeout expiry in the outer loop, but we also need to check it in the inner loop or we can lock up forever waiting for a CPU to hit real mode. Signed-off-by: Anton Blanchard Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker

powerpc/kexec: Fix memory corruption from unallocated slaves

2012-05-17T15:20:25Z

commit 3d2cea732d68aa270c360f55d8669820ebce188a upstream. Commit 1fc711f7ffb01089efc58042cfdbac8573d1b59a (powerpc/kexec: Fix race in kexec shutdown) moved the write to signal the cpu had exited the kernel from before the transition to real mode in kexec_smp_wait to kexec_wait. Unfornately it missed that kexec_wait is used both by cpus leaving the kernel and by secondary slave cpus that were not allocated a paca for what ever reason -- they could be beyond nr_cpus or not described in the current device tree for whatever reason (for example, kexec-load was not refreshed after a cpu hotplug operation). Cpus coming through that path they will write to paca[NR_CPUS] which is beyond the space allocated for the paca data and overwrite memory not allocated to pacas but very likely still real mode accessable). Move the write back to kexec_smp_wait, which is used only by cpus that found their paca, but after the transition to real mode. Signed-off-by: Milton Miller Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker

powerpc: rtas_flash needs to use rtas_data_buf

2011-06-26T16:47:10Z

commit bd2b64a12bf55bec0d1b949e3dca3f8863409646 upstream. When trying to flash a machine via the update_flash command, Anton received the following error: Restarting system. FLASH: kernel bug...flash list header addr above 4GB The code in question has a comment that the flash list should be in the kernel data and therefore under 4GB: /* NOTE: the "first" block list is a global var with no data * blocks in the kernel data segment. We do this because * we want to ensure this block_list addr is under 4GB. */ Unfortunately the Kconfig option is marked tristate which means the variable may not be in the kernel data and could be above 4GB. Instead of relying on the data segment being below 4GB, use the static data buffer allocated by the kernel for use by rtas. Since we don't use the header struct directly anymore, convert it to a simple pointer. Reported-By: Anton Blanchard Signed-Off-By: Milton Miller Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker

powerpc: Fix default_machine_crash_shutdown #ifdef botch

2011-06-26T16:47:10Z

commit c2be05481f6125254c45b78f334d4dd09c701c82 upstream. crash_kexec_wait_realmode() is defined only if CONFIG_PPC_STD_MMU_64 and CONFIG_SMP, but is called if CONFIG_PPC_STD_MMU_64 even if !CONFIG_SMP. Fix the conditional compilation around the invocation. [PG: commit b3df895aebe091b1657 "powerpc/kexec: Add support for FSL-BookE" introduced the PPC_STD_MMU_64 check this refers to, but we don't want to cherry pick that whole addition to stable just for one #ifdef line.] Signed-off-by: Paul E. McKenney Acked-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker

powerpc/kdump: Fix race in kdump shutdown

2011-06-26T16:47:10Z

commit 60adec6226bbcf061d4c2d10944fced209d1847d upstream. When we are crashing, the crashing/primary CPU IPIs the secondaries to turn off IRQs, go into real mode and wait in kexec_wait. While this is happening, the primary tears down all the MMU maps. Unfortunately the primary doesn't check to make sure the secondaries have entered real mode before doing this. On PHYP machines, the secondaries can take a long time shutting down the IRQ controller as RTAS calls are need. These RTAS calls need to be serialised which resilts in the secondaries contending in lock_rtas() and hence taking a long time to shut down. We've hit this on large POWER7 machines, where some secondaries are still waiting in lock_rtas(), when the primary tears down the HPTEs. This patch makes sure all secondaries are in real mode before the primary tears down the MMU. It uses the new kexec_state entry in the paca. It times out if the secondaries don't reach real mode after 10sec. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker

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/kexec: Fix orphaned offline CPUs across kexec

2011-06-26T16:46:59Z

commit e8e5c2155b0035b6e04f29be67f6444bc914005b upstream. When CPU hotplug is used, some CPUs may be offline at the time a kexec is performed. The subsequent kernel may expect these CPUs to be already running, and will declare them stuck. On pseries, there's also a soft-offline (cede) state that CPUs may be in; this can also cause problems as the kexeced kernel may ask RTAS if they're online -- and RTAS would say they are. The CPU will either appear stuck, or will cause a crash as we replace its cede loop beneath it. This patch kicks each present offline CPU awake before the kexec, so that none are forever lost to these assumptions in the subsequent kernel. Now, the behaviour is that all available CPUs that were offlined are now online & usable after the kexec. This mimics the behaviour of a full reboot (on which all CPUs will be restarted). Signed-off-by: Matt Evans Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Gortmaker