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2011-05-04powerpc: Save Come-From Address Register (CFAR) in exception framePaul Mackerras
Recent 64-bit server processors (POWER6 and POWER7) have a "Come-From Address Register" (CFAR), that records the address of the most recent branch or rfid (return from interrupt) instruction for debugging purposes. This saves the value of the CFAR in the exception entry code and stores it in the exception frame. We also make xmon print the CFAR value in its register dump code. Rather than extend the pt_regs struct at this time, we steal the orig_gpr3 field, which is only used for system calls, and use it for the CFAR value for all exceptions/interrupts other than system calls. This means we don't save the CFAR on system calls, which is not a great problem since system calls tend not to happen unexpectedly, and also avoids adding the overhead of reading the CFAR to the system call entry path. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-04powerpc: Save register r9-r13 values accurately on interrupt with bad stackPaul Mackerras
When we take an interrupt or exception from kernel mode and the stack pointer is obviously not a kernel address (i.e. the top bit is 0), we switch to an emergency stack, save register values and panic. However, on 64-bit server machines, we don't actually save the values of r9 - r13 at the time of the interrupt, but rather values corrupted by the exception entry code for r12-r13, and nothing at all for r9-r11. This fixes it by passing a pointer to the register save area in the paca through to the bad_stack code in r3. The register values are saved in one of the paca register save areas (depending on which exception this is). Using the pointer in r3, the bad_stack code now retrieves the saved values of r9 - r13 and stores them in the exception frame on the emergency stack. This also stores the normal exception frame marker ("regshere") in the exception frame. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-04powerpc/irq: Stop exporting irq_mapGrant Likely
First step in eliminating irq_map[] table entirely Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc: Free up some CPU feature bits by moving out MMU-related featuresMatt Evans
Some of the 64bit PPC CPU features are MMU-related, so this patch moves them to MMU_FTR_ bits. All cpu_has_feature()-style tests are moved to mmu_has_feature(), and seven feature bits are freed as a result. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc/rtas: Only sleep in rtas_busy_delay if we have useful work to doAnton Blanchard
RTAS returns extended error codes as a hint of how long the OS might want to wait before retrying a call. If we have nothing else useful to do we may as well call back straight away. This was found when testing the new dynamic dma window feature. Firmware split the zeroing of the TCE table into 32k chunks but returned 9901 (which is a suggested wait of 10ms). All up this took about 10 minutes to complete since msleep is jiffies based and will round 10ms up to 20ms. With the patch below we take 3 seconds to complete the same test. The hint firmware is returning in the RTAS call should definitely be decreased, but even if we slept 1ms each iteration this would take 32s. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc: Use MSR_64BIT in placesMichael Ellerman
Use the new MSR_64BIT in a few places. Some of these are already ifdef'ed for BOOKE vs BOOKS, but it's still clearer, MSR_SF does not immediately parse as "MSR bit for 64bit". Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc/irq: Dump chip data pointer in virq_mappingMichael Ellerman
This can be useful for differentiating interrupts on the same host but with different chip data. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc/pci: Properly initialize IO workaround "private"Michael Ellerman
Even when no initfunc is provided. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc/pci: Make IO workarounds init implicit when first bus is registeredMichael Ellerman
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc/pci: Move IO workarounds to the common kernel dirMichael Ellerman
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc: Per process DSCR + some fixes (try#4)Alexey Kardashevskiy
The DSCR (aka Data Stream Control Register) is supported on some server PowerPC chips and allow some control over the prefetch of data streams. This patch allows the value to be specified per thread by emulating the corresponding mfspr and mtspr instructions. Children of such threads inherit the value. Other threads use a default value that can be specified in sysfs - /sys/devices/system/cpu/dscr_default. If a thread starts with non default value in the sysfs entry, all children threads inherit this non default value even if the sysfs value is changed later. Signed-off-by: Alexey Kardashevskiy <aik@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc/book3e: Flush IPROT protected TLB entries leftover by firmwareJack Miller
When we set up the TLB for ourselves on Book3E, we need to flush out any old mappings established by the firmware or bootloader. At present we attempt this with a tlbilx to flush everything, but this will leave behind any entries with the IPROT bit set. There are several good reason firmware might establish mappings with IPROT, and in fact ePAPR compliant firmwares are required to establish their initial mapped area with IPROT. This patch, therefore adds more complex code to scan through the TLB upon entry and flush away any entries that are not our own. Signed-off-by: Jack Miller <jack@codezen.org> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc/book3e: Use way 3 for linear mapping bolted entryBenjamin Herrenschmidt
An erratum on A2 can lead to the bolted entry we insert for the linear mapping being evicted, to avoid that write the bolted entry to way 3. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc: Index crit/dbg/mcheck stacks using cpu number on 64bitMichael Ellerman
In exc_lvl_ctx_init() we index into the crit/dbg/mcheck stacks using the hard cpu id, but that assumes the hard cpu id is zero based and contiguous. That is not the case on A2. The root of the problem is that the 32bit code has no equivalent of the paca to allow it to do the hard->soft mapping in assembler. Until the 32bit code is updated to handle that, index the stacks using the soft cpu ids on 64bit and hard on 32 bit. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc: Add A2 cpu supportBenjamin Herrenschmidt
Add the cputable entry, regs and setup & restore entries for the PowerPC A2 core. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc/smp: smp_ops->kick_cpu() should be able to failMichael Ellerman
When we start a cpu we use smp_ops->kick_cpu(), which currently returns void, it should be able to fail. Convert it to return int, and update all uses. Convert all the current error cases to return -ENOENT, which is what would eventually be returned by __cpu_up() currently when it doesn't detect the cpu as coming up in time. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Improve prom_printf()Benjamin Herrenschmidt
Adds the ability to print decimal numbers and adds some more format string variants Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Perform an isync to synchronize CPUs coming out of secondary_holdBenjamin Herrenschmidt
We need to do that to guarantee they see any code change done by dynamic patching during boot. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Add NAP mode support on Power7 in HV modeBenjamin Herrenschmidt
Wakeup comes from the system reset handler with a potential loss of the non-hypervisor CPU state. We save the non-volatile state on the stack and a pointer to it in the PACA, which the system reset handler uses to restore things Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Properly handshake CPUs going out of boot spin loopBenjamin Herrenschmidt
We need to wait a bit for them to have done their CPU setup or we might end up with translation and EE on with different LPCR values between threads Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Call CPU ->restore callback earlier on secondary CPUsBenjamin Herrenschmidt
We do it before we loop on the PACA start flag. This way, we get a chance to set critical SPRs on all CPUs before Linux tries to start them up, which avoids problems when changing some bits such as LPCR bits that need to be identical on all threads of a core or similar things like that. Ideally, some of that should also be done before the MMU is enabled, but that's a separate issue which would require moving some of the SMP startup code earlier, let's not get there for now, it works with that change alone. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Initialize TLB and LPID register on HV mode Power7Benjamin Herrenschmidt
In case entry from the bootloader isn't "clean" Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Initialize LPCR:DPFD on power7 to a sane defaultBenjamin Herrenschmidt
This sets the default data stream prefetch size for operating systems that don't set their own value in DSCR. We use 4 which is "medium". Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Always use SPRN_SPRG_HSCRATCH0 when running in HV modePaul Mackerras
This uses feature sections to arrange that we always use HSPRG1 as the scratch register in the interrupt entry code rather than SPRG2 when we're running in hypervisor mode on POWER7. This will ensure that we don't trash the guest's SPRG2 when we are running KVM guests. To simplify the code, we define GET_SCRATCH0() and SET_SCRATCH0() macros like the GET_PACA/SET_PACA macros. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: More work to support HV exceptionsBenjamin Herrenschmidt
Rework exception macros a bit to split offset from vector and add some basic support for HDEC, HDSI, HISI and a few more. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Base support for exceptions using HSRR0/1Benjamin Herrenschmidt
Pass the register type to the prolog, also provides alternate "HV" version of hardware interrupt (0x500) and adjust LPES accordingly We tag those interrupts by setting bit 0x2 in the trap number Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: In HV mode, use HSPRG0 for PACABenjamin Herrenschmidt
When running in Hypervisor mode (arch 2.06 or later), we store the PACA in HSPRG0 instead of SPRG1. The architecture specifies that SPRGs may be lost during a "nap" power management operation (though they aren't currently on POWER7) and this enables use of SPRG1 by KVM guests. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20powerpc: Define CPU feature for Architected 2.06 HV modeBenjamin Herrenschmidt
This bit indicates that we are operating in hypervisor mode on a CPU compliant to architecture 2.06 or later (currently server only). We set it on POWER7 and have a boot-time CPU setup function that clears it if MSR:HV isn't set (booting under a hypervisor). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-18powerpc/perf_event: Skip updating kernel counters if register value shrinksEric B Munson
Because of speculative event roll back, it is possible for some event coutners to decrease between reads on POWER7. This causes a problem with the way that counters are updated. Delta calues are calculated in a 64 bit value and the top 32 bits are masked. If the register value has decreased, this leaves us with a very large positive value added to the kernel counters. This patch protects against this by skipping the update if the delta would be negative. This can lead to a lack of precision in the coutner values, but from my testing the value is typcially fewer than 10 samples at a time. Signed-off-by: Eric B Munson <emunson@mgebm.net> Cc: stable@kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-18powerpc: Fix oops if scan_dispatch_log is called too earlyAnton Blanchard
We currently enable interrupts before the dispatch log for the boot cpu is setup. If a timer interrupt comes in early enough we oops in scan_dispatch_log: Unable to handle kernel paging request for data at address 0x00000010 ... .scan_dispatch_log+0xb0/0x170 .account_system_vtime+0xa0/0x220 .irq_enter+0x88/0xc0 .do_IRQ+0x48/0x230 The patch below adds a check to scan_dispatch_log to ensure the dispatch log has been allocated. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-18powerpc/kexec: Fix regression causing compile failure on UPPaul Gortmaker
Recent commit b987812b3fcaf70fdf0037589e5d2f5f2453e6ce caused a compile failure on UP because a considerably large block of the file was included within CONFIG_SMP, hence making a stub function not exposed on UP builds when it needed to be. Relocate the stub to the #else /* ! CONFIG_SMP */ section and also annotate the relevant else/endif so that nobody else falls into the same trap I did. Reported-by: Michael Guntsche <mike@it-loops.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-18Merge remote branch 'kumar/merge' into mergeBenjamin Herrenschmidt
2011-04-12powerpc/book3e: Fix CPU feature handling on 64-bit e5500Kumar Gala
The CPU_FTRS_POSSIBLE and CPU_FTRS_ALWAYS defines did not encompass e5500 CPU features when built for 64-bit. This causes issues with cpu_has_feature() as it utilizes the POSSIBLE & ALWAYS defines as part of its check. Create a unique CPU_FTRS_E5500 (as its different from CPU_FTRS_E500MC), created a new group for 64-bit Book3e based CPUs and add CPU_FTRS_E5500 to that group. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2011-04-12powerpc: Check device status before adding serial devicePrabhakar Kushwaha
serial port nodes with the property status="disabled" are not usable and so avoid adding "disabled" port with the system. Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2011-04-11PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKSRafael J. Wysocki
Xen save/restore is going to use hibernate device callbacks for quiescing devices and putting them back to normal operations and it would need to select CONFIG_HIBERNATION for this purpose. However, that also would cause the hibernate interfaces for user space to be enabled, which might confuse user space, because the Xen kernels don't support hibernation. Moreover, it would be wasteful, as it would make the Xen kernels include a substantial amount of code that they would never use. To address this issue introduce new power management Kconfig option CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code that is necessary for the hibernate device callbacks to work and make CONFIG_HIBERNATION select it. Then, Xen save/restore will be able to select CONFIG_HIBERNATE_CALLBACKS without dragging the entire hibernate code along with it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
2011-04-07Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6Linus Torvalds
* 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6: Fix common misspellings
2011-04-05powerpc: Set nr_cpu_ids early and use it to free PACAsRyan Grimm
Without this, "holes" in the CPU numbering can cause us to free too many PACAs Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-05powerpc/kexec: Fix mismatched ifdefs for PPC64/SMP.Paul Gortmaker
Commit b3df895aebe091b1657 "powerpc/kexec: Add support for FSL-BookE" introduced the original PPC_STD_MMU_64 checks around the function crash_kexec_wait_realmode(). Then commit c2be05481f61252 "powerpc: Fix default_machine_crash_shutdown #ifdef botch" changed the ifdef around the calling site to add a check on SMP, but the ifdef around the function itself was left unchanged, leaving an unused function for PPC_STD_MMU_64=y and SMP=n Rather than have two ifdefs that can get out of sync like this, simply put the corrected conditional around the function and use a stub to get rid of one set of ifdefs completely. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/smp: Increase vdso_data->processorCount, not just decrease itBenjamin Herrenschmidt
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/smp: Create idle threads on demand and properly reset themBenjamin Herrenschmidt
Instead of creating idle threads at boot for all possible CPUs, we create them on demand, like x86 or ARM, and we properly call init_idle to re-initialize an idle thread when a CPU was unplugged and is now re-plugged. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/smp: Don't expose per-cpu "cpu_state" arrayBenjamin Herrenschmidt
Instead, keep it static, expose an accessor and use that from the PowerMac code. Avoids easy namespace collisions and will make it easier to consolidate with other implementations. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/smp: Add a smp_ops->bringup_up() done callbackBenjamin Herrenschmidt
This allows us to stop abusing smp_ops->setup_cpu() for cleanup tasks that have to take place after the initial boot time CPU bringup. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/pmac/smp: Properly NAP offlined CPU on G5Benjamin Herrenschmidt
The current code soft-disables, and then goes to NAP mode which turns interrupts on. That means that if an interrupt occurs, we will hit the masked interrupt code path which isn't what we want, as it will return with EE off, which will either get us out of NAP mode, or fail to enter it (according to spec). Instead, let's just rely on the fact that it is safe to take decrementer interrupts on an offline CPU and leave interrupts enabled. We can also get rid of the special case in asm for power4_cpu_offline_powersave() and just use power4_idle(). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/pmac/smp: Rename fixup_irqs() to migrate_irqs() and use it on ppc32Benjamin Herrenschmidt
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/smp: Remove unused smp_ops->cpu_enable()Benjamin Herrenschmidt
Remove the last remnants of cpu_enable(), everybody uses the normal __cpu_up() path now Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/smp: Remove unused generic_cpu_enable()Benjamin Herrenschmidt
Nobody uses it, besides we should always use the normal __cpu_up path anyways Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/smp: Fix generic_mach_cpu_die()Benjamin Herrenschmidt
This is used by some "soft" hotplug implementations. I needs to call idle_task_exit() when the CPU is going away, and we remove the now no-longer needed set_cpu_online() and local_irq_enable() which are handled by the return to start_secondary Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc/smp: soft-replugged CPUs must go back to start_secondaryBenjamin Herrenschmidt
Various thing are torn down when a CPU is hot-unplugged. That CPU is expected to go back to start_secondary when re-plugged to re initialize everything, such as clock sources, maps, ... Some implementations just return from cpu_die() callback in the idle loop when the CPU is "re-plugged". This is not enough. We fix it using a little asm trampoline which resets the stack and calls back into start_secondary as if we were all fresh from boot. The trampoline already existed on ppc64, but we add it for ppc32 Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01powerpc: Make decrementer interrupt robust against offlined CPUsBenjamin Herrenschmidt
With some implementations, it is possible that a timer interrupt occurs every few seconds on an offline CPU. In this case, just re-arm the decrementer and return immediately Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>