- 20 Oct, 2017 6 commits
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Michael Neuling authored
Unfortunately userspace can construct a sigcontext which enables suspend. Thus userspace can force Linux into a path where trechkpt is executed. This patch blocks this from happening on POWER9 by sanity checking sigcontexts passed in. ptrace doesn't have this problem as only MSR SE and BE can be changed via ptrace. This patch also adds a number of WARN_ON()s in case we ever enter suspend when we shouldn't. This should not happen, but if it does the symptoms are soft lockup warnings which are not obviously TM related, so the WARN_ON()s should make it obvious what's happening. Signed-off-by:
Michael Neuling <mikey@neuling.org> Signed-off-by:
Cyril Bur <cyrilbur@gmail.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Some Power9 revisions can run in a mode where TM operates without suspended state. If we find ourself on a CPU that might be in this mode, we query OPAL to check, and if so we reenable TM in CPU features, and enable a new user feature to signal to userspace that we are in this mode. We do not enable the "normal" user feature, PPC_FEATURE2_HTM, but we do enable PPC_FEATURE2_HTM_NOSC because that indicates to userspace that the kernel will abort transactions on syscall entry, which is true regardless of the suspend mode. Signed-off-by: -
Michael Ellerman authored
Some CPUs can operate in a mode where TM (Transactional Memory) is enabled but the suspended state of TM is disabled. In this mode tsuspend does not enter suspended state, instead the transaction is aborted. Similarly any other event that would lead to suspended state instead aborts the transaction. There is also an ABI change, in that in this mode processes are not allowed to sigreturn with an MSR that would lead to suspended state, Linux will instead return an error to the sigreturn syscall. Signed-off-by: -
Cyril Bur authored
Currently the kernel relies on firmware to inform it whether or not the CPU supports HTM and as long as the kernel was built with CONFIG_PPC_TRANSACTIONAL_MEM=y then it will allow userspace to make use of the facility. There may be situations where it would be advantageous for the kernel to not allow userspace to use HTM, currently the only way to achieve this is to recompile the kernel with CONFIG_PPC_TRANSACTIONAL_MEM=n. This patch adds a simple commandline option so that HTM can be disabled at boot time. Signed-off-by:
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Michael Ellerman authored
Bring in some KVM commits we need (the TM one in particular).
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Michael Ellerman authored
Currently we use CPU_FTR_TM to decide if the CPU/kernel can support TM (Transactional Memory), and if it's true we advertise that to Qemu (or similar) via KVM_CAP_PPC_HTM. PPC_FEATURE2_HTM is the user-visible feature bit, which indicates that the CPU and kernel can support TM. Currently CPU_FTR_TM and PPC_FEATURE2_HTM always have the same value, either true or false, so using the former for KVM_CAP_PPC_HTM is correct. However some Power9 CPUs can operate in a mode where TM is enabled but TM suspended state is disabled. In this mode CPU_FTR_TM is true, but PPC_FEATURE2_HTM is false. Instead a different PPC_FEATURE2 bit is set, to indicate that this different mode of TM is available. It is not safe to let guests use TM as-is, when the CPU is in this mode. So to prevent that from happening, use PPC_FEATURE2_HTM to determine the value of KVM_CAP_PPC_HTM. Signed-off-by:
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- 19 Oct, 2017 1 commit
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Paul Mackerras authored
This reverts commit 94a04bc2. In order to run HPT guests on a radix POWER9 host, we will have to run the host in single-threaded mode, because POWER9 processors do not currently support running some threads of a core in HPT mode while others are in radix mode ("mixed mode"). That means that we will need the same mechanisms that are used on POWER8 to make the secondary threads available to KVM, which were disabled on POWER9 by commit 94a04bc2. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org> Signed-off-by:
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- 16 Oct, 2017 9 commits
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Michael Bringmann authored
powerpc/vphn: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. This patch fixes an end-of-updates processing problem observed occasionally in numa_update_cpu_topology(). Signed-off-by:
Michael Bringmann <mwb@linux.vnet.ibm.com> Signed-off-by:
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Michael Bringmann authored
powerpc/hotplug: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. During hotplug CPU operations, this patch resets the timer on topology update work function to a small value to better ensure that the CPU topology is detected and configured sooner. Signed-off-by:
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Michael Bringmann authored
powerpc/vphn: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. This patch updates the initialization checks to independently recognize PRRN or VPHN support. Signed-off-by:
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Michael Bringmann authored
powerpc/vphn: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. This patch corrects the currently broken capability to set the topology for shared CPUs in LPARs. At boot time for shared CPU lpars, the topology for each CPU was being set to node zero. Now when numa_update_cpu_topology() is called appropriately, the Virtual Processor Home Node (VPHN) capabilities information provided by the pHyp allows the appropriate node in the shared configuration to be selected for the CPU. Signed-off-by:
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Balbir Singh authored
If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by:
Balbir Singh <bsingharora@gmail.com> Reviewed-by:
Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
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Balbir Singh authored
Hookup instruction errors (UE) for memory offling via memory_failure() in a manner similar to load/store errors (derror). Since we have access to the NIP, the conversion is a one step process in this case. Signed-off-by:
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Balbir Singh authored
Extract physical_address for UE errors by walking the page tables for the mm and address at the NIP, to extract the instruction. Then use the instruction to find the effective address via analyse_instr(). We might have page table walking races, but we expect them to be rare, the physical address extraction is best effort. The idea is to then hook up this infrastructure to memory failure eventually. Signed-off-by:
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Balbir Singh authored
Use the same alignment as Effective address. Signed-off-by:
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Balbir Singh authored
There are no users of get_mce_fault_addr() since commit 1363875b ("powerpc/64s: fix handling of non-synchronous machine checks") removed the last usage. Signed-off-by:
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- 13 Oct, 2017 3 commits
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Kamalesh Babulal authored
Use WARN_ON(), while running out of stubs in stub_for_addr() and abort loading of the module instead of BUG_ON(). Signed-off-by:
Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by:
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Vaibhav Jain authored
For PSL9 currently we aren't dumping the PSL FIR register when a PSL error interrupt is triggered. Contents of this register are useful in debugging AFU issues. This patch fixes issue by adding a new service_layer_ops callback cxl_native_err_irq_dump_regs_psl9() to dump the PSL_FIR registers on a PSL error interrupt thereby bringing the behavior in line with PSL on POWER-8. Also the existing service_layer_ops callback for PSL8 has been renamed to cxl_native_err_irq_dump_regs_psl8(). Signed-off-by:
Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by:
Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by:
Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by:
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Cyril Bur authored
Turns out pthreads returns an errno and doesn't set errno. This doesn't play well with perror(). Signed-off-by:
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- 10 Oct, 2017 1 commit
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Vaibhav Jain authored
PSL9 doesn't have a FIR2 register as was the case with PSL8. However currently the register definitions in 'cxl.h' have a definition for PSL9_FIR2 that actually points to PSL9_FIR_MASK register in the P1 area at offset 0x308. So this patch renames the def PSL9_FIR2 to PSL9_FIR_MASK and updates the references in the code to point to the new identifier. It also removes the code to dump contents of FIR2 (FIR_MASK actually) in cxl_native_irq_dump_regs_psl9(). Fixes: f24be42a ("cxl: Add psl9 specific code") Reported-by:
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- 06 Oct, 2017 7 commits
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Christophe Lombard authored
The PSL initialization sequence has been updated to DD2. This patch adapts to the changes, retaining compatibility with DD1. The patch includes some changes to DD1 fix-ups as well. Tests performed on some of the old/new hardware. The function is_page_fault(), for POWER9, lists the Translation Checkout Responses where the page fault will be handled by copro_handle_mm_fault(). This list is too restrictive and not necessary. This patches removes this restriction and all page faults, whatever the reason, will be handled. In this case, the interruption is always acknowledged. The following features will be added soon: - phb reset when switching to capi mode. - cxllib update to support new functions. Signed-off-by:
Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by:
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Kautuk Consul authored
Add a check for p->state == TASK_RUNNING so that any wake-ups on task_struct p in the interim lead to 0 being returned by get_wchan(). Signed-off-by:
Kautuk Consul <kautuk.consul.1980@gmail.com> [mpe: Confirmed other architectures do similar] Signed-off-by:
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Seth Forshee authored
Currently sprintf is used, and while paths should never exceed the size of the buffer it is theoretically possible since dirent.d_name is 256 bytes. As a result this trips -Wformat-overflow, and since the test is built with -Wall -Werror the causes the build to fail. Switch to using snprintf and skip any paths which are too long for the filename buffer. Signed-off-by:
Seth Forshee <seth.forshee@canonical.com> Signed-off-by:
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Seth Forshee authored
Several callers to epapr_hypercall() pass an uninitialized stack allocated array for the input arguments, presumably because they have no input arguments. However this can produce errors like this one arch/powerpc/include/asm/epapr_hcalls.h:470:42: error: 'in' may be used uninitialized in this function [-Werror=maybe-uninitialized] unsigned long register r3 asm("r3") = in[0]; ~~^~~ Fix callers to this function to always zero-initialize the input arguments array to prevent this. Signed-off-by: -
Michael Neuling authored
This is useful, especially for developers. Signed-off-by:
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Guilherme G. Piccoli authored
It might be useful to quickly get the uptime of a running system on xmon, without needing to grab data from memory and doing math on struct addresses. For example, it'd be useful to check for how long after a crash a system is on xmon shell or if some test was started after the first test crashed (and this 2nd test crashed too into xmon). This small patch adds the 'U' command, to accomplish this. Suggested-by:
Murilo Fossa Vicentini <muvic@linux.vnet.ibm.com> Signed-off-by:
Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> [mpe: Display units (seconds), add sync()/__delay() sequence] Signed-off-by:
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Michael Ellerman authored
In opal_event_shutdown() we free all the IRQs hanging off the opal_event_irqchip. However it's not safe to do so if we're called from IRQ context, because free_irq() wants to synchronise versus IRQ context. This can lead to warnings and a stuck system. For example from sysrq-b: Trying to free IRQ 17 from IRQ context! ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/irq/manage.c:1461 __free_irq+0x398/0x8d0 ... NIP __free_irq+0x398/0x8d0 LR __free_irq+0x394/0x8d0 Call Trace: __free_irq+0x394/0x8d0 (unreliable) free_irq+0xa4/0x140 opal_event_shutdown+0x128/0x180 opal_shutdown+0x1c/0xb0 pnv_shutdown+0x20/0x40 machine_restart+0x38/0x90 emergency_restart+0x28/0x40 sysrq_handle_reboot+0x24/0x40 __handle_sysrq+0x198/0x590 hvc_poll+0x48c/0x8c0 hvc_handle_interrupt+0x1c/0x50 __handle_irq_event_percpu+0xe8/0x6e0 handle_irq_event_percpu+0x34/0xe0 handle_irq_event+0xc4/0x210 handle_level_irq+0x250/0x770 generic_handle_irq+0x5c/0xa0 opal_handle_events+0x11c/0x240 opal_interrupt+0x38/0x50 __handle_irq_event_percpu+0xe8/0x6e0 handle_irq_event_percpu+0x34/0xe0 handle_irq_event+0xc4/0x210 handle_fasteoi_irq+0x174/0xa10 generic_handle_irq+0x5c/0xa0 __do_irq+0xbc/0x4e0 call_do_irq+0x14/0x24 do_IRQ+0x18c/0x540 hardware_interrupt_common+0x158/0x180 We can avoid that by using disable_irq_nosync() rather than free_irq(). Although it doesn't fully free the IRQ, it should be sufficient when we're shutting down, particularly in an emergency. Add an in_interrupt() check and use free_irq() when we're shutting down normally. It's probably OK to use disable_irq_nosync() in that case too, but for now it's safer to leave that behaviour as-is. Fixes: 9f0fd049 ("powerpc/powernv: Add a virtual irqchip for opal events") Reported-by:Anton Blanchard <anton@samba.org> Signed-off-by:
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- 05 Oct, 2017 2 commits
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Naveen N. Rao authored
Fix a circa 2005 FIXME by implementing a check to ensure that we actually got into the jprobe break handler() due to the trap in jprobe_return(). Acked-by:
Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by:
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Naveen N. Rao authored
KPROBES_SANITY_TEST throws the below splat when CONFIG_PREEMPT is enabled: Kprobe smoke test: started DEBUG_LOCKS_WARN_ON(val > preempt_count()) ------------[ cut here ]------------ WARNING: CPU: 19 PID: 1 at kernel/sched/core.c:3094 preempt_count_sub+0xcc/0x140 Modules linked in: CPU: 19 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc7-nnr+ #97 task: c0000000fea80000 task.stack: c0000000feb00000 NIP: c00000000011d3dc LR: c00000000011d3d8 CTR: c000000000a090d0 REGS: c0000000feb03400 TRAP: 0700 Not tainted (4.13.0-rc7-nnr+) MSR: 8000000000021033 <SF,ME,IR,DR,RI,LE> CR: 28000282 XER: 00000000 CFAR: c00000000015aa18 SOFTE: 0 <snip> NIP preempt_count_sub+0xcc/0x140 LR preempt_count_sub+0xc8/0x140 Call Trace: preempt_count_sub+0xc8/0x140 (unreliable) kprobe_handler+0x228/0x4b0 program_check_exception+0x58/0x3b0 program_check_common+0x16c/0x170 --- interrupt: 0 at kprobe_target+0x8/0x20 LR = init_test_probes+0x248/0x7d0 kp+0x0/0x80 (unreliable) livepatch_handler+0x38/0x74 init_kprobes+0x1d8/0x208 do_one_initcall+0x68/0x1d0 kernel_init_freeable+0x298/0x374 kernel_init+0x24/0x160 ret_from_kernel_thread+0x5c/0x70 Instruction dump: 419effdc 3d22001b 39299240 81290000 2f890000 409effc8 3c82ffcb 3c62ffcb 3884bc68 3863bc18 4803d5fd 60000000 <0fe00000> 4bffffa8 60000000 60000000 ---[ end trace 432dd46b4ce3d29f ]--- Kprobe smoke test: passed successfully The issue is that we aren't disabling preemption in kprobe_ftrace_handler(). Disable it. Fixes: ead514d5 ("powerpc/kprobes: Add support for KPROBES_ON_FTRACE") Acked-by:
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- 04 Oct, 2017 11 commits
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Naveen N. Rao authored
Kamalesh pointed out that we are getting the below call traces with livepatched functions when we enable CONFIG_PREEMPT: [ 495.470721] BUG: using __this_cpu_read() in preemptible [00000000] code: cat/8394 [ 495.471167] caller is is_current_kprobe_addr+0x30/0x90 [ 495.471171] CPU: 4 PID: 8394 Comm: cat Tainted: G K 4.13.0-rc7-nnr+ #95 [ 495.471173] Call Trace: [ 495.471178] [c00000008fd9b960] [c0000000009f039c] dump_stack+0xec/0x160 (unreliable) [ 495.471184] [c00000008fd9b9a0] [c00000000059169c] check_preemption_disabled+0x15c/0x170 [ 495.471187] [c00000008fd9ba30] [c000000000046460] is_current_kprobe_addr+0x30/0x90 [ 495.471191] [c00000008fd9ba60] [c00000000004e9a0] ftrace_call+0x1c/0xb8 [ 495.471195] [c00000008fd9bc30] [c000000000376fd8] seq_read+0x238/0x5c0 [ 495.471199] [c00000008fd9bcd0] [c0000000003cfd78] proc_reg_read+0x88/0xd0 [ 495.471203] [c00000008fd9bd00] [c00000000033e5d4] __vfs_read+0x44/0x1b0 [ 495.471206] [c00000008fd9bd90] [c0000000003402ec] vfs_read+0xbc/0x1b0 [ 495.471210] [c00000008fd9bde0] [c000000000342138] SyS_read+0x68/0x110 [ 495.471214] [c00000008fd9be30] [c00000000000bc6c] system_call+0x58/0x6c Commit c05b8c44 ("powerpc/kprobes: Skip livepatch_handler() for jprobes") introduced a helper is_current_kprobe_addr() to help determine if the current function has been livepatched or if it has a jprobe installed, both of which modify the NIP. This was subsequently renamed to __is_active_jprobe(). In the case of a jprobe, kprobe_ftrace_handler() disables pre-emption before calling into setjmp_pre_handler() which returns without disabling pre-emption. This is done to ensure that the jprobe handler won't disappear beneath us if the jprobe is unregistered between the setjmp_pre_handler() and the subsequent longjmp_break_handler() called from the jprobe handler. Due to this, we can use __this_cpu_read() in __is_active_jprobe() with the pre-emption check as we know that pre-emption will be disabled. However, if this function has been livepatched, we are still doing this check and when we do so, pre-emption won't necessarily be disabled. This results in the call trace shown above. Fix this by only invoking __is_active_jprobe() when pre-emption is disabled. And since we now guard this within a pre-emption check, we can instead use raw_cpu_read() to get the current_kprobe value skipping the check done by __this_cpu_read(). Fixes: c05b8c44 ("powerpc/kprobes: Skip livepatch_handler() for jprobes") Reported-by:
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Naveen N. Rao authored
In commit c05b8c44 ("powerpc/kprobes: Skip livepatch_handler() for jprobes"), we added a helper is_current_kprobe_addr() to help detect if the modified regs->nip was due to a jprobe or livepatch. Masami felt that the function name was not quite clear. To that end, this patch renames is_current_kprobe_addr() to __is_active_jprobe() and adds a comment to (hopefully) better clarify the purpose of this helper. The helper has also now been moved to kprobes-ftrace.c so that it is only available for KPROBES_ON_FTRACE. Signed-off-by:
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Naveen N. Rao authored
Currently, we disable instruction emulation if emulate_step() fails for any reason. However, such failures could be transient and specific to a particular run. Instead, only disable instruction emulation if we have never been able to emulate this. If we had emulated this instruction successfully at least once, then we single step only this probe hit and continue to try emulating the instruction in subsequent probe hits. Signed-off-by:
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Naveen N. Rao authored
1. This is only used in kprobes.c, so make it static. 2. Remove the un-necessary (ret == 0) comparison in the else clause. Reviewed-by:
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Joel Stanley authored
This configuration is used by the OpenPower firmware for it's Linux-as-bootloader implementation. Also known as the Petitboot kernel, this configuration broke in 4.12 (CPU_HOTPLUG=n), so add it to the upstream tree in order to get better coverage. Signed-off-by:
Joel Stanley <joel@jms.id.au> Signed-off-by:
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Sandipan Das authored
This fixes the emulated behaviour of existing fixed-point shift right algebraic instructions that are supposed to set both the CA and CA32 bits of XER when running on a system that is compliant with POWER ISA v3.0 independent of whether the system is executing in 32-bit mode or 64-bit mode. The following instructions are affected: * Shift Right Algebraic Word Immediate (srawi[.]) * Shift Right Algebraic Word (sraw[.]) * Shift Right Algebraic Doubleword Immediate (sradi[.]) * Shift Right Algebraic Doubleword (srad[.]) Fixes: 0016a4cf ("powerpc: Emulate most Book I instructions in emulate_step()") Signed-off-by:
Sandipan Das <sandipan@linux.vnet.ibm.com> Signed-off-by:
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Sandipan Das authored
There are existing fixed-point arithmetic instructions that always set the CA bit of XER to reflect the carry out of bit 0 in 64-bit mode and out of bit 32 in 32-bit mode. In ISA v3.0, these instructions also always set the CA32 bit of XER to reflect the carry out of bit 32. This fixes the emulated behaviour of such instructions when running on a system that is compliant with POWER ISA v3.0. The following instructions are affected: * Add Immediate Carrying (addic) * Add Immediate Carrying and Record (addic.) * Subtract From Immediate Carrying (subfic) * Add Carrying (addc[.]) * Subtract From Carrying (subfc[.]) * Add Extended (adde[.]) * Subtract From Extended (subfe[.]) * Add to Minus One Extended (addme[.]) * Subtract From Minus One Extended (subfme[.]) * Add to Zero Extended (addze[.]) * Subtract From Zero Extended (subfze[.]) Fixes: 0016a4cf ("powerpc: Emulate most Book I instructions in emulate_step()") Signed-off-by:
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Sandipan Das authored
This adds definitions for the OV32 and CA32 bits of XER that were introduced in POWER ISA v3.0. There are some existing instructions that currently set the OV and CA bits based on certain conditions. The emulation behaviour of all these instructions needs to be updated to set these new bits accordingly. Signed-off-by:
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Allen Pais authored
Use setup_timer function instead of initializing timer with the function and data fields. Signed-off-by:
Allen Pais <allen.lkml@gmail.com> Signed-off-by:
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Allen Pais authored
Use setup_timer function instead of initializing timer with the function and data fields. Signed-off-by:
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Allen Pais authored
Use setup_timer function instead of initializing timer with the function and data fields. Signed-off-by:
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