user/sven/linux.git/arch/powerpc/kernel/misc.S, branch v4.9.147

ppc: move exports to definitions

2016-08-08T03:50:09Z

Signed-off-by: Al Viro

powerpc: Rename __get_SP() to current_stack_pointer()

2014-10-15T00:23:20Z

Michael points out that __get_SP() is a pretty horrible function name. Let's give it a better name. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman

powerpc: Reimplement __get_SP() as a function not a define

2014-10-15T00:23:19Z

Li Zhong points out an issue with our current __get_SP() implementation. If ftrace function tracing is enabled (ie -pg profiling using _mcount) we spill a stack frame on 64bit all the time. If a function calls __get_SP() and later calls a function that is tail call optimised, we will pop the stack frame and the value returned by __get_SP() is no longer valid. An example from Li can be found in save_stack_trace -> save_context_stack: c0000000000432c0 <.save_stack_trace>: c0000000000432c0: mflr r0 c0000000000432c4: std r0,16(r1) c0000000000432c8: stdu r1,-128(r1) <-- stack frame for _mcount c0000000000432cc: std r3,112(r1) c0000000000432d0: bl <._mcount> c0000000000432d4: nop c0000000000432d8: mr r4,r1 <-- __get_SP() c0000000000432dc: ld r5,632(r13) c0000000000432e0: ld r3,112(r1) c0000000000432e4: li r6,1 c0000000000432e8: addi r1,r1,128 <-- pop stack frame c0000000000432ec: ld r0,16(r1) c0000000000432f0: mtlr r0 c0000000000432f4: b <.save_context_stack> <-- tail call optimized save_context_stack ends up with a stack pointer below the current one, and it is likely to be scribbled over. Fix this by making __get_SP() a function which returns the callers stack frame. Also replace inline assembly which grabs the stack pointer in save_stack_trace and show_stack with __get_SP(). This also fixes an issue with perf_arch_fetch_caller_regs(). It currently unwinds the stack once, which will skip a valid stack frame on a leaf function. With the __get_SP() fixes in this patch, we never need to unwind the stack frame to get to the first interesting frame. We have to export __get_SP() because perf_arch_fetch_caller_regs() (which is used in modules) calls it from a header file. Reported-by: Li Zhong Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman

powerpc: switch to generic sys_execve()/kernel_execve()

2012-10-01T03:35:51Z

the only non-obvious part is that current_pt_regs() is really needed here - task_pt_regs() is NULL for kernel threads; it's OK for ptrace uses (the thing task_pt_regs() is intended for), but not for us. Signed-off-by: Al Viro

powerpc: Remove legacy iSeries bits from assembly files

2012-03-08T23:54:59Z

This removes the various bits of assembly in the kernel entry, exception handling and SLB management code that were specific to running under the legacy iSeries hypervisor which is no longer supported. Signed-off-by: Benjamin Herrenschmidt

powerpc: Remove unneeded cpu_setup/restore from POWER7 cputable entry

2010-11-29T04:48:22Z

These are not needed so just remove them Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt

perf: Drop the skip argument from perf_arch_fetch_regs_caller

2010-06-08T21:31:27Z

Drop this argument now that we always want to rewind only to the state of the first caller. It means frame pointers are not necessary anymore to reliably get the source of an event. But this also means we need this helper to be a macro now, as an inline function is not an option since we need to know when to provide a default implentation. Signed-off-by: Frederic Weisbecker Signed-off-by: Paul Mackerras Cc: David Miller Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo

perf: Always build the powerpc perf_arch_fetch_caller_regs version

2010-04-03T10:42:00Z

Now that software events use perf_arch_fetch_caller_regs() too, we need the powerpc version to be always built. Fixes the following build error: (.text+0x3210): undefined reference to `perf_arch_fetch_caller_regs' (.text+0x3324): undefined reference to `perf_arch_fetch_caller_regs' (.text+0x33bc): undefined reference to `perf_arch_fetch_caller_regs' (.text+0x33ec): undefined reference to `perf_arch_fetch_caller_regs' (.text+0xd4a0): undefined reference to `perf_arch_fetch_caller_regs' arch/powerpc/kernel/built-in.o:(.text+0xd528): more undefined references to `perf_arch_fetch_caller_regs' follow make[1]: *** [.tmp_vmlinux1] Error 1 make: *** [sub-make] Error 2 Reported-by: Michael Ellerman Reported-by: Ingo Molnar Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras

powerpc/perf_events: Fix call-graph recording, add perf_arch_fetch_caller_regs

2010-03-18T05:48:29Z

This implements a powerpc version of perf_arch_fetch_caller_regs to get correct call-graphs. It's implemented in assembly because that way we can be sure there isn't a stack frame for perf_arch_fetch_caller_regs. If it was in C, gcc might or might not create a stack frame for it, which would affect the number of levels we have to skip. With this, we see results from perf record -e lock:lock_acquire like this: # Samples: 24878 # # Overhead Command Shared Object Symbol # ........ .............. ................. ...... # 14.99% perf [kernel.kallsyms] [k] ._raw_spin_lock | --- ._raw_spin_lock | |--25.00%-- .alloc_fd | (nil) | | | |--50.00%-- .anon_inode_getfd | | .sys_perf_event_open | | syscall_exit | | syscall | | create_counter | | __cmd_record | | run_builtin | | main | | 0xfd2e704 | | 0xfd2e8c0 | | (nil) ... etc. Signed-off-by: Paul Mackerras Acked-by: Benjamin Herrenschmidt Cc: anton@samba.org Cc: linuxppc-dev@ozlabs.org Cc: Peter Zijlstra Cc: Frederic Weisbecker LKML-Reference: <20100318050513.GA6575@drongo> Signed-off-by: Ingo Molnar

powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit

2008-09-15T18:08:35Z

Using LOAD_REG_IMMEDIATE to get the address of kernel symbols generates 5 instructions where LOAD_REG_ADDR can do it in one, and will generate R_PPC64_ADDR16_* relocations in the output when we get to making the kernel as a position-independent executable, which we'd rather not have to handle. This changes various bits of assembly code to use LOAD_REG_ADDR when we need to get the address of a symbol, or to use suitable position-independent code for cases where we can't access the TOC for various reasons, or if we're not running at the address we were linked at. It also cleans up a few minor things; there's no reason to save and restore SRR0/1 around RTAS calls, __mmu_off can get the return address from LR more conveniently than the caller can supply it in R4 (and we already assume elsewhere that EA == RA if the MMU is on in early boot), and enable_64b_mode was using 5 instructions where 2 would do. Signed-off-by: Paul Mackerras