kernel.git/arch/powerpc/kernel/entry_64.S, branch linux-3.17.y

powerpc: do_notify_resume can be called with bad thread_info flags argument

2014-11-14T18:10:39Z

commit 808be31426af57af22268ef0fcb42617beb3d15b upstream. Back in 7230c5644188 ("powerpc: Rework lazy-interrupt handling") we added a call out to restore_interrupts() (written in c) before calling do_notify_resume: bl restore_interrupts addi r3,r1,STACK_FRAME_OVERHEAD bl do_notify_resume Unfortunately do_notify_resume takes two arguments, the second one being the thread_info flags: void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) We do populate r4 (the second argument) earlier, but restore_interrupts() is free to muck it up all it wants. My guess is the gcc compiler gods shone down on us and its register allocator never used r4. Sometimes, rarely, luck is on our side. LLVM on the other hand did trample r4. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/book3s: Add basic infrastructure to handle HMI in Linux.

2014-08-05T06:33:48Z

Handle Hypervisor Maintenance Interrupt (HMI) in Linux. This patch implements basic infrastructure to handle HMI in Linux host. The design is to invoke opal handle hmi in real mode for recovery and set irq_pending when we hit HMI. During check_irq_replay pull opal hmi event and print hmi info on console. Signed-off-by: Mahesh Salgaonkar Signed-off-by: Benjamin Herrenschmidt

powerpc: Remove MMU_FTR_SLB

2014-07-28T04:10:23Z

We now only support cpus that use an SLB, so we don't need an MMU feature to indicate that. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc: Correct DSCR during TM context switch

2014-06-11T07:02:56Z

Correct the DSCR SPR becoming temporarily corrupted if a task is context switched during a transaction. The problem occurs while suspending the task and is caused by saving the DSCR to thread.dscr after it has already been set to the CPU's default value: __switch_to() calls __switch_to_tm() which calls tm_reclaim_task() which calls tm_reclaim_thread() which calls tm_reclaim() where the DSCR is set to the CPU's default __switch_to() calls _switch() where thread.dscr is set to the DSCR When the task is resumed, it's transaction will be doomed (as usual) and the DSCR SPR will be corrupted, although the checkpointed value will be correct. Therefore the DSCR will be immediately corrected by the transaction aborting, unless it has been suspended. In that case the incorrect value can be seen by the task until it resumes the transaction. The fix is to treat the DSCR similarly to the TAR and save it early in __switch_to(). A program exposing the problem is added to the kernel self tests as: tools/testing/selftests/powerpc/tm/tm-resched-dscr. Signed-off-by: Sam Bobroff CC: [v3.10+] Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix regression of per-CPU DSCR setting

2014-05-28T03:35:40Z

Since commit "efcac65 powerpc: Per process DSCR + some fixes (try#4)" it is no longer possible to set the DSCR on a per-CPU basis. The old behaviour was to minipulate the DSCR SPR directly but this is no longer sufficient: the value is quickly overwritten by context switching. This patch stores the per-CPU DSCR value in a kernel variable rather than directly in the SPR and it is used whenever a process has not set the DSCR itself. The sysfs interface (/sys/devices/system/cpu/cpuN/dscr) is unchanged. Writes to the old global default (/sys/devices/system/cpu/dscr_default) now set all of the per-CPU values and reads return the last written value. The new per-CPU default is added to the paca_struct and is used everywhere outside of sysfs.c instead of the old global default. Signed-off-by: Sam Bobroff Signed-off-by: Benjamin Herrenschmidt

powerpc: ftrace_caller, _mcount is exported to modules so needs _GLOBAL_TOC()

2014-04-23T00:05:33Z

When testing the ftrace function tracer, I realised that ftrace_caller and mcount are called from modules and they both call into C, therefore they need the ABIv2 global entry point to establish r2. Signed-off-by: Anton Blanchard

powerpc: Fix kernel thread creation on ABIv2

2014-04-23T00:05:23Z

Change how we setup registers for ret_from_kernel_thread. In ABIv1, instead of passing a function descriptor in, dereference it and pass the target in directly. Use ppc_global_function_entry to get it right on both ABIv1 and ABIv2. Signed-off-by: Anton Blanchard

powerpc: ABIv2 function calls must place target address in r12

2014-04-23T00:05:20Z

To establish addressability quickly, ABIv2 requires the target address of the function being called to be in r12. Fix a number of places in assembly code that we do indirect function calls. We need to avoid function descriptors on ABIv2 too. Signed-off-by: Anton Blanchard

powerpc: Don't use a function descriptor for system call table

2014-04-23T00:05:17Z

There is no need to create a function descriptor for the system call table. By using one we force the system call table into the text section and it really belongs in the rodata section. This also removes another use of dot symbols. Signed-off-by: Anton Blanchard

powerpc: Remove superflous function descriptors in assembly only code

2014-04-23T00:05:17Z

We have a number of places where we load the text address of a local function and indirectly branch to it in assembly. Since it is an indirect branch binutils will not know to use the function text address, so that trick wont work. There is no need for these functions to have a function descriptor so we can replace it with a label and remove the dot symbol. Signed-off-by: Anton Blanchard