kernel.git/arch/s390/kernel/early.c, branch linux-4.6.y

locking/lockdep: Eliminate lockdep_init()

2016-02-09T11:03:25Z

Lockdep is initialized at compile time now. Get rid of lockdep_init(). Signed-off-by: Andrey Ryabinin Signed-off-by: Andrew Morton Cc: Linus Torvalds Cc: Mike Krinkin Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Cc: mm-commits@vger.kernel.org Signed-off-by: Ingo Molnar

s390: remove all usages of PSW_ADDR_INSN

2016-01-19T11:14:03Z

Yet another leftover from the 31 bit era. The usual operation "y = x & PSW_ADDR_INSN" with the PSW_ADDR_INSN mask is a nop for CONFIG_64BIT. Therefore remove all usages and hope the code is a bit less confusing. Signed-off-by: Heiko Carstens Reviewed-by: David Hildenbrand

s390: remove all usages of PSW_ADDR_AMODE

2016-01-19T11:14:02Z

This is a leftover from the 31 bit area. For CONFIG_64BIT the usual operation "y = x | PSW_ADDR_AMODE" is a nop. Therefore remove all usages of PSW_ADDR_AMODE and make the code a bit less confusing. Signed-off-by: Heiko Carstens Reviewed-by: David Hildenbrand

s390/dump: rework CPU register dump code

2015-11-27T08:24:14Z

To collect the CPU registers of the crashed system allocated a single page with memblock_alloc_base and use it as a copy buffer. Replace the stop-and-store-status sigp with a store-status-at-address sigp in smp_save_dump_cpus() and smp_store_status(). In both cases the target CPU is already stopped and store-status-at-address avoids the detour via the absolute zero page. For kexec simplify s390_reset_system and call store_status() before the prefix register of the boot CPU has been set to zero. Use STPX to store the prefix register and remove dump_prefix_page. Acked-by: Michael Holzheu Signed-off-by: Martin Schwidefsky

s390/fpu: always enable the vector facility if it is available

2015-10-14T12:32:08Z

If the kernel detects that the s390 hardware supports the vector facility, it is enabled by default at an early stage. To force it off, use the novx kernel parameter. Note that there is a small time window, where the vector facility is enabled before it is forced to be off. With enabling the vector facility by default, the FPU save and restore functions can be improved. They do not longer require to manage expensive control register updates to enable or disable the vector enablement control for particular processes. Signed-off-by: Hendrik Brueckner Reviewed-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/diag: add a statistic for diagnose calls

2015-10-14T12:32:06Z

Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose calls have been done by each CPU in the system. Signed-off-by: Martin Schwidefsky

s390: remove 31 bit support

2015-03-25T10:49:33Z

Remove the 31 bit support in order to reduce maintenance cost and effectively remove dead code. Since a couple of years there is no distribution left that comes with a 31 bit kernel. The 31 bit kernel also has been broken since more than a year before anybody noticed. In addition I added a removal warning to the kernel shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning message") which let everybody know about the plan to remove 31 bit code. We didn't get any response. Given that the last 31 bit only machine was introduced in 1999 let's remove the code. Anybody with 31 bit user space code can still use the compat mode. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/spinlock: disabled compare-and-delay by default

2015-02-19T17:05:38Z

Until we have hard performance data about the effects of CAD in the spinlock loop disable the instruction by default. Signed-off-by: Martin Schwidefsky

s390/spinlock: add compare-and-delay to lock wait loops

2015-01-23T14:17:04Z

Add the compare-and-delay instruction to the spin-lock and rw-lock retry loops. A CPU executing the compare-and-delay instruction stops until the lock value has changed. This is done to make the locking code for contended locks to behave better in regard to the multi- hreading facility. A thread of a core executing a compare-and-delay will allow the other threads of a core to get a larger share of the core resources. Signed-off-by: Martin Schwidefsky

s390/ftrace,kprobes: allow to patch first instruction

2014-10-27T12:27:27Z

If the function tracer is enabled, allow to set kprobes on the first instruction of a function (which is the function trace caller): If no kprobe is set handling of enabling and disabling function tracing of a function simply patches the first instruction. Either it is a nop (right now it's an unconditional branch, which skips the mcount block), or it's a branch to the ftrace_caller() function. If a kprobe is being placed on a function tracer calling instruction we encode if we actually have a nop or branch in the remaining bytes after the breakpoint instruction (illegal opcode). This is possible, since the size of the instruction used for the nop and branch is six bytes, while the size of the breakpoint is only two bytes. Therefore the first two bytes contain the illegal opcode and the last four bytes contain either "0" for nop or "1" for branch. The kprobes code will then execute/simulate the correct instruction. Instruction patching for kprobes and function tracer is always done with stop_machine(). Therefore we don't have any races where an instruction is patched concurrently on a different cpu. Besides that also the program check handler which executes the function trace caller instruction won't be executed concurrently to any stop_machine() execution. This allows to keep full fault based kprobes handling which generates correct pt_regs contents automatically. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky