kernel.git/arch/s390/kernel/early.c, branch linux-3.19.y

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

s390: add support for vector extension

2014-10-09T07:14:13Z

The vector extension introduces 32 128-bit vector registers and a set of instruction to operate on the vector registers. The kernel can control the use of vector registers for the problem state program with a bit in control register 0. Once enabled for a process the kernel needs to retain the content of the vector registers on context switch. The signal frame is extended to include the vector registers. Two new register sets NT_S390_VXRS_LOW and NT_S390_VXRS_HIGH are added to the regset interface for the debugger and core dumps. Signed-off-by: Martin Schwidefsky

s390: remove unused MACHINE_FLAG_RRBM

2014-09-09T06:53:26Z

Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/mm: Convert bootmem to memblock

2014-05-20T06:58:40Z

The original bootmem allocator is getting replaced by memblock. To cover the needs of the s390 kdump implementation the physical memory list is used. With this patch the bootmem allocator and its bitmaps are completely removed from s390. Signed-off-by: Philipp Hachtmann Signed-off-by: Martin Schwidefsky

s390/mm,tlb: optimize TLB flushing for zEC12

2014-04-03T12:31:00Z

The zEC12 machines introduced the local-clearing control for the IDTE and IPTE instruction. If the control is set only the TLB of the local CPU is cleared of entries, either all entries of a single address space for IDTE, or the entry for a single page-table entry for IPTE. Without the local-clearing control the TLB flush is broadcasted to all CPUs in the configuration, which is expensive. The reset of the bit mask of the CPUs that need flushing after a non-local IDTE is tricky. As TLB entries for an address space remain in the TLB even if the address space is detached a new bit field is required to keep track of attached CPUs vs. CPUs in the need of a flush. After a non-local flush with IDTE the bit-field of attached CPUs is copied to the bit-field of CPUs in need of a flush. The ordering of operations on cpu_attach_mask, attach_count and mm_cpumask(mm) is such that an underindication in mm_cpumask(mm) is prevented but an overindication in mm_cpumask(mm) is possible. Signed-off-by: Martin Schwidefsky

s390/setup: get rid of MACHINE_HAS_MVCOS machine flag

2014-02-21T07:50:15Z

MACHINE_HAS_MVCOS is used exactly once when the machine is brought up. There is no need to cache the flag in the machine_flags. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/sclp: Consolidate early sclp init calls to sclp_early_detect()

2013-11-15T13:08:41Z

The new function calls the old ones. The sclp_event_mask_early() is removed and replaced by one invocation of sclp_set_event_mask(0, 0). Reviewed-by: Heiko Carstens Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky

s390/sclp: Determine HSA size dynamically for zfcpdump

2013-11-15T13:08:40Z

Currently we have hardcoded the HSA size to 32 MiB. With this patch the HSA size is determined dynamically via SCLP in early.c. Reviewed-by: Heiko Carstens Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky

s390/mm: do not initialize storage keys

2013-10-24T15:17:00Z

With dirty and referenced bits implemented in software it is unnecessary to initialize the storage key for every page. With this patch not a single storage key operation is done for a system that does not use KVM. For KVM set_pte_at/pgste_set_key will do the initialization for the guest view of the storage key when the mapping for the page is established in the host. Signed-off-by: Martin Schwidefsky

s390/mem_detect: limit memory detection loop to "mem=" parameter

2013-05-02T13:50:26Z

The current memory detection loop will detect all present memory of a machine. This is true even if the user specified the "mem=" parameter on the kernel command line. This can be a problem since the memory detection may cause a fully populated host page table for the guest, even for those parts of the memory that the guest will never use afterwards. So fix this and only detect memory up to a user supplied "mem=" limit if specified. Reported-by: Michael Johanssen Reviewed-by: Michael Holzheu Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky