kernel.git/arch/x86/include/asm/atomic.h, branch linux-4.13.y

locking/x86: Remove the unused atomic_inc_short() methd

2017-06-08T08:33:50Z

It is completely unused and implemented only on x86. Remove it. Suggested-by: Mark Rutland Signed-off-by: Dmitry Vyukov Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Andrey Ryabinin Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170526172900.91058-1-dvyukov@google.com Signed-off-by: Ingo Molnar

locking/atomic/x86: Use atomic_try_cmpxchg()

2017-03-23T07:54:41Z

Better code generation: text data bss name 10665111 4530096 843776 defconfig-build/vmlinux.3 10655703 4530096 843776 defconfig-build/vmlinux.4 Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

locking/atomic: Introduce atomic_try_cmpxchg()

2017-03-23T07:54:40Z

Add a new cmpxchg interface: bool try_cmpxchg(u{8,16,32,64} *ptr, u{8,16,32,64} *val, u{8,16,32,64} new); Where the boolean returns the result of the compare; and thus if the exchange happened; and in case of failure, the new value of *ptr is returned in *val. This allows simplification/improvement of loops like: for (;;) { new = val $op $imm; old = cmpxchg(ptr, val, new); if (old == val) break; val = old; } into: do { } while (!try_cmpxchg(ptr, &val, val $op $imm)); while also generating better code (GCC6 and onwards). Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-07-25T22:34:18Z

Pull x86 mm updates from Ingo Molnar: "Various x86 low level modifications: - preparatory work to support virtually mapped kernel stacks (Andy Lutomirski) - support for 64-bit __get_user() on 32-bit kernels (Benjamin LaHaise) - (involved) workaround for Knights Landing CPU erratum (Dave Hansen) - MPX enhancements (Dave Hansen) - mremap() extension to allow remapping of the special VDSO vma, for purposes of user level context save/restore (Dmitry Safonov) - hweight and entry code cleanups (Borislav Petkov) - bitops code generation optimizations and cleanups with modern GCC (H. Peter Anvin) - syscall entry code optimizations (Paolo Bonzini)" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits) x86/mm/cpa: Add missing comment in populate_pdg() x86/mm/cpa: Fix populate_pgd(): Stop trying to deallocate failed PUDs x86/syscalls: Add compat_sys_preadv64v2/compat_sys_pwritev64v2 x86/smp: Remove unnecessary initialization of thread_info::cpu x86/smp: Remove stack_smp_processor_id() x86/uaccess: Move thread_info::addr_limit to thread_struct x86/dumpstack: Rename thread_struct::sig_on_uaccess_error to sig_on_uaccess_err x86/uaccess: Move thread_info::uaccess_err and thread_info::sig_on_uaccess_err to thread_struct x86/dumpstack: When OOPSing, rewind the stack before do_exit() x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm x86/dumpstack/64: Handle faults when printing the "Stack: " part of an OOPS x86/dumpstack: Try harder to get a call trace on stack overflow x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables() x86/mm/cpa: In populate_pgd(), don't set the PGD entry until it's populated x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() x86/mm: Use pte_none() to test for empty PTE x86/mm: Disallow running with 32-bit PTEs to work around erratum x86/mm: Ignore A/D bits in pte/pmd/pud_none() x86/mm: Move swap offset/type up in PTE to work around erratum x86/entry: Inline enter_from_user_mode() ...

locking/atomic: Remove linux/atomic.h:atomic_fetch_or()

2016-06-16T08:48:32Z

Since all architectures have this implemented now natively, remove this dead code. Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

locking/atomic, arch/x86: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()

2016-06-16T08:48:31Z

Implement FETCH-OP atomic primitives, these are very similar to the existing OP-RETURN primitives we already have, except they return the value of the atomic variable _before_ modification. This is especially useful for irreversible operations -- such as bitops (because it becomes impossible to reconstruct the state prior to modification). Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

x86, asm: change the GEN_*_RMWcc() macros to not quote the condition

2016-06-08T19:41:20Z

Change the lexical defintion of the GEN_*_RMWcc() macros to not take the condition code as a quoted string. This will help support changing them to use the new __GCC_ASM_FLAG_OUTPUTS__ feature in a subsequent patch. Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1465414726-197858-4-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski Reviewed-by: Borislav Petkov Acked-by: Peter Zijlstra (Intel)

x86, asm: use bool for bitops and other assembly outputs

2016-06-08T19:41:20Z

The gcc people have confirmed that using "bool" when combined with inline assembly always is treated as a byte-sized operand that can be assumed to be 0 or 1, which is exactly what the SET instruction emits. Change the output types and intermediate variables of as many operations as practical to "bool". Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1465414726-197858-3-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski Reviewed-by: Borislav Petkov Acked-by: Peter Zijlstra (Intel)

x86/headers: Don't include asm/processor.h in asm/atomic.h

2015-12-06T11:56:03Z

asm/atomic.h doesn't really need asm/processor.h anymore. Everything it uses has moved to other header files. So remove that include. processor.h is a nasty header that includes lots of other headers and makes it prone to include loops. Removing the include here makes asm/atomic.h a "leaf" header that can be safely included in most other headers. The only fallout is in the lib/atomic tester which relied on this implicit include. Give it an explicit include. (the include is in ifdef because the user is also in ifdef) Signed-off-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/1449018060-1742-1-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar

atomic, arch: Audit atomic_{read,set}()

2015-09-23T07:54:28Z

This patch makes sure that atomic_{read,set}() are at least {READ,WRITE}_ONCE(). We already had the 'requirement' that atomic_read() should use ACCESS_ONCE(), and most archs had this, but a few were lacking. All are now converted to use READ_ONCE(). And, by a symmetry and general paranoia argument, upgrade atomic_set() to use WRITE_ONCE(). Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Dmitry Vyukov Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: james.hogan@imgtec.com Cc: linux-kernel@vger.kernel.org Cc: oleg@redhat.com Cc: will.deacon@arm.com Signed-off-by: Ingo Molnar