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Merge tag 'arm64-mmiowb' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

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Pull mmiowb removal from Will Deacon:
 "Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb())

  Remove mmiowb() from the kernel memory barrier API and instead, for
  architectures that need it, hide the barrier inside spin_unlock() when
  MMIO has been performed inside the critical section.

  The only relatively recent changes have been addressing review
  comments on the documentation, which is in a much better shape thanks
  to the efforts of Ben and Ingo.

  I was initially planning to split this into two pull requests so that
  you could run the coccinelle script yourself, however it's been plain
  sailing in linux-next so I've just included the whole lot here to keep
  things simple"

* tag 'arm64-mmiowb' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (23 commits)
  docs/memory-barriers.txt: Update I/O section to be clearer about CPU vs thread
  docs/memory-barriers.txt: Fix style, spacing and grammar in I/O section
  arch: Remove dummy mmiowb() definitions from arch code
  net/ethernet/silan/sc92031: Remove stale comment about mmiowb()
  i40iw: Redefine i40iw_mmiowb() to do nothing
  scsi/qla1280: Remove stale comment about mmiowb()
  drivers: Remove explicit invocations of mmiowb()
  drivers: Remove useless trailing comments from mmiowb() invocations
  Documentation: Kill all references to mmiowb()
  riscv/mmiowb: Hook up mmwiob() implementation to asm-generic code
  powerpc/mmiowb: Hook up mmwiob() implementation to asm-generic code
  ia64/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
  mips/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
  sh/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
  m68k/io: Remove useless definition of mmiowb()
  nds32/io: Remove useless definition of mmiowb()
  x86/io: Remove useless definition of mmiowb()
  arm64/io: Remove useless definition of mmiowb()
  ARM/io: Remove useless definition of mmiowb()
  mmiowb: Hook up mmiowb helpers to spinlocks and generic I/O accessors
  ...
This commit is contained in:
Linus Torvalds
2019-05-06 16:57:52 -07:00
parent 14be4c61c2 9726840d9c
commit dd4e5d6106
181 changed files with 343 additions and 828 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
kernel/locking/spinlock.c
View File

@@ -22,6 +22,13 @@
#include <linux/debug_locks.h>
#include <linux/export.h>
#ifdef CONFIG_MMIOWB
#ifndef arch_mmiowb_state
DEFINE_PER_CPU(struct mmiowb_state, __mmiowb_state);
EXPORT_PER_CPU_SYMBOL(__mmiowb_state);
#endif
#endif
/*
* If lockdep is enabled then we use the non-preemption spin-ops
* even on CONFIG_PREEMPT, because lockdep assumes that interrupts are

6
kernel/locking/spinlock_debug.c
View File

@@ -111,6 +111,7 @@ void do_raw_spin_lock(raw_spinlock_t *lock)
{
debug_spin_lock_before(lock);
arch_spin_lock(&lock->raw_lock);
mmiowb_spin_lock();
debug_spin_lock_after(lock);
}
@@ -118,8 +119,10 @@ int do_raw_spin_trylock(raw_spinlock_t *lock)
{
int ret = arch_spin_trylock(&lock->raw_lock);
if (ret)
if (ret) {
mmiowb_spin_lock();
debug_spin_lock_after(lock);
}
#ifndef CONFIG_SMP
/*
* Must not happen on UP:
@@ -131,6 +134,7 @@ int do_raw_spin_trylock(raw_spinlock_t *lock)
void do_raw_spin_unlock(raw_spinlock_t *lock)
{
mmiowb_spin_unlock();
debug_spin_unlock(lock);
arch_spin_unlock(&lock->raw_lock);
}