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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-07 02:57:52 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-07 02:57:52 +0300
commitdd4e5d6106b2380e2c1238406d26df8b2fe1c42c (patch)
tree33eb172237dd8873de02d5b881bf17cf58d05fab /arch/powerpc
parent14be4c61c205dcb0a72251c1e2790814181bd9ba (diff)
parent9726840d9cf0d42377e1591263d7c1d9ae0988ac (diff)
downloadlinux-dd4e5d6106b2380e2c1238406d26df8b2fe1c42c.tar.xz
Merge tag 'arm64-mmiowb' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
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 ...
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/Kconfig1
-rw-r--r--arch/powerpc/include/asm/io.h33
-rw-r--r--arch/powerpc/include/asm/mmiowb.h18
-rw-r--r--arch/powerpc/include/asm/paca.h6
-rw-r--r--arch/powerpc/include/asm/spinlock.h17
-rw-r--r--arch/powerpc/xmon/xmon.c5
6 files changed, 31 insertions, 49 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 88a4fb3647a2..fa7219ffeadc 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -125,6 +125,7 @@ config PPC
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_KCOV
+ select ARCH_HAS_MMIOWB if PPC64
select ARCH_HAS_PHYS_TO_DMA
select ARCH_HAS_PMEM_API if PPC64
select ARCH_HAS_PTE_SPECIAL
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index 4b73847e9b95..1fad67b46409 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -34,14 +34,11 @@ extern struct pci_dev *isa_bridge_pcidev;
#include <asm/byteorder.h>
#include <asm/synch.h>
#include <asm/delay.h>
+#include <asm/mmiowb.h>
#include <asm/mmu.h>
#include <asm/ppc_asm.h>
#include <asm/pgtable.h>
-#ifdef CONFIG_PPC64
-#include <asm/paca.h>
-#endif
-
#define SIO_CONFIG_RA 0x398
#define SIO_CONFIG_RD 0x399
@@ -107,12 +104,6 @@ extern bool isa_io_special;
*
*/
-#ifdef CONFIG_PPC64
-#define IO_SET_SYNC_FLAG() do { local_paca->io_sync = 1; } while(0)
-#else
-#define IO_SET_SYNC_FLAG()
-#endif
-
#define DEF_MMIO_IN_X(name, size, insn) \
static inline u##size name(const volatile u##size __iomem *addr) \
{ \
@@ -127,7 +118,7 @@ static inline void name(volatile u##size __iomem *addr, u##size val) \
{ \
__asm__ __volatile__("sync;"#insn" %1,%y0" \
: "=Z" (*addr) : "r" (val) : "memory"); \
- IO_SET_SYNC_FLAG(); \
+ mmiowb_set_pending(); \
}
#define DEF_MMIO_IN_D(name, size, insn) \
@@ -144,7 +135,7 @@ static inline void name(volatile u##size __iomem *addr, u##size val) \
{ \
__asm__ __volatile__("sync;"#insn"%U0%X0 %1,%0" \
: "=m" (*addr) : "r" (val) : "memory"); \
- IO_SET_SYNC_FLAG(); \
+ mmiowb_set_pending(); \
}
DEF_MMIO_IN_D(in_8, 8, lbz);
@@ -652,24 +643,6 @@ static inline void name at \
#include <asm-generic/iomap.h>
-#ifdef CONFIG_PPC32
-#define mmiowb()
-#else
-/*
- * Enforce synchronisation of stores vs. spin_unlock
- * (this does it explicitly, though our implementation of spin_unlock
- * does it implicitely too)
- */
-static inline void mmiowb(void)
-{
- unsigned long tmp;
-
- __asm__ __volatile__("sync; li %0,0; stb %0,%1(13)"
- : "=&r" (tmp) : "i" (offsetof(struct paca_struct, io_sync))
- : "memory");
-}
-#endif /* !CONFIG_PPC32 */
-
static inline void iosync(void)
{
__asm__ __volatile__ ("sync" : : : "memory");
diff --git a/arch/powerpc/include/asm/mmiowb.h b/arch/powerpc/include/asm/mmiowb.h
new file mode 100644
index 000000000000..74a00127eb20
--- /dev/null
+++ b/arch/powerpc/include/asm/mmiowb.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_MMIOWB_H
+#define _ASM_POWERPC_MMIOWB_H
+
+#ifdef CONFIG_MMIOWB
+
+#include <linux/compiler.h>
+#include <asm/barrier.h>
+#include <asm/paca.h>
+
+#define arch_mmiowb_state() (&local_paca->mmiowb_state)
+#define mmiowb() mb()
+
+#endif /* CONFIG_MMIOWB */
+
+#include <asm-generic/mmiowb.h>
+
+#endif /* _ASM_POWERPC_MMIOWB_H */
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index e843bc5d1a0f..134e912d403f 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -34,6 +34,8 @@
#include <asm/cpuidle.h>
#include <asm/atomic.h>
+#include <asm-generic/mmiowb_types.h>
+
register struct paca_struct *local_paca asm("r13");
#if defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_SMP)
@@ -171,7 +173,6 @@ struct paca_struct {
u16 trap_save; /* Used when bad stack is encountered */
u8 irq_soft_mask; /* mask for irq soft masking */
u8 irq_happened; /* irq happened while soft-disabled */
- u8 io_sync; /* writel() needs spin_unlock sync */
u8 irq_work_pending; /* IRQ_WORK interrupt while soft-disable */
u8 nap_state_lost; /* NV GPR values lost in power7_idle */
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
@@ -264,6 +265,9 @@ struct paca_struct {
#ifdef CONFIG_STACKPROTECTOR
unsigned long canary;
#endif
+#ifdef CONFIG_MMIOWB
+ struct mmiowb_state mmiowb_state;
+#endif
} ____cacheline_aligned;
extern void copy_mm_to_paca(struct mm_struct *mm);
diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index 685c72310f5d..15b39c407c4e 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -39,19 +39,6 @@
#define LOCK_TOKEN 1
#endif
-#if defined(CONFIG_PPC64) && defined(CONFIG_SMP)
-#define CLEAR_IO_SYNC (get_paca()->io_sync = 0)
-#define SYNC_IO do { \
- if (unlikely(get_paca()->io_sync)) { \
- mb(); \
- get_paca()->io_sync = 0; \
- } \
- } while (0)
-#else
-#define CLEAR_IO_SYNC
-#define SYNC_IO
-#endif
-
#ifdef CONFIG_PPC_PSERIES
#define vcpu_is_preempted vcpu_is_preempted
static inline bool vcpu_is_preempted(int cpu)
@@ -99,7 +86,6 @@ static inline unsigned long __arch_spin_trylock(arch_spinlock_t *lock)
static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
- CLEAR_IO_SYNC;
return __arch_spin_trylock(lock) == 0;
}
@@ -130,7 +116,6 @@ extern void __rw_yield(arch_rwlock_t *lock);
static inline void arch_spin_lock(arch_spinlock_t *lock)
{
- CLEAR_IO_SYNC;
while (1) {
if (likely(__arch_spin_trylock(lock) == 0))
break;
@@ -148,7 +133,6 @@ void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
{
unsigned long flags_dis;
- CLEAR_IO_SYNC;
while (1) {
if (likely(__arch_spin_trylock(lock) == 0))
break;
@@ -167,7 +151,6 @@ void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
- SYNC_IO;
__asm__ __volatile__("# arch_spin_unlock\n\t"
PPC_RELEASE_BARRIER: : :"memory");
lock->slock = 0;
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index a0f44f992360..13c6a47e6150 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2429,7 +2429,10 @@ static void dump_one_paca(int cpu)
DUMP(p, trap_save, "%#-*x");
DUMP(p, irq_soft_mask, "%#-*x");
DUMP(p, irq_happened, "%#-*x");
- DUMP(p, io_sync, "%#-*x");
+#ifdef CONFIG_MMIOWB
+ DUMP(p, mmiowb_state.nesting_count, "%#-*x");
+ DUMP(p, mmiowb_state.mmiowb_pending, "%#-*x");
+#endif
DUMP(p, irq_work_pending, "%#-*x");
DUMP(p, nap_state_lost, "%#-*x");
DUMP(p, sprg_vdso, "%#-*llx");