powerpc/mmiowb: Hook up mmwiob() implementation to asm-generic code

In a bid to kill off explicit mmiowb() usage in driver code, hook up
the asm-generic mmiowb() tracking code but provide a definition of
arch_mmiowb_state() so that the tracking data can remain in the paca
as it does at present

This replaces the existing (flawed) implementation.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 2d0be82c30619bd405949b64c2847603caf5a67d..5e3d0853c31d238272d047ca55f9bd0d4ca8d56e 100644 (file)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -132,6 +132,7 @@ 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/Kbuild b/arch/powerpc/include/asm/Kbuild
index 74b6605ca55fc05d5bb14d2c8dd91072e467edfa..a0c132bedfae86965c2f7c850098b65420c2c5fc 100644 (file)
--- a/arch/powerpc/include/asm/Kbuild
+++ b/arch/powerpc/include/asm/Kbuild
@@ -7,7 +7,6 @@ generic-y += export.h
 generic-y += irq_regs.h
 generic-y += local64.h
 generic-y += mcs_spinlock.h
-generic-y += mmiowb.h
 generic-y += preempt.h
 generic-y += rwsem.h
 generic-y += vtime.h

diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index 4b73847e9b955872248aa0b659fff2f4abfaf897..1fad67b4640926ad6660ffce74d84d0b050d3f0e 100644 (file)
--- 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 (file)
index 0000000..b101806
--- /dev/null
+++ b/arch/powerpc/include/asm/mmiowb.h
@@ -0,0 +1,20 @@
+/* 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()
+
+#else
+#define mmiowb()               do { } while (0)
+#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 e843bc5d1a0f25e69be674bb1f634da6dbb46ffd..134e912d403fb417b67e088516aecbb8695139e3 100644 (file)
--- 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 685c72310f5d0e5506d5973d6250449376b7ef46..15b39c407c4e99a46455b862eb551dcd502fb4fc 100644 (file)
--- 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 a0f44f9923608929d352596e43af8311698c3467..13c6a47e61505632a7e2fab533a03a912e5d08a2 100644 (file)
--- 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");