[PATCH 0/6] Further NOP/sysreg cleanups

[PATCH 0/6] Further NOP/sysreg cleanups

[Will Deacon]

There's clearly something going round our office, as both Rutland and I
ended up doing some mundane NOP and sysreg cleanups for the arm64 headers.

I plan to queue the first three patches here, but the GIC stuff can wait,
as it depends on Vladimir's patch (included here for completeness) and
this is hardly urgent.

Will

--->8

Vladimir Murzin (1):
  arm64: KVM: Move GIC accessors to arch_gicv3.h

Will Deacon (5):
  arm64: sysreg: replace open-coded mrs_s/msr_s with
    {read,write}_sysreg_s
  arm64: barriers: introduce nops and __nops macros for NOP sequences
  arm64: lse: convert lse alternatives NOP padding to use __nops
  irqchip/gic-v3: Convert arm64 GIC accessors to {read,write}_sysreg_s
  irqchip/gic-v3: Use nops macro for Cavium ThunderX erratum 23154

 arch/arm64/include/asm/arch_gicv3.h | 33 +++++++++----------
 arch/arm64/include/asm/assembler.h  |  9 ++++++
 arch/arm64/include/asm/atomic_lse.h | 64 ++++++++++++++++---------------------
 arch/arm64/include/asm/barrier.h    |  3 ++
 arch/arm64/include/asm/cmpxchg.h    |  4 +--
 arch/arm64/include/asm/cputype.h    |  6 +---
 arch/arm64/include/asm/spinlock.h   | 27 +++++++---------
 arch/arm64/include/asm/sysreg.h     | 16 ++++++++++
 arch/arm64/kvm/hyp/vgic-v3-sr.c     | 13 --------
 9 files changed, 83 insertions(+), 92 deletions(-)

-- 
2.1.4

[PATCH 1/6] arm64: sysreg: replace open-coded mrs_s/msr_s with {read, write}_sysreg_s

[Will Deacon]

Similar to our {read,write}_sysreg accessors for architected, named
system registers, this patch introduces {read,write}_sysreg_s variants
that can take arbitrary sys_reg output and therefore access IMPDEF
registers or registers that unsupported by binutils.

Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/cputype.h |  6 +-----
 arch/arm64/include/asm/sysreg.h  | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 9d9fd4b9a72e..26a68ddb11c1 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -93,11 +93,7 @@
 
 #include <asm/sysreg.h>
 
-#define read_cpuid(reg) ({						\
-	u64 __val;							\
-	asm("mrs_s	%0, " __stringify(SYS_ ## reg) : "=r" (__val));	\
-	__val;								\
-})
+#define read_cpuid(reg)			read_sysreg_s(SYS_ ## reg)
 
 /*
  * The CPU ID never changes at run time, so we might as well tell the
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index cc06794b7346..10d76d417d17 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -279,6 +279,22 @@ static inline void config_sctlr_el1(u32 clear, u32 set)
 		     : : "r" (__val));				\
 } while (0)
 
+/*
+ * For registers without architectural names, or simply unsupported by
+ * GAS.
+ */
+#define read_sysreg_s(r) ({					\
+	u64 __val;						\
+	asm volatile("mrs_s %0, " __stringify(r) : "=r" (__val));	\
+	__val;							\
+})
+
+#define write_sysreg_s(v, r) do {					\
+	u64 __val = (u64)v;					\
+	asm volatile("msr_s " __stringify(r) ", %0"		\
+		     : : "r" (__val));				\
+} while (0)
+
 #endif
 
 #endif	/* __ASM_SYSREG_H */
-- 
2.1.4

[PATCH 2/6] arm64: barriers: introduce nops and __nops macros for NOP sequences

[Will Deacon]

NOP sequences tend to get used for padding out alternative sections
and uarch-specific pipeline flushes in errata workarounds.

This patch adds macros for generating these sequences as both inline
asm blocks, but also as strings suitable for embedding in other asm
blocks directly.

Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/assembler.h | 9 +++++++++
 arch/arm64/include/asm/barrier.h   | 3 +++
 2 files changed, 12 insertions(+)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index d5025c69ca81..43a75e2fe931 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -87,6 +87,15 @@
 	.endm
 
 /*
+ * NOP sequence
+ */
+	.macro	nops, num
+	.rept	\num
+	nop
+	.endr
+	.endm
+
+/*
  * Emit an entry into the exception table
  */
 	.macro		_asm_extable, from, to
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index 4eea7f618dce..4e0497f581a0 100644
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -20,6 +20,9 @@
 
 #ifndef __ASSEMBLY__
 
+#define __nops(n)	".rept	" #n "\nnop\n.endr\n"
+#define nops(n)		asm volatile(__nops(n))
+
 #define sev()		asm volatile("sev" : : : "memory")
 #define wfe()		asm volatile("wfe" : : : "memory")
 #define wfi()		asm volatile("wfi" : : : "memory")
-- 
2.1.4

[PATCH 3/6] arm64: lse: convert lse alternatives NOP padding to use __nops

[Will Deacon]

The LSE atomics are implemented using alternative code sequences of
different lengths, and explicit NOP padding is used to ensure the
patching works correctly.

This patch converts the bulk of the LSE code over to using the __nops
macro, which makes it slightly clearer as to what is going on and also
consolidates all of the padding at the end of the various sequences.

Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/atomic_lse.h | 64 ++++++++++++++++---------------------
 arch/arm64/include/asm/cmpxchg.h    |  4 +--
 arch/arm64/include/asm/spinlock.h   | 27 +++++++---------
 3 files changed, 39 insertions(+), 56 deletions(-)

diff --git a/arch/arm64/include/asm/atomic_lse.h b/arch/arm64/include/asm/atomic_lse.h
index b5890be8f257..7457ce082b5f 100644
--- a/arch/arm64/include/asm/atomic_lse.h
+++ b/arch/arm64/include/asm/atomic_lse.h
@@ -86,8 +86,8 @@ static inline int atomic_add_return##name(int i, atomic_t *v)		\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
-	__LL_SC_ATOMIC(add_return##name),				\
+	__LL_SC_ATOMIC(add_return##name)				\
+	__nops(1),							\
 	/* LSE atomics */						\
 	"	ldadd" #mb "	%w[i], w30, %[v]\n"			\
 	"	add	%w[i], %w[i], w30")				\
@@ -112,8 +112,8 @@ static inline void atomic_and(int i, atomic_t *v)
 
 	asm volatile(ARM64_LSE_ATOMIC_INSN(
 	/* LL/SC */
-	"	nop\n"
-	__LL_SC_ATOMIC(and),
+	__LL_SC_ATOMIC(and)
+	__nops(1),
 	/* LSE atomics */
 	"	mvn	%w[i], %w[i]\n"
 	"	stclr	%w[i], %[v]")
@@ -130,8 +130,8 @@ static inline int atomic_fetch_and##name(int i, atomic_t *v)		\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
-	__LL_SC_ATOMIC(fetch_and##name),				\
+	__LL_SC_ATOMIC(fetch_and##name)					\
+	__nops(1),							\
 	/* LSE atomics */						\
 	"	mvn	%w[i], %w[i]\n"					\
 	"	ldclr" #mb "	%w[i], %w[i], %[v]")			\
@@ -156,8 +156,8 @@ static inline void atomic_sub(int i, atomic_t *v)
 
 	asm volatile(ARM64_LSE_ATOMIC_INSN(
 	/* LL/SC */
-	"	nop\n"
-	__LL_SC_ATOMIC(sub),
+	__LL_SC_ATOMIC(sub)
+	__nops(1),
 	/* LSE atomics */
 	"	neg	%w[i], %w[i]\n"
 	"	stadd	%w[i], %[v]")
@@ -174,9 +174,8 @@ static inline int atomic_sub_return##name(int i, atomic_t *v)		\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
 	__LL_SC_ATOMIC(sub_return##name)				\
-	"	nop",							\
+	__nops(2),							\
 	/* LSE atomics */						\
 	"	neg	%w[i], %w[i]\n"					\
 	"	ldadd" #mb "	%w[i], w30, %[v]\n"			\
@@ -203,8 +202,8 @@ static inline int atomic_fetch_sub##name(int i, atomic_t *v)		\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
-	__LL_SC_ATOMIC(fetch_sub##name),				\
+	__LL_SC_ATOMIC(fetch_sub##name)					\
+	__nops(1),							\
 	/* LSE atomics */						\
 	"	neg	%w[i], %w[i]\n"					\
 	"	ldadd" #mb "	%w[i], %w[i], %[v]")			\
@@ -284,8 +283,8 @@ static inline long atomic64_add_return##name(long i, atomic64_t *v)	\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
-	__LL_SC_ATOMIC64(add_return##name),				\
+	__LL_SC_ATOMIC64(add_return##name)				\
+	__nops(1),							\
 	/* LSE atomics */						\
 	"	ldadd" #mb "	%[i], x30, %[v]\n"			\
 	"	add	%[i], %[i], x30")				\
@@ -310,8 +309,8 @@ static inline void atomic64_and(long i, atomic64_t *v)
 
 	asm volatile(ARM64_LSE_ATOMIC_INSN(
 	/* LL/SC */
-	"	nop\n"
-	__LL_SC_ATOMIC64(and),
+	__LL_SC_ATOMIC64(and)
+	__nops(1),
 	/* LSE atomics */
 	"	mvn	%[i], %[i]\n"
 	"	stclr	%[i], %[v]")
@@ -328,8 +327,8 @@ static inline long atomic64_fetch_and##name(long i, atomic64_t *v)	\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
-	__LL_SC_ATOMIC64(fetch_and##name),				\
+	__LL_SC_ATOMIC64(fetch_and##name)				\
+	__nops(1),							\
 	/* LSE atomics */						\
 	"	mvn	%[i], %[i]\n"					\
 	"	ldclr" #mb "	%[i], %[i], %[v]")			\
@@ -354,8 +353,8 @@ static inline void atomic64_sub(long i, atomic64_t *v)
 
 	asm volatile(ARM64_LSE_ATOMIC_INSN(
 	/* LL/SC */
-	"	nop\n"
-	__LL_SC_ATOMIC64(sub),
+	__LL_SC_ATOMIC64(sub)
+	__nops(1),
 	/* LSE atomics */
 	"	neg	%[i], %[i]\n"
 	"	stadd	%[i], %[v]")
@@ -372,9 +371,8 @@ static inline long atomic64_sub_return##name(long i, atomic64_t *v)	\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
 	__LL_SC_ATOMIC64(sub_return##name)				\
-	"	nop",							\
+	__nops(2),							\
 	/* LSE atomics */						\
 	"	neg	%[i], %[i]\n"					\
 	"	ldadd" #mb "	%[i], x30, %[v]\n"			\
@@ -401,8 +399,8 @@ static inline long atomic64_fetch_sub##name(long i, atomic64_t *v)	\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
-	__LL_SC_ATOMIC64(fetch_sub##name),				\
+	__LL_SC_ATOMIC64(fetch_sub##name)				\
+	__nops(1),							\
 	/* LSE atomics */						\
 	"	neg	%[i], %[i]\n"					\
 	"	ldadd" #mb "	%[i], %[i], %[v]")			\
@@ -426,13 +424,8 @@ static inline long atomic64_dec_if_positive(atomic64_t *v)
 
 	asm volatile(ARM64_LSE_ATOMIC_INSN(
 	/* LL/SC */
-	"	nop\n"
 	__LL_SC_ATOMIC64(dec_if_positive)
-	"	nop\n"
-	"	nop\n"
-	"	nop\n"
-	"	nop\n"
-	"	nop",
+	__nops(6),
 	/* LSE atomics */
 	"1:	ldr	x30, %[v]\n"
 	"	subs	%[ret], x30, #1\n"
@@ -464,9 +457,8 @@ static inline unsigned long __cmpxchg_case_##name(volatile void *ptr,	\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
-		__LL_SC_CMPXCHG(name)					\
-	"	nop",							\
+	__LL_SC_CMPXCHG(name)						\
+	__nops(2),							\
 	/* LSE atomics */						\
 	"	mov	" #w "30, %" #w "[old]\n"			\
 	"	cas" #mb #sz "\t" #w "30, %" #w "[new], %[v]\n"		\
@@ -517,10 +509,8 @@ static inline long __cmpxchg_double##name(unsigned long old1,		\
 									\
 	asm volatile(ARM64_LSE_ATOMIC_INSN(				\
 	/* LL/SC */							\
-	"	nop\n"							\
-	"	nop\n"							\
-	"	nop\n"							\
-	__LL_SC_CMPXCHG_DBL(name),					\
+	__LL_SC_CMPXCHG_DBL(name)					\
+	__nops(3),							\
 	/* LSE atomics */						\
 	"	casp" #mb "\t%[old1], %[old2], %[new1], %[new2], %[v]\n"\
 	"	eor	%[old1], %[old1], %[oldval1]\n"			\
diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
index bd86a79491bc..91b26d26af8a 100644
--- a/arch/arm64/include/asm/cmpxchg.h
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -43,10 +43,8 @@ static inline unsigned long __xchg_case_##name(unsigned long x,		\
 	"	cbnz	%w1, 1b\n"					\
 	"	" #mb,							\
 	/* LSE atomics */						\
-	"	nop\n"							\
-	"	nop\n"							\
 	"	swp" #acq_lse #rel #sz "\t%" #w "3, %" #w "0, %2\n"	\
-	"	nop\n"							\
+		__nops(3)						\
 	"	" #nop_lse)						\
 	: "=&r" (ret), "=&r" (tmp), "+Q" (*(u8 *)ptr)			\
 	: "r" (x)							\
diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h
index e875a5a551d7..28f8c2174f8a 100644
--- a/arch/arm64/include/asm/spinlock.h
+++ b/arch/arm64/include/asm/spinlock.h
@@ -66,8 +66,7 @@ static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
 	ARM64_LSE_ATOMIC_INSN(
 	/* LL/SC */
 "	stxr	%w1, %w0, %2\n"
-"	nop\n"
-"	nop\n",
+	__nops(2),
 	/* LSE atomics */
 "	mov	%w1, %w0\n"
 "	cas	%w0, %w0, %2\n"
@@ -99,9 +98,7 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
 	/* LSE atomics */
 "	mov	%w2, %w5\n"
 "	ldadda	%w2, %w0, %3\n"
-"	nop\n"
-"	nop\n"
-"	nop\n"
+	__nops(3)
 	)
 
 	/* Did we get the lock? */
@@ -165,8 +162,8 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock)
 	"	stlrh	%w1, %0",
 	/* LSE atomics */
 	"	mov	%w1, #1\n"
-	"	nop\n"
-	"	staddlh	%w1, %0")
+	"	staddlh	%w1, %0\n"
+	__nops(1))
 	: "=Q" (lock->owner), "=&r" (tmp)
 	:
 	: "memory");
@@ -212,7 +209,7 @@ static inline void arch_write_lock(arch_rwlock_t *rw)
 	"	cbnz	%w0, 1b\n"
 	"	stxr	%w0, %w2, %1\n"
 	"	cbnz	%w0, 2b\n"
-	"	nop",
+	__nops(1),
 	/* LSE atomics */
 	"1:	mov	%w0, wzr\n"
 	"2:	casa	%w0, %w2, %1\n"
@@ -241,8 +238,7 @@ static inline int arch_write_trylock(arch_rwlock_t *rw)
 	/* LSE atomics */
 	"	mov	%w0, wzr\n"
 	"	casa	%w0, %w2, %1\n"
-	"	nop\n"
-	"	nop")
+	__nops(2))
 	: "=&r" (tmp), "+Q" (rw->lock)
 	: "r" (0x80000000)
 	: "memory");
@@ -290,8 +286,8 @@ static inline void arch_read_lock(arch_rwlock_t *rw)
 	"	add	%w0, %w0, #1\n"
 	"	tbnz	%w0, #31, 1b\n"
 	"	stxr	%w1, %w0, %2\n"
-	"	nop\n"
-	"	cbnz	%w1, 2b",
+	"	cbnz	%w1, 2b\n"
+	__nops(1),
 	/* LSE atomics */
 	"1:	wfe\n"
 	"2:	ldxr	%w0, %2\n"
@@ -317,9 +313,8 @@ static inline void arch_read_unlock(arch_rwlock_t *rw)
 	"	cbnz	%w1, 1b",
 	/* LSE atomics */
 	"	movn	%w0, #0\n"
-	"	nop\n"
-	"	nop\n"
-	"	staddl	%w0, %2")
+	"	staddl	%w0, %2\n"
+	__nops(2))
 	: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
 	:
 	: "memory");
@@ -344,7 +339,7 @@ static inline int arch_read_trylock(arch_rwlock_t *rw)
 	"	tbnz	%w1, #31, 1f\n"
 	"	casa	%w0, %w1, %2\n"
 	"	sbc	%w1, %w1, %w0\n"
-	"	nop\n"
+	__nops(1)
 	"1:")
 	: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
 	:
-- 
2.1.4

[PATCH 4/6] arm64: KVM: Move GIC accessors to arch_gicv3.h

[Will Deacon]

From: Vladimir Murzin <vladimir.murzin@arm.com>

Since we are going to share vgic-v3 save/restore code with ARM
keep arch specific accessors separately.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/arch_gicv3.h | 13 +++++++++++++
 arch/arm64/kvm/hyp/vgic-v3-sr.c     | 13 -------------
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/include/asm/arch_gicv3.h b/arch/arm64/include/asm/arch_gicv3.h
index 8ec88e5b290f..ae7dbd79e257 100644
--- a/arch/arm64/include/asm/arch_gicv3.h
+++ b/arch/arm64/include/asm/arch_gicv3.h
@@ -79,6 +79,19 @@
 #include <linux/stringify.h>
 #include <asm/barrier.h>
 
+#define read_gicreg(r)							\
+	({								\
+		u64 reg;						\
+		asm volatile("mrs_s %0, " __stringify(r) : "=r" (reg));	\
+		reg;							\
+	})
+
+#define write_gicreg(v,r)						\
+	do {								\
+		u64 __val = (v);					\
+		asm volatile("msr_s " __stringify(r) ", %0" : : "r" (__val));\
+	} while (0)
+
 /*
  * Low-level accessors
  *
diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index 5f8f80b4a224..f2dbd2e76dbd 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -24,19 +24,6 @@
 #define vtr_to_max_lr_idx(v)		((v) & 0xf)
 #define vtr_to_nr_pri_bits(v)		(((u32)(v) >> 29) + 1)
 
-#define read_gicreg(r)							\
-	({								\
-		u64 reg;						\
-		asm volatile("mrs_s %0, " __stringify(r) : "=r" (reg));	\
-		reg;							\
-	})
-
-#define write_gicreg(v,r)						\
-	do {								\
-		u64 __val = (v);					\
-		asm volatile("msr_s " __stringify(r) ", %0" : : "r" (__val));\
-	} while (0)
-
 static u64 __hyp_text __gic_v3_get_lr(unsigned int lr)
 {
 	switch (lr & 0xf) {
-- 
2.1.4

[PATCH 5/6] irqchip/gic-v3: Convert arm64 GIC accessors to {read, write}_sysreg_s

[Will Deacon]

The GIC system registers are accessed using open-coded wrappers around
the mrs_s/msr_s asm macros.

This patch moves the code over to the {read,wrote}_sysreg_s accessors
instead, reducing the amount of explicit asm blocks in the arch headers.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/arch_gicv3.h | 45 ++++++++++++++-----------------------
 1 file changed, 17 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/include/asm/arch_gicv3.h b/arch/arm64/include/asm/arch_gicv3.h
index ae7dbd79e257..0d41944d965d 100644
--- a/arch/arm64/include/asm/arch_gicv3.h
+++ b/arch/arm64/include/asm/arch_gicv3.h
@@ -79,18 +79,8 @@
 #include <linux/stringify.h>
 #include <asm/barrier.h>
 
-#define read_gicreg(r)							\
-	({								\
-		u64 reg;						\
-		asm volatile("mrs_s %0, " __stringify(r) : "=r" (reg));	\
-		reg;							\
-	})
-
-#define write_gicreg(v,r)						\
-	do {								\
-		u64 __val = (v);					\
-		asm volatile("msr_s " __stringify(r) ", %0" : : "r" (__val));\
-	} while (0)
+#define read_gicreg			read_sysreg_s
+#define write_gicreg			write_sysreg_s
 
 /*
  * Low-level accessors
@@ -101,13 +91,13 @@
 
 static inline void gic_write_eoir(u32 irq)
 {
-	asm volatile("msr_s " __stringify(ICC_EOIR1_EL1) ", %0" : : "r" ((u64)irq));
+	write_sysreg_s(irq, ICC_EOIR1_EL1);
 	isb();
 }
 
 static inline void gic_write_dir(u32 irq)
 {
-	asm volatile("msr_s " __stringify(ICC_DIR_EL1) ", %0" : : "r" ((u64)irq));
+	write_sysreg_s(irq, ICC_DIR_EL1);
 	isb();
 }
 
@@ -115,7 +105,7 @@ static inline u64 gic_read_iar_common(void)
 {
 	u64 irqstat;
 
-	asm volatile("mrs_s %0, " __stringify(ICC_IAR1_EL1) : "=r" (irqstat));
+	irqstat = read_sysreg_s(ICC_IAR1_EL1);
 	dsb(sy);
 	return irqstat;
 }
@@ -133,10 +123,12 @@ static inline u64 gic_read_iar_cavium_thunderx(void)
 
 	asm volatile(
 		"nop;nop;nop;nop\n\t"
-		"nop;nop;nop;nop\n\t"
-		"mrs_s %0, " __stringify(ICC_IAR1_EL1) "\n\t"
-		"nop;nop;nop;nop"
-		: "=r" (irqstat));
+		"nop;nop;nop;nop");
+
+	irqstat = read_sysreg_s(ICC_IAR1_EL1);
+
+	asm volatile(
+		"nop;nop;nop;nop");
 	mb();
 
 	return irqstat;
@@ -144,37 +136,34 @@ static inline u64 gic_read_iar_cavium_thunderx(void)
 
 static inline void gic_write_pmr(u32 val)
 {
-	asm volatile("msr_s " __stringify(ICC_PMR_EL1) ", %0" : : "r" ((u64)val));
+	write_sysreg_s(val, ICC_PMR_EL1);
 }
 
 static inline void gic_write_ctlr(u32 val)
 {
-	asm volatile("msr_s " __stringify(ICC_CTLR_EL1) ", %0" : : "r" ((u64)val));
+	write_sysreg_s(val, ICC_CTLR_EL1);
 	isb();
 }
 
 static inline void gic_write_grpen1(u32 val)
 {
-	asm volatile("msr_s " __stringify(ICC_GRPEN1_EL1) ", %0" : : "r" ((u64)val));
+	write_sysreg_s(val, ICC_GRPEN1_EL1);
 	isb();
 }
 
 static inline void gic_write_sgi1r(u64 val)
 {
-	asm volatile("msr_s " __stringify(ICC_SGI1R_EL1) ", %0" : : "r" (val));
+	write_sysreg_s(val, ICC_SGI1R_EL1);
 }
 
 static inline u32 gic_read_sre(void)
 {
-	u64 val;
-
-	asm volatile("mrs_s %0, " __stringify(ICC_SRE_EL1) : "=r" (val));
-	return val;
+	return read_sysreg_s(ICC_SRE_EL1);
 }
 
 static inline void gic_write_sre(u32 val)
 {
-	asm volatile("msr_s " __stringify(ICC_SRE_EL1) ", %0" : : "r" ((u64)val));
+	write_sysreg_s(val, ICC_SRE_EL1);
 	isb();
 }
 
-- 
2.1.4

[PATCH 6/6] irqchip/gic-v3: Use nops macro for Cavium ThunderX erratum 23154

[Will Deacon]

The workaround for Cavium ThunderX erratum 23154 has a homebrew
pipeflush built out of NOP sequences around the read of the IAR.

This patch converts the code to use the new nops macro, which makes it
a little easier to read.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/arch_gicv3.h | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/include/asm/arch_gicv3.h b/arch/arm64/include/asm/arch_gicv3.h
index 0d41944d965d..258f0e118375 100644
--- a/arch/arm64/include/asm/arch_gicv3.h
+++ b/arch/arm64/include/asm/arch_gicv3.h
@@ -121,14 +121,9 @@ static inline u64 gic_read_iar_cavium_thunderx(void)
 {
 	u64 irqstat;
 
-	asm volatile(
-		"nop;nop;nop;nop\n\t"
-		"nop;nop;nop;nop");
-
+	nops(8);
 	irqstat = read_sysreg_s(ICC_IAR1_EL1);
-
-	asm volatile(
-		"nop;nop;nop;nop");
+	nops(4);
 	mb();
 
 	return irqstat;
-- 
2.1.4

[PATCH 1/6] arm64: sysreg: replace open-coded mrs_s/msr_s with {read,write}_sysreg_s

[Mark Rutland]

On Fri, Sep 09, 2016 at 12:16:00PM +0100, Will Deacon wrote:
> Similar to our {read,write}_sysreg accessors for architected, named
> system registers, this patch introduces {read,write}_sysreg_s variants
> that can take arbitrary sys_reg output and therefore access IMPDEF
> registers or registers that unsupported by binutils.
> 
> Signed-off-by: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm64/include/asm/cputype.h |  6 +-----
>  arch/arm64/include/asm/sysreg.h  | 16 ++++++++++++++++
>  2 files changed, 17 insertions(+), 5 deletions(-)

> +#define write_sysreg_s(v, r) do {					\
> +	u64 __val = (u64)v;					\
> +	asm volatile("msr_s " __stringify(r) ", %0"		\
> +		     : : "r" (__val));				\
> +} while (0)

As with my patches, can we please make write_sysreg_s allow the zero
register? i.e. use the "%x0" tempate and "rZ" constraint. The mrs_s asm
template should handle that correctly.

With that:

Reviewed-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.