linux-kernel - [PATCH 4.4 30/75] ARM: Move system register accessors to asm/cp15.h

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Date:   Fri,  8 Nov 2019 19:49:47 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Russell King <rmk+kernel@...linux.org.uk>,
        Marc Zyngier <marc.zyngier@....com>,
        Vladimir Murzin <vladimir.murzin@....com>,
        Christoffer Dall <christoffer.dall@...aro.org>,
        Ard Biesheuvel <ardb@...nel.org>
Subject: [PATCH 4.4 30/75] ARM: Move system register accessors to asm/cp15.h

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

Commit 4f2546384150e78cad8045e59a9587fabcd9f9fe upstream.

Headers linux/irqchip/arm-gic.v3.h and arch/arm/include/asm/kvm_hyp.h
are included in virt/kvm/arm/hyp/vgic-v3-sr.c and both define macros
called __ACCESS_CP15 and __ACCESS_CP15_64 which obviously creates a
conflict. These macros were introduced independently for GIC and KVM
and, in fact, do the same thing.

As an option we could add prefixes to KVM and GIC version of macros so
they won't clash, but it'd introduce code duplication.  Alternatively,
we could keep macro in, say, GIC header and include it in KVM one (or
vice versa), but such dependency would not look nicer.

So we follow arm64 way (it handles this via sysreg.h) and move only
single set of macros to asm/cp15.h

Cc: Russell King <rmk+kernel@...linux.org.uk>
Acked-by: Marc Zyngier <marc.zyngier@....com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@....com>
Signed-off-by: Christoffer Dall <christoffer.dall@...aro.org>
Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/arm/include/asm/arch_gicv3.h |   27 +++++++++++----------------
 arch/arm/include/asm/cp15.h       |   15 +++++++++++++++
 2 files changed, 26 insertions(+), 16 deletions(-)

--- a/arch/arm/include/asm/arch_gicv3.h
+++ b/arch/arm/include/asm/arch_gicv3.h
@@ -22,9 +22,7 @@
 
 #include <linux/io.h>
 #include <asm/barrier.h>
-
-#define __ACCESS_CP15(CRn, Op1, CRm, Op2)	p15, Op1, %0, CRn, CRm, Op2
-#define __ACCESS_CP15_64(Op1, CRm)		p15, Op1, %Q0, %R0, CRm
+#include <asm/cp15.h>
 
 #define ICC_EOIR1			__ACCESS_CP15(c12, 0, c12, 1)
 #define ICC_DIR				__ACCESS_CP15(c12, 0, c11, 1)
@@ -102,58 +100,55 @@
 
 static inline void gic_write_eoir(u32 irq)
 {
-	asm volatile("mcr " __stringify(ICC_EOIR1) : : "r" (irq));
+	write_sysreg(irq, ICC_EOIR1);
 	isb();
 }
 
 static inline void gic_write_dir(u32 val)
 {
-	asm volatile("mcr " __stringify(ICC_DIR) : : "r" (val));
+	write_sysreg(val, ICC_DIR);
 	isb();
 }
 
 static inline u32 gic_read_iar(void)
 {
-	u32 irqstat;
+	u32 irqstat = read_sysreg(ICC_IAR1);
 
-	asm volatile("mrc " __stringify(ICC_IAR1) : "=r" (irqstat));
 	dsb(sy);
+
 	return irqstat;
 }
 
 static inline void gic_write_pmr(u32 val)
 {
-	asm volatile("mcr " __stringify(ICC_PMR) : : "r" (val));
+	write_sysreg(val, ICC_PMR);
 }
 
 static inline void gic_write_ctlr(u32 val)
 {
-	asm volatile("mcr " __stringify(ICC_CTLR) : : "r" (val));
+	write_sysreg(val, ICC_CTLR);
 	isb();
 }
 
 static inline void gic_write_grpen1(u32 val)
 {
-	asm volatile("mcr " __stringify(ICC_IGRPEN1) : : "r" (val));
+	write_sysreg(val, ICC_IGRPEN1);
 	isb();
 }
 
 static inline void gic_write_sgi1r(u64 val)
 {
-	asm volatile("mcrr " __stringify(ICC_SGI1R) : : "r" (val));
+	write_sysreg(val, ICC_SGI1R);
 }
 
 static inline u32 gic_read_sre(void)
 {
-	u32 val;
-
-	asm volatile("mrc " __stringify(ICC_SRE) : "=r" (val));
-	return val;
+	return read_sysreg(ICC_SRE);
 }
 
 static inline void gic_write_sre(u32 val)
 {
-	asm volatile("mcr " __stringify(ICC_SRE) : : "r" (val));
+	write_sysreg(val, ICC_SRE);
 	isb();
 }
 
--- a/arch/arm/include/asm/cp15.h
+++ b/arch/arm/include/asm/cp15.h
@@ -49,6 +49,21 @@
 
 #ifdef CONFIG_CPU_CP15
 
+#define __ACCESS_CP15(CRn, Op1, CRm, Op2)	\
+	"mrc", "mcr", __stringify(p15, Op1, %0, CRn, CRm, Op2), u32
+#define __ACCESS_CP15_64(Op1, CRm)		\
+	"mrrc", "mcrr", __stringify(p15, Op1, %Q0, %R0, CRm), u64
+
+#define __read_sysreg(r, w, c, t) ({				\
+	t __val;						\
+	asm volatile(r " " c : "=r" (__val));			\
+	__val;							\
+})
+#define read_sysreg(...)		__read_sysreg(__VA_ARGS__)
+
+#define __write_sysreg(v, r, w, c, t)	asm volatile(w " " c : : "r" ((t)(v)))
+#define write_sysreg(v, ...)		__write_sysreg(v, __VA_ARGS__)
+
 extern unsigned long cr_alignment;	/* defined in entry-armv.S */
 
 static inline unsigned long get_cr(void)