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authorLinus Torvalds <torvalds@linux-foundation.org>2018-04-12 09:15:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-12 09:15:48 -0700
commitc17b0aadb7d8f87de56a4a374a8131519c0f7422 (patch)
tree764af3fc7e29ffcb24f93b648f163358fb6e60a4 /include/asm-generic/io.h
parente241e3f2bf975788a1b70dff2eb5180ca395b28e (diff)
parenta71e7c44ffb7baea0c0795824afc34cc0bc1a301 (diff)
Merge tag 'asm-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic fixes from Arnd Bergmann: "I have one regression fix for a minor build problem after the architecture removal series, plus a rework of the barriers in the readl/writel functions, thanks to work by Sinan Kaya: This started from a discussion on the linuxpcc and rdma mailing lists[1]. To summarize, we decided that architectures are responsible to serialize readl() and writel() accesses on a device MMIO space relative to DMA performed by that device. This series provides a pessimistic implementation of that behavior for asm-generic/io.h, which is in turn used by a number of architectures (h8300, microblaze, nios2, openrisc, s390, sparc, um, unicore32, and xtensa). Some of those presumably need no extra barriers, or something weaker than rmb()/wmb(), and they are advised to override the new default for better performance. For inb()/outb(), the same barriers are used, but architectures might want to add another barrier to outb() here if that can guarantee non-posted behavior (some architectures can, others cannot do that). The readl_relaxed()/writel_relaxed() family of functions retains the existing behavior with no extra barriers" [1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2018-March/170481.html * tag 'asm-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: io: change writeX_relaxed() to remove barriers io: change readX_relaxed() to remove barriers dts: remove cris & metag dts hard link file io: change inX() to have their own IO barrier overrides io: change outX() to have their own IO barrier overrides io: define stronger ordering for the default writeX() implementation io: define stronger ordering for the default readX() implementation io: define several IO & PIO barrier types for the asm-generic version
Diffstat (limited to 'include/asm-generic/io.h')
-rw-r--r--include/asm-generic/io.h161
1 files changed, 143 insertions, 18 deletions
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 04c4cc6fd820..66d1d45fa2e1 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -25,6 +25,50 @@
#define mmiowb() do {} while (0)
#endif
+#ifndef __io_br
+#define __io_br() barrier()
+#endif
+
+/* prevent prefetching of coherent DMA data ahead of a dma-complete */
+#ifndef __io_ar
+#ifdef rmb
+#define __io_ar() rmb()
+#else
+#define __io_ar() barrier()
+#endif
+#endif
+
+/* flush writes to coherent DMA data before possibly triggering a DMA read */
+#ifndef __io_bw
+#ifdef wmb
+#define __io_bw() wmb()
+#else
+#define __io_bw() barrier()
+#endif
+#endif
+
+/* serialize device access against a spin_unlock, usually handled there. */
+#ifndef __io_aw
+#define __io_aw() barrier()
+#endif
+
+#ifndef __io_pbw
+#define __io_pbw() __io_bw()
+#endif
+
+#ifndef __io_paw
+#define __io_paw() __io_aw()
+#endif
+
+#ifndef __io_pbr
+#define __io_pbr() __io_br()
+#endif
+
+#ifndef __io_par
+#define __io_par() __io_ar()
+#endif
+
+
/*
* __raw_{read,write}{b,w,l,q}() access memory in native endianness.
*
@@ -110,7 +154,12 @@ static inline void __raw_writeq(u64 value, volatile void __iomem *addr)
#define readb readb
static inline u8 readb(const volatile void __iomem *addr)
{
- return __raw_readb(addr);
+ u8 val;
+
+ __io_br();
+ val = __raw_readb(addr);
+ __io_ar();
+ return val;
}
#endif
@@ -118,7 +167,12 @@ static inline u8 readb(const volatile void __iomem *addr)
#define readw readw
static inline u16 readw(const volatile void __iomem *addr)
{
- return __le16_to_cpu(__raw_readw(addr));
+ u16 val;
+
+ __io_br();
+ val = __le16_to_cpu(__raw_readw(addr));
+ __io_ar();
+ return val;
}
#endif
@@ -126,7 +180,12 @@ static inline u16 readw(const volatile void __iomem *addr)
#define readl readl
static inline u32 readl(const volatile void __iomem *addr)
{
- return __le32_to_cpu(__raw_readl(addr));
+ u32 val;
+
+ __io_br();
+ val = __le32_to_cpu(__raw_readl(addr));
+ __io_ar();
+ return val;
}
#endif
@@ -135,7 +194,12 @@ static inline u32 readl(const volatile void __iomem *addr)
#define readq readq
static inline u64 readq(const volatile void __iomem *addr)
{
- return __le64_to_cpu(__raw_readq(addr));
+ u64 val;
+
+ __io_br();
+ val = __le64_to_cpu(__raw_readq(addr));
+ __io_ar();
+ return val;
}
#endif
#endif /* CONFIG_64BIT */
@@ -144,7 +208,9 @@ static inline u64 readq(const volatile void __iomem *addr)
#define writeb writeb
static inline void writeb(u8 value, volatile void __iomem *addr)
{
+ __io_bw();
__raw_writeb(value, addr);
+ __io_aw();
}
#endif
@@ -152,7 +218,9 @@ static inline void writeb(u8 value, volatile void __iomem *addr)
#define writew writew
static inline void writew(u16 value, volatile void __iomem *addr)
{
+ __io_bw();
__raw_writew(cpu_to_le16(value), addr);
+ __io_aw();
}
#endif
@@ -160,7 +228,9 @@ static inline void writew(u16 value, volatile void __iomem *addr)
#define writel writel
static inline void writel(u32 value, volatile void __iomem *addr)
{
+ __io_bw();
__raw_writel(__cpu_to_le32(value), addr);
+ __io_aw();
}
#endif
@@ -169,7 +239,9 @@ static inline void writel(u32 value, volatile void __iomem *addr)
#define writeq writeq
static inline void writeq(u64 value, volatile void __iomem *addr)
{
+ __io_bw();
__raw_writeq(__cpu_to_le64(value), addr);
+ __io_aw();
}
#endif
#endif /* CONFIG_64BIT */
@@ -180,35 +252,67 @@ static inline void writeq(u64 value, volatile void __iomem *addr)
* accesses.
*/
#ifndef readb_relaxed
-#define readb_relaxed readb
+#define readb_relaxed readb_relaxed
+static inline u8 readb_relaxed(const volatile void __iomem *addr)
+{
+ return __raw_readb(addr);
+}
#endif
#ifndef readw_relaxed
-#define readw_relaxed readw
+#define readw_relaxed readw_relaxed
+static inline u16 readw_relaxed(const volatile void __iomem *addr)
+{
+ return __le16_to_cpu(__raw_readw(addr));
+}
#endif
#ifndef readl_relaxed
-#define readl_relaxed readl
+#define readl_relaxed readl_relaxed
+static inline u32 readl_relaxed(const volatile void __iomem *addr)
+{
+ return __le32_to_cpu(__raw_readl(addr));
+}
#endif
#if defined(readq) && !defined(readq_relaxed)
-#define readq_relaxed readq
+#define readq_relaxed readq_relaxed
+static inline u64 readq_relaxed(const volatile void __iomem *addr)
+{
+ return __le64_to_cpu(__raw_readq(addr));
+}
#endif
#ifndef writeb_relaxed
-#define writeb_relaxed writeb
+#define writeb_relaxed writeb_relaxed
+static inline void writeb_relaxed(u8 value, volatile void __iomem *addr)
+{
+ __raw_writeb(value, addr);
+}
#endif
#ifndef writew_relaxed
-#define writew_relaxed writew
+#define writew_relaxed writew_relaxed
+static inline void writew_relaxed(u16 value, volatile void __iomem *addr)
+{
+ __raw_writew(cpu_to_le16(value), addr);
+}
#endif
#ifndef writel_relaxed
-#define writel_relaxed writel
+#define writel_relaxed writel_relaxed
+static inline void writel_relaxed(u32 value, volatile void __iomem *addr)
+{
+ __raw_writel(__cpu_to_le32(value), addr);
+}
#endif
#if defined(writeq) && !defined(writeq_relaxed)
-#define writeq_relaxed writeq
+#define writeq_relaxed writeq_relaxed
+static inline void writeq_relaxed(u64 value, volatile void __iomem *addr)
+{
+ __raw_writeq(__cpu_to_le64(value), addr);
+}
#endif
/*
@@ -363,7 +467,12 @@ static inline void writesq(volatile void __iomem *addr, const void *buffer,
#define inb inb
static inline u8 inb(unsigned long addr)
{
- return readb(PCI_IOBASE + addr);
+ u8 val;
+
+ __io_pbr();
+ val = __raw_readb(PCI_IOBASE + addr);
+ __io_par();
+ return val;
}
#endif
@@ -371,7 +480,12 @@ static inline u8 inb(unsigned long addr)
#define inw inw
static inline u16 inw(unsigned long addr)
{
- return readw(PCI_IOBASE + addr);
+ u16 val;
+
+ __io_pbr();
+ val = __le16_to_cpu(__raw_readw(PCI_IOBASE + addr));
+ __io_par();
+ return val;
}
#endif
@@ -379,7 +493,12 @@ static inline u16 inw(unsigned long addr)
#define inl inl
static inline u32 inl(unsigned long addr)
{
- return readl(PCI_IOBASE + addr);
+ u32 val;
+
+ __io_pbr();
+ val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr));
+ __io_par();
+ return val;
}
#endif
@@ -387,7 +506,9 @@ static inline u32 inl(unsigned long addr)
#define outb outb
static inline void outb(u8 value, unsigned long addr)
{
- writeb(value, PCI_IOBASE + addr);
+ __io_pbw();
+ __raw_writeb(value, PCI_IOBASE + addr);
+ __io_paw();
}
#endif
@@ -395,7 +516,9 @@ static inline void outb(u8 value, unsigned long addr)
#define outw outw
static inline void outw(u16 value, unsigned long addr)
{
- writew(value, PCI_IOBASE + addr);
+ __io_pbw();
+ __raw_writew(cpu_to_le16(value), PCI_IOBASE + addr);
+ __io_paw();
}
#endif
@@ -403,7 +526,9 @@ static inline void outw(u16 value, unsigned long addr)
#define outl outl
static inline void outl(u32 value, unsigned long addr)
{
- writel(value, PCI_IOBASE + addr);
+ __io_pbw();
+ __raw_writel(cpu_to_le32(value), PCI_IOBASE + addr);
+ __io_paw();
}
#endif