Please refer to the PCI specification for more information on interactions
between PCI transactions.
- (*) readX_relaxed()
-
- These are similar to readX(), but are not guaranteed to be ordered in any
- way. Be aware that there is no I/O read barrier available.
+ (*) readX_relaxed(), writeX_relaxed()
+
+ These are similar to readX() and writeX(), but provide weaker memory
+ ordering guarantees. Specifically, they do not guarantee ordering with
+ respect to normal memory accesses (e.g. DMA buffers) nor do they guarantee
+ ordering with respect to LOCK or UNLOCK operations. If the latter is
+ required, an mmiowb() barrier can be used. Note that relaxed accesses to
+ the same peripheral are guaranteed to be ordered with respect to each
+ other.
(*) ioreadX(), iowriteX()
else
*(volatile unsigned int __force *) addr = b;
}
+#define writeb_relaxed(b, addr) writeb(b, addr)
+#define writew_relaxed(b, addr) writew(b, addr)
+#define writel_relaxed(b, addr) writel(b, addr)
#define __raw_writeb writeb
#define __raw_writew writew
#define __raw_writel writel
__flush_PCI_writes();
}
+#define writeb_relaxed writeb
+#define writew_relaxed writew
+#define writel_relaxed writel
/* Values for nocacheflag and cmode */
#define IOMAP_FULL_CACHING 0
#define writew(v,a) __writew((v), (a))
#define writel(v,a) __writel((v), (a))
#define writeq(v,a) __writeq((v), (a))
+#define writeb_relaxed(v,a) __writeb((v), (a))
+#define writew_relaxed(v,a) __writew((v), (a))
+#define writel_relaxed(v,a) __writel((v), (a))
+#define writeq_relaxed(v,a) __writeq((v), (a))
#define __raw_writeb writeb
#define __raw_writew writew
#define __raw_writel writel
#define __raw_writeb writeb
#define __raw_writew writew
#define __raw_writel writel
+#define writeb_relaxed writeb
+#define writew_relaxed writew
+#define writel_relaxed writel
#define ioread8 read
#define ioread16 readw
#else
#include <asm/io_mm.h>
#endif
+
+#define readb_relaxed(addr) readb(addr)
+#define readw_relaxed(addr) readw(addr)
+#define readl_relaxed(addr) readl(addr)
+
+#define writeb_relaxed(b, addr) writeb(b, addr)
+#define writew_relaxed(b, addr) writew(b, addr)
+#define writel_relaxed(b, addr) writel(b, addr)
#define readl(addr) \
({ unsigned int __v = (*(volatile unsigned int *) (addr)); __v; })
-#define readb_relaxed(addr) readb(addr)
-#define readw_relaxed(addr) readw(addr)
-#define readl_relaxed(addr) readl(addr)
-
#define writeb(b,addr) (void)((*(volatile unsigned char *) (addr)) = (b))
#define writew(b,addr) (void)((*(volatile unsigned short *) (addr)) = (b))
#define writel(b,addr) (void)((*(volatile unsigned int *) (addr)) = (b))
#include <asm-generic/io.h>
-#define readb_relaxed readb
-#define readw_relaxed readw
-#define readl_relaxed readl
-
-#define writeb_relaxed writeb
-#define writew_relaxed writew
-#define writel_relaxed writel
-
#endif /* _ASM_MICROBLAZE_IO_H */
#define __raw_writew writew
#define __raw_writel writel
+#define writeb_relaxed writeb
+#define writew_relaxed writew
+#define writel_relaxed writel
+
/*****************************************************************************/
/*
* traditional input/output functions
#define writel writel
#define writeq writeq
-#define readb_relaxed(addr) readb(addr)
-#define readw_relaxed(addr) readw(addr)
-#define readl_relaxed(addr) readl(addr)
-#define readq_relaxed(addr) readq(addr)
+#define readb_relaxed(addr) readb(addr)
+#define readw_relaxed(addr) readw(addr)
+#define readl_relaxed(addr) readl(addr)
+#define readq_relaxed(addr) readq(addr)
+#define writeb_relaxed(b, addr) writeb(b, addr)
+#define writew_relaxed(w, addr) writew(w, addr)
+#define writel_relaxed(l, addr) writel(l, addr)
+#define writeq_relaxed(q, addr) writeq(q, addr)
#define mmiowb() do { } while (0)
/*
* We don't do relaxed operations yet, at least not with this semantic
*/
-#define readb_relaxed(addr) readb(addr)
-#define readw_relaxed(addr) readw(addr)
-#define readl_relaxed(addr) readl(addr)
-#define readq_relaxed(addr) readq(addr)
+#define readb_relaxed(addr) readb(addr)
+#define readw_relaxed(addr) readw(addr)
+#define readl_relaxed(addr) readl(addr)
+#define readq_relaxed(addr) readq(addr)
+#define writeb_relaxed(v, addr) writeb(v, addr)
+#define writew_relaxed(v, addr) writew(v, addr)
+#define writel_relaxed(v, addr) writel(v, addr)
+#define writeq_relaxed(v, addr) writeq(v, addr)
#ifdef CONFIG_PPC32
#define mmiowb()
#define __raw_writel zpci_write_u32
#define __raw_writeq zpci_write_u64
-#define readb_relaxed readb
-#define readw_relaxed readw
-#define readl_relaxed readl
-#define readq_relaxed readq
-
#endif /* CONFIG_PCI */
#include <asm-generic/io.h>
* Defines used for both SPARC32 and SPARC64
*/
+/* Relaxed accessors for MMIO */
+#define readb_relaxed(__addr) readb(__addr)
+#define readw_relaxed(__addr) readw(__addr)
+#define readl_relaxed(__addr) readl(__addr)
+
+#define writeb_relaxed(__b, __addr) writeb(__b, __addr)
+#define writew_relaxed(__w, __addr) writew(__w, __addr)
+#define writel_relaxed(__l, __addr) writel(__l, __addr)
+
/* Big endian versions of memory read/write routines */
#define readb_be(__addr) __raw_readb(__addr)
#define readw_be(__addr) __raw_readw(__addr)
#include <linux/kernel.h>
#include <linux/ioport.h> /* struct resource */
-#define readb_relaxed(__addr) readb(__addr)
-#define readw_relaxed(__addr) readw(__addr)
-#define readl_relaxed(__addr) readl(__addr)
-
#define IO_SPACE_LIMIT 0xffffffff
#define memset_io(d,c,sz) _memset_io(d,c,sz)
}
#define readq readq
+#define readq_relaxed readq
static inline u64 readq(const volatile void __iomem *addr)
{ u64 ret;
}
#define writeq writeq
+#define writeq_relaxed writeq
static inline void writeq(u64 q, volatile void __iomem *addr)
{
__asm__ __volatile__("stxa\t%r0, [%1] %2\t/* pci_writeq */"
: "memory");
}
-
#define inb inb
static inline u8 inb(unsigned long addr)
{
outsl((unsigned long __force)port, buf, count);
}
-#define readb_relaxed(__addr) readb(__addr)
-#define readw_relaxed(__addr) readw(__addr)
-#define readl_relaxed(__addr) readl(__addr)
-#define readq_relaxed(__addr) readq(__addr)
-
/* Valid I/O Space regions are anywhere, because each PCI bus supported
* can live in an arbitrary area of the physical address range.
*/
#define readw_relaxed readw
#define readl_relaxed readl
#define readq_relaxed readq
+#define writeb_relaxed writeb
+#define writew_relaxed writew
+#define writel_relaxed writel
+#define writeq_relaxed writeq
#define ioread8 readb
#define ioread16 readw
#define __raw_readw __readw
#define __raw_readl __readl
+#define writeb_relaxed(v, a) __writeb(v, a)
+#define writew_relaxed(v, a) __writew(v, a)
+#define writel_relaxed(v, a) __writel(v, a)
#define __raw_writeb __writeb
#define __raw_writew __writew
#define __raw_writel __writel
build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
#define readq_relaxed(a) readq(a)
+#define writeq_relaxed(v, a) writeq(v, a)
#define __raw_readq(a) readq(a)
#define __raw_writeq(val, addr) writeq(val, addr)
#endif /* CONFIG_MMU */
-/*
- * Generic I/O
- */
-#define readb_relaxed readb
-#define readw_relaxed readw
-#define readl_relaxed readl
-
#endif /* __KERNEL__ */
#include <asm-generic/io.h>
#endif
#endif /* CONFIG_64BIT */
+/*
+ * {read,write}{b,w,l,q}_relaxed() are like the regular version, but
+ * are not guaranteed to provide ordering against spinlocks or memory
+ * accesses.
+ */
+#ifndef readb_relaxed
+#define readb_relaxed readb
+#endif
+
+#ifndef readw_relaxed
+#define readw_relaxed readw
+#endif
+
+#ifndef readl_relaxed
+#define readl_relaxed readl
+#endif
+
+#ifndef readq_relaxed
+#define readq_relaxed readq
+#endif
+
+#ifndef writeb_relaxed
+#define writeb_relaxed writeb
+#endif
+
+#ifndef writew_relaxed
+#define writew_relaxed writew
+#endif
+
+#ifndef writel_relaxed
+#define writel_relaxed writel
+#endif
+
+#ifndef writeq_relaxed
+#define writeq_relaxed writeq
+#endif
+
/*
* {read,write}s{b,w,l,q}() repeatedly access the same memory address in
* native endianness in 8-, 16-, 32- or 64-bit chunks (@count times).