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kernel-ark/include/asm-blackfin/io.h
Michael Hennerich 5c91fb902d Blackfin arch: Add assembly function insl_16 
/*
 * CPUs often take a performance hit when accessing unaligned memory
 * locations. The actual performance hit varies, it can be small if the
 * hardware handles it or large if we have to take an exception and fix
 * it
 * in software.
 *
 * Since an ethernet header is 14 bytes network drivers often end up
 * with
 * the IP header at an unaligned offset. The IP header can be aligned by
 * shifting the start of the packet by 2 bytes. Drivers should do this
 * with:
 *
 * skb_reserve(NET_IP_ALIGN);
 *
 * The downside to this alignment of the IP header is that the DMA is
 * now
 * unaligned. On some architectures the cost of an unaligned DMA is high
 * and this cost outweighs the gains made by aligning the IP header.
 *
 * Since this trade off varies between architectures, we allow
 * NET_IP_ALIGN
 * to be overridden.
 */

This new function insl_16 allows to read form 32-bit IO and writes to
16-bit aligned memory. This is useful in above described scenario -
In particular with the AXIS AX88180 Gigabit Ethernet MAC.
Once the device is in 32-bit mode, reads from the RX FIFO always
decrements 4bytes.
While on the other side the destination address in SDRAM is always
16-bit aligned.
If we use skb_reserve(0) the receive buffer is 32-bit aligned but later
we hit a unaligned exception in the IP code.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
2007-11-17 23:46:58 +08:00

213 lines
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#ifndef _BFIN_IO_H
#define _BFIN_IO_H
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
#include <linux/types.h>
#endif
#include <linux/compiler.h>
/*
* These are for ISA/PCI shared memory _only_ and should never be used
* on any other type of memory, including Zorro memory. They are meant to
* access the bus in the bus byte order which is little-endian!.
*
* readX/writeX() are used to access memory mapped devices. On some
* architectures the memory mapped IO stuff needs to be accessed
* differently. On the bfin architecture, we just read/write the
* memory location directly.
*/
#ifndef __ASSEMBLY__
static inline unsigned char readb(const volatile void __iomem *addr)
{
unsigned int val;
int tmp;
__asm__ __volatile__ ("cli %1;\n\t"
"NOP; NOP; SSYNC;\n\t"
"%0 = b [%2] (z);\n\t"
"sti %1;\n\t"
: "=d"(val), "=d"(tmp): "a"(addr)
);
return (unsigned char) val;
}
static inline unsigned short readw(const volatile void __iomem *addr)
{
unsigned int val;
int tmp;
__asm__ __volatile__ ("cli %1;\n\t"
"NOP; NOP; SSYNC;\n\t"
"%0 = w [%2] (z);\n\t"
"sti %1;\n\t"
: "=d"(val), "=d"(tmp): "a"(addr)
);
return (unsigned short) val;
}
static inline unsigned int readl(const volatile void __iomem *addr)
{
unsigned int val;
int tmp;
__asm__ __volatile__ ("cli %1;\n\t"
"NOP; NOP; SSYNC;\n\t"
"%0 = [%2];\n\t"
"sti %1;\n\t"
: "=d"(val), "=d"(tmp): "a"(addr)
);
return val;
}
#endif /* __ASSEMBLY__ */
#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))
#define __raw_readb readb
#define __raw_readw readw
#define __raw_readl readl
#define __raw_writeb writeb
#define __raw_writew writew
#define __raw_writel writel
#define memset_io(a,b,c) memset((void *)(a),(b),(c))
#define memcpy_fromio(a,b,c) memcpy((a),(void *)(b),(c))
#define memcpy_toio(a,b,c) memcpy((void *)(a),(b),(c))
#define inb(addr) readb(addr)
#define inw(addr) readw(addr)
#define inl(addr) readl(addr)
#define outb(x,addr) ((void) writeb(x,addr))
#define outw(x,addr) ((void) writew(x,addr))
#define outl(x,addr) ((void) writel(x,addr))
#define inb_p(addr) inb(addr)
#define inw_p(addr) inw(addr)
#define inl_p(addr) inl(addr)
#define outb_p(x,addr) outb(x,addr)
#define outw_p(x,addr) outw(x,addr)
#define outl_p(x,addr) outl(x,addr)
#define ioread8_rep(a,d,c) insb(a,d,c)
#define ioread16_rep(a,d,c) insw(a,d,c)
#define ioread32_rep(a,d,c) insl(a,d,c)
#define iowrite8_rep(a,s,c) outsb(a,s,c)
#define iowrite16_rep(a,s,c) outsw(a,s,c)
#define iowrite32_rep(a,s,c) outsl(a,s,c)
#define ioread8(X) readb(X)
#define ioread16(X) readw(X)
#define ioread32(X) readl(X)
#define iowrite8(val,X) writeb(val,X)
#define iowrite16(val,X) writew(val,X)
#define iowrite32(val,X) writel(val,X)
#define IO_SPACE_LIMIT 0xffffffff
/* Values for nocacheflag and cmode */
#define IOMAP_NOCACHE_SER 1
#ifndef __ASSEMBLY__
extern void outsb(unsigned long port, const void *addr, unsigned long count);
extern void outsw(unsigned long port, const void *addr, unsigned long count);
extern void outsl(unsigned long port, const void *addr, unsigned long count);
extern void insb(unsigned long port, void *addr, unsigned long count);
extern void insw(unsigned long port, void *addr, unsigned long count);
extern void insl(unsigned long port, void *addr, unsigned long count);
extern void insl_16(unsigned long port, void *addr, unsigned long count);
extern void dma_outsb(unsigned long port, const void *addr, unsigned short count);
extern void dma_outsw(unsigned long port, const void *addr, unsigned short count);
extern void dma_outsl(unsigned long port, const void *addr, unsigned short count);
extern void dma_insb(unsigned long port, void *addr, unsigned short count);
extern void dma_insw(unsigned long port, void *addr, unsigned short count);
extern void dma_insl(unsigned long port, void *addr, unsigned short count);
/*
* Map some physical address range into the kernel address space.
*/
static inline void __iomem *__ioremap(unsigned long physaddr, unsigned long size,
int cacheflag)
{
return (void __iomem *)physaddr;
}
/*
* Unmap a ioremap()ed region again
*/
static inline void iounmap(void *addr)
{
}
/*
* __iounmap unmaps nearly everything, so be careful
* it doesn't free currently pointer/page tables anymore but it
* wans't used anyway and might be added later.
*/
static inline void __iounmap(void *addr, unsigned long size)
{
}
/*
* Set new cache mode for some kernel address space.
* The caller must push data for that range itself, if such data may already
* be in the cache.
*/
static inline void kernel_set_cachemode(void *addr, unsigned long size,
int cmode)
{
}
static inline void __iomem *ioremap(unsigned long physaddr, unsigned long size)
{
return __ioremap(physaddr, size, IOMAP_NOCACHE_SER);
}
static inline void __iomem *ioremap_nocache(unsigned long physaddr,
unsigned long size)
{
return __ioremap(physaddr, size, IOMAP_NOCACHE_SER);
}
extern void blkfin_inv_cache_all(void);
#endif
#define ioport_map(port, nr) ((void __iomem*)(port))
#define ioport_unmap(addr)
/* Pages to physical address... */
#define page_to_phys(page) ((page - mem_map) << PAGE_SHIFT)
#define page_to_bus(page) ((page - mem_map) << PAGE_SHIFT)
#define mm_ptov(vaddr) ((void *) (vaddr))
#define mm_vtop(vaddr) ((unsigned long) (vaddr))
#define phys_to_virt(vaddr) ((void *) (vaddr))
#define virt_to_phys(vaddr) ((unsigned long) (vaddr))
#define virt_to_bus virt_to_phys
#define bus_to_virt phys_to_virt
/*
* Convert a physical pointer to a virtual kernel pointer for /dev/mem
* access
*/
#define xlate_dev_mem_ptr(p) __va(p)
/*
* Convert a virtual cached pointer to an uncached pointer
*/
#define xlate_dev_kmem_ptr(p) p
#endif /* __KERNEL__ */
#endif /* _BFIN_IO_H */
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