Commit 4e3ff3c5 authored by Julian Vetter's avatar Julian Vetter Committed by Helge Deller
Browse files

parisc: Remove memcpy_fromio 



Fully migrate parisc to the IO functions from lib/iomem_copy.c. In a
recent patch the functions memset_io and memcpy_toio were removed, but
the memcpy_fromio was kept, because for very short sequences it does
half word accesses, whereas the functions in lib/iomem_copy.c do byte
accesses until the memory is naturally aligned and then do machine word
accesses. But I don't think the single half-word access merits keeping
the arch specific implementation, so, remove it as well.

Signed-off-by: default avatarJulian Vetter <julian@outer-limits.org>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 579e5fd9

arch/parisc/include/asm/io.h

+0 −3
Original line number Diff line number Diff line
@@ -135,9 +135,6 @@ static inline void gsc_writeq(unsigned long long val, unsigned long addr) 


#define pci_iounmap			pci_iounmap



void memcpy_fromio(void *dst, const volatile void __iomem *src, int count);

#define memcpy_fromio memcpy_fromio



/* Port-space IO */



#define inb_p inb

arch/parisc/kernel/parisc_ksyms.c

+0 −1
Original line number Diff line number Diff line
@@ -43,7 +43,6 @@ EXPORT_SYMBOL($global$); 
#endif



#include <asm/io.h>

EXPORT_SYMBOL(memcpy_fromio);



extern void $$divI(void);

extern void $$divU(void);

arch/parisc/lib/io.c

+0 −61
Original line number Diff line number Diff line
@@ -12,67 +12,6 @@ 
#include <linux/module.h>

#include <asm/io.h>



/*

** Copies a block of memory from a device in an efficient manner.

** Assumes the device can cope with 32-bit transfers.  If it can't,

** don't use this function.

**

** CR16 counts on C3000 reading 256 bytes from Symbios 896 RAM:

**	27341/64    = 427 cyc per int

**	61311/128   = 478 cyc per short

**	122637/256  = 479 cyc per byte

** Ergo bus latencies dominant (not transfer size).

**      Minimize total number of transfers at cost of CPU cycles.

**	TODO: only look at src alignment and adjust the stores to dest.

*/

void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)

{

	/* first compare alignment of src/dst */ 

	if ( (((unsigned long)dst ^ (unsigned long)src) & 1) || (count < 2) )

		goto bytecopy;



	if ( (((unsigned long)dst ^ (unsigned long)src) & 2) || (count < 4) )

		goto shortcopy;



	/* Then check for misaligned start address */

	if ((unsigned long)src & 1) {

		*(u8 *)dst = readb(src);

		src++;

		dst++;

		count--;

		if (count < 2) goto bytecopy;

	}



	if ((unsigned long)src & 2) {

		*(u16 *)dst = __raw_readw(src);

		src += 2;

		dst += 2;

		count -= 2;

	}



	while (count > 3) {

		*(u32 *)dst = __raw_readl(src);

		dst += 4;

		src += 4;

		count -= 4;

	}



 shortcopy:

	while (count > 1) {

		*(u16 *)dst = __raw_readw(src);

		src += 2;

		dst += 2;

		count -= 2;

	}



 bytecopy:

	while (count--) {

		*(char *)dst = readb(src);

		src++;

		dst++;

	}

}



/*

 * Read COUNT 8-bit bytes from port PORT into memory starting at

 * SRC.