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parisc: Remove memcpy_fromio

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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: Julian Vetter <julian@outer-limits.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Julian Vetter 2025-01-30 14:48:25 +01:00 committed by Helge Deller
parent 579e5fd927
commit 4e3ff3c585
3 changed files with 0 additions and 65 deletions
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3
arch/parisc/include/asm/io.h
View File

@ -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

1
arch/parisc/kernel/parisc_ksyms.c
View File

@ -43,7 +43,6 @@ EXPORT_SYMBOL($global$);
#endif
#include <asm/io.h>
EXPORT_SYMBOL(memcpy_fromio);
extern void $$divI(void);
extern void $$divU(void);

61
arch/parisc/lib/io.c
View File

@ -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.