diff mbox series

parisc: Remove memcpy_fromio

Message ID 20250130134825.2646380-1-julian@outer-limits.org (mailing list archive)
State New
Headers show
Series parisc: Remove memcpy_fromio | expand

Commit Message

Julian Vetter Jan. 30, 2025, 1:48 p.m. UTC
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>
---
 arch/parisc/include/asm/io.h      |  3 --
 arch/parisc/kernel/parisc_ksyms.c |  1 -
 arch/parisc/lib/io.c              | 61 -------------------------------
 3 files changed, 65 deletions(-)
diff mbox series

Patch

diff --git a/arch/parisc/include/asm/io.h b/arch/parisc/include/asm/io.h
index 3143cf29ce27..61173a2b38e4 100644
--- a/arch/parisc/include/asm/io.h
+++ b/arch/parisc/include/asm/io.h
@@ -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
diff --git a/arch/parisc/kernel/parisc_ksyms.c b/arch/parisc/kernel/parisc_ksyms.c
index 1c366b0d3134..509146a52725 100644
--- a/arch/parisc/kernel/parisc_ksyms.c
+++ b/arch/parisc/kernel/parisc_ksyms.c
@@ -43,7 +43,6 @@  EXPORT_SYMBOL($global$);
 #endif
 
 #include <asm/io.h>
-EXPORT_SYMBOL(memcpy_fromio);
 
 extern void $$divI(void);
 extern void $$divU(void);
diff --git a/arch/parisc/lib/io.c b/arch/parisc/lib/io.c
index 6e81200dc87a..3c7e617f5a93 100644
--- a/arch/parisc/lib/io.c
+++ b/arch/parisc/lib/io.c
@@ -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.