arm64: optimize memcpy_{from,to}io() and memset_io() (70ddb63a) · Commits · 戴 / test

arch/arm64/kernel/io.c

+56 −10

Original line number	Diff line number	Diff line
		@@ -25,12 +25,26 @@
		*/
		void __memcpy_fromio(void to, const volatile void __iomem from, size_t count)
		{
		unsigned char *t = to;
		while (count) {
		while (count && (!IS_ALIGNED((unsigned long)from, 8) \|\|
		!IS_ALIGNED((unsigned long)to, 8))) {
		(u8 )to = __raw_readb(from);
		from++;
		to++;
		count--;
		*t = readb(from);
		t++;
		}

		while (count >= 8) {
		(u64 )to = __raw_readq(from);
		from += 8;
		to += 8;
		count -= 8;
		}

		while (count) {
		(u8 )to = __raw_readb(from);
		from++;
		to++;
		count--;
		}
		}
		EXPORT_SYMBOL(__memcpy_fromio);
		@@ -40,12 +54,26 @@ EXPORT_SYMBOL(__memcpy_fromio);
		*/
		void __memcpy_toio(volatile void __iomem to, const void from, size_t count)
		{
		const unsigned char *f = from;
		while (count) {
		while (count && (!IS_ALIGNED((unsigned long)to, 8) \|\|
		!IS_ALIGNED((unsigned long)from, 8))) {
		__raw_writeb((volatile u8 )from, to);
		from++;
		to++;
		count--;
		writeb(*f, to);
		f++;
		}

		while (count >= 8) {
		__raw_writeq((volatile u64 )from, to);
		from += 8;
		to += 8;
		count -= 8;
		}

		while (count) {
		__raw_writeb((volatile u8 )from, to);
		from++;
		to++;
		count--;
		}
		}
		EXPORT_SYMBOL(__memcpy_toio);
		@@ -55,10 +83,28 @@ EXPORT_SYMBOL(__memcpy_toio);
		*/
		void __memset_io(volatile void __iomem *dst, int c, size_t count)
		{
		while (count) {
		u64 qc = (u8)c;

		qc \|= qc << 8;
		qc \|= qc << 16;
		qc \|= qc << 32;

		while (count && !IS_ALIGNED((unsigned long)dst, 8)) {
		__raw_writeb(c, dst);
		dst++;
		count--;
		writeb(c, dst);
		}

		while (count >= 8) {
		__raw_writeq(qc, dst);
		dst += 8;
		count -= 8;
		}

		while (count) {
		__raw_writeb(c, dst);
		dst++;
		count--;
		}
		}
		EXPORT_SYMBOL(__memset_io);

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