Commit cb14c4d6 authored by Milton Miller's avatar Milton Miller Committed by Paul Mackerras
Browse files

[PATCH] ppc64: Clean up CR handling 



Make the 16550 and real mode 16550 use tail recursion like the scc code
instead of repeating the routine except for the character sent.

Gcc recoginizes the tail recursion and handles it efficently without
stack allocations.  The maple real putc shrinks from 188 to 104 bytes
of instructions.  udbg_putc drops from 188 to 140 bytes.

Signed-off-by: default avatarMilton Miller <miltonm@bga.com>
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 5fdabaab

arch/ppc64/kernel/udbg.c

+4 −12
Original line number Original line Diff line number Diff line
@@ -169,12 +169,8 @@ void udbg_maple_real_putc(unsigned char c) 
		while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)

		while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)

			/* wait for idle */;

			/* wait for idle */;

		real_writeb(c, &udbg_comport->thr); eieio();

		real_writeb(c, &udbg_comport->thr); eieio();

		if (c == '\n') {

		if (c == '\n')

			/* Also put a CR.  This is for convenience. */

			udbg_maple_real_putc('\r');

			while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)

				/* wait for idle */;

			real_writeb('\r', &udbg_comport->thr); eieio();

		}

	}

	}

}

}
@@ -194,12 +190,8 @@ void udbg_putc(unsigned char c) 
		while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0)

		while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0)

			/* wait for idle */;

			/* wait for idle */;

		out_8(&udbg_comport->thr, c);

		out_8(&udbg_comport->thr, c);

		if (c == '\n') {

		if (c == '\n')

			/* Also put a CR.  This is for convenience. */

			udbg_putc('\r');

			while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0)

				/* wait for idle */; 

			out_8(&udbg_comport->thr, '\r');

		}

	}

	}

#ifdef CONFIG_PPC_PMAC

#ifdef CONFIG_PPC_PMAC

	else if (sccc) {

	else if (sccc) {

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