summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorMilton Miller <miltonm@bga.com>2005-09-06 11:55:00 +1000
committerPaul Mackerras <paulus@samba.org>2005-09-06 16:07:36 +1000
commitcb14c4d641b4e083fae7ce4a0e8a3973cecb7554 (patch)
tree68f5365c31beb472c5c4df25fbcb3422cb7d76eb /arch
parent5fdabaab01ee8928597aae8a0178a3a4f7b66365 (diff)
downloadlinux-3.10-cb14c4d641b4e083fae7ce4a0e8a3973cecb7554.tar.gz
linux-3.10-cb14c4d641b4e083fae7ce4a0e8a3973cecb7554.tar.bz2
linux-3.10-cb14c4d641b4e083fae7ce4a0e8a3973cecb7554.zip
[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: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/ppc64/kernel/udbg.c16
1 files changed, 4 insertions, 12 deletions
diff --git a/arch/ppc64/kernel/udbg.c b/arch/ppc64/kernel/udbg.c
index c0da45540f0..155670a40c3 100644
--- a/arch/ppc64/kernel/udbg.c
+++ b/arch/ppc64/kernel/udbg.c
@@ -169,12 +169,8 @@ void udbg_maple_real_putc(unsigned char c)
while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
/* wait for idle */;
real_writeb(c, &udbg_comport->thr); eieio();
- if (c == '\n') {
- /* Also put a CR. This is for convenience. */
- while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
- /* wait for idle */;
- real_writeb('\r', &udbg_comport->thr); eieio();
- }
+ if (c == '\n')
+ udbg_maple_real_putc('\r');
}
}
@@ -194,12 +190,8 @@ void udbg_putc(unsigned char c)
while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0)
/* wait for idle */;
out_8(&udbg_comport->thr, c);
- if (c == '\n') {
- /* Also put a CR. This is for convenience. */
- while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0)
- /* wait for idle */;
- out_8(&udbg_comport->thr, '\r');
- }
+ if (c == '\n')
+ udbg_putc('\r');
}
#ifdef CONFIG_PPC_PMAC
else if (sccc) {