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authorMike Frysinger <vapier@gentoo.org>2011-04-18 22:37:38 (GMT)
committerMike Frysinger <vapier@gentoo.org>2011-05-25 12:13:43 (GMT)
commit00b5c50e47dacd4d288c6b265e00f85711b9ac64 (patch)
tree817e6662c5c91b5e3a8a4130a3af4a287782fe91
parent8c0541035007bd8bbacfc5d71c696cdf37696794 (diff)
downloadlinux-00b5c50e47dacd4d288c6b265e00f85711b9ac64.tar.xz
Blackfin: optimize MMR reads during startup a bit
Since the value of these MMRs aren't changing, store the value in a local variable and work off of that. This avoids multiple MMR reads which are implicitly forced by the volatile markings. Signed-off-by: Mike Frysinger <vapier@gentoo.org>
-rw-r--r--arch/blackfin/kernel/setup.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/blackfin/kernel/setup.c b/arch/blackfin/kernel/setup.c
index 904a25d..2f48f03 100644
--- a/arch/blackfin/kernel/setup.c
+++ b/arch/blackfin/kernel/setup.c
@@ -853,6 +853,7 @@ void __init native_machine_early_platform_add_devices(void)
void __init setup_arch(char **cmdline_p)
{
+ u32 mmr;
unsigned long sclk, cclk;
native_machine_early_platform_add_devices();
@@ -923,17 +924,14 @@ void __init setup_arch(char **cmdline_p)
bfin_read_IMDMA_D1_IRQ_STATUS();
}
#endif
- printk(KERN_INFO "Hardware Trace ");
- if (bfin_read_TBUFCTL() & 0x1)
- printk(KERN_CONT "Active ");
- else
- printk(KERN_CONT "Off ");
- if (bfin_read_TBUFCTL() & 0x2)
- printk(KERN_CONT "and Enabled\n");
- else
- printk(KERN_CONT "and Disabled\n");
- printk(KERN_INFO "Boot Mode: %i\n", bfin_read_SYSCR() & 0xF);
+ mmr = bfin_read_TBUFCTL();
+ printk(KERN_INFO "Hardware Trace %s and %sabled\n",
+ (mmr & 0x1) ? "active" : "off",
+ (mmr & 0x2) ? "en" : "dis");
+
+ mmr = bfin_read_SYSCR();
+ printk(KERN_INFO "Boot Mode: %i\n", mmr & 0xF);
/* Newer parts mirror SWRST bits in SYSCR */
#if defined(CONFIG_BF53x) || defined(CONFIG_BF561) || \
@@ -941,7 +939,7 @@ void __init setup_arch(char **cmdline_p)
_bfin_swrst = bfin_read_SWRST();
#else
/* Clear boot mode field */
- _bfin_swrst = bfin_read_SYSCR() & ~0xf;
+ _bfin_swrst = mmr & ~0xf;
#endif
#ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT