[U-Boot] [PATCH] ARM: remove bogus cp_delay() function
Lothar Waßmann
LW at KARO-electronics.de
Thu Jun 8 07:48:41 UTC 2017
The cp_delay() function was introduced because of a missing 'volatile'
attribute to the 'asm' statement in get_cr() which led to the 'mrc'
instruction in get_cr() being optimised out eventually.
This has been fixed in commit 53fd4b8c22bb ("arm: mmu: Add missing volatile for reading SCTLR register")
but the bogus cp_delay() function which was introduced as a workaround
for the malfunctioning get_cr() was never removed.
Signed-off-by: Lothar Waßmann <LW at KARO-electronics.de>
---
arch/arm/lib/cache-cp15.c | 15 +--------------
1 file changed, 1 insertion(+), 14 deletions(-)
diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c
index e9bbcf5..2334edb 100644
--- a/arch/arm/lib/cache-cp15.c
+++ b/arch/arm/lib/cache-cp15.c
@@ -22,16 +22,6 @@ __weak void arm_init_domains(void)
{
}
-static void cp_delay (void)
-{
- volatile int i;
-
- /* copro seems to need some delay between reading and writing */
- for (i = 0; i < 100; i++)
- nop();
- asm volatile("" : : : "memory");
-}
-
void set_section_dcache(int section, enum dcache_option option)
{
#ifdef CONFIG_ARMV7_LPAE
@@ -196,7 +186,6 @@ static inline void mmu_setup(void)
/* and enable the mmu */
reg = get_cr(); /* get control reg. */
- cp_delay();
set_cr(reg | CR_M);
}
@@ -214,7 +203,6 @@ static void cache_enable(uint32_t cache_bit)
if ((cache_bit == CR_C) && !mmu_enabled())
mmu_setup();
reg = get_cr(); /* get control reg. */
- cp_delay();
set_cr(reg | cache_bit);
}
@@ -224,7 +212,6 @@ static void cache_disable(uint32_t cache_bit)
uint32_t reg;
reg = get_cr();
- cp_delay();
if (cache_bit == CR_C) {
/* if cache isn;t enabled no need to disable */
@@ -234,7 +221,7 @@ static void cache_disable(uint32_t cache_bit)
cache_bit |= CR_M;
}
reg = get_cr();
- cp_delay();
+
if (cache_bit == (CR_C | CR_M))
flush_dcache_all();
set_cr(reg & ~cache_bit);
--
2.1.4
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