[ARM] nommu: manage the CP15 things
All the current CP15 access codes in ARM arch can be categorized and
conditioned by the defines as follows:
Related operation Safe condition
a. any CP15 access !CPU_CP15
b. alignment trap CPU_CP15_MMU
c. D-cache(C-bit) CPU_CP15
d. I-cache CPU_CP15 && !( CPU_ARM610 || CPU_ARM710 ||
CPU_ARM720 || CPU_ARM740 ||
CPU_XSCALE || CPU_XSC3 )
e. alternate vector CPU_CP15 && !CPU_ARM740
f. TTB CPU_CP15_MMU
g. Domain CPU_CP15_MMU
h. FSR/FAR CPU_CP15_MMU
For example, alternate vector is supported if and only if
"CPU_CP15 && !CPU_ARM740" is satisfied.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0810d27..2673fee 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -621,6 +621,7 @@
config ALIGNMENT_TRAP
bool
+ depends on CPU_CP15_MMU
default y if !ARCH_EBSA110
help
ARM processors can not fetch/store information which is not
@@ -852,7 +853,7 @@
source "drivers/connector/Kconfig"
-if ALIGNMENT_TRAP
+if ALIGNMENT_TRAP || !CPU_CP15_MMU
source "drivers/mtd/Kconfig"
endif
diff --git a/arch/arm/Kconfig-nommu b/arch/arm/Kconfig-nommu
index e1574be..f087376 100644
--- a/arch/arm/Kconfig-nommu
+++ b/arch/arm/Kconfig-nommu
@@ -25,6 +25,14 @@
hex 'FLASH Size' if SET_MEM_PARAM
default 0x00400000
+config PROCESSOR_ID
+ hex
+ default 0x00007700
+ depends on !CPU_CP15
+ help
+ If processor has no CP15 register, this processor ID is
+ used instead of the auto-probing which utilizes the register.
+
config REMAP_VECTORS_TO_RAM
bool 'Install vectors to the begining of RAM' if DRAM_BASE
depends on DRAM_BASE
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 2adc152..adddc71 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -51,7 +51,11 @@
endif
ifeq ($(CONFIG_CPU_BIG_ENDIAN),y)
+ifeq ($(CONFIG_CPU_CP15),y)
OBJS += big-endian.o
+else
+# The endian should be set by h/w design.
+endif
endif
#
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 75df1f7..e5ab51b 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -82,9 +82,11 @@
kphex r6, 8 /* processor id */
kputc #':'
kphex r7, 8 /* architecture id */
+#ifdef CONFIG_CPU_CP15
kputc #':'
mrc p15, 0, r0, c1, c0
kphex r0, 8 /* control reg */
+#endif
kputc #'\n'
kphex r5, 8 /* decompressed kernel start */
kputc #'-'
@@ -507,7 +509,11 @@
*/
call_cache_fn: adr r12, proc_types
+#ifdef CONFIG_CPU_CP15
mrc p15, 0, r6, c0, c0 @ get processor ID
+#else
+ ldr r6, =CONFIG_PROCESSOR_ID
+#endif
1: ldr r1, [r12, #0] @ get value
ldr r2, [r12, #4] @ get mask
eor r1, r1, r6 @ (real ^ match)
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index ac9eb3d..698a537 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -9,7 +9,6 @@
* published by the Free Software Foundation.
*
* Common kernel startup code (non-paged MM)
- * for 32-bit CPUs which has a process ID register(CP15).
*
*/
#include <linux/linkage.h>
@@ -40,7 +39,11 @@
ENTRY(stext)
msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | SVC_MODE @ ensure svc mode
@ and irqs disabled
+#ifndef CONFIG_CPU_CP15
+ ldr r9, =CONFIG_PROCESSOR_ID
+#else
mrc p15, 0, r9, c0, c0 @ get processor id
+#endif
bl __lookup_processor_type @ r5=procinfo r9=cpuid
movs r10, r5 @ invalid processor (r5=0)?
beq __error_p @ yes, error 'p'
@@ -58,6 +61,7 @@
*/
.type __after_proc_init, %function
__after_proc_init:
+#ifdef CONFIG_CPU_CP15
mrc p15, 0, r0, c1, c0, 0 @ read control reg
#ifdef CONFIG_ALIGNMENT_TRAP
orr r0, r0, #CR_A
@@ -74,6 +78,7 @@
bic r0, r0, #CR_I
#endif
mcr p15, 0, r0, c1, c0, 0 @ write control reg
+#endif /* CONFIG_CPU_CP15 */
mov pc, r13 @ clear the BSS and jump
@ to start_kernel
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 3079535..bf35c17 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -221,16 +221,26 @@
processor_modes[processor_mode(regs)],
thumb_mode(regs) ? " (T)" : "",
get_fs() == get_ds() ? "kernel" : "user");
+#if CONFIG_CPU_CP15
{
- unsigned int ctrl, transbase, dac;
+ unsigned int ctrl;
__asm__ (
" mrc p15, 0, %0, c1, c0\n"
- " mrc p15, 0, %1, c2, c0\n"
- " mrc p15, 0, %2, c3, c0\n"
- : "=r" (ctrl), "=r" (transbase), "=r" (dac));
- printk("Control: %04X Table: %08X DAC: %08X\n",
- ctrl, transbase, dac);
+ : "=r" (ctrl));
+ printk("Control: %04X\n", ctrl);
}
+#ifdef CONFIG_CPU_CP15_MMU
+ {
+ unsigned int transbase, dac;
+ __asm__ (
+ " mrc p15, 0, %0, c2, c0\n"
+ " mrc p15, 0, %1, c3, c0\n"
+ : "=r" (transbase), "=r" (dac));
+ printk("Table: %08X DAC: %08X\n",
+ transbase, dac);
+ }
+#endif
+#endif
}
void show_regs(struct pt_regs * regs)
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index c7fb835..0ac11ea 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -445,15 +445,15 @@
of your chipset/board/processor.
config CPU_ICACHE_DISABLE
- bool "Disable I-Cache"
- depends on CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM1020 || CPU_V6
+ bool "Disable I-Cache (I-bit)"
+ depends on CPU_CP15 && !(CPU_ARM610 || CPU_ARM710 || CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)
help
Say Y here to disable the processor instruction cache. Unless
you have a reason not to or are unsure, say N.
config CPU_DCACHE_DISABLE
- bool "Disable D-Cache"
- depends on CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM1020 || CPU_V6
+ bool "Disable D-Cache (C-bit)"
+ depends on CPU_CP15
help
Say Y here to disable the processor data cache. Unless
you have a reason not to or are unsure, say N.
diff --git a/arch/arm/mm/cache-v4.S b/arch/arm/mm/cache-v4.S
index b8ad5d5..b290806 100644
--- a/arch/arm/mm/cache-v4.S
+++ b/arch/arm/mm/cache-v4.S
@@ -29,9 +29,13 @@
* Clean and invalidate the entire cache.
*/
ENTRY(v4_flush_kern_cache_all)
+#ifdef CPU_CP15
mov r0, #0
mcr p15, 0, r0, c7, c7, 0 @ flush ID cache
mov pc, lr
+#else
+ /* FALLTHROUGH */
+#endif
/*
* flush_user_cache_range(start, end, flags)
@@ -44,9 +48,13 @@
* - flags - vma_area_struct flags describing address space
*/
ENTRY(v4_flush_user_cache_range)
+#ifdef CPU_CP15
mov ip, #0
mcreq p15, 0, ip, c7, c7, 0 @ flush ID cache
mov pc, lr
+#else
+ /* FALLTHROUGH */
+#endif
/*
* coherent_kern_range(start, end)
@@ -108,8 +116,10 @@
* - end - virtual end address
*/
ENTRY(v4_dma_flush_range)
+#ifdef CPU_CP15
mov r0, #0
mcr p15, 0, r0, c7, c7, 0 @ flush ID cache
+#endif
/* FALLTHROUGH */
/*