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ARM: imx: replicate the diagnostic register of boot cpu into secondary cores 

The diagnostic register holds the errata bits.  Mostly bootloader
does not bring up secondary cores, so that when errata bits are set
in bootloader, they are set only for boot cpu.  But on a SMP
configuration, it should be equally done on every single core.
Set up the diagnostic register for secondary cores by replicating
the register from boot cpu.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
This commit is contained in:
Shawn Guo 2013-04-16 22:11:19 +08:00
parent 0e574461c4
commit 087bb28329
2 changed files with 26 additions and 0 deletions
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12
arch/arm/mach-imx/headsmp.S
View File

@ -18,8 +18,20 @@
.section ".text.head", "ax"
#ifdef CONFIG_SMP
diag_reg_offset:
.word g_diag_reg - .
.macro set_diag_reg
adr r0, diag_reg_offset
ldr r1, [r0]
add r1, r1, r0 @ r1 = physical &g_diag_reg
ldr r0, [r1]
mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
.endm
ENTRY(v7_secondary_startup)
bl v7_invalidate_l1
set_diag_reg
b secondary_startup
ENDPROC(v7_secondary_startup)
#endif

14
arch/arm/mach-imx/platsmp.c
View File

@ -12,6 +12,7 @@
#include <linux/init.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
#include <asm/smp_scu.h>
#include <asm/mach/map.h>
@ -21,6 +22,7 @@
#define SCU_STANDBY_ENABLE (1 << 5)
u32 g_diag_reg;
static void __iomem *scu_base;
static struct map_desc scu_io_desc __initdata = {
@ -80,6 +82,18 @@ void imx_smp_prepare(void)
static void __init imx_smp_prepare_cpus(unsigned int max_cpus)
{
imx_smp_prepare();
/*
* The diagnostic register holds the errata bits. Mostly bootloader
* does not bring up secondary cores, so that when errata bits are set
* in bootloader, they are set only for boot cpu. But on a SMP
* configuration, it should be equally done on every single core.
* Read the register from boot cpu here, and will replicate it into
* secondary cores when booting them.
*/
asm("mrc p15, 0, %0, c15, c0, 1" : "=r" (g_diag_reg) : : "cc");
__cpuc_flush_dcache_area(&g_diag_reg, sizeof(g_diag_reg));
outer_clean_range(__pa(&g_diag_reg), __pa(&g_diag_reg + 1));
}
struct smp_operations imx_smp_ops __initdata = {