Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 087bb283 authored by Shawn Guo's avatar Shawn Guo
Browse files

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: default avatarShawn Guo <shawn.guo@linaro.org>
Acked-by: default avatarDirk Behme <dirk.behme@de.bosch.com>
parent 0e574461

arch/arm/mach-imx/headsmp.S

+12 −0
Original line number Diff line number Diff line
@@ -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

arch/arm/mach-imx/platsmp.c

+14 −0
Original line number Diff line number Diff line
@@ -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 = {