ARM: mpu: add MPU initialisation for secondary cores
The MPU initialisation on the primary core is performed in two stages, one
minimal stage to ensure the CPU can boot and a second one after
sanity_check_meminfo. As the memory configuration is known by the time we
boot secondary cores only a single step is necessary, provided the values
for DRSR are passed to secondaries.
This patch implements this arrangement. The configuration generated for the
MPU regions is made available to the secondary core, which can then use the
asm MPU intialisation code to program a complete region configuration.
This is necessary for SMP configurations without an MMU, as the MPU
initialisation is the only way to ensure that memory is specified as
'shared'.
Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
CC: Nicolas Pitre <nico@linaro.org>
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 44d1c00..e17d934 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -45,6 +45,7 @@
#include <asm/smp_plat.h>
#include <asm/virt.h>
#include <asm/mach/arch.h>
+#include <asm/mpu.h>
/*
* as from 2.5, kernels no longer have an init_tasks structure
@@ -87,6 +88,10 @@
* its stack and the page tables.
*/
secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
+#ifdef CONFIG_ARM_MPU
+ secondary_data.mpu_rgn_szr = mpu_rgn_info.rgns[MPU_RAM_REGION].drsr;
+#endif
+
#ifdef CONFIG_MMU
secondary_data.pgdir = virt_to_phys(idmap_pgd);
secondary_data.swapper_pg_dir = virt_to_phys(swapper_pg_dir);
@@ -114,9 +119,8 @@
pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
}
- secondary_data.stack = NULL;
- secondary_data.pgdir = 0;
+ memset(&secondary_data, 0, sizeof(secondary_data));
return ret;
}