ARM: add SMP support for Broadcom mobile SoCs
This patch adds SMP support for BCM281XX and BCM21664 family SoCs.
This feature is controlled with a distinct config option such that
an SMP-enabled multi-v7 binary can be configured to run these SoCs
in uniprocessor mode. Since this SMP functionality is used for
multiple Broadcom mobile chip families the config option is called
ARCH_BCM_MOBILE_SMP (for lack of a better name).
On SoCs of this type, the secondary core is not held in reset on
power-on. Instead it loops in a ROM-based holding pen. To release
it, one must write into a special register a jump address whose
low-order bits have been replaced with a secondary core's id, then
trigger an event with SEV. On receipt of an event, the ROM code
will examine the register's contents, and if the low-order bits
match its cpu id, it will clear them and write the value back to the
register just prior to jumping to the address specified.
The location of the special register is defined in the device tree
using a "secondary-boot-reg" property in a node whose "enable-method"
matches.
Derived from code originally provided by Ray Jui <rjui@broadcom.com>
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
index 41c8391..6bafa2d 100644
--- a/arch/arm/mach-bcm/Kconfig
+++ b/arch/arm/mach-bcm/Kconfig
@@ -9,7 +9,6 @@
bool "Broadcom Mobile SoC Support" if ARCH_MULTI_V7
select ARCH_REQUIRE_GPIOLIB
select ARM_ERRATA_754322
- select ARM_ERRATA_764369 if SMP
select ARM_ERRATA_775420
select ARM_GIC
select GPIO_BCM_KONA
@@ -26,16 +25,18 @@
config ARCH_BCM_281XX
bool "Broadcom BCM281XX SoC family"
default y
+ select HAVE_SMP
help
- Enable support for the the BCM281XX family, which includes
+ Enable support for the BCM281XX family, which includes
BCM11130, BCM11140, BCM11351, BCM28145 and BCM28155
variants.
config ARCH_BCM_21664
bool "Broadcom BCM21664 SoC family"
default y
+ select HAVE_SMP
help
- Enable support for the the BCM21664 family, which includes
+ Enable support for the BCM21664 family, which includes
BCM21663 and BCM21664 variants.
config ARCH_BCM_MOBILE_L2_CACHE
@@ -49,6 +50,17 @@
bool
depends on ARCH_BCM_281XX || ARCH_BCM_21664
+config ARCH_BCM_MOBILE_SMP
+ bool "Broadcom mobile SoC SMP support"
+ depends on (ARCH_BCM_281XX || ARCH_BCM_21664) && SMP
+ default y
+ select HAVE_ARM_SCU
+ select ARM_ERRATA_764369
+ help
+ SMP support for the BCM281XX and BCM21664 SoC families.
+ Provided as an option so SMP support for SoCs of this type
+ can be disabled for an SMP-enabled kernel.
+
endmenu
endif