[PATCH v3 RESEND 2/5] ARM: add SMP support for Broadcom mobile SoCs
From: Matt Porter <hidden>
Date: 2014-05-15 19:19:15
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linux-devicetree, lkml
On Thu, May 15, 2014 at 01:17:00PM -0500, Alex Elder wrote:
On 05/15/2014 01:03 PM, Florian Fainelli wrote:quoted
Hi Alex, 2014-05-15 10:58 GMT-07:00 Alex Elder [off-list ref]:quoted
This patch adds SMP support for BCM281XX and BCM21664 family SoCs. This feature is controlled with a distinct config option such that a 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 [off-list ref] Signed-off-by: Alex Elder <redacted> --- arch/arm/mach-bcm/Kconfig | 18 +++- arch/arm/mach-bcm/Makefile | 3 + arch/arm/mach-bcm/platsmp.c | 201 ++++++++++++++++++++++++++++++++++++++++++++Could we make that name a little bit more specific to the mobile SoCs?Sure. I thought about that but naming stuff here has been a sort of ongoing struggle... "Kona" made some sense, in some cases, but it's not perfect. Simlar with "mobile." I'll propose "kona_smp.c". OK with you? Unless I get a better suggestion I'll plan to go with that next time around.
Works for me. -Matt