Messages in this thread | | | From | Vineet Gupta <> | Subject | [PATCH 0/4] ARC rework SMP boot waiting to handle IO-Coherency case | Date | Mon, 16 Jan 2017 12:57:53 -0800 |
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ARC SMP supports halt-on-reset and run-on-reset for non master cores. run-on-reset is applicable for internal bitfiles as well as debugger assisted boots (where all cores are started together)
run-on-reset uses a poll-shared-flag-in-mem-n-spin approach which is not efficient and moreover is wrong when IO-Coherency is being setup by Master in early boot, expecting absolutely NO noise on coherency unit by other cores.
To solve this we wither need to move all the SLC/IOC setup code in head.S which is super pain, or we make run-to-reset behave as if halt-on-reset with hardware assist to resume the non masters at right time.
Vineet Gupta (4): ARC: smp-boot: waiting API for run-from-reset need not jump to entry point ARC: smp-boot: run-on-reset: add callback to allow non masters to wait ARCv2: smp: MCIP: remove debug aid to halt all cores when one halts ARCv2: smp-boot: MCIP: use Inter-Core-Debug unit to kick start non master cpus
arch/arc/include/asm/mcip.h | 1 + arch/arc/include/asm/smp.h | 3 +++ arch/arc/kernel/head.S | 14 +++++++------- arch/arc/kernel/mcip.c | 34 ++++++++++++++++++++++++++++++---- arch/arc/kernel/smp.c | 15 +++++++++++++-- 5 files changed, 54 insertions(+), 13 deletions(-)
-- 2.7.4
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