Vineet Gupta 3b57533b46 ARC: [plat-hsdk] Remap CCMs super early in asm boot trampoline ... ARC HSDK platform stopped booting on released v5.10-rc1, getting stuck in startup of non master SMP cores. This was bisected to upstream commit 7fef431be9 "(mm/page_alloc: place pages to tail in __free_pages_core())" That commit itself is harmless, it just exposed a subtle assumption in our platform code (hence CC'ing linux-mm just as FYI in case some other arches / platforms trip on it). The upstream commit is semantically disruptive as it reverses the order of page allocations (actually it can be good test for hardware verification to exercise different memory patterns altogether). For ARC HSDK platform that meant a remapped memory region (pertaining to unused Closely Coupled Memory) started getting used early for dynamice allocations, while not effectively remapped on all the cores, triggering memory error exception on those cores. The fix is to move the CCM remapping from early platform code to to early core boot code. And while it is undesirable to riddle common boot code with platform quirks, there is no other way to do this since the faltering code involves setting up stack itself so even function calls are not allowed at that point. If anyone is interested, all the gory details can be found at Link below. Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/32 Cc: David Hildenbrand <david@redhat.com> Cc: linux-mm@kvack.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com>		2020-11-02 11:45:09 -08:00
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Kconfig	arc: plat-hsdk: fix kconfig dependency warning when !RESET_CONTROLLER	2020-10-05 21:02:29 -07:00
Makefile	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
platform.c	ARC: [plat-hsdk] Remap CCMs super early in asm boot trampoline	2020-11-02 11:45:09 -08:00