kernel.git/arch/arc/kernel/head.S, branch linux-4.20.y

ARC: U-boot: check arguments paranoidly

2019-02-27T09:09:55Z

commit a66f2e57bd566240d8b3884eedf503928fbbe557 upstream. Handle U-boot arguments paranoidly: * don't allow to pass unknown tag. * try to use external device tree blob only if corresponding tag (TAG_DTB) is set. * don't check uboot_tag if kernel build with no ARC_UBOOT_SUPPORT. NOTE: If U-boot args are invalid we skip them and try to use embedded device tree blob. We can't panic on invalid U-boot args as we really pass invalid args due to bug in U-boot code. This happens if we don't provide external DTB to U-boot and don't set 'bootargs' U-boot environment variable (which is default case at least for HSDK board) In that case we will pass {r0 = 1 (bootargs in r2); r1 = 0; r2 = 0;} to linux which is invalid. While I'm at it refactor U-boot arguments handling code. Cc: stable@vger.kernel.org Tested-by: Corentin LABBE Signed-off-by: Eugeniy Paltsev Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman

ARCv2: Enable unaligned access in early ASM code

2019-02-27T09:09:55Z

commit 252f6e8eae909bc075a1b1e3b9efb095ae4c0b56 upstream. It is currently done in arc_init_IRQ() which might be too late considering gcc 7.3.1 onwards (GNU 2018.03) generates unaligned memory accesses by default Cc: stable@vger.kernel.org #4.4+ Signed-off-by: Eugeniy Paltsev Signed-off-by: Vineet Gupta [vgupta: rewrote changelog] Signed-off-by: Greg Kroah-Hartman

ARC: smp-boot: Decouple Non masters waiting API from jump to entry point

2017-01-24T19:12:28Z

For run-on-reset SMP configs, non master cores call a routine which waits until Master gives it a "go" signal (currently using a shared mem flag). The same routine then jumps off the well known entry point of all non Master cores i.e. @first_lines_of_secondary This patch moves out the last part into one single place in early boot code. This is better in terms of absraction (the wait API only waits) and returns, leaving out the "jump off to" part. In actual implementation this requires some restructuring of the early boot code as well as Master now jumps to BSS setup explicitly, vs. falling thru into it before. Technically this patch doesn't cause any functional change, it just moves the ugly #ifdef'ry from assembly code to "C" Signed-off-by: Vineet Gupta

ARC: boot: Non Master cpus only need to call EARLY_CPU_SETUP once

2015-10-28T10:43:42Z

With prev fixes, all cores now start via common entry point @stext which already calls EARLY_CPU_SETUP for all cores - so no need to invoke it again Signed-off-by: Vineet Gupta

ARC: boot: Support Halt-on-reset and Run-on-reset SMP booting modes

2015-10-28T10:38:17Z

For Run-on-reset, non masters need to spin wait. For Halt-on-reset they can jump to entry point directly. Also while at it, made reset vector handler as "the" entry point for kernel including host debugger based boot (which uses the ELF header entry point) Signed-off-by: Vineet Gupta

ARCv2: Support for ARCv2 ISA and HS38x cores

2015-06-22T08:36:55Z

The notable features are: - SMP configurations of upto 4 cores with coherency - Optional L2 Cache and IO-Coherency - Revised Interrupt Architecture (multiple priorites, reg banks, auto stack switch, auto regfile save/restore) - MMUv4 (PIPT dcache, Huge Pages) - Instructions for * 64bit load/store: LDD, STD * Hardware assisted divide/remainder: DIV, REM * Function prologue/epilogue: ENTER_S, LEAVE_S * IRQ enable/disable: CLRI, SETI * pop count: FFS, FLS * SETcc, BMSKN, XBFU... Signed-off-by: Vineet Gupta

ARC: explicit'ify uboot support

2015-06-19T12:39:27Z

Signed-off-by: Vineet Gupta

ARC: RIP @running_on_hw

2014-10-13T09:16:17Z

* No active users of this flag anymore * flag itself was no longer usable with new simualtor which acts just like hardware, not providing the special chip-id = 0xffff which good old ISS used to do. Signed-off-by: Vineet Gupta

ARC: optimize kernel bss clearing in early boot code

2014-06-26T04:44:05Z

using ARC ZOL which reduces tot num of instructions by half Signed-off-by: Vineet Gupta

ARC: Disable caches in early boot if so configured

2014-06-03T09:44:48Z

Requested-by: Noam Camus Signed-off-by: Vineet Gupta