linux_dsm_epyc7002/arch/csky/kernel/head.S
Guo Ren aefd9461d3 csky: Fixup cpu speculative execution to IO area
For the memory size ( > 512MB, < 1GB), the MSA setting is:

 - SSEG0: PHY_START        , PHY_START + 512MB
 - SSEG1: PHY_START + 512MB, PHY_START + 1GB

But the real memory is no more than 1GB, there is a gap between the
end size of memory and border of 1GB. CPU could speculatively
execute to that gap and if the gap of the bus couldn't respond to
the CPU request, then the crash will happen.

Now make the setting with:

 - SSEG0: PHY_START        , PHY_START + 512MB (no change)
 - SSEG1: Disabled (We use highmem to use the memory of 512MB~1GB)

We also deprecated zhole_szie[] settings, it's only used by arm
style CPUs. All memory gap should use Reserved setting of dts in
csky system.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
2020-04-03 12:40:07 +08:00

37 lines
587 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/page.h>
#include <abi/entry.h>
__HEAD
ENTRY(_start)
SETUP_MMU
/* set stack point */
lrw r6, init_thread_union + THREAD_SIZE
mov sp, r6
jmpi csky_start
END(_start)
#ifdef CONFIG_SMP
.align 10
ENTRY(_start_smp_secondary)
SETUP_MMU
/* copy msa1 from CPU0 */
lrw r6, secondary_msa1
ld.w r6, (r6, 0)
mtcr r6, cr<31, 15>
/* set stack point */
lrw r6, secondary_stack
ld.w r6, (r6, 0)
mov sp, r6
jmpi csky_start_secondary
END(_start_smp_secondary)
#endif