mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-30 07:46:44 +07:00
893f38d144
Jens found the following crash/regression:
[ 0.000000] found SMP MP-table at [ffff8800000fdd80] fdd80
[ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 0-fff BIOS data page
and
[ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 6000-7fff TRAMPOLINE
and bisected it to b24c2a9 ("x86: Move find_smp_config()
earlier and avoid bootmem usage").
It turns out the BIOS is using the first 64k for mptable,
without reserving it.
So try to find good range for the real-mode trampoline instead of
hard coding it, in case some bios tries to use that range for sth.
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <4B21630A.6000308@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
40 lines
989 B
C
40 lines
989 B
C
#include <linux/io.h>
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#include <asm/trampoline.h>
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#include <asm/e820.h>
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#if defined(CONFIG_X86_64) && defined(CONFIG_ACPI_SLEEP)
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#define __trampinit
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#define __trampinitdata
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#else
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#define __trampinit __cpuinit
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#define __trampinitdata __cpuinitdata
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#endif
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/* ready for x86_64 and x86 */
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unsigned char *__trampinitdata trampoline_base;
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void __init reserve_trampoline_memory(void)
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{
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unsigned long mem;
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/* Has to be in very low memory so we can execute real-mode AP code. */
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mem = find_e820_area(0, 1<<20, TRAMPOLINE_SIZE, PAGE_SIZE);
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if (mem == -1L)
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panic("Cannot allocate trampoline\n");
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trampoline_base = __va(mem);
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reserve_early(mem, mem + TRAMPOLINE_SIZE, "TRAMPOLINE");
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}
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/*
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* Currently trivial. Write the real->protected mode
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* bootstrap into the page concerned. The caller
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* has made sure it's suitably aligned.
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*/
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unsigned long __trampinit setup_trampoline(void)
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{
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memcpy(trampoline_base, trampoline_data, TRAMPOLINE_SIZE);
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return virt_to_phys(trampoline_base);
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}
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