A RISC-V Fix for 5.9

I collected a single fix during the merge window: we managed to break the early
 trap setup on !MMU, this patch fixes it.
 
 The power keeps going on here so I haven't have a chance to give this the
 testing I usually would, but I don't have a Kendryte anyway so I doubt I'd pick
 up anything subtle even if I was to test.  The patch seems pretty safe and it's
 still early, so I don't see any reason to let it sit around.
 
 It's fairly late so if it misses the merge window that's not a big deal.  I'll
 definately have stuff for next week, so I'll just start from whenever this
 lands.
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Merge tag 'riscv-for-linus-5.9-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fix from Palmer Dabbelt:
 "I collected a single fix during the merge window: we managed to break
  the early trap setup on !MMU, this fixes it"

* tag 'riscv-for-linus-5.9-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Setup exception vector for nommu platform
This commit is contained in:
Linus Torvalds 2020-08-15 18:54:42 -07:00
commit d84835b118
1 changed files with 17 additions and 8 deletions

View File

@ -77,16 +77,10 @@ relocate:
csrw CSR_SATP, a0
.align 2
1:
/* Set trap vector to exception handler */
la a0, handle_exception
/* Set trap vector to spin forever to help debug */
la a0, .Lsecondary_park
csrw CSR_TVEC, a0
/*
* Set sup0 scratch register to 0, indicating to exception vector that
* we are presently executing in kernel.
*/
csrw CSR_SCRATCH, zero
/* Reload the global pointer */
.option push
.option norelax
@ -144,9 +138,23 @@ secondary_start_common:
la a0, swapper_pg_dir
call relocate
#endif
call setup_trap_vector
tail smp_callin
#endif /* CONFIG_SMP */
.align 2
setup_trap_vector:
/* Set trap vector to exception handler */
la a0, handle_exception
csrw CSR_TVEC, a0
/*
* Set sup0 scratch register to 0, indicating to exception vector that
* we are presently executing in kernel.
*/
csrw CSR_SCRATCH, zero
ret
.Lsecondary_park:
/* We lack SMP support or have too many harts, so park this hart */
wfi
@ -240,6 +248,7 @@ clear_bss_done:
call relocate
#endif /* CONFIG_MMU */
call setup_trap_vector
/* Restore C environment */
la tp, init_task
sw zero, TASK_TI_CPU(tp)