On 26.10.2023 00:41, Shawn Anastasio wrote:
> Implement a basic exception handler that dumps the CPU state to the
> console, as well as the code required to set the correct exception
> vector table's base address in setup.c.
>
> Signed-off-by: Shawn Anastasio <sanasta...@raptorengineering.com>
Despite me being unhappy about the disconnect of the constants
Acked-by: Jan Beulich <jbeul...@suse.com>
One further remark/suggestion though (happy to take care of while
committing):
> --- /dev/null
> +++ b/xen/arch/ppc/ppc64/exceptions-asm.S
> @@ -0,0 +1,135 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +
> +#include <asm/asm-defns.h>
> +#include <asm/processor.h>
> +
> + .section .text.exceptions, "ax", %progbits
> +
> + /* Helper to dump CPU state to struct cpu_user_regs pointed to by r1. */
> +ENTRY(exception_common)
> + /*
> + * Save GPRs 1-31. TODO: The value of %r1 has already been modified by
> the
> + * ISR, so the value we save isn't the exact value we had on entry.
> + */
> + SAVE_GPRS(1, 31, %r1)
Wouldn't this comment ...
> + /* Save LR, CTR, CR */
> + mflr %r0
> + std %r0, UREGS_lr(%r1)
> + mfctr %r0
> + std %r0, UREGS_ctr(%r1)
> + mfcr %r0
> + stw %r0, UREGS_cr(%r1) /* 32-bit */
> +
> + /* Save Exception Registers */
> + mfsrr0 %r0
> + std %r0, UREGS_pc(%r1)
> + mfsrr1 %r0
> + std %r0, UREGS_msr(%r1)
> + mfdsisr %r0
> + stw %r0, UREGS_dsisr(%r1) /* 32-bit */
> + mfdar %r0
> + std %r0, UREGS_dar(%r1)
> + li %r0, -1 /* OS's SRR0/SRR1 have been clobbered */
> + std %r0, UREGS_srr0(%r1)
> + std %r0, UREGS_srr1(%r1)
> +
> + /* Setup TOC and a stack frame then call C exception handler */
> + mr %r3, %r1
> + bcl 20, 31, 1f
> +1: mflr %r12
> + addis %r2, %r12, .TOC.-1b@ha
> + addi %r2, %r2, .TOC.-1b@l
> +
> + li %r0, 0
> + stdu %r0, -STACK_FRAME_OVERHEAD(%r1)
> + bl exception_handler
> +
> + .size exception_common, . - exception_common
> + .type exception_common, %function
> +
> + /* Same as exception_common, but for exceptions that set HSRR{0,1} */
> +ENTRY(h_exception_common)
> + /* Save GPRs 1-31 */
> + SAVE_GPRS(1, 31, %r1)
... better be repeated here?
Jan
