[Skiboot] [PATCH 4/5] nvlink: Add freeze and fence error injection
Alistair Popple
alistair at popple.id.au
Thu Jan 14 14:14:13 AEDT 2016
On Thu, 7 Jan 2016 14:36:31 Russell Currey wrote:
> Enable NPU freeze and fence injection through debugfs.
>
> For example, if a NPU is PCI bus 8, a freeze on PE 0 can be injected with:
>
> echo 0:0:0:0:0 >> /sys/kernel/debug/powerpc/PCI0008/err_injct
>
> or a fence on PE 2 on PCI bus 9 with:
>
> echo 2:1:0:0:0 >> /sys/kernel/debug/powerpc/PCI0009/err_injct
>
> These will cause the appropriate EEH event to occur upon a DMA to the
> NVLink.
>
> Signed-off-by: Russell Currey <ruscur at russell.cc>
> ---
> hw/npu.c | 31 ++++++++++++++++++++++++++++++-
> 1 file changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/hw/npu.c b/hw/npu.c
> index 9440f17..ba61d2d 100644
> --- a/hw/npu.c
> +++ b/hw/npu.c
> @@ -1016,6 +1016,35 @@ static int64_t npu_freeze_status(struct phb *phb __unused,
> return OPAL_SUCCESS;
> }
>
> +/* Sets the NPU to trigger an error when a DMA occurs */
> +static int64_t npu_err_inject(struct phb *phb, uint32_t pe_no,
> + uint32_t type, uint32_t func __unused,
> + uint64_t addr __unused, uint64_t mask __unused)
> +{
> + struct npu *p = phb_to_npu(phb);
> + struct npu_dev *dev;
> +
> + if (pe_no > NPU_NUM_OF_PES) {
> + prlog(PR_ERR, "NPU: error injection failed, bad PE given\n");
> + return OPAL_SUCCESS;
Shouldn't we return some kind of failure code rather than OPAL_SUCCESS?
> + }
> +
> + dev = &p->devices[pe_no];
The assumption pe_no == device number doesn't always hold, particularly with
the kernel patches to assign PE#s per GPU rather than per-link. We need to
find the struct npu_dev by PE# rather than device number (we could add a
pe_num field to struct npu_dev for example).
> +
> + /* TODO: extend this to conform to OPAL injection standards */
> + if (type > 1) {
> + prlog(PR_ERR, "NPU: invalid error injection type\n");
> + } else if (type == 1) {
> + /* Emulate fence mode. */
> + p->fenced = true;
> + } else {
> + /* Cause a freeze with an invalid MMIO write. */
> + in_be64((void *)dev->bar.base);
> + }
> +
> + return OPAL_SUCCESS;
> +}
> +
> static const struct phb_ops npu_ops = {
> .lock = npu_lock,
> .unlock = npu_unlock,
> @@ -1055,7 +1084,7 @@ static const struct phb_ops npu_ops = {
> .eeh_freeze_clear = NULL,
> .eeh_freeze_set = NULL,
> .next_error = NULL,
> - .err_inject = NULL,
> + .err_inject = npu_err_inject,
> .get_diag_data = NULL,
> .get_diag_data2 = NULL,
> .set_capi_mode = NULL,
>
More information about the Skiboot
mailing list