Re: [PATCH v1 2/7] fpga: dfl: check feature type before parse irq info
From: Tom Rix <trix@redhat.com>
Date: 2022-02-15 14:51:35
Also in:
linux-fpga, lkml
On 2/14/22 3:26 AM, Tianfei zhang wrote:
From: Tianfei Zhang <redacted> The feature ID of "Port User Interrupt" and the "PMCI Subsystem" are identical, 0x12, but one is for FME, other is for Port. It should check the feature type While parsing the irq info in parse_feature_irqs().
This seems like a bug fix and not part of iofs feature. Split this out of the patchset. This is a workaround a hardware problem, there should be some comments to the effect that you can't trust _this_ or _that_ feature id and some special handling earlier. The ambiguity of feature id is a problem, and this sort of bug will happen again. What can be done to prevent this in the future ?
quoted hunk ↗ jump to hunk
Signed-off-by: Tianfei Zhang <redacted> --- drivers/fpga/dfl.c | 11 +++++++++++ 1 file changed, 11 insertions(+)diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index 599bb21d86af..26f8cf890700 100644 --- a/drivers/fpga/dfl.c +++ b/drivers/fpga/dfl.c@@ -940,9 +940,14 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo, { void __iomem *base = binfo->ioaddr + ofst; unsigned int i, ibase, inr = 0; + enum dfl_id_type type; int virq; u64 v; + type = feature_dev_id_type(binfo->feature_dev); + if (type >= DFL_ID_MAX) + return -EINVAL; + /* * Ideally DFL framework should only read info from DFL header, but * current version DFL only provides mmio resources information for@@ -959,16 +964,22 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo, */ switch (fid) { case PORT_FEATURE_ID_UINT: + if (type != PORT_ID) + break;
Instead of embedding a break in the switch, break the switch into fme switch and port switch if (type == PORT_ID) port-switch else if (type == FME_ID fme-switch Tom
v = readq(base + PORT_UINT_CAP); ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); break; case PORT_FEATURE_ID_ERROR: + if (type != PORT_ID) + break; v = readq(base + PORT_ERROR_CAP); ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); break; case FME_FEATURE_ID_GLOBAL_ERR: + if (type != FME_ID) + break; v = readq(base + FME_ERROR_CAP); ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v);