| Message ID | 20210916210733.153388-1-russell.h.weight@intel.com |
|---|---|
| State | Accepted |
| Commit | e9a9970bf520c99e530d8f1fa5b5c22671fad4ef |
| Headers | show |
| Series | [1/1] fpga: dfl: Avoid reads to AFU CSRs during enumeration | expand |
On Thu, Sep 16, 2021 at 02:07:33PM -0700, Russ Weight wrote: > CSR address space for Accelerator Functional Units (AFU) is not available > during the early Device Feature List (DFL) enumeration. Early access > to this space results in invalid data and port errors. This change adds > a condition to prevent an early read from the AFU CSR space. > > Signed-off-by: Russ Weight <russell.h.weight@intel.com> > > Fixes: 23bcda750558 ("fpga: dfl: expose feature revision from struct > dfl_device") Nit, please keep this all on one line or our tools will complain about it when we commit it to our trees :( thanks, greg k-h
On Fri, Sep 17, 2021 at 07:42:28AM +0200, Greg KH wrote: > On Thu, Sep 16, 2021 at 02:07:33PM -0700, Russ Weight wrote: > > CSR address space for Accelerator Functional Units (AFU) is not available > > during the early Device Feature List (DFL) enumeration. Early access > > to this space results in invalid data and port errors. This change adds > > a condition to prevent an early read from the AFU CSR space. > > > > Signed-off-by: Russ Weight <russell.h.weight@intel.com> > > > > Fixes: 23bcda750558 ("fpga: dfl: expose feature revision from struct > > dfl_device") > > Nit, please keep this all on one line or our tools will complain about > it when we commit it to our trees :( I had caught that and fixed it when applying :) Thanks, Moritz
On 9/16/21 3:50 PM, Moritz Fischer wrote: > On Thu, Sep 16, 2021 at 03:34:39PM -0700, Russ Weight wrote: >> On 9/16/21 3:24 PM, Moritz Fischer wrote: >>> On Thu, Sep 16, 2021 at 02:07:33PM -0700, Russ Weight wrote: >>>> CSR address space for Accelerator Functional Units (AFU) is not available >>>> during the early Device Feature List (DFL) enumeration. Early access >>>> to this space results in invalid data and port errors. This change adds >>>> a condition to prevent an early read from the AFU CSR space. >>>> >>>> Signed-off-by: Russ Weight <russell.h.weight@intel.com> >>>> >>>> Fixes: 23bcda750558 ("fpga: dfl: expose feature revision from struct >>>> dfl_device") >>> Did you mean: >>> >>> Fixes: 1604986c3e6b ("fpga: dfl: expose feature revision from struct dfl_device") >> Oops - I must have been looking at the wrong branch. Yes - you have the >> correct commit ID >>> And for future please don't line break those, or we'll get yelled at :) >> Got it. >> >> Thanks! >> - Russ >>> I can locally fix it up, no need to resubmit >>> >>> - Moritz > Applied w/changes to fixes, Can a signed-off tag still be added? Signed-off-by: Roger Christensen <rc@silicom.dk> There was also a suggestion the the variable v could be declared within the scope of the "if" statement instead of being declared at function scope. I haven't seen that done much (at all?) in kernel code. - Russ > > - Moritz
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index c99b78ee008a..f86666cf2c6a 100644 --- a/drivers/fpga/dfl.c +++ b/drivers/fpga/dfl.c @@ -1019,16 +1019,18 @@ create_feature_instance(struct build_feature_devs_info *binfo, { unsigned int irq_base, nr_irqs; struct dfl_feature_info *finfo; + u8 revision = 0; int ret; - u8 revision; u64 v; - v = readq(binfo->ioaddr + ofst); - revision = FIELD_GET(DFH_REVISION, v); + if (fid != FEATURE_ID_AFU) { + v = readq(binfo->ioaddr + ofst); + revision = FIELD_GET(DFH_REVISION, v); - /* read feature size and id if inputs are invalid */ - size = size ? size : feature_size(v); - fid = fid ? fid : feature_id(v); + /* read feature size and id if inputs are invalid */ + size = size ? size : feature_size(v); + fid = fid ? fid : feature_id(v); + } if (binfo->len - ofst < size) return -EINVAL;
CSR address space for Accelerator Functional Units (AFU) is not available during the early Device Feature List (DFL) enumeration. Early access to this space results in invalid data and port errors. This change adds a condition to prevent an early read from the AFU CSR space. Signed-off-by: Russ Weight <russell.h.weight@intel.com> Fixes: 23bcda750558 ("fpga: dfl: expose feature revision from struct dfl_device") Cc: stable@vger.kernel.org --- drivers/fpga/dfl.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)