[PATCH 1/4] fpga mgr: Introduce FPGA capabilities

atull
2016-11-14T23:23:08Z

On Mon, 14 Nov 2016, Moritz Fischer wrote:

Hi Moritz,

> Hi Alan,
>
> On Mon, Nov 14, 2016 at 6:06 AM, atull <atull@opensource.altera.com> wrote:
> > On Mon, 7 Nov 2016, Moritz Fischer wrote:
> >
> >> Add FPGA capabilities as a way to express the capabilities
> >> of a given FPGA manager.
> >>
> >> Removes code duplication by comparing the low-level driver's
> >> capabilities at the framework level rather than having each driver
> >> check for supported operations in the write_init() callback.
> >>
> >> This allows for extending with additional capabilities, similar
> >> to the the dmaengine framework's implementation.
> >>
> >> Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
> >> Cc: Alan Tull <atull@opensource.altera.com>
> >> Cc: Michal Simek <michal.simek@xilinx.com>
> >> Cc: S?ren Brinkmann <soren.brinkmann@xilinx.com>
> >> Cc: linux-kernel at vger.kernel.org
> >> Cc: linux-arm-kernel at lists.infradead.org
> >> ---
> >>
> >> Changes from RFC:
> >> * in the RFC the caps weren't actually stored into the struct fpga_mgr
> >>
> >> Note:
> >>
> >> If people disagree on the typedef being a 'false positive' I can fix
> >> that in a future rev of the patchset.
> >>
> >> Thanks,
> >>
> >> Moritz
> >>
> >> ---
> >> drivers/fpga/fpga-mgr.c | 15 ++++++++++++++
> >> drivers/fpga/socfpga.c | 10 +++++-----
> >> drivers/fpga/zynq-fpga.c | 7 ++++++-
> >> include/linux/fpga/fpga-mgr.h | 46 ++++++++++++++++++++++++++++++++++++++++++-
> >> 4 files changed, 71 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> >> index 953dc91..ed57c17 100644
> >> --- a/drivers/fpga/fpga-mgr.c
> >> +++ b/drivers/fpga/fpga-mgr.c
> >> @@ -49,6 +49,18 @@ int fpga_mgr_buf_load(struct fpga_manager *mgr, u32 flags, const char *buf,
> >> struct device *dev = &mgr->dev;
> >> int ret;
> >>
> >> + if (flags & FPGA_MGR_PARTIAL_RECONFIG &&
> >> + !fpga_mgr_has_cap(FPGA_MGR_CAP_PARTIAL_RECONF, mgr->caps)) {
> >> + dev_err(dev, "Partial reconfiguration not supported\n");
> >> + return -ENOTSUPP;
> >> + }
> >> +
> >> + if (flags & FPGA_MGR_FULL_RECONFIG &&
> >> + !fpga_mgr_has_cap(FPGA_MGR_CAP_FULL_RECONF, mgr->caps)) {
> >> + dev_err(dev, "Full reconfiguration not supported\n");
> >> + return -ENOTSUPP;
> >> + }
> >> +
> >
> > Could you move the checks to their own function like
> > 'fpga_mgr_check_caps()' or something? I really like it if we can keep
> > the functions short, like a screen or so where it's practicle to do
> > so and I could see the number of caps growing here.
>
> Absolutely. Great suggestion.
>
> > The only counter argument I could think of is if a cap affects the sequence
> > in this function. Hmmm...
>
> Oh you mean the cap being there affecting the sequence in *this* function?
> I'd suggest we address that when we run into a cap that requires this.

Yes, I agree.

Alan

>
> Cheers,
>
> Moritz
>