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

Moritz Fischer
2016-11-14T17:26:59Z

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.

Cheers,

Moritz