From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753308AbdCMSBA (ORCPT ); Mon, 13 Mar 2017 14:01:00 -0400 Received: from mail-qk0-f193.google.com ([209.85.220.193]:32879 "EHLO mail-qk0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752015AbdCMSAv (ORCPT ); Mon, 13 Mar 2017 14:00:51 -0400 MIME-Version: 1.0 In-Reply-To: <1489105090-4996-3-git-send-email-yi1.li@linux.intel.com> References: <1489105090-4996-1-git-send-email-yi1.li@linux.intel.com> <1489105090-4996-3-git-send-email-yi1.li@linux.intel.com> From: Alan Tull Date: Mon, 13 Mar 2017 13:00:49 -0500 Message-ID: Subject: Re: [RFC 2/2] fpga manager: Add fpga_mgr_firmware_stream API To: "Li, Yi" Cc: ming.lei@canonical.com, mcgrof@kernel.org, Greg Kroah-Hartman , atull , Moritz Fischer , linux-kernel , linux-fpga@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 9, 2017 at 6:18 PM, wrote: Hi Yi, Thanks for your RFC. I believe this functionality is badly needed. I had a few comments about the chunk size and some nits about comments below... > From: Yi Li > > Add fpga_mgr_firmware_stream API, which can load and program firmware > > in trucks to FPGA instead of the whole file. > > Signed-off-by: Yi Li > --- > drivers/fpga/fpga-mgr.c | 77 +++++++++++++++++++++++++++++++++++++++++++ > include/linux/fpga/fpga-mgr.h | 4 +++ > 2 files changed, 81 insertions(+) > > diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c > index 3206a53..bb55b80 100644 > --- a/drivers/fpga/fpga-mgr.c > +++ b/drivers/fpga/fpga-mgr.c > @@ -27,10 +27,15 @@ > #include > #include > #include > +#include > > static DEFINE_IDA(fpga_mgr_ida); > static struct class *fpga_mgr_class; > > +static int streamsize = SZ_4K; > +module_param(streamsize, int, 0664); > +MODULE_PARM_DESC(streamsize, "buffer size for firmware streaming"); I think we could fix the chunk size at PAGE_SIZE unless someone can state a reason for needing something different. Below I have one reason why we will sometimes need > PAGE_SIZE. > + > /* > * Call the low level driver's write_init function. This will do the > * device-specific things to get the FPGA into the state where it is ready to > @@ -309,6 +314,78 @@ int fpga_mgr_firmware_load(struct fpga_manager *mgr, > } > EXPORT_SYMBOL_GPL(fpga_mgr_firmware_load); > > +/** > + * fpga_mgr_firmware_load - request firmware and load to fpga > + * @mgr: fpga manager > + * @info: fpga image specific information > + * @image_name: name of image file on the firmware search path > + * > + * Request an FPGA image using the firmware class, then write out to the FPGA. > + * Update the state before each step to provide info on what step failed if > + * there is a failure. This code assumes the caller got the mgr pointer > + * from of_fpga_mgr_get() or fpga_mgr_get() and checked that it is not an error > + * code. > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +int fpga_mgr_firmware_stream(struct fpga_manager *mgr, > + struct fpga_image_info *info, > + const char *image_name) No need for both fpga_mgr_firmware_load and fpga_mgr_firmware_stream. Just replace the old fpga_mgr_firmware_load with this function. > +{ > + struct device *dev = &mgr->dev; > + const struct firmware *fw = NULL; > + int ret; > + size_t size = INT_MAX, offset = 0; > + bool start_flag = 1; > + > + dev_info(dev, "writing %s to %s with buffer size %d\n", > + image_name, mgr->name, streamsize); > + > + mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ; > + > + while (size > 0) { > + ret = stream_firmware(&fw, image_name, dev, offset, streamsize); > + if (ret) { > + dev_err(dev, "Error reading firmware %d\n", ret); > + mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ_ERR; > + break; > + } > + > + /* > + * init. > + */ We don't really need this comment. > + if (start_flag) { > + ret = fpga_mgr_write_init_buf(mgr, info, fw->data, > + fw->size); When the fpga manager is registered, one of the ops is initial_header_size, which specifies how much buffer the write_init needs. So this call could fail if initial_header_size < streamsize. I suggest that you make the streamsize equal to the smallest multiple of PAGE_SIZE that is >= initial_header_size. > + start_flag = 0; > + if (ret) > + break; > + } > + > + /* > + * Write the FPGA image to the FPGA. > + */ Or this comment. > + mgr->state = FPGA_MGR_STATE_WRITE; > + ret = mgr->mops->write(mgr, fw->data, fw->size); > + if (ret) { > + dev_err(dev, "Error while writing image data to FPGA\n"); > + mgr->state = FPGA_MGR_STATE_WRITE_ERR; > + break; > + } > + > + offset += fw->size; > + size -= fw->size; > + if (fw->size < streamsize) > + break; > + } > + > + ret = fpga_mgr_write_complete(mgr, info); > + > + release_firmware(fw); > + return ret; > +} > +EXPORT_SYMBOL_GPL(fpga_mgr_firmware_stream); > + > int fpga_mgr_load(struct fpga_manager *mgr, struct fpga_image_info *info) > { > if (info->firmware_name) > diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h > index 0f5072c..a25362e 100644 > --- a/include/linux/fpga/fpga-mgr.h > +++ b/include/linux/fpga/fpga-mgr.h > @@ -151,6 +151,10 @@ int fpga_mgr_firmware_load(struct fpga_manager *mgr, > struct fpga_image_info *info, > const char *image_name); > > +int fpga_mgr_firmware_stream(struct fpga_manager *mgr, > + struct fpga_image_info *info, > + const char *image_name); Don't need both fpga_mgr_firmware_load and fpga_mgr_firmware_stream, so no need to change the header. > + > int fpga_mgr_load(struct fpga_manager *mgr, struct fpga_image_info *info); > > int fpga_mgr_lock(struct fpga_manager *mgr); > -- > 2.7.4 >