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Message-ID: <8351febc-2493-89c3-86ea-9e7660b6d3ee@redhat.com>
Date: Sat, 11 Sep 2021 06:13:08 -0700
From: Tom Rix <trix@...hat.com>
To: Russ Weight <russell.h.weight@...el.com>,
Xu Yilun <yilun.xu@...el.com>
Cc: mdf@...nel.org, linux-fpga@...r.kernel.org,
linux-kernel@...r.kernel.org, lgoncalv@...hat.com,
hao.wu@...el.com, matthew.gerlach@...el.com
Subject: Re: [PATCH v15 6/6] fpga: image-load: enable cancel of image upload
On 9/10/21 4:38 PM, Russ Weight wrote:
>
> On 9/10/21 7:55 AM, Xu Yilun wrote:
>> On Wed, Sep 08, 2021 at 07:18:46PM -0700, Russ Weight wrote:
>>> Extend the FPGA Image Load class driver to include a cancel IOCTL that
>>> can be used to request that an image upload be canceled. The IOCTL may
>>> return EBUSY if it cannot be canceled by software or ENODEV if there
>>> is no update in progress.
>>>
>>> Signed-off-by: Russ Weight <russell.h.weight@...el.com>
>>> ---
>>> v15:
>>> - Compare to previous patch:
>>> [PATCH v14 6/6] fpga: sec-mgr: enable cancel of secure update
>>> - Changed file, symbol, and config names to reflect the new driver name
>>> - Cancel is now initiated by IOCT instead of sysfs
>>> - Removed signed-off/reviewed-by tags
>>> v14:
>>> - Updated ABI documentation date and kernel version
>>> v13:
>>> - No change
>>> v12:
>>> - Updated Date and KernelVersion fields in ABI documentation
>>> v11:
>>> - No change
>>> v10:
>>> - Rebased to 5.12-rc2 next
>>> - Updated Date and KernelVersion in ABI documentation
>>> v9:
>>> - Updated Date and KernelVersion in ABI documentation
>>> v8:
>>> - No change
>>> v7:
>>> - Changed Date in documentation file to December 2020
>>> v6:
>>> - No change
>>> v5:
>>> - No change
>>> v4:
>>> - Changed from "Intel FPGA Security Manager" to FPGA Security Manager"
>>> and removed unnecessary references to "Intel".
>>> - Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
>>> v3:
>>> - No change
>>> v2:
>>> - Bumped documentation date and version
>>> - Minor code cleanup per review comments
>>> ---
>>> ---
>>> Documentation/fpga/fpga-image-load.rst | 6 ++++
>>> drivers/fpga/fpga-image-load.c | 45 +++++++++++++++++++++++---
>>> include/linux/fpga/fpga-image-load.h | 1 +
>>> include/uapi/linux/fpga-image-load.h | 1 +
>>> 4 files changed, 49 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/Documentation/fpga/fpga-image-load.rst b/Documentation/fpga/fpga-image-load.rst
>>> index 3d5eb51223e3..763e7833a6ea 100644
>>> --- a/Documentation/fpga/fpga-image-load.rst
>>> +++ b/Documentation/fpga/fpga-image-load.rst
>>> @@ -37,3 +37,9 @@ FPGA_IMAGE_LOAD_STATUS:
>>> Collect status for an on-going image upload. The status returned includes
>>> how much data remains to be transferred, the progress of the image load,
>>> and error information in the case of a failure.
>>> +
>>> +FPGA_IMAGE_LOAD_CANCEL:
>>> +
>>> +Request that a on-going image upload be cancelled. This IOCTL may return
>>> +EBUSY if it cannot be cancelled by software or ENODEV if there is no update
>>> +in progress.
>>> diff --git a/drivers/fpga/fpga-image-load.c b/drivers/fpga/fpga-image-load.c
>>> index 6ec0a39f07b3..c32e4b1ea35a 100644
>>> --- a/drivers/fpga/fpga-image-load.c
>>> +++ b/drivers/fpga/fpga-image-load.c
>>> @@ -46,6 +46,24 @@ static void fpga_image_dev_error(struct fpga_image_load *imgld,
>>> imgld->lops->cancel(imgld);
>>> }
>>>
>>> +static int fpga_image_prog_transition(struct fpga_image_load *imgld,
>>> + enum fpga_image_prog new_progress)
>>> +{
>>> + int ret = 0;
>>> +
>>> + mutex_lock(&imgld->lock);
>>> + if (imgld->request_cancel) {
>>> + imgld->err_progress = imgld->progress;
>>> + imgld->err_code = FPGA_IMAGE_ERR_CANCELED;
>>> + imgld->lops->cancel(imgld);
>>> + ret = -ECANCELED;
>>> + } else {
>>> + imgld->progress = new_progress;
>>> + }
>>> + mutex_unlock(&imgld->lock);
>>> + return ret;
>>> +}
>>> +
>>> static void fpga_image_prog_complete(struct fpga_image_load *imgld)
>>> {
>>> mutex_lock(&imgld->lock);
>>> @@ -77,8 +95,10 @@ static void fpga_image_do_load(struct work_struct *work)
>>> goto modput_exit;
>>> }
>>>
>>> - fpga_image_update_progress(imgld, FPGA_IMAGE_PROG_WRITING);
>>> - while (imgld->remaining_size) {
>>> + if (fpga_image_prog_transition(imgld, FPGA_IMAGE_PROG_WRITING))
>>> + goto done;
>>> +
>>> + while (imgld->remaining_size && !imgld->request_cancel) {
>>> ret = imgld->lops->write_blk(imgld, offset);
>>> if (ret != FPGA_IMAGE_ERR_NONE) {
>>> fpga_image_dev_error(imgld, ret);
>>> @@ -88,7 +108,9 @@ static void fpga_image_do_load(struct work_struct *work)
>>> offset = size - imgld->remaining_size;
>>> }
>>>
>>> - fpga_image_update_progress(imgld, FPGA_IMAGE_PROG_PROGRAMMING);
>>> + if (fpga_image_prog_transition(imgld, FPGA_IMAGE_PROG_PROGRAMMING))
>>> + goto done;
>>> +
>>> ret = imgld->lops->poll_complete(imgld);
>>> if (ret != FPGA_IMAGE_ERR_NONE)
>>> fpga_image_dev_error(imgld, ret);
>>> @@ -159,6 +181,7 @@ static int fpga_image_load_ioctl_write(struct fpga_image_load *imgld,
>>> imgld->remaining_size = wb.size;
>>> imgld->err_code = FPGA_IMAGE_ERR_NONE;
>>> imgld->progress = FPGA_IMAGE_PROG_STARTING;
>>> + imgld->request_cancel = false;
>>> reinit_completion(&imgld->update_done);
>>> schedule_work(&imgld->work);
>>> return 0;
>>> @@ -189,7 +212,7 @@ static long fpga_image_load_ioctl(struct file *filp, unsigned int cmd,
>>> unsigned long arg)
>>> {
>>> struct fpga_image_load *imgld = filp->private_data;
>>> - int ret = -ENOTTY;
>>> + int ret = 0;
>>>
>>> mutex_lock(&imgld->lock);
>>>
>>> @@ -200,6 +223,17 @@ static long fpga_image_load_ioctl(struct file *filp, unsigned int cmd,
>>> case FPGA_IMAGE_LOAD_STATUS:
>>> ret = fpga_image_load_ioctl_status(imgld, arg);
>>> break;
>>> + case FPGA_IMAGE_LOAD_CANCEL:
>>> + if (imgld->progress == FPGA_IMAGE_PROG_PROGRAMMING)
>>> + ret = -EBUSY;
>>> + else if (imgld->progress == FPGA_IMAGE_PROG_IDLE)
>>> + ret = -ENODEV;
>>> + else
>>> + imgld->request_cancel = true;
>>> + break;
>>> + default:
>>> + ret = -ENOTTY;
>>> + break;
>>> }
>>>
>>> mutex_unlock(&imgld->lock);
>>> @@ -374,6 +408,9 @@ void fpga_image_load_unregister(struct fpga_image_load *imgld)
>>> goto unregister;
>>> }
>>>
>>> + if (imgld->progress != FPGA_IMAGE_PROG_PROGRAMMING)
>>> + imgld->request_cancel = true;
>>> +
>> Why we cancel the programing rather than waiting for programing done?
> This isn't new - it is the way the security manager was implemented.
>
> Updates can take up to 40 minutes for the N3000. If a person tries
> to unload the driver modules, should we hang for 40 minutes? Or should
> we try to cancel the update and allow the module to be unloaded?
> I think it is reasonable to cancel the update (if possible) under these
> circumstances. What do you think?
I do not think stalling a shutdown for 40 minutes is good.
Is there a chance that cancelling would brick the card?
After restarting, can the hw detect an interrupted update ?
Tom
>
> - Russ
>
>> Thanks,
>> Yilun
>>
>>> mutex_unlock(&imgld->lock);
>>> wait_for_completion(&imgld->update_done);
>>>
>>> diff --git a/include/linux/fpga/fpga-image-load.h b/include/linux/fpga/fpga-image-load.h
>>> index 68f3105b51d2..4e51b9fd1724 100644
>>> --- a/include/linux/fpga/fpga-image-load.h
>>> +++ b/include/linux/fpga/fpga-image-load.h
>>> @@ -52,6 +52,7 @@ struct fpga_image_load {
>>> enum fpga_image_prog progress;
>>> enum fpga_image_prog err_progress; /* progress at time of failure */
>>> enum fpga_image_err err_code; /* image load error code */
>>> + bool request_cancel;
>>> bool driver_unload;
>>> struct eventfd_ctx *finished;
>>> void *priv;
>>> diff --git a/include/uapi/linux/fpga-image-load.h b/include/uapi/linux/fpga-image-load.h
>>> index 6a995bcc0fb7..8d0dfa1f9b77 100644
>>> --- a/include/uapi/linux/fpga-image-load.h
>>> +++ b/include/uapi/linux/fpga-image-load.h
>>> @@ -39,6 +39,7 @@ enum fpga_image_err {
>>>
>>> #define FPGA_IMAGE_LOAD_WRITE _IOW(FPGA_IMAGE_LOAD_MAGIC, 0, struct fpga_image_write)
>>> #define FPGA_IMAGE_LOAD_STATUS _IOR(FPGA_IMAGE_LOAD_MAGIC, 1, struct fpga_image_status)
>>> +#define FPGA_IMAGE_LOAD_CANCEL _IO(FPGA_IMAGE_LOAD_MAGIC, 2)
>>>
>>> /**
>>> * FPGA_IMAGE_LOAD_WRITE - _IOW(FPGA_IMAGE_LOAD_MAGIC, 0,
>>> --
>>> 2.25.1
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