| Message ID | 20240618100302.72886-4-paul@crapouillou.net (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | iio: new DMABUF based API v11 | expand |
Hi Paul, kernel test robot noticed the following build errors: [auto build test ERROR on jic23-iio/togreg] [also build test ERROR on vkoul-dmaengine/next linus/master v6.10-rc4 next-20240618] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Paul-Cercueil/dmaengine-Add-API-function-dmaengine_prep_peripheral_dma_vec/20240618-180602 base: https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg patch link: https://lore.kernel.org/r/20240618100302.72886-4-paul%40crapouillou.net patch subject: [PATCH v11 3/7] iio: core: Add new DMABUF interface infrastructure config: x86_64-randconfig-161-20240619 (https://download.01.org/0day-ci/archive/20240619/202406191014.9JAzwRV6-lkp@intel.com/config) compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240619/202406191014.9JAzwRV6-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202406191014.9JAzwRV6-lkp@intel.com/ All errors (new ones prefixed by >>): >> drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump from this goto statement to its label 1715 | goto err_dmabuf_unmap_attachment; | ^ drivers/iio/industrialio-buffer.c:1720:2: note: jump bypasses initialization of variable with __attribute__((cleanup)) 1720 | guard(mutex)(&buffer->dmabufs_mutex); | ^ include/linux/cleanup.h:164:15: note: expanded from macro 'guard' 164 | CLASS(_name, __UNIQUE_ID(guard)) | ^ include/linux/compiler.h:189:29: note: expanded from macro '__UNIQUE_ID' 189 | #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) | ^ include/linux/compiler_types.h:84:22: note: expanded from macro '__PASTE' 84 | #define __PASTE(a,b) ___PASTE(a,b) | ^ include/linux/compiler_types.h:83:23: note: expanded from macro '___PASTE' 83 | #define ___PASTE(a,b) a##b | ^ <scratch space>:126:1: note: expanded from here 126 | __UNIQUE_ID_guard696 | ^ drivers/iio/industrialio-buffer.c:1704:3: error: cannot jump from this goto statement to its label 1704 | goto err_resv_unlock; | ^ drivers/iio/industrialio-buffer.c:1720:2: note: jump bypasses initialization of variable with __attribute__((cleanup)) 1720 | guard(mutex)(&buffer->dmabufs_mutex); | ^ include/linux/cleanup.h:164:15: note: expanded from macro 'guard' 164 | CLASS(_name, __UNIQUE_ID(guard)) | ^ include/linux/compiler.h:189:29: note: expanded from macro '__UNIQUE_ID' 189 | #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) | ^ include/linux/compiler_types.h:84:22: note: expanded from macro '__PASTE' 84 | #define __PASTE(a,b) ___PASTE(a,b) | ^ include/linux/compiler_types.h:83:23: note: expanded from macro '___PASTE' 83 | #define ___PASTE(a,b) a##b | ^ <scratch space>:126:1: note: expanded from here 126 | __UNIQUE_ID_guard696 | ^ drivers/iio/industrialio-buffer.c:1695:3: error: cannot jump from this goto statement to its label 1695 | goto err_dmabuf_detach; | ^ drivers/iio/industrialio-buffer.c:1720:2: note: jump bypasses initialization of variable with __attribute__((cleanup)) 1720 | guard(mutex)(&buffer->dmabufs_mutex); | ^ include/linux/cleanup.h:164:15: note: expanded from macro 'guard' 164 | CLASS(_name, __UNIQUE_ID(guard)) | ^ include/linux/compiler.h:189:29: note: expanded from macro '__UNIQUE_ID' 189 | #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) | ^ include/linux/compiler_types.h:84:22: note: expanded from macro '__PASTE' 84 | #define __PASTE(a,b) ___PASTE(a,b) | ^ include/linux/compiler_types.h:83:23: note: expanded from macro '___PASTE' 83 | #define ___PASTE(a,b) a##b | ^ <scratch space>:126:1: note: expanded from here 126 | __UNIQUE_ID_guard696 | ^ drivers/iio/industrialio-buffer.c:1690:3: error: cannot jump from this goto statement to its label 1690 | goto err_dmabuf_put; | ^ drivers/iio/industrialio-buffer.c:1720:2: note: jump bypasses initialization of variable with __attribute__((cleanup)) 1720 | guard(mutex)(&buffer->dmabufs_mutex); | ^ include/linux/cleanup.h:164:15: note: expanded from macro 'guard' 164 | CLASS(_name, __UNIQUE_ID(guard)) | ^ include/linux/compiler.h:189:29: note: expanded from macro '__UNIQUE_ID' 189 | #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) | ^ include/linux/compiler_types.h:84:22: note: expanded from macro '__PASTE' 84 | #define __PASTE(a,b) ___PASTE(a,b) | ^ include/linux/compiler_types.h:83:23: note: expanded from macro '___PASTE' 83 | #define ___PASTE(a,b) a##b | ^ <scratch space>:126:1: note: expanded from here 126 | __UNIQUE_ID_guard696 | ^ drivers/iio/industrialio-buffer.c:1684:3: error: cannot jump from this goto statement to its label 1684 | goto err_free_priv; | ^ drivers/iio/industrialio-buffer.c:1720:2: note: jump bypasses initialization of variable with __attribute__((cleanup)) 1720 | guard(mutex)(&buffer->dmabufs_mutex); | ^ include/linux/cleanup.h:164:15: note: expanded from macro 'guard' 164 | CLASS(_name, __UNIQUE_ID(guard)) | ^ include/linux/compiler.h:189:29: note: expanded from macro '__UNIQUE_ID' 189 | #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) | ^ include/linux/compiler_types.h:84:22: note: expanded from macro '__PASTE' 84 | #define __PASTE(a,b) ___PASTE(a,b) | ^ include/linux/compiler_types.h:83:23: note: expanded from macro '___PASTE' 83 | #define ___PASTE(a,b) a##b vim +1715 drivers/iio/industrialio-buffer.c 1655 1656 static int iio_buffer_attach_dmabuf(struct iio_dev_buffer_pair *ib, 1657 int __user *user_fd, bool nonblock) 1658 { 1659 struct iio_dev *indio_dev = ib->indio_dev; 1660 struct iio_buffer *buffer = ib->buffer; 1661 struct dma_buf_attachment *attach; 1662 struct iio_dmabuf_priv *priv, *each; 1663 struct dma_buf *dmabuf; 1664 int err, fd; 1665 1666 if (!buffer->access->attach_dmabuf 1667 || !buffer->access->detach_dmabuf 1668 || !buffer->access->enqueue_dmabuf) 1669 return -EPERM; 1670 1671 if (copy_from_user(&fd, user_fd, sizeof(fd))) 1672 return -EFAULT; 1673 1674 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 1675 if (!priv) 1676 return -ENOMEM; 1677 1678 spin_lock_init(&priv->lock); 1679 priv->context = dma_fence_context_alloc(1); 1680 1681 dmabuf = dma_buf_get(fd); 1682 if (IS_ERR(dmabuf)) { 1683 err = PTR_ERR(dmabuf); 1684 goto err_free_priv; 1685 } 1686 1687 attach = dma_buf_attach(dmabuf, indio_dev->dev.parent); 1688 if (IS_ERR(attach)) { 1689 err = PTR_ERR(attach); 1690 goto err_dmabuf_put; 1691 } 1692 1693 err = iio_dma_resv_lock(dmabuf, nonblock); 1694 if (err) 1695 goto err_dmabuf_detach; 1696 1697 priv->dir = buffer->direction == IIO_BUFFER_DIRECTION_IN 1698 ? DMA_FROM_DEVICE : DMA_TO_DEVICE; 1699 1700 priv->sgt = dma_buf_map_attachment(attach, priv->dir); 1701 if (IS_ERR(priv->sgt)) { 1702 err = PTR_ERR(priv->sgt); 1703 dev_err(&indio_dev->dev, "Unable to map attachment: %d\n", err); 1704 goto err_resv_unlock; 1705 } 1706 1707 kref_init(&priv->ref); 1708 priv->buffer = buffer; 1709 priv->attach = attach; 1710 attach->importer_priv = priv; 1711 1712 priv->block = buffer->access->attach_dmabuf(buffer, attach); 1713 if (IS_ERR(priv->block)) { 1714 err = PTR_ERR(priv->block); > 1715 goto err_dmabuf_unmap_attachment; 1716 } 1717 1718 dma_resv_unlock(dmabuf->resv); 1719 1720 guard(mutex)(&buffer->dmabufs_mutex); 1721 1722 /* 1723 * Check whether we already have an attachment for this driver/DMABUF 1724 * combo. If we do, refuse to attach. 1725 */ 1726 list_for_each_entry(each, &buffer->dmabufs, entry) { 1727 if (each->attach->dev == indio_dev->dev.parent 1728 && each->attach->dmabuf == dmabuf) { 1729 /* 1730 * We unlocked the reservation object, so going through 1731 * the cleanup code would mean re-locking it first. 1732 * At this stage it is simpler to free the attachment 1733 * using iio_buffer_dma_put(). 1734 */ 1735 iio_buffer_dmabuf_put(attach); 1736 return -EBUSY; 1737 } 1738 } 1739 1740 /* Otherwise, add the new attachment to our dmabufs list. */ 1741 list_add(&priv->entry, &buffer->dmabufs); 1742 1743 return 0; 1744 1745 err_dmabuf_unmap_attachment: 1746 dma_buf_unmap_attachment(attach, priv->sgt, priv->dir); 1747 err_resv_unlock: 1748 dma_resv_unlock(dmabuf->resv); 1749 err_dmabuf_detach: 1750 dma_buf_detach(dmabuf, attach); 1751 err_dmabuf_put: 1752 dma_buf_put(dmabuf); 1753 err_free_priv: 1754 kfree(priv); 1755 1756 return err; 1757 } 1758
On Wed, 2024-06-19 at 11:15 +0800, kernel test robot wrote: > Hi Paul, > > kernel test robot noticed the following build errors: > > [auto build test ERROR on jic23-iio/togreg] > [also build test ERROR on vkoul-dmaengine/next linus/master v6.10-rc4 next- > 20240618] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: > https://github.com/intel-lab-lkp/linux/commits/Paul-Cercueil/dmaengine-Add-API-function-dmaengine_prep_peripheral_dma_vec/20240618-180602 > base: https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg > patch link: > https://lore.kernel.org/r/20240618100302.72886-4-paul%40crapouillou.net > patch subject: [PATCH v11 3/7] iio: core: Add new DMABUF interface infrastructure > config: x86_64-randconfig-161-20240619 > (https://download.01.org/0day-ci/archive/20240619/202406191014.9JAzwRV6-lkp@intel.c > om/config) > compiler: clang version 18.1.5 > (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1) > reproduce (this is a W=1 build): > (https://download.01.org/0day-ci/archive/20240619/202406191014.9JAzwRV6-lkp@intel.c > om/reproduce) > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > > Reported-by: kernel test robot <lkp@intel.com> > > Closes: > > https://lore.kernel.org/oe-kbuild-all/202406191014.9JAzwRV6-lkp@intel.com/ > > All errors (new ones prefixed by >>): > > > > drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump from this goto > > > statement to its label > 1715 | goto err_dmabuf_unmap_attachment; > | ^ > drivers/iio/industrialio-buffer.c:1720:2: note: jump bypasses initialization of I guess the compiler produces code that will run the cleanup function on an uninitialized variable. I would then go back to plain mutex() instead of moving guard() to a place where it does not make sense only to shut up the warnings. - Nuno Sá
… > All errors (new ones prefixed by >>): > > >> drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump from this goto statement to its label > 1715 | goto err_dmabuf_unmap_attachment; … Would you dare to transform the remaining goto chain into further applications of scope-based resource management? Regards, Markus
Hi Markus, Le mercredi 19 juin 2024 à 12:03 +0200, Markus Elfring a écrit : > … > > All errors (new ones prefixed by >>): > > > > > > drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump > > > > from this goto statement to its label > > 1715 | goto err_dmabuf_unmap_attachment; > … > > Would you dare to transform the remaining goto chain into further > applications > of scope-based resource management? We discussed this after v6 or v7, DRM/DMABUF maintainers were not keen on doing that *just yet*. Cheers, -Paul
>> Would you dare to transform the remaining goto chain into further applications >> of scope-based resource management? > > We discussed this after v6 or v7, DRM/DMABUF maintainers were not keen > on doing that *just yet*. * Would you like to add any links for corresponding development discussions? * Will the desire grow for further collateral evolution according to affected software components? Regards, Markus
Le mercredi 19 juin 2024 à 13:13 +0200, Markus Elfring a écrit : > > > Would you dare to transform the remaining goto chain into further > > > applications > > > of scope-based resource management? > > > > We discussed this after v6 or v7, DRM/DMABUF maintainers were not > > keen > > on doing that *just yet*. > > * Would you like to add any links for corresponding development > discussions? https://lore.kernel.org/linux-iio/219abc43b4fdd4a13b307ed2efaa0e6869e68e3f.camel@gmail.com/T/#eefd360069c4261aec9621fafde30924706571c94 (and responses below) It's more nuanced than I remembered. Christian was OK to add cleanup.h support to the DMABUF code as long as the examples were updated as well, but those aren't good candidates as they don't free up the resources in all code paths. > > * Will the desire grow for further collateral evolution according to > affected software components? Not sure what you mean by that. Cheers, -Paul
… > +++ b/drivers/iio/industrialio-buffer.c … > +static void iio_buffer_dmabuf_release(struct kref *ref) > +{ … > + dma_resv_lock(dmabuf->resv, NULL); > + dma_buf_unmap_attachment(attach, priv->sgt, priv->dir); > + dma_resv_unlock(dmabuf->resv); … Under which circumstances will another lock guard become applicable? https://elixir.bootlin.com/linux/v6.10-rc4/source/include/linux/cleanup.h#L179 Regards, Markus
… > https://lore.kernel.org/linux-iio/219abc43b4fdd4a13b307ed2efaa0e6869e68e3f.camel@gmail.com/T/#eefd360069c4261aec9621fafde30924706571c94 > > (and responses below) > > It's more nuanced than I remembered. … >> * Will the desire grow for further collateral evolution according to >> affected software components? > > Not sure what you mean by that. Advanced programming interfaces were added a while ago. Example: https://elixir.bootlin.com/linux/v6.10-rc4/source/include/linux/cleanup.h#L8 Corresponding attempts for increasing API usage need to adapt to remaining change reluctance, don't they? Regards, Markus
Le mercredi 19 juin 2024 à 13:43 +0200, Markus Elfring a écrit : > … > > +++ b/drivers/iio/industrialio-buffer.c > … > > +static void iio_buffer_dmabuf_release(struct kref *ref) > > +{ > … > > + dma_resv_lock(dmabuf->resv, NULL); > > + dma_buf_unmap_attachment(attach, priv->sgt, priv->dir); > > + dma_resv_unlock(dmabuf->resv); > … > > Under which circumstances will another lock guard become applicable? > https://elixir.bootlin.com/linux/v6.10-rc4/source/include/linux/cleanup.h#L179 As soon as "struct dma_resv" gets a DEFINE_GUARD(). -Paul
Le mercredi 19 juin 2024 à 13:56 +0200, Markus Elfring a écrit : > … > > https://lore.kernel.org/linux-iio/219abc43b4fdd4a13b307ed2efaa0e6869e68e3f.camel@gmail.com/T/#eefd360069c4261aec9621fafde30924706571c94 > > > > (and responses below) > > > > It's more nuanced than I remembered. > … > > > > > * Will the desire grow for further collateral evolution according > > > to > > > affected software components? > > > > Not sure what you mean by that. > > Advanced programming interfaces were added a while ago. > > Example: > https://elixir.bootlin.com/linux/v6.10-rc4/source/include/linux/cleanup.h#L8 > > Corresponding attempts for increasing API usage need to adapt to > remaining change reluctance, > don't they? Sure, I guess. But that does not change the fact that I cannot use cleanup.h magic in this patchset, yet, as the required changes would have to be done in a separate one. Cheers, -Paul
On Wed, 2024-06-19 at 14:21 +0200, Paul Cercueil wrote: > Le mercredi 19 juin 2024 à 13:56 +0200, Markus Elfring a écrit : > > … > > > https://lore.kernel.org/linux-iio/219abc43b4fdd4a13b307ed2efaa0e6869e68e3f.camel@gmail.com/T/#eefd360069c4261aec9621fafde30924706571c94 > > > > > > (and responses below) > > > > > > It's more nuanced than I remembered. > > … > > > > > > > > * Will the desire grow for further collateral evolution according > > > > to > > > > affected software components? > > > > > > Not sure what you mean by that. > > > > Advanced programming interfaces were added a while ago. > > > > Example: > > https://elixir.bootlin.com/linux/v6.10-rc4/source/include/linux/cleanup.h#L8 > > > > Corresponding attempts for increasing API usage need to adapt to > > remaining change reluctance, > > don't they? > > Sure, I guess. > > But that does not change the fact that I cannot use cleanup.h magic in > this patchset, yet, as the required changes would have to be done in a > separate one. > > Not to speak on the added churn in doing that now. This is already v11 and complicated enough for us to add another dependency. Moreover, yes, cleanup stuff is very nice but if some interface/API does not support it, it's not up to the developer using that interface/API on some other patch series to add support for it. - Nuno Sá
>> … >>> +++ b/drivers/iio/industrialio-buffer.c >> … >>> +static void iio_buffer_dmabuf_release(struct kref *ref) >>> +{ >> … >>> + dma_resv_lock(dmabuf->resv, NULL); >>> + dma_buf_unmap_attachment(attach, priv->sgt, priv->dir); >>> + dma_resv_unlock(dmabuf->resv); >> … >> >> Under which circumstances will another lock guard become applicable? >> https://elixir.bootlin.com/linux/v6.10-rc4/source/include/linux/cleanup.h#L179 > > As soon as "struct dma_resv" gets a DEFINE_GUARD(). Would any contributor like to add a macro call accordingly? Regards, Markus
… > All errors (new ones prefixed by >>): > >>> drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump from this goto statement to its label > 1715 | goto err_dmabuf_unmap_attachment; … Which software design options would you like to try out next so that such a questionable compilation error message will be avoided finally? Regards, Markus
On 20-06-24, 12:45, Markus Elfring wrote: > … > > All errors (new ones prefixed by >>): > > > >>> drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump from this goto statement to its label > > 1715 | goto err_dmabuf_unmap_attachment; > … > > Which software design options would you like to try out next > so that such a questionable compilation error message will be avoided finally? The one where all emails from Markus go to dev/null
On Thu, 20 Jun 2024, Vinod Koul wrote: > On 20-06-24, 12:45, Markus Elfring wrote: > > … > > > All errors (new ones prefixed by >>): > > > > > >>> drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump from this goto statement to its label > > > 1715 | goto err_dmabuf_unmap_attachment; > > … > > > > Which software design options would you like to try out next > > so that such a questionable compilation error message will be avoided finally? > > The one where all emails from Markus go to dev/null Play nice please. Documentation/process/code-of-conduct.rst
On 20-06-24, 18:05, Lee Jones wrote: > On Thu, 20 Jun 2024, Vinod Koul wrote: > > > On 20-06-24, 12:45, Markus Elfring wrote: > > > … > > > > All errors (new ones prefixed by >>): > > > > > > > >>> drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump from this goto statement to its label > > > > 1715 | goto err_dmabuf_unmap_attachment; > > > … > > > > > > Which software design options would you like to try out next > > > so that such a questionable compilation error message will be avoided finally? > > > > The one where all emails from Markus go to dev/null > > Play nice please. Would love to... but Markus has been repeat offender Sadly, I am yet to see a constructive approach or even better a helpful patch which improve something, rather than vague suggestions on the list
On Fri, 2024-06-21 at 12:39 +0530, Vinod Koul wrote: > On 20-06-24, 18:05, Lee Jones wrote: > > On Thu, 20 Jun 2024, Vinod Koul wrote: > > > > > On 20-06-24, 12:45, Markus Elfring wrote: > > > > … > > > > > All errors (new ones prefixed by >>): > > > > > > > > > > > > drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump from > > > > > > > this goto statement to its label > > > > > 1715 | goto err_dmabuf_unmap_attachment; > > > > … > > > > > > > > Which software design options would you like to try out next > > > > so that such a questionable compilation error message will be avoided > > > > finally? > > > > > > The one where all emails from Markus go to dev/null > > > > Play nice please. > > Would love to... but Markus has been repeat offender > > Sadly, I am yet to see a constructive approach or even better a helpful > patch which improve something, rather than vague suggestions on the list > Yeah, just look at how many automatic replies he get's from Greg pretty much saying to ignore his comments. - Nuno Sá
> Sadly, I am yet to see a constructive approach or even better a helpful > patch which improve something, rather than vague suggestions on the list Can you get any more constructive impressions from another data representation? https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=author&q=Elfring Are you aware how many change suggestions (also from my selection) are still in various waiting queues? Regards, Markus
> Yeah, just look at how many automatic replies he get's from Greg pretty much > saying to ignore his comments. Does your feedback just indicate recurring communication difficulties? Regards, Markus
On Fri, 21 Jun 2024, Nuno Sá wrote: > On Fri, 2024-06-21 at 12:39 +0530, Vinod Koul wrote: > > On 20-06-24, 18:05, Lee Jones wrote: > > > On Thu, 20 Jun 2024, Vinod Koul wrote: > > > > > > > On 20-06-24, 12:45, Markus Elfring wrote: > > > > > … > > > > > > All errors (new ones prefixed by >>): > > > > > > > > > > > > > > drivers/iio/industrialio-buffer.c:1715:3: error: cannot jump from > > > > > > > > this goto statement to its label > > > > > > 1715 | goto err_dmabuf_unmap_attachment; > > > > > … > > > > > > > > > > Which software design options would you like to try out next > > > > > so that such a questionable compilation error message will be avoided > > > > > finally? > > > > > > > > The one where all emails from Markus go to dev/null > > > > > > Play nice please. > > > > Would love to... but Markus has been repeat offender > > > > Sadly, I am yet to see a constructive approach or even better a helpful > > patch which improve something, rather than vague suggestions on the list Right, there are communication issues. Doesn't mean we have to lower our own standards. > Yeah, just look at how many automatic replies he get's from Greg pretty much > saying to ignore his comments. Yes, Greg is also grumpy about it, but at least he remains polite.
On Fri, 21 Jun 2024, Markus Elfring wrote: > > Sadly, I am yet to see a constructive approach or even better a helpful > > patch which improve something, rather than vague suggestions on the list > > Can you get any more constructive impressions from another data representation? > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=author&q=Elfring > > Are you aware how many change suggestions (also from my selection) are still > in various waiting queues? No one is doubting your overall contributions Markus. The issue is one of communication and the way reviews are conducted. Reviewing other people's work is challenging and requires a certain skill-set, of which _excellent_ communication skills are non-negotiable. Why not concentrate on more complex submissions for a while and grow your repertoire of common review points, rather than repeating the same few over and over? Reading other, more experienced maintainer's reviews would also be a good use of your time.
> The issue is one of communication and the way reviews are conducted. > > Reviewing other people's work is challenging and requires a certain > skill-set, of which _excellent_ communication skills are non-negotiable. Patch feedback and change tolerance can vary also according to involved communities. > Why not concentrate on more complex submissions for a while and grow > your repertoire of common review points, Further collateral evolution can be considered there depending on corresponding development resources. > rather than repeating the same few over and over? Some factors are probably known also according to corresponding statistics. Several contributors are stumbling on recurring improvement possibilities in published information. > Reading other, more experienced maintainer's reviews would also be a good use > of your time. I am trying to influence adjustments in desirable directions for a while. Regards, Markus
On Fri, 21 Jun 2024, Markus Elfring wrote: > > The issue is one of communication and the way reviews are conducted. > > > > Reviewing other people's work is challenging and requires a certain > > skill-set, of which _excellent_ communication skills are non-negotiable. > > Patch feedback and change tolerance can vary also according to involved communities. Agreed. For this community, I suggest you build your skills for a while longer. > > Why not concentrate on more complex submissions for a while and grow > > your repertoire of common review points, > > Further collateral evolution can be considered there depending on > corresponding development resources. > > > rather than repeating the same few over and over? > > Some factors are probably known also according to corresponding statistics. > Several contributors are stumbling on recurring improvement possibilities > in published information. Right, this will always be true, however the few you've picked up on are not important enough to keep reiterating. By doing so, you're receiving undesirable attention. > > Reading other, more experienced maintainer's reviews would also be a good use > > of your time. > > I am trying to influence adjustments in desirable directions for a while. Never stop trying to improve. These are only my opinions of course. Take the advice or leave it. There's no need to reply to this.
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig index 9c351ffc7bed..661127aed2f9 100644 --- a/drivers/iio/Kconfig +++ b/drivers/iio/Kconfig @@ -14,6 +14,7 @@ if IIO config IIO_BUFFER bool "Enable buffer support within IIO" + select DMA_SHARED_BUFFER help Provide core support for various buffer based data acquisition methods. diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 0138b21b244f..2c36354adc9e 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -9,15 +9,20 @@ * - Better memory allocation techniques? * - Alternative access techniques? */ +#include <linux/atomic.h> #include <linux/anon_inodes.h> #include <linux/cleanup.h> #include <linux/kernel.h> #include <linux/export.h> #include <linux/device.h> +#include <linux/dma-buf.h> +#include <linux/dma-fence.h> +#include <linux/dma-resv.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/cdev.h> #include <linux/slab.h> +#include <linux/mm.h> #include <linux/poll.h> #include <linux/sched/signal.h> @@ -29,6 +34,34 @@ #include <linux/iio/buffer.h> #include <linux/iio/buffer_impl.h> +#define DMABUF_ENQUEUE_TIMEOUT_MS 5000 + +MODULE_IMPORT_NS(DMA_BUF); + +struct iio_dmabuf_priv { + struct list_head entry; + struct kref ref; + + struct iio_buffer *buffer; + struct iio_dma_buffer_block *block; + + u64 context; + + /* Spinlock used for locking the dma_fence */ + spinlock_t lock; + + struct dma_buf_attachment *attach; + struct sg_table *sgt; + enum dma_data_direction dir; + atomic_t seqno; +}; + +struct iio_dma_fence { + struct dma_fence base; + struct iio_dmabuf_priv *priv; + struct work_struct work; +}; + static const char * const iio_endian_prefix[] = { [IIO_BE] = "be", [IIO_LE] = "le", @@ -333,6 +366,8 @@ void iio_buffer_init(struct iio_buffer *buffer) { INIT_LIST_HEAD(&buffer->demux_list); INIT_LIST_HEAD(&buffer->buffer_list); + INIT_LIST_HEAD(&buffer->dmabufs); + mutex_init(&buffer->dmabufs_mutex); init_waitqueue_head(&buffer->pollq); kref_init(&buffer->ref); if (!buffer->watermark) @@ -1526,14 +1561,55 @@ static void iio_buffer_unregister_legacy_sysfs_groups(struct iio_dev *indio_dev) kfree(iio_dev_opaque->legacy_scan_el_group.attrs); } +static void iio_buffer_dmabuf_release(struct kref *ref) +{ + struct iio_dmabuf_priv *priv = container_of(ref, struct iio_dmabuf_priv, ref); + struct dma_buf_attachment *attach = priv->attach; + struct iio_buffer *buffer = priv->buffer; + struct dma_buf *dmabuf = attach->dmabuf; + + dma_resv_lock(dmabuf->resv, NULL); + dma_buf_unmap_attachment(attach, priv->sgt, priv->dir); + dma_resv_unlock(dmabuf->resv); + + buffer->access->detach_dmabuf(buffer, priv->block); + + dma_buf_detach(attach->dmabuf, attach); + dma_buf_put(dmabuf); + kfree(priv); +} + +static void iio_buffer_dmabuf_get(struct dma_buf_attachment *attach) +{ + struct iio_dmabuf_priv *priv = attach->importer_priv; + + kref_get(&priv->ref); +} + +static void iio_buffer_dmabuf_put(struct dma_buf_attachment *attach) +{ + struct iio_dmabuf_priv *priv = attach->importer_priv; + + kref_put(&priv->ref, iio_buffer_dmabuf_release); +} + static int iio_buffer_chrdev_release(struct inode *inode, struct file *filep) { struct iio_dev_buffer_pair *ib = filep->private_data; struct iio_dev *indio_dev = ib->indio_dev; struct iio_buffer *buffer = ib->buffer; + struct iio_dmabuf_priv *priv, *tmp; wake_up(&buffer->pollq); + guard(mutex)(&buffer->dmabufs_mutex); + + /* Close all attached DMABUFs */ + list_for_each_entry_safe(priv, tmp, &buffer->dmabufs, entry) { + list_del_init(&priv->entry); + iio_buffer_dmabuf_put(priv->attach); + } + kfree(ib); clear_bit(IIO_BUSY_BIT_POS, &buffer->flags); iio_device_put(indio_dev); @@ -1541,11 +1617,391 @@ static int iio_buffer_chrdev_release(struct inode *inode, struct file *filep) return 0; } +static int iio_dma_resv_lock(struct dma_buf *dmabuf, bool nonblock) +{ + if (!nonblock) + return dma_resv_lock_interruptible(dmabuf->resv, NULL); + + if (!dma_resv_trylock(dmabuf->resv)) + return -EBUSY; + + return 0; +} + +static struct dma_buf_attachment * +iio_buffer_find_attachment(struct iio_dev_buffer_pair *ib, + struct dma_buf *dmabuf, bool nonblock) +{ + struct device *dev = ib->indio_dev->dev.parent; + struct iio_buffer *buffer = ib->buffer; + struct dma_buf_attachment *attach = NULL; + struct iio_dmabuf_priv *priv; + + guard(mutex)(&buffer->dmabufs_mutex); + + list_for_each_entry(priv, &buffer->dmabufs, entry) { + if (priv->attach->dev == dev + && priv->attach->dmabuf == dmabuf) { + attach = priv->attach; + break; + } + } + + if (attach) + iio_buffer_dmabuf_get(attach); + + return attach ?: ERR_PTR(-EPERM); +} + +static int iio_buffer_attach_dmabuf(struct iio_dev_buffer_pair *ib, + int __user *user_fd, bool nonblock) +{ + struct iio_dev *indio_dev = ib->indio_dev; + struct iio_buffer *buffer = ib->buffer; + struct dma_buf_attachment *attach; + struct iio_dmabuf_priv *priv, *each; + struct dma_buf *dmabuf; + int err, fd; + + if (!buffer->access->attach_dmabuf + || !buffer->access->detach_dmabuf + || !buffer->access->enqueue_dmabuf) + return -EPERM; + + if (copy_from_user(&fd, user_fd, sizeof(fd))) + return -EFAULT; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + spin_lock_init(&priv->lock); + priv->context = dma_fence_context_alloc(1); + + dmabuf = dma_buf_get(fd); + if (IS_ERR(dmabuf)) { + err = PTR_ERR(dmabuf); + goto err_free_priv; + } + + attach = dma_buf_attach(dmabuf, indio_dev->dev.parent); + if (IS_ERR(attach)) { + err = PTR_ERR(attach); + goto err_dmabuf_put; + } + + err = iio_dma_resv_lock(dmabuf, nonblock); + if (err) + goto err_dmabuf_detach; + + priv->dir = buffer->direction == IIO_BUFFER_DIRECTION_IN + ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + + priv->sgt = dma_buf_map_attachment(attach, priv->dir); + if (IS_ERR(priv->sgt)) { + err = PTR_ERR(priv->sgt); + dev_err(&indio_dev->dev, "Unable to map attachment: %d\n", err); + goto err_resv_unlock; + } + + kref_init(&priv->ref); + priv->buffer = buffer; + priv->attach = attach; + attach->importer_priv = priv; + + priv->block = buffer->access->attach_dmabuf(buffer, attach); + if (IS_ERR(priv->block)) { + err = PTR_ERR(priv->block); + goto err_dmabuf_unmap_attachment; + } + + dma_resv_unlock(dmabuf->resv); + + guard(mutex)(&buffer->dmabufs_mutex); + + /* + * Check whether we already have an attachment for this driver/DMABUF + * combo. If we do, refuse to attach. + */ + list_for_each_entry(each, &buffer->dmabufs, entry) { + if (each->attach->dev == indio_dev->dev.parent + && each->attach->dmabuf == dmabuf) { + /* + * We unlocked the reservation object, so going through + * the cleanup code would mean re-locking it first. + * At this stage it is simpler to free the attachment + * using iio_buffer_dma_put(). + */ + iio_buffer_dmabuf_put(attach); + return -EBUSY; + } + } + + /* Otherwise, add the new attachment to our dmabufs list. */ + list_add(&priv->entry, &buffer->dmabufs); + + return 0; + +err_dmabuf_unmap_attachment: + dma_buf_unmap_attachment(attach, priv->sgt, priv->dir); +err_resv_unlock: + dma_resv_unlock(dmabuf->resv); +err_dmabuf_detach: + dma_buf_detach(dmabuf, attach); +err_dmabuf_put: + dma_buf_put(dmabuf); +err_free_priv: + kfree(priv); + + return err; +} + +static int iio_buffer_detach_dmabuf(struct iio_dev_buffer_pair *ib, + int __user *user_req, bool nonblock) +{ + struct iio_buffer *buffer = ib->buffer; + struct iio_dev *indio_dev = ib->indio_dev; + struct iio_dmabuf_priv *priv; + struct dma_buf *dmabuf; + int dmabuf_fd, ret = -EPERM; + + if (copy_from_user(&dmabuf_fd, user_req, sizeof(dmabuf_fd))) + return -EFAULT; + + dmabuf = dma_buf_get(dmabuf_fd); + if (IS_ERR(dmabuf)) + return PTR_ERR(dmabuf); + + guard(mutex)(&buffer->dmabufs_mutex); + + list_for_each_entry(priv, &buffer->dmabufs, entry) { + if (priv->attach->dev == indio_dev->dev.parent + && priv->attach->dmabuf == dmabuf) { + list_del(&priv->entry); + + /* Unref the reference from iio_buffer_attach_dmabuf() */ + iio_buffer_dmabuf_put(priv->attach); + ret = 0; + break; + } + } + + dma_buf_put(dmabuf); + + return ret; +} + +static const char * +iio_buffer_dma_fence_get_driver_name(struct dma_fence *fence) +{ + return "iio"; +} + +static void iio_buffer_dma_fence_release(struct dma_fence *fence) +{ + struct iio_dma_fence *iio_fence = + container_of(fence, struct iio_dma_fence, base); + + kfree(iio_fence); +} + +static const struct dma_fence_ops iio_buffer_dma_fence_ops = { + .get_driver_name = iio_buffer_dma_fence_get_driver_name, + .get_timeline_name = iio_buffer_dma_fence_get_driver_name, + .release = iio_buffer_dma_fence_release, +}; + +static int iio_buffer_enqueue_dmabuf(struct iio_dev_buffer_pair *ib, + struct iio_dmabuf __user *iio_dmabuf_req, + bool nonblock) +{ + struct iio_buffer *buffer = ib->buffer; + struct iio_dmabuf iio_dmabuf; + struct dma_buf_attachment *attach; + struct iio_dmabuf_priv *priv; + struct iio_dma_fence *fence; + struct dma_buf *dmabuf; + unsigned long timeout; + bool cookie, cyclic, dma_to_ram; + long retl; + u32 seqno; + int ret; + + if (copy_from_user(&iio_dmabuf, iio_dmabuf_req, sizeof(iio_dmabuf))) + return -EFAULT; + + if (iio_dmabuf.flags & ~IIO_BUFFER_DMABUF_SUPPORTED_FLAGS) + return -EINVAL; + + cyclic = iio_dmabuf.flags & IIO_BUFFER_DMABUF_CYCLIC; + + /* Cyclic flag is only supported on output buffers */ + if (cyclic && buffer->direction != IIO_BUFFER_DIRECTION_OUT) + return -EINVAL; + + dmabuf = dma_buf_get(iio_dmabuf.fd); + if (IS_ERR(dmabuf)) + return PTR_ERR(dmabuf); + + if (!iio_dmabuf.bytes_used || iio_dmabuf.bytes_used > dmabuf->size) { + ret = -EINVAL; + goto err_dmabuf_put; + } + + attach = iio_buffer_find_attachment(ib, dmabuf, nonblock); + if (IS_ERR(attach)) { + ret = PTR_ERR(attach); + goto err_dmabuf_put; + } + + priv = attach->importer_priv; + + fence = kmalloc(sizeof(*fence), GFP_KERNEL); + if (!fence) { + ret = -ENOMEM; + goto err_attachment_put; + } + + fence->priv = priv; + + seqno = atomic_add_return(1, &priv->seqno); + + /* + * The transfers are guaranteed to be processed in the order they are + * enqueued, so we can use a simple incrementing sequence number for + * the dma_fence. + */ + dma_fence_init(&fence->base, &iio_buffer_dma_fence_ops, + &priv->lock, priv->context, seqno); + + ret = iio_dma_resv_lock(dmabuf, nonblock); + if (ret) + goto err_fence_put; + + timeout = nonblock ? 0 : msecs_to_jiffies(DMABUF_ENQUEUE_TIMEOUT_MS); + dma_to_ram = buffer->direction == IIO_BUFFER_DIRECTION_IN; + + /* Make sure we don't have writers */ + retl = dma_resv_wait_timeout(dmabuf->resv, + dma_resv_usage_rw(dma_to_ram), + true, timeout); + if (retl == 0) + retl = -EBUSY; + if (retl < 0) { + ret = (int)retl; + goto err_resv_unlock; + } + + if (buffer->access->lock_queue) + buffer->access->lock_queue(buffer); + + ret = dma_resv_reserve_fences(dmabuf->resv, 1); + if (ret) + goto err_queue_unlock; + + dma_resv_add_fence(dmabuf->resv, &fence->base, + dma_to_ram ? DMA_RESV_USAGE_WRITE : DMA_RESV_USAGE_READ); + dma_resv_unlock(dmabuf->resv); + + cookie = dma_fence_begin_signalling(); + + ret = buffer->access->enqueue_dmabuf(buffer, priv->block, &fence->base, + priv->sgt, iio_dmabuf.bytes_used, + cyclic); + if (ret) { + /* + * DMABUF enqueue failed, but we already added the fence. + * Signal the error through the fence completion mechanism. + */ + iio_buffer_signal_dmabuf_done(&fence->base, ret); + } + + if (buffer->access->unlock_queue) + buffer->access->unlock_queue(buffer); + + dma_fence_end_signalling(cookie); + dma_buf_put(dmabuf); + + return ret; + +err_queue_unlock: + if (buffer->access->unlock_queue) + buffer->access->unlock_queue(buffer); +err_resv_unlock: + dma_resv_unlock(dmabuf->resv); +err_fence_put: + dma_fence_put(&fence->base); +err_attachment_put: + iio_buffer_dmabuf_put(attach); +err_dmabuf_put: + dma_buf_put(dmabuf); + + return ret; +} + +static void iio_buffer_cleanup(struct work_struct *work) +{ + struct iio_dma_fence *fence = + container_of(work, struct iio_dma_fence, work); + struct iio_dmabuf_priv *priv = fence->priv; + struct dma_buf_attachment *attach = priv->attach; + + dma_fence_put(&fence->base); + iio_buffer_dmabuf_put(attach); +} + +void iio_buffer_signal_dmabuf_done(struct dma_fence *fence, int ret) +{ + struct iio_dma_fence *iio_fence = + container_of(fence, struct iio_dma_fence, base); + bool cookie = dma_fence_begin_signalling(); + + /* + * Get a reference to the fence, so that it's not freed as soon as + * it's signaled. + */ + dma_fence_get(fence); + + fence->error = ret; + dma_fence_signal(fence); + dma_fence_end_signalling(cookie); + + /* + * The fence will be unref'd in iio_buffer_cleanup. + * It can't be done here, as the unref functions might try to lock the + * resv object, which can deadlock. + */ + INIT_WORK(&iio_fence->work, iio_buffer_cleanup); + schedule_work(&iio_fence->work); +} +EXPORT_SYMBOL_GPL(iio_buffer_signal_dmabuf_done); + +static long iio_buffer_chrdev_ioctl(struct file *filp, + unsigned int cmd, unsigned long arg) +{ + struct iio_dev_buffer_pair *ib = filp->private_data; + void __user *_arg = (void __user *)arg; + bool nonblock = filp->f_flags & O_NONBLOCK; + + switch (cmd) { + case IIO_BUFFER_DMABUF_ATTACH_IOCTL: + return iio_buffer_attach_dmabuf(ib, _arg, nonblock); + case IIO_BUFFER_DMABUF_DETACH_IOCTL: + return iio_buffer_detach_dmabuf(ib, _arg, nonblock); + case IIO_BUFFER_DMABUF_ENQUEUE_IOCTL: + return iio_buffer_enqueue_dmabuf(ib, _arg, nonblock); + default: + return -EINVAL; + } +} + static const struct file_operations iio_buffer_chrdev_fileops = { .owner = THIS_MODULE, .llseek = noop_llseek, .read = iio_buffer_read, .write = iio_buffer_write, + .unlocked_ioctl = iio_buffer_chrdev_ioctl, + .compat_ioctl = compat_ptr_ioctl, .poll = iio_buffer_poll, .release = iio_buffer_chrdev_release, }; @@ -1994,6 +2450,7 @@ static void iio_buffer_release(struct kref *ref) { struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref); + mutex_destroy(&buffer->dmabufs_mutex); buffer->access->release(buffer); } diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h index 89c3fd7c29ca..e72552e026f3 100644 --- a/include/linux/iio/buffer_impl.h +++ b/include/linux/iio/buffer_impl.h @@ -9,8 +9,12 @@ #include <uapi/linux/iio/buffer.h> #include <linux/iio/buffer.h> +struct dma_buf_attachment; +struct dma_fence; struct iio_dev; +struct iio_dma_buffer_block; struct iio_buffer; +struct sg_table; /** * INDIO_BUFFER_FLAG_FIXED_WATERMARK - Watermark level of the buffer can not be @@ -39,6 +43,16 @@ struct iio_buffer; * device stops sampling. Calles are balanced with @enable. * @release: called when the last reference to the buffer is dropped, * should free all resources allocated by the buffer. + * @attach_dmabuf: called from userspace via ioctl to attach one external + * DMABUF. + * @detach_dmabuf: called from userspace via ioctl to detach one previously + * attached DMABUF. + * @enqueue_dmabuf: called from userspace via ioctl to queue this DMABUF + * object to this buffer. Requires a valid DMABUF fd, that + * was previouly attached to this buffer. + * @lock_queue: called when the core needs to lock the buffer queue; + * it is used when enqueueing DMABUF objects. + * @unlock_queue: used to unlock a previously locked buffer queue * @modes: Supported operating modes by this buffer type * @flags: A bitmask combination of INDIO_BUFFER_FLAG_* * @@ -68,6 +82,17 @@ struct iio_buffer_access_funcs { void (*release)(struct iio_buffer *buffer); + struct iio_dma_buffer_block * (*attach_dmabuf)(struct iio_buffer *buffer, + struct dma_buf_attachment *attach); + void (*detach_dmabuf)(struct iio_buffer *buffer, + struct iio_dma_buffer_block *block); + int (*enqueue_dmabuf)(struct iio_buffer *buffer, + struct iio_dma_buffer_block *block, + struct dma_fence *fence, struct sg_table *sgt, + size_t size, bool cyclic); + void (*lock_queue)(struct iio_buffer *buffer); + void (*unlock_queue)(struct iio_buffer *buffer); + unsigned int modes; unsigned int flags; }; @@ -136,6 +161,12 @@ struct iio_buffer { /* @ref: Reference count of the buffer. */ struct kref ref; + + /* @dmabufs: List of DMABUF attachments */ + struct list_head dmabufs; /* P: dmabufs_mutex */ + + /* @dmabufs_mutex: Protects dmabufs */ + struct mutex dmabufs_mutex; }; /** @@ -159,6 +190,8 @@ void iio_buffer_init(struct iio_buffer *buffer); struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer); void iio_buffer_put(struct iio_buffer *buffer); +void iio_buffer_signal_dmabuf_done(struct dma_fence *fence, int ret); + #else /* CONFIG_IIO_BUFFER */ static inline void iio_buffer_get(struct iio_buffer *buffer) {} diff --git a/include/uapi/linux/iio/buffer.h b/include/uapi/linux/iio/buffer.h index 13939032b3f6..c666aa95e532 100644 --- a/include/uapi/linux/iio/buffer.h +++ b/include/uapi/linux/iio/buffer.h @@ -5,6 +5,28 @@ #ifndef _UAPI_IIO_BUFFER_H_ #define _UAPI_IIO_BUFFER_H_ +#include <linux/types.h> + +/* Flags for iio_dmabuf.flags */ +#define IIO_BUFFER_DMABUF_CYCLIC (1 << 0) +#define IIO_BUFFER_DMABUF_SUPPORTED_FLAGS 0x00000001 + +/** + * struct iio_dmabuf - Descriptor for a single IIO DMABUF object + * @fd: file descriptor of the DMABUF object + * @flags: one or more IIO_BUFFER_DMABUF_* flags + * @bytes_used: number of bytes used in this DMABUF for the data transfer. + * Should generally be set to the DMABUF's size. + */ +struct iio_dmabuf { + __u32 fd; + __u32 flags; + __u64 bytes_used; +}; + #define IIO_BUFFER_GET_FD_IOCTL _IOWR('i', 0x91, int) +#define IIO_BUFFER_DMABUF_ATTACH_IOCTL _IOW('i', 0x92, int) +#define IIO_BUFFER_DMABUF_DETACH_IOCTL _IOW('i', 0x93, int) +#define IIO_BUFFER_DMABUF_ENQUEUE_IOCTL _IOW('i', 0x94, struct iio_dmabuf) #endif /* _UAPI_IIO_BUFFER_H_ */