From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>,
Raj Ashok <ashok.raj@intel.com>,
Jean-Philippe Brucker <jean-philippe.brucker@arm.com>,
iommu@lists.linux-foundation.org,
LKML <linux-kernel@vger.kernel.org>,
Alex Williamson <alex.williamson@redhat.com>,
David Woodhouse <dwmw2@infradead.org>,
Jonathan Cameron <jic23@kernel.org>
Subject: Re: [PATCH v5 16/19] iommu/vt-d: Misc macro clean up for SVM
Date: Fri, 16 Aug 2019 00:17:44 +0300 [thread overview]
Message-ID: <CAHp75VdD4SpA3oR8KBr6WihLkBgaaUn6f7tFdO7H-2n-hbun_Q@mail.gmail.com> (raw)
In-Reply-To: <1565900005-62508-17-git-send-email-jacob.jun.pan@linux.intel.com>
On Thu, Aug 15, 2019 at 11:52 PM Jacob Pan
<jacob.jun.pan@linux.intel.com> wrote:
>
> Use combined macros for_each_svm_dev() to simplify SVM device iteration
> and error checking.
>
> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> ---
> drivers/iommu/intel-svm.c | 85 +++++++++++++++++++++++------------------------
> 1 file changed, 41 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
> index 5a688a5..ea6f2e2 100644
> --- a/drivers/iommu/intel-svm.c
> +++ b/drivers/iommu/intel-svm.c
> @@ -218,6 +218,10 @@ static const struct mmu_notifier_ops intel_mmuops = {
> static DEFINE_MUTEX(pasid_mutex);
> static LIST_HEAD(global_svm_list);
>
> +#define for_each_svm_dev(svm, dev) \
> + list_for_each_entry(sdev, &svm->devs, list) \
> + if (dev == sdev->dev) \
This should be
if (dev != sdev->dev) {} else
and no trailing \ is neeeded.
The rationale of above form to avoid
for_each_foo() {
} else {
...WTF?!..
}
> +
> int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops)
> {
> struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
> @@ -263,15 +267,13 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
> goto out;
> }
>
> - list_for_each_entry(sdev, &svm->devs, list) {
> - if (dev == sdev->dev) {
> - if (sdev->ops != ops) {
> - ret = -EBUSY;
> - goto out;
> - }
> - sdev->users++;
> - goto success;
> + for_each_svm_dev(svm, dev) {
> + if (sdev->ops != ops) {
> + ret = -EBUSY;
> + goto out;
> }
> + sdev->users++;
> + goto success;
> }
>
> break;
> @@ -408,48 +410,43 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
> goto out;
>
> svm = ioasid_find(NULL, pasid, NULL);
> - if (IS_ERR(svm)) {
> + if (IS_ERR_OR_NULL(svm)) {
> ret = PTR_ERR(svm);
> goto out;
> }
>
> - if (!svm)
> - goto out;
> + for_each_svm_dev(svm, dev) {
> + ret = 0;
> + sdev->users--;
> + if (!sdev->users) {
> + list_del_rcu(&sdev->list);
> + /* Flush the PASID cache and IOTLB for this device.
> + * Note that we do depend on the hardware *not* using
> + * the PASID any more. Just as we depend on other
> + * devices never using PASIDs that they have no right
> + * to use. We have a *shared* PASID table, because it's
> + * large and has to be physically contiguous. So it's
> + * hard to be as defensive as we might like. */
> + intel_pasid_tear_down_entry(iommu, dev, svm->pasid);
> + intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, !svm->mm);
> + kfree_rcu(sdev, rcu);
> +
> + if (list_empty(&svm->devs)) {
> + ioasid_free(svm->pasid);
> + if (svm->mm)
> + mmu_notifier_unregister(&svm->notifier, svm->mm);
>
> - list_for_each_entry(sdev, &svm->devs, list) {
> - if (dev == sdev->dev) {
> - ret = 0;
> - sdev->users--;
> - if (!sdev->users) {
> - list_del_rcu(&sdev->list);
> - /* Flush the PASID cache and IOTLB for this device.
> - * Note that we do depend on the hardware *not* using
> - * the PASID any more. Just as we depend on other
> - * devices never using PASIDs that they have no right
> - * to use. We have a *shared* PASID table, because it's
> - * large and has to be physically contiguous. So it's
> - * hard to be as defensive as we might like. */
> - intel_pasid_tear_down_entry(iommu, dev, svm->pasid);
> - intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, !svm->mm);
> - kfree_rcu(sdev, rcu);
> -
> - if (list_empty(&svm->devs)) {
> - ioasid_free(svm->pasid);
> - if (svm->mm)
> - mmu_notifier_unregister(&svm->notifier, svm->mm);
> -
> - list_del(&svm->list);
> -
> - /* We mandate that no page faults may be outstanding
> - * for the PASID when intel_svm_unbind_mm() is called.
> - * If that is not obeyed, subtle errors will happen.
> - * Let's make them less subtle... */
> - memset(svm, 0x6b, sizeof(*svm));
> - kfree(svm);
> - }
> + list_del(&svm->list);
> +
> + /* We mandate that no page faults may be outstanding
> + * for the PASID when intel_svm_unbind_mm() is called.
> + * If that is not obeyed, subtle errors will happen.
> + * Let's make them less subtle... */
> + memset(svm, 0x6b, sizeof(*svm));
> + kfree(svm);
> }
> - break;
> }
> + break;
> }
> out:
> mutex_unlock(&pasid_mutex);
> @@ -585,7 +582,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
> * to unbind the mm while any page faults are outstanding.
> * So we only need RCU to protect the internal idr code. */
> rcu_read_unlock();
> - if (IS_ERR(svm) || !svm) {
> + if (IS_ERR_OR_NULL(svm)) {
> pr_err("%s: Page request for invalid PASID %d: %08llx %08llx\n",
> iommu->name, req->pasid, ((unsigned long long *)req)[0],
> ((unsigned long long *)req)[1]);
> --
> 2.7.4
>
--
With Best Regards,
Andy Shevchenko
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2019-08-15 21:17 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-15 20:13 [PATCH v5 00/19] Shared virtual address IOMMU and VT-d support Jacob Pan
2019-08-15 20:13 ` [PATCH v5 01/19] iommu: Add a timeout parameter for PRQ response Jacob Pan
2019-08-15 20:13 ` [PATCH v5 02/19] iommu: handle page response timeout Jacob Pan
2019-08-15 20:13 ` [PATCH v5 03/19] trace/iommu: Add sva trace events Jacob Pan
2019-08-15 20:13 ` [PATCH v5 04/19] iommu: Use device fault trace event Jacob Pan
2019-08-15 20:13 ` [PATCH v5 05/19] iommu: Introduce attach/detach_pasid_table API Jacob Pan
2019-08-15 20:13 ` [PATCH v5 06/19] iommu: Introduce cache_invalidate API Jacob Pan
2019-08-15 20:13 ` [PATCH v5 07/19] iommu: Add I/O ASID allocator Jacob Pan
2019-08-15 20:13 ` [PATCH v5 08/19] iommu/ioasid: Add custom allocators Jacob Pan
2019-08-15 20:13 ` [PATCH v5 09/19] iommu: Introduce guest PASID bind function Jacob Pan
2019-08-15 20:13 ` [PATCH v5 10/19] iommu/vt-d: Enlightened PASID allocation Jacob Pan
2019-08-15 20:13 ` [PATCH v5 11/19] iommu/vt-d: Add custom allocator for IOASID Jacob Pan
2019-08-15 20:13 ` [PATCH v5 12/19] iommu/vt-d: Replace Intel specific PASID allocator with IOASID Jacob Pan
2019-08-15 20:13 ` [PATCH v5 13/19] iommu/vt-d: Move domain helper to header Jacob Pan
2019-08-15 20:13 ` [PATCH v5 14/19] iommu/vt-d: Avoid duplicated code for PASID setup Jacob Pan
2019-08-15 20:13 ` [PATCH v5 15/19] iommu/vt-d: Add nested translation helper function Jacob Pan
2019-08-15 20:13 ` [PATCH v5 16/19] iommu/vt-d: Misc macro clean up for SVM Jacob Pan
2019-08-15 21:17 ` Andy Shevchenko [this message]
2019-08-15 22:50 ` Jacob Pan
2019-08-15 20:13 ` [PATCH v5 17/19] iommu/vt-d: Add bind guest PASID support Jacob Pan
2019-08-15 20:13 ` [PATCH v5 18/19] iommu/vt-d: Support flushing more translation cache types Jacob Pan
2019-08-15 20:13 ` [PATCH v5 19/19] iommu/vt-d: Add svm/sva invalidate function Jacob Pan
2019-08-26 17:12 ` [PATCH v5 00/19] Shared virtual address IOMMU and VT-d support Jacob Pan
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