On 10/4/23 4:56 AM, Niklas Schnelle wrote:
> Together with enabling the Function Measurement Block
> zpci_fmb_enable_device() also resets the software counters. This allows
> to use "echo 0 > /sys/kernel/debug/pci/<dev>/statistics" followed by
> echo "1 > /../statistics" to reset all counters. In commit c76c067e488c
> ("s390/pci: Use dma-iommu layer") this use of the now obsolete counters
> in struct zpci_device was missed as was their removal. Fix this by
> resetting the new counters and removing the old ones.
>
> Fixes: c76c067e488c ("s390/pci: Use dma-iommu layer")
> Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
Reviewed-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
Verified that I could reproduce the initial issue + tested the fix using NVMe and mlx devices
> ---
> Note: This is based on and references commit IDs from Joerg Roedel's
> iommu/next branch and should go in via the iommu tree.
> ---
> arch/s390/include/asm/pci.h | 4 ----
> arch/s390/pci/pci.c | 13 ++++++++++---
> 2 files changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
> index 3f74f1cf37df..e91cd6bbc330 100644
> --- a/arch/s390/include/asm/pci.h
> +++ b/arch/s390/include/asm/pci.h
> @@ -173,10 +173,6 @@ struct zpci_dev {
> struct zpci_fmb *fmb;
> u16 fmb_update; /* update interval */
> u16 fmb_length;
> - /* software counters */
> - atomic64_t allocated_pages;
> - atomic64_t mapped_pages;
> - atomic64_t unmapped_pages;
>
> u8 version;
> enum pci_bus_speed max_bus_speed;
> diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
> index 563cb72d9ed0..63fd9e1d9f22 100644
> --- a/arch/s390/pci/pci.c
> +++ b/arch/s390/pci/pci.c
> @@ -157,6 +157,7 @@ int zpci_unregister_ioat(struct zpci_dev *zdev, u8 dmaas)
> int zpci_fmb_enable_device(struct zpci_dev *zdev)
> {
> u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_SET_MEASURE);
> + struct zpci_iommu_ctrs *ctrs;
> struct zpci_fib fib = {0};
> u8 cc, status;
>
> @@ -169,9 +170,15 @@ int zpci_fmb_enable_device(struct zpci_dev *zdev)
> WARN_ON((u64) zdev->fmb & 0xf);
>
> /* reset software counters */
> - atomic64_set(&zdev->allocated_pages, 0);
> - atomic64_set(&zdev->mapped_pages, 0);
> - atomic64_set(&zdev->unmapped_pages, 0);
> + ctrs = zpci_get_iommu_ctrs(zdev);
> + if (ctrs) {
> + atomic64_set(&ctrs->mapped_pages, 0);
> + atomic64_set(&ctrs->unmapped_pages, 0);
> + atomic64_set(&ctrs->global_rpcits, 0);
> + atomic64_set(&ctrs->sync_map_rpcits, 0);
> + atomic64_set(&ctrs->sync_rpcits, 0);
> + }
> +
>
> fib.fmb_addr = virt_to_phys(zdev->fmb);
> fib.gd = zdev->gisa;
>
> ---
> base-commit: 8e5ab3f54a1061c2be3e1fbcda01fbe604c3450e
> change-id: 20231002-dma_iommu_fix-0a5397992f15
>
> Best regards,
