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| author | Niklas Schnelle <schnelle@linux.ibm.com> | 2021-07-16 12:53:37 +0300 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2021-08-25 12:03:34 +0300 |
| commit | 1f3f76812d5dfc791193b39c2140a8bd09962c0e (patch) | |
| tree | 8f61dd33029e218e765af3ad8753856ad6d5881b /arch/s390/pci/pci_dma.c | |
| parent | cc049eecfb7adc4bfecd05eb25e425d8def96fce (diff) | |
| download | linux-1f3f76812d5dfc791193b39c2140a8bd09962c0e.tar.xz | |
s390/pci: improve DMA translation init and exit
Currently zpci_dma_init_device()/zpci_dma_exit_device() is called as
part of zpci_enable_device()/zpci_disable_device() and errors for
zpci_dma_exit_device() are always ignored even if we could abort.
Improve upon this by moving zpci_dma_exit_device() out of
zpci_disable_device() and check for errors whenever we have a way to
abort the current operation. Note that for example in
zpci_event_hard_deconfigured() the device is expected to be gone so we
really can't abort and proceed even in case of error.
Similarly move the cc == 3 special case out of zpci_unregister_ioat()
and into the callers allowing to abort when finding an already disabled
devices precludes proceeding with the operation.
While we are at it log IOAT register/unregister errors in the s390
debugfs log,
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/pci/pci_dma.c')
| -rw-r--r-- | arch/s390/pci/pci_dma.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index ebc9a49523aa..58f2f7abea96 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -590,10 +590,11 @@ int zpci_dma_init_device(struct zpci_dev *zdev) } } - rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, - (u64) zdev->dma_table); - if (rc) + if (zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, + (u64)zdev->dma_table)) { + rc = -EIO; goto free_bitmap; + } return 0; free_bitmap: @@ -608,17 +609,25 @@ out: return rc; } -void zpci_dma_exit_device(struct zpci_dev *zdev) +int zpci_dma_exit_device(struct zpci_dev *zdev) { + int cc = 0; + /* * At this point, if the device is part of an IOMMU domain, this would * be a strong hint towards a bug in the IOMMU API (common) code and/or * simultaneous access via IOMMU and DMA API. So let's issue a warning. */ WARN_ON(zdev->s390_domain); - - if (zpci_unregister_ioat(zdev, 0)) - return; + if (zdev_enabled(zdev)) + cc = zpci_unregister_ioat(zdev, 0); + /* + * cc == 3 indicates the function is gone already. This can happen + * if the function was deconfigured/disabled suddenly and we have not + * received a new handle yet. + */ + if (cc && cc != 3) + return -EIO; dma_cleanup_tables(zdev->dma_table); zdev->dma_table = NULL; @@ -626,8 +635,8 @@ void zpci_dma_exit_device(struct zpci_dev *zdev) zdev->iommu_bitmap = NULL; vfree(zdev->lazy_bitmap); zdev->lazy_bitmap = NULL; - zdev->next_bit = 0; + return 0; } static int __init dma_alloc_cpu_table_caches(void) |