| Message ID | 1470158617-7022-12-git-send-email-eric.auger@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index 6a3cb14..02c1c71 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -63,10 +63,18 @@ static int msi_compose(struct irq_data *irq_data, { int ret = 0; - if (erase) + if (erase) { memset(msg, 0, sizeof(*msg)); - else + } else { + struct device *dev; + ret = irq_chip_compose_msi_msg(irq_data, msg); + if (ret) + return ret; + + dev = msi_desc_to_dev(irq_data_get_msi_desc(irq_data)); + ret = iommu_msi_msg_pa_to_va(dev, msg); + } return ret; }
Currently the msi_compose() uses the doorbell's physical address. However in case the MSI doorbell is accessed through an IOMMU that does not bypass the MSI transactions we need to use an IOVA instead. iommu_msi_msg_pa_to_va helper, part of the iommu-msi API, detects the above case and swaps the MSI doorbell physical address with a pre-allocated/mapped IOVA. That way the device will send the MSI with this IOVA and the address will be translated by the IOMMU into the target MSI doorbell PA. Signed-off-by: Eric Auger <eric.auger@redhat.com> --- v11 -> v12: - remove WARN_ON. iommu domain cannot dissapear while msi still are enabled so the userspace cannot induce a kernel panic. v8 -> v9: - Braces on both sides of the 'else' in msi_compose v7 -> v8: - use iommu_msi_msg_pa_to_va - add WARN_ON v6 -> v7: - allocation/mapping is done at an earlier stage. We now just perform the iova lookup. So it is safe now to be called in a code that cannot sleep. iommu_msi_set_doorbell_iova is moved in the dma-reserved-iommu API: I think it cleans things up with respect to various #ifdef CONFIGS. v5: - use macros to increase the readability - add comments - fix a typo that caused a compilation error if CONFIG_IOMMU_API is not set --- kernel/irq/msi.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)