[PATCH v11 10/10] genirq/msi: use the MSI doorbell's IOVA when requested
Thomas Gleixner
tglx at linutronix.de
Wed Jul 20 02:09:28 PDT 2016
On Tue, 19 Jul 2016, Eric Auger wrote:
First of all - valid for all patches:
Subject: sys/subsys: Sentence starts with an uppercase letter
Now for this particular one:
genirq/msi: use the MSI doorbell's IOVA when requested
> On MSI message composition we now use the MSI doorbell's IOVA in
> place of the doorbell's PA in case the device is upstream to an
> IOMMU that requires MSI addresses to be mapped. The doorbell's
> allocation and mapping happened on an early stage (pci_enable_msi).
This changelog is completely useless. At least I cannot figure out what that
patch actually does. And the implementation is not self explaining either.
> @@ -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));
> + WARN_ON(iommu_msi_msg_pa_to_va(dev, msg));
What the heck is this call doing? And why is there only a WARN_ON and not a
proper error return code handling?
Thanks,
tglx
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