| Message ID | 1470158617-7022-3-git-send-email-eric.auger@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2 Aug 2016, Eric Auger wrote: > Currently the MSI message is composed by directly calling > irq_chip_compose_msi_msg and erased by setting the memory to zero. > > On some platforms, we will need to complexify this composition to > properly handle MSI emission through IOMMU. Also we will need to track > when the MSI message is erased. I just can't find how you do that. After applying the series the > + if (erase) > + memset(msg, 0, sizeof(*msg)); branch is still just a memset(). The wrapper is fine for the compose side, but having the extra argument just to wrap the memset() for no gain is silly. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Thomas, On 09/08/2016 11:19, Thomas Gleixner wrote: > On Tue, 2 Aug 2016, Eric Auger wrote: > >> Currently the MSI message is composed by directly calling >> irq_chip_compose_msi_msg and erased by setting the memory to zero. >> >> On some platforms, we will need to complexify this composition to >> properly handle MSI emission through IOMMU. Also we will need to track >> when the MSI message is erased. > > I just can't find how you do that. After applying the series the > >> + if (erase) >> + memset(msg, 0, sizeof(*msg)); > > branch is still just a memset(). The wrapper is fine for the compose side, but > having the extra argument just to wrap the memset() for no gain is silly. Yes you're right: this was true in the first releases of the series where the iommu mapping/unmapping were done at composition & erase time. Now the mapping/unmapping is done on msi_domain_alloc/free_irqs, this is not mandated anymore. I will keep the wrapper for the compose side and remove the rest + update the commit message accordingly. Thank you for your time. Eric > > Thanks, > > tglx > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index 9b0ba4a..72bf4d6 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -55,6 +55,19 @@ static inline void irq_chip_write_msi_msg(struct irq_data *data, data->chip->irq_write_msi_msg(data, msg); } +static int msi_compose(struct irq_data *irq_data, + struct msi_msg *msg, bool erase) +{ + int ret = 0; + + if (erase) + memset(msg, 0, sizeof(*msg)); + else + ret = irq_chip_compose_msi_msg(irq_data, msg); + + return ret; +} + /** * msi_domain_set_affinity - Generic affinity setter function for MSI domains * @irq_data: The irq data associated to the interrupt @@ -73,7 +86,7 @@ int msi_domain_set_affinity(struct irq_data *irq_data, ret = parent->chip->irq_set_affinity(parent, mask, force); if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) { - BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg)); + BUG_ON(msi_compose(irq_data, &msg, false)); irq_chip_write_msi_msg(irq_data, &msg); } @@ -85,7 +98,7 @@ static void msi_domain_activate(struct irq_domain *domain, { struct msi_msg msg; - BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg)); + BUG_ON(msi_compose(irq_data, &msg, false)); irq_chip_write_msi_msg(irq_data, &msg); } @@ -94,7 +107,7 @@ static void msi_domain_deactivate(struct irq_domain *domain, { struct msi_msg msg; - memset(&msg, 0, sizeof(msg)); + msi_compose(irq_data, &msg, true); irq_chip_write_msi_msg(irq_data, &msg); }
Currently the MSI message is composed by directly calling irq_chip_compose_msi_msg and erased by setting the memory to zero. On some platforms, we will need to complexify this composition to properly handle MSI emission through IOMMU. Also we will need to track when the MSI message is erased. We propose to introduce a common wrapper for actual composition and erasure, msi_compose. Signed-off-by: Eric Auger <eric.auger@redhat.com> --- v4 -> v5: - just introduce the msi-compose wrapper without adding new functionalities v3 -> v4: - that code was formely in irq-gic-common.c "irqchip/gicv2m/v3-its-pci-msi: IOMMU map the MSI frame when needed" also the [un]mapping was done in irq_write_msi_msg; now done on compose v2 -> v3: - protect iova/addr manipulation with CONFIG_ARCH_DMA_ADDR_T_64BIT and CONFIG_PHYS_ADDR_T_64BIT - only expose gic_pci_msi_domain_write_msg in case CONFIG_IOMMU_API & CONFIG_PCI_MSI_IRQ_DOMAIN are set. - gic_set/unset_msi_addr duly become static --- kernel/irq/msi.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)