> -----Original Message----- > From: iommu-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx [mailto:iommu- > bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Robin Murphy > Sent: Monday, September 12, 2016 21:44 > To: will.deacon@xxxxxxx; joro@xxxxxxxxxx; iommu@lists.linux- > foundation.org; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: devicetree@xxxxxxxxxxxxxxx; punit.agrawal@xxxxxxx; > thunder.leizhen@xxxxxxxxxx > Subject: [PATCH v7 21/22] iommu/dma: Add support for mapping MSIs > > When an MSI doorbell is located downstream of an IOMMU, attaching devices > to a DMA ops domain and switching on translation leads to a rude shock when > their attempt to write to the physical address returned by the irqchip driver > faults (or worse, writes into some already-mapped > buffer) and no interrupt is forthcoming. > > Address this by adding a hook for relevant irqchip drivers to call from their > compose_msi_msg() callback, to swizzle the physical address with an > appropriatly-mapped IOVA for any device attached to one of our DMA ops > domains. > > Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx> > Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> > --- > drivers/iommu/dma-iommu.c | 136 > ++++++++++++++++++++++++++++++++++----- > drivers/irqchip/irq-gic-v2m.c | 3 + > drivers/irqchip/irq-gic-v3-its.c | 3 + > include/linux/dma-iommu.h | 9 +++ > 4 files changed, 136 insertions(+), 15 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index > 00c8a08d56e7..4329d18080cf 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -25,10 +25,28 @@ > #include <linux/huge_mm.h> > #include <linux/iommu.h> > #include <linux/iova.h> > +#include <linux/irq.h> > #include <linux/mm.h> > #include <linux/scatterlist.h> > #include <linux/vmalloc.h> > > +struct iommu_dma_msi_page { > + struct list_head list; > + dma_addr_t iova; > + phys_addr_t phys; > +}; > + > +struct iommu_dma_cookie { > + struct iova_domain iovad; > + struct list_head msi_page_list; > + spinlock_t msi_lock; > +}; > + > +static inline struct iova_domain *cookie_iovad(struct iommu_domain > +*domain) { > + return &((struct iommu_dma_cookie *)domain->iova_cookie)->iovad; } > + > int iommu_dma_init(void) > { > return iova_cache_get(); > @@ -43,15 +61,19 @@ int iommu_dma_init(void) > */ > int iommu_get_dma_cookie(struct iommu_domain *domain) { > - struct iova_domain *iovad; > + struct iommu_dma_cookie *cookie; > > if (domain->iova_cookie) > return -EEXIST; > > - iovad = kzalloc(sizeof(*iovad), GFP_KERNEL); > - domain->iova_cookie = iovad; > + cookie = kzalloc(sizeof(*cookie), GFP_KERNEL); > + if (!cookie) > + return -ENOMEM; > > - return iovad ? 0 : -ENOMEM; > + spin_lock_init(&cookie->msi_lock); > + INIT_LIST_HEAD(&cookie->msi_page_list); > + domain->iova_cookie = cookie; > + return 0; > } > EXPORT_SYMBOL(iommu_get_dma_cookie); > > @@ -63,14 +85,20 @@ EXPORT_SYMBOL(iommu_get_dma_cookie); > */ > void iommu_put_dma_cookie(struct iommu_domain *domain) { > - struct iova_domain *iovad = domain->iova_cookie; > + struct iommu_dma_cookie *cookie = domain->iova_cookie; > + struct iommu_dma_msi_page *msi, *tmp; > > - if (!iovad) > + if (!cookie) > return; > > - if (iovad->granule) > - put_iova_domain(iovad); > - kfree(iovad); > + if (cookie->iovad.granule) > + put_iova_domain(&cookie->iovad); > + > + list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list) { > + list_del(&msi->list); > + kfree(msi); > + } > + kfree(cookie); > domain->iova_cookie = NULL; > } > EXPORT_SYMBOL(iommu_put_dma_cookie); > @@ -88,7 +116,7 @@ EXPORT_SYMBOL(iommu_put_dma_cookie); > */ > int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t > base, u64 size) { > - struct iova_domain *iovad = domain->iova_cookie; > + struct iova_domain *iovad = cookie_iovad(domain); > unsigned long order, base_pfn, end_pfn; > > if (!iovad) > @@ -155,7 +183,7 @@ int dma_direction_to_prot(enum dma_data_direction > dir, bool coherent) static struct iova *__alloc_iova(struct iommu_domain > *domain, size_t size, > dma_addr_t dma_limit) > { > - struct iova_domain *iovad = domain->iova_cookie; > + struct iova_domain *iovad = cookie_iovad(domain); > unsigned long shift = iova_shift(iovad); > unsigned long length = iova_align(iovad, size) >> shift; > > @@ -171,7 +199,7 @@ static struct iova *__alloc_iova(struct iommu_domain > *domain, size_t size, > /* The IOVA allocator knows what we mapped, so just unmap whatever that > was */ static void __iommu_dma_unmap(struct iommu_domain *domain, > dma_addr_t dma_addr) { > - struct iova_domain *iovad = domain->iova_cookie; > + struct iova_domain *iovad = cookie_iovad(domain); > unsigned long shift = iova_shift(iovad); > unsigned long pfn = dma_addr >> shift; > struct iova *iova = find_iova(iovad, pfn); @@ -294,7 +322,7 @@ struct > page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp, > void (*flush_page)(struct device *, const void *, phys_addr_t)) { > struct iommu_domain *domain = iommu_get_domain_for_dev(dev); > - struct iova_domain *iovad = domain->iova_cookie; > + struct iova_domain *iovad = cookie_iovad(domain); > struct iova *iova; > struct page **pages; > struct sg_table sgt; > @@ -386,7 +414,7 @@ dma_addr_t iommu_dma_map_page(struct device > *dev, struct page *page, { > dma_addr_t dma_addr; > struct iommu_domain *domain = iommu_get_domain_for_dev(dev); > - struct iova_domain *iovad = domain->iova_cookie; > + struct iova_domain *iovad = cookie_iovad(domain); > phys_addr_t phys = page_to_phys(page) + offset; > size_t iova_off = iova_offset(iovad, phys); > size_t len = iova_align(iovad, size + iova_off); @@ -495,7 +523,7 @@ > int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, > int nents, int prot) > { > struct iommu_domain *domain = iommu_get_domain_for_dev(dev); > - struct iova_domain *iovad = domain->iova_cookie; > + struct iova_domain *iovad = cookie_iovad(domain); > struct iova *iova; > struct scatterlist *s, *prev = NULL; > dma_addr_t dma_addr; > @@ -587,3 +615,81 @@ int iommu_dma_mapping_error(struct device *dev, > dma_addr_t dma_addr) { > return dma_addr == DMA_ERROR_CODE; > } > + > +static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device > *dev, > + phys_addr_t msi_addr, struct iommu_domain *domain) { > + struct iommu_dma_cookie *cookie = domain->iova_cookie; > + struct iommu_dma_msi_page *msi_page; > + struct iova_domain *iovad = &cookie->iovad; > + struct iova *iova; > + int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; > + > + msi_addr &= ~(phys_addr_t)iova_mask(iovad); > + list_for_each_entry(msi_page, &cookie->msi_page_list, list) > + if (msi_page->phys == msi_addr) > + return msi_page; > + > + msi_page = kzalloc(sizeof(*msi_page), GFP_ATOMIC); > + if (!msi_page) > + return NULL; > + > + iova = __alloc_iova(domain, iovad->granule, dma_get_mask(dev)); I think this should be 'iova = __alloc_iova(domain, iovad->granule, dma_get_mask(dev));' as __alloc_iova takes input parameter as 'struct iova_domain *' Regards, Nipun > + if (!iova) > + goto out_free_page; > + > + msi_page->phys = msi_addr; > + msi_page->iova = iova_dma_addr(iovad, iova); > + if (iommu_map(domain, msi_page->iova, msi_addr, iovad->granule, > prot)) > + goto out_free_iova; > + > + INIT_LIST_HEAD(&msi_page->list); > + list_add(&msi_page->list, &cookie->msi_page_list); > + return msi_page; > + > +out_free_iova: > + __free_iova(iovad, iova); > +out_free_page: > + kfree(msi_page); > + return NULL; > +} > + > +void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg) { > + struct device *dev = msi_desc_to_dev(irq_get_msi_desc(irq)); > + struct iommu_domain *domain = iommu_get_domain_for_dev(dev); > + struct iommu_dma_cookie *cookie; > + struct iommu_dma_msi_page *msi_page; > + phys_addr_t msi_addr = (u64)msg->address_hi << 32 | msg->address_lo; > + unsigned long flags; > + > + if (!domain || !domain->iova_cookie) > + return; > + > + cookie = domain->iova_cookie; > + > + /* > + * We disable IRQs to rule out a possible inversion against > + * irq_desc_lock if, say, someone tries to retarget the affinity > + * of an MSI from within an IPI handler. > + */ > + spin_lock_irqsave(&cookie->msi_lock, flags); > + msi_page = iommu_dma_get_msi_page(dev, msi_addr, domain); > + spin_unlock_irqrestore(&cookie->msi_lock, flags); > + > + if (WARN_ON(!msi_page)) { > + /* > + * We're called from a void callback, so the best we can do is > + * 'fail' by filling the message with obviously bogus values. > + * Since we got this far due to an IOMMU being present, it's > + * not like the existing address would have worked anyway... > + */ > + msg->address_hi = ~0U; > + msg->address_lo = ~0U; > + msg->data = ~0U; > + } else { > + msg->address_hi = upper_32_bits(msi_page->iova); > + msg->address_lo &= iova_mask(&cookie->iovad); > + msg->address_lo += lower_32_bits(msi_page->iova); > + } > +} > diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c index > 35eb7ac5d21f..863e073c6f7f 100644 > --- a/drivers/irqchip/irq-gic-v2m.c > +++ b/drivers/irqchip/irq-gic-v2m.c > @@ -16,6 +16,7 @@ > #define pr_fmt(fmt) "GICv2m: " fmt > > #include <linux/acpi.h> > +#include <linux/dma-iommu.h> > #include <linux/irq.h> > #include <linux/irqdomain.h> > #include <linux/kernel.h> > @@ -108,6 +109,8 @@ static void gicv2m_compose_msi_msg(struct irq_data > *data, struct msi_msg *msg) > > if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET) > msg->data -= v2m->spi_offset; > + > + iommu_dma_map_msi_msg(data->irq, msg); > } > > static struct irq_chip gicv2m_irq_chip = { diff --git a/drivers/irqchip/irq-gic-v3- > its.c b/drivers/irqchip/irq-gic-v3-its.c > index 36b9c28a5c91..98ff669d5962 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -18,6 +18,7 @@ > #include <linux/bitmap.h> > #include <linux/cpu.h> > #include <linux/delay.h> > +#include <linux/dma-iommu.h> > #include <linux/interrupt.h> > #include <linux/log2.h> > #include <linux/mm.h> > @@ -655,6 +656,8 @@ static void its_irq_compose_msi_msg(struct irq_data > *d, struct msi_msg *msg) > msg->address_lo = addr & ((1UL << 32) - 1); > msg->address_hi = addr >> 32; > msg->data = its_get_event_id(d); > + > + iommu_dma_map_msi_msg(d->irq, msg); > } > > static struct irq_chip its_irq_chip = { diff --git a/include/linux/dma-iommu.h > b/include/linux/dma-iommu.h index 81c5c8d167ad..5ee806e41b5c 100644 > --- a/include/linux/dma-iommu.h > +++ b/include/linux/dma-iommu.h > @@ -21,6 +21,7 @@ > > #ifdef CONFIG_IOMMU_DMA > #include <linux/iommu.h> > +#include <linux/msi.h> > > int iommu_dma_init(void); > > @@ -62,9 +63,13 @@ void iommu_dma_unmap_sg(struct device *dev, struct > scatterlist *sg, int nents, int iommu_dma_supported(struct device *dev, u64 > mask); int iommu_dma_mapping_error(struct device *dev, dma_addr_t > dma_addr); > > +/* The DMA API isn't _quite_ the whole story, though... */ void > +iommu_dma_map_msi_msg(int irq, struct msi_msg *msg); > + > #else > > struct iommu_domain; > +struct msi_msg; > > static inline int iommu_dma_init(void) > { > @@ -80,6 +85,10 @@ static inline void iommu_put_dma_cookie(struct > iommu_domain *domain) { } > > +static inline void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg) > +{ } > + > #endif /* CONFIG_IOMMU_DMA */ > #endif /* __KERNEL__ */ > #endif /* __DMA_IOMMU_H */ > -- > 2.8.1.dirty > > _______________________________________________ > iommu mailing list > iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx > https://lists.linuxfoundation.org/mailman/listinfo/iommu -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
