> -----Original Message----- > From: Robin Murphy [mailto:robin.murphy@xxxxxxx] > Sent: Wednesday, October 05, 2016 15:26 > To: Nipun Gupta <nipun.gupta@xxxxxxx> > Cc: will.deacon@xxxxxxx; joro@xxxxxxxxxx; iommu@lists.linux- > foundation.org; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; punit.agrawal@xxxxxxx; > thunder.leizhen@xxxxxxxxxx > Subject: Re: [PATCH v7 21/22] iommu/dma: Add support for mapping MSIs > > On 05/10/16 08:00, Nipun Gupta wrote: > > > > > >> -----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));' > > Er, yes... I fully agree. That's why it is exactly that. > > > as __alloc_iova takes input parameter as 'struct iova_domain *' > > Joking aside, though, I guess you've overlooked the change introduced by > c987ff0d3cb3 ("iommu/dma: Respect IOMMU aperture when allocating")? Ooops!! My bad. That's right, I missed out this change. Thanks, Nipun > > Robin. > > > > > 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
