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")? 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
