This adds an IOMMU API implementation for s390 PCI devices. Reviewed-by: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx> Signed-off-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> --- MAINTAINERS | 7 + arch/s390/Kconfig | 1 + arch/s390/include/asm/pci.h | 4 + arch/s390/include/asm/pci_dma.h | 5 +- arch/s390/pci/pci_dma.c | 37 +++-- drivers/iommu/Kconfig | 7 + drivers/iommu/Makefile | 1 + drivers/iommu/s390-iommu.c | 337 ++++++++++++++++++++++++++++++++++++++++ 8 files changed, 386 insertions(+), 13 deletions(-) create mode 100644 drivers/iommu/s390-iommu.c diff --git a/MAINTAINERS b/MAINTAINERS index 23da5da..8845410 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8937,6 +8937,13 @@ F: drivers/s390/net/*iucv* F: include/net/iucv/ F: net/iucv/ +S390 IOMMU (PCI) +M: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> +L: linux-s390@xxxxxxxxxxxxxxx +W: http://www.ibm.com/developerworks/linux/linux390/ +S: Supported +F: drivers/iommu/s390-iommu.c + S3C24XX SD/MMC Driver M: Ben Dooks <ben-linux@xxxxxxxxx> L: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx (moderated for non-subscribers) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 1d57000..74db332 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -582,6 +582,7 @@ menuconfig PCI bool "PCI support" select HAVE_DMA_ATTRS select PCI_MSI + select IOMMU_SUPPORT help Enable PCI support. diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h index 34d9603..c873e68 100644 --- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -62,6 +62,8 @@ struct zpci_bar_struct { u8 size; /* order 2 exponent */ }; +struct s390_domain; + /* Private data per function */ struct zpci_dev { struct pci_dev *pdev; @@ -118,6 +120,8 @@ struct zpci_dev { struct dentry *debugfs_dev; struct dentry *debugfs_perf; + + struct s390_domain *s390_domain; /* s390 IOMMU domain data */ }; static inline bool zdev_enabled(struct zpci_dev *zdev) diff --git a/arch/s390/include/asm/pci_dma.h b/arch/s390/include/asm/pci_dma.h index 30b4c17..7a7abf1 100644 --- a/arch/s390/include/asm/pci_dma.h +++ b/arch/s390/include/asm/pci_dma.h @@ -192,5 +192,8 @@ static inline unsigned long *get_st_pto(unsigned long entry) /* Prototypes */ int zpci_dma_init_device(struct zpci_dev *); void zpci_dma_exit_device(struct zpci_dev *); - +void dma_free_seg_table(unsigned long); +unsigned long *dma_alloc_cpu_table(void); +void dma_cleanup_tables(unsigned long *); +void dma_update_cpu_trans(unsigned long *, void *, dma_addr_t, int); #endif diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index 37505b8..37d10f7 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -24,7 +24,7 @@ static int zpci_refresh_global(struct zpci_dev *zdev) zdev->iommu_pages * PAGE_SIZE); } -static unsigned long *dma_alloc_cpu_table(void) +unsigned long *dma_alloc_cpu_table(void) { unsigned long *table, *entry; @@ -114,12 +114,12 @@ static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr return &pto[px]; } -static void dma_update_cpu_trans(struct zpci_dev *zdev, void *page_addr, - dma_addr_t dma_addr, int flags) +void dma_update_cpu_trans(unsigned long *dma_table, void *page_addr, + dma_addr_t dma_addr, int flags) { unsigned long *entry; - entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr); + entry = dma_walk_cpu_trans(dma_table, dma_addr); if (!entry) { WARN_ON_ONCE(1); return; @@ -156,7 +156,8 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa, goto no_refresh; for (i = 0; i < nr_pages; i++) { - dma_update_cpu_trans(zdev, page_addr, dma_addr, flags); + dma_update_cpu_trans(zdev->dma_table, page_addr, dma_addr, + flags); page_addr += PAGE_SIZE; dma_addr += PAGE_SIZE; } @@ -181,7 +182,7 @@ no_refresh: return rc; } -static void dma_free_seg_table(unsigned long entry) +void dma_free_seg_table(unsigned long entry) { unsigned long *sto = get_rt_sto(entry); int sx; @@ -193,21 +194,18 @@ static void dma_free_seg_table(unsigned long entry) dma_free_cpu_table(sto); } -static void dma_cleanup_tables(struct zpci_dev *zdev) +void dma_cleanup_tables(unsigned long *table) { - unsigned long *table; int rtx; - if (!zdev || !zdev->dma_table) + if (!table) return; - table = zdev->dma_table; for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++) if (reg_entry_isvalid(table[rtx])) dma_free_seg_table(table[rtx]); dma_free_cpu_table(table); - zdev->dma_table = NULL; } static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev, @@ -416,6 +414,13 @@ int zpci_dma_init_device(struct zpci_dev *zdev) { int rc; + /* + * At this point, if the device is part of an IOMMU domain, this would + * be a strong hint towards a bug in the IOMMU API (common) code and/or + * simultaneous access via IOMMU and DMA API. So let's issue a warning. + */ + WARN_ON(zdev->s390_domain); + spin_lock_init(&zdev->iommu_bitmap_lock); spin_lock_init(&zdev->dma_table_lock); @@ -450,8 +455,16 @@ out_clean: void zpci_dma_exit_device(struct zpci_dev *zdev) { + /* + * At this point, if the device is part of an IOMMU domain, this would + * be a strong hint towards a bug in the IOMMU API (common) code and/or + * simultaneous access via IOMMU and DMA API. So let's issue a warning. + */ + WARN_ON(zdev->s390_domain); + zpci_unregister_ioat(zdev, 0); - dma_cleanup_tables(zdev); + dma_cleanup_tables(zdev->dma_table); + zdev->dma_table = NULL; vfree(zdev->iommu_bitmap); zdev->iommu_bitmap = NULL; zdev->next_bit = 0; diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index e3b2c2e..0330fb4 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -377,4 +377,11 @@ config ARM_SMMU_V3 Say Y here if your system includes an IOMMU device implementing the ARM SMMUv3 architecture. +config S390_IOMMU + def_bool y if S390 && PCI + depends on S390 && PCI + select IOMMU_API + help + Support for the IOMMU API for s390 PCI devices. + endif # IOMMU_SUPPORT diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index dc6f511..c0a0649 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -24,3 +24,4 @@ obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o obj-$(CONFIG_SHMOBILE_IOMMU) += shmobile-iommu.o obj-$(CONFIG_SHMOBILE_IPMMU) += shmobile-ipmmu.o obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o +obj-$(CONFIG_S390_IOMMU) += s390-iommu.o diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c new file mode 100644 index 0000000..cbe198c --- /dev/null +++ b/drivers/iommu/s390-iommu.c @@ -0,0 +1,337 @@ +/* + * IOMMU API for s390 PCI devices + * + * Copyright IBM Corp. 2015 + * Author(s): Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> + */ + +#include <linux/pci.h> +#include <linux/iommu.h> +#include <linux/iommu-helper.h> +#include <linux/pci.h> +#include <linux/sizes.h> +#include <asm/pci_dma.h> + +/* + * Physically contiguous memory regions can be mapped with 4 KiB alignment, + * we allow all page sizes that are an order of 4KiB (no special large page + * support so far). + */ +#define S390_IOMMU_PGSIZES (~0xFFFUL) + +struct s390_domain { + struct iommu_domain domain; + struct list_head devices; + unsigned long *dma_table; + spinlock_t dma_table_lock; + spinlock_t list_lock; +}; + +struct s390_domain_device { + struct list_head list; + struct zpci_dev *zdev; +}; + +static struct s390_domain *to_s390_domain(struct iommu_domain *dom) +{ + return container_of(dom, struct s390_domain, domain); +} + +static bool s390_iommu_capable(enum iommu_cap cap) +{ + switch (cap) { + case IOMMU_CAP_CACHE_COHERENCY: + return true; + case IOMMU_CAP_INTR_REMAP: + return true; + default: + return false; + } +} + +struct iommu_domain *s390_domain_alloc(unsigned domain_type) +{ + struct s390_domain *s390_domain; + + if (domain_type != IOMMU_DOMAIN_UNMANAGED) + return NULL; + + s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL); + if (!s390_domain) + return NULL; + + s390_domain->dma_table = dma_alloc_cpu_table(); + if (!s390_domain->dma_table) { + kfree(s390_domain); + return NULL; + } + + spin_lock_init(&s390_domain->dma_table_lock); + spin_lock_init(&s390_domain->list_lock); + INIT_LIST_HEAD(&s390_domain->devices); + + return &s390_domain->domain; +} + +void s390_domain_free(struct iommu_domain *domain) +{ + struct s390_domain *s390_domain = to_s390_domain(domain); + + dma_cleanup_tables(s390_domain->dma_table); + kfree(s390_domain); +} + +static int s390_iommu_attach_device(struct iommu_domain *domain, + struct device *dev) +{ + struct s390_domain *s390_domain = to_s390_domain(domain); + struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; + struct s390_domain_device *domain_device; + unsigned long flags; + int rc; + + if (!zdev) + return -ENODEV; + + domain_device = kzalloc(sizeof(*domain_device), GFP_KERNEL); + if (!domain_device) + return -ENOMEM; + + if (zdev->dma_table) + zpci_dma_exit_device(zdev); + + zdev->dma_table = s390_domain->dma_table; + rc = zpci_register_ioat(zdev, 0, zdev->start_dma + PAGE_OFFSET, + zdev->start_dma + zdev->iommu_size - 1, + (u64) zdev->dma_table); + if (rc) + goto out_restore; + + spin_lock_irqsave(&s390_domain->list_lock, flags); + /* First device defines the DMA range limits */ + if (list_empty(&s390_domain->devices)) { + domain->geometry.aperture_start = zdev->start_dma; + domain->geometry.aperture_end = zdev->end_dma; + domain->geometry.force_aperture = true; + /* Allow only devices with identical DMA range limits */ + } else if (domain->geometry.aperture_start != zdev->start_dma || + domain->geometry.aperture_end != zdev->end_dma) { + rc = -EINVAL; + spin_unlock_irqrestore(&s390_domain->list_lock, flags); + goto out_restore; + } + domain_device->zdev = zdev; + zdev->s390_domain = s390_domain; + list_add(&domain_device->list, &s390_domain->devices); + spin_unlock_irqrestore(&s390_domain->list_lock, flags); + + return 0; + +out_restore: + zpci_dma_init_device(zdev); + kfree(domain_device); + + return rc; +} + +static void s390_iommu_detach_device(struct iommu_domain *domain, + struct device *dev) +{ + struct s390_domain *s390_domain = to_s390_domain(domain); + struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; + struct s390_domain_device *domain_device, *tmp; + unsigned long flags; + int found = 0; + + if (!zdev) + return; + + spin_lock_irqsave(&s390_domain->list_lock, flags); + list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices, + list) { + if (domain_device->zdev == zdev) { + list_del(&domain_device->list); + kfree(domain_device); + found = 1; + break; + } + } + spin_unlock_irqrestore(&s390_domain->list_lock, flags); + + if (found) { + zdev->s390_domain = NULL; + zpci_unregister_ioat(zdev, 0); + zpci_dma_init_device(zdev); + } +} + +static int s390_iommu_add_device(struct device *dev) +{ + struct iommu_group *group; + int rc; + + group = iommu_group_get(dev); + if (!group) { + group = iommu_group_alloc(); + if (IS_ERR(group)) + return PTR_ERR(group); + } + + rc = iommu_group_add_device(group, dev); + iommu_group_put(group); + + return rc; +} + +static void s390_iommu_remove_device(struct device *dev) +{ + struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; + struct iommu_domain *domain; + + /* + * This is a workaround for a scenario where the IOMMU API common code + * "forgets" to call the detach_dev callback: After binding a device + * to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers + * the attach_dev), removing the device via + * "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev, + * only remove_device will be called via the BUS_NOTIFY_REMOVED_DEVICE + * notifier. + * + * So let's call detach_dev from here if it hasn't been called before. + */ + if (zdev && zdev->s390_domain) { + domain = iommu_get_domain_for_dev(dev); + if (domain) + s390_iommu_detach_device(domain, dev); + } + + iommu_group_remove_device(dev); +} + +static int s390_iommu_update_trans(struct s390_domain *s390_domain, + unsigned long pa, dma_addr_t dma_addr, + size_t size, int flags) +{ + struct s390_domain_device *domain_device; + u8 *page_addr = (u8 *) (pa & PAGE_MASK); + dma_addr_t start_dma_addr = dma_addr; + unsigned long irq_flags, nr_pages, i; + int rc = 0; + + if (dma_addr < s390_domain->domain.geometry.aperture_start || + dma_addr + size > s390_domain->domain.geometry.aperture_end) + return -EINVAL; + + nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; + if (!nr_pages) + return 0; + + spin_lock_irqsave(&s390_domain->dma_table_lock, irq_flags); + for (i = 0; i < nr_pages; i++) { + dma_update_cpu_trans(s390_domain->dma_table, page_addr, + dma_addr, flags); + page_addr += PAGE_SIZE; + dma_addr += PAGE_SIZE; + } + + spin_lock(&s390_domain->list_lock); + list_for_each_entry(domain_device, &s390_domain->devices, list) { + rc = zpci_refresh_trans((u64) domain_device->zdev->fh << 32, + start_dma_addr, nr_pages * PAGE_SIZE); + if (rc) + break; + } + spin_unlock(&s390_domain->list_lock); + spin_unlock_irqrestore(&s390_domain->dma_table_lock, irq_flags); + + return rc; +} + +static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot) +{ + struct s390_domain *s390_domain = to_s390_domain(domain); + int flags = ZPCI_PTE_VALID, rc = 0; + + if (!(prot & IOMMU_READ)) + return -EINVAL; + + if (!(prot & IOMMU_WRITE)) + flags |= ZPCI_TABLE_PROTECTED; + + rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova, + size, flags); + + return rc; +} + +static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain, + dma_addr_t iova) +{ + struct s390_domain *s390_domain = to_s390_domain(domain); + unsigned long *sto, *pto, *rto, flags; + unsigned int rtx, sx, px; + phys_addr_t phys = 0; + + if (iova < domain->geometry.aperture_start || + iova > domain->geometry.aperture_end) + return 0; + + rtx = calc_rtx(iova); + sx = calc_sx(iova); + px = calc_px(iova); + rto = s390_domain->dma_table; + + spin_lock_irqsave(&s390_domain->dma_table_lock, flags); + if (rto && reg_entry_isvalid(rto[rtx])) { + sto = get_rt_sto(rto[rtx]); + if (sto && reg_entry_isvalid(sto[sx])) { + pto = get_st_pto(sto[sx]); + if (pto && pt_entry_isvalid(pto[px])) + phys = pto[px] & ZPCI_PTE_ADDR_MASK; + } + } + spin_unlock_irqrestore(&s390_domain->dma_table_lock, flags); + + return phys; +} + +static size_t s390_iommu_unmap(struct iommu_domain *domain, + unsigned long iova, size_t size) +{ + struct s390_domain *s390_domain = to_s390_domain(domain); + int flags = ZPCI_PTE_INVALID; + phys_addr_t paddr; + int rc; + + paddr = s390_iommu_iova_to_phys(domain, iova); + if (!paddr) + return 0; + + rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova, + size, flags); + if (rc) + return 0; + + return size; +} + +static struct iommu_ops s390_iommu_ops = { + .capable = s390_iommu_capable, + .domain_alloc = s390_domain_alloc, + .domain_free = s390_domain_free, + .attach_dev = s390_iommu_attach_device, + .detach_dev = s390_iommu_detach_device, + .map = s390_iommu_map, + .unmap = s390_iommu_unmap, + .iova_to_phys = s390_iommu_iova_to_phys, + .add_device = s390_iommu_add_device, + .remove_device = s390_iommu_remove_device, + .pgsize_bitmap = S390_IOMMU_PGSIZES, +}; + +static int __init s390_iommu_init(void) +{ + return bus_set_iommu(&pci_bus_type, &s390_iommu_ops); +} +subsys_initcall(s390_iommu_init); -- 2.3.8 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
