diff options
author | Niklas Schnelle <schnelle@linux.ibm.com> | 2023-09-28 17:31:37 +0300 |
---|---|---|
committer | Joerg Roedel <jroedel@suse.de> | 2023-10-02 09:43:00 +0300 |
commit | c76c067e488ccd55734c3e750799caf2c5956db6 (patch) | |
tree | c4489302a1c2a119afcba4b54535cb4d8c65cbee /drivers/iommu/s390-iommu.c | |
parent | b6f888709a155b4e748aded93afc9fa43aaa28dd (diff) | |
download | linux-c76c067e488ccd55734c3e750799caf2c5956db6.tar.xz |
s390/pci: Use dma-iommu layer
While s390 already has a standard IOMMU driver and previous changes have
added I/O TLB flushing operations this driver is currently only used for
user-space PCI access such as vfio-pci. For the DMA API s390 instead
utilizes its own implementation in arch/s390/pci/pci_dma.c which drives
the same hardware and shares some code but requires a complex and
fragile hand over between DMA API and IOMMU API use of a device and
despite code sharing still leads to significant duplication and
maintenance effort. Let's utilize the common code DMAP API
implementation from drivers/iommu/dma-iommu.c instead allowing us to
get rid of arch/s390/pci/pci_dma.c.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-3-9e5fc4dacc36@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/s390-iommu.c')
-rw-r--r-- | drivers/iommu/s390-iommu.c | 400 |
1 files changed, 359 insertions, 41 deletions
diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c index 560d0957f9be..bb9e48c82644 100644 --- a/drivers/iommu/s390-iommu.c +++ b/drivers/iommu/s390-iommu.c @@ -14,16 +14,300 @@ #include <linux/rcupdate.h> #include <asm/pci_dma.h> +#include "dma-iommu.h" + static const struct iommu_ops s390_iommu_ops; +static struct kmem_cache *dma_region_table_cache; +static struct kmem_cache *dma_page_table_cache; + +static u64 s390_iommu_aperture; +static u32 s390_iommu_aperture_factor = 1; + struct s390_domain { struct iommu_domain domain; struct list_head devices; + struct zpci_iommu_ctrs ctrs; unsigned long *dma_table; spinlock_t list_lock; struct rcu_head rcu; }; +static inline unsigned int calc_rtx(dma_addr_t ptr) +{ + return ((unsigned long)ptr >> ZPCI_RT_SHIFT) & ZPCI_INDEX_MASK; +} + +static inline unsigned int calc_sx(dma_addr_t ptr) +{ + return ((unsigned long)ptr >> ZPCI_ST_SHIFT) & ZPCI_INDEX_MASK; +} + +static inline unsigned int calc_px(dma_addr_t ptr) +{ + return ((unsigned long)ptr >> PAGE_SHIFT) & ZPCI_PT_MASK; +} + +static inline void set_pt_pfaa(unsigned long *entry, phys_addr_t pfaa) +{ + *entry &= ZPCI_PTE_FLAG_MASK; + *entry |= (pfaa & ZPCI_PTE_ADDR_MASK); +} + +static inline void set_rt_sto(unsigned long *entry, phys_addr_t sto) +{ + *entry &= ZPCI_RTE_FLAG_MASK; + *entry |= (sto & ZPCI_RTE_ADDR_MASK); + *entry |= ZPCI_TABLE_TYPE_RTX; +} + +static inline void set_st_pto(unsigned long *entry, phys_addr_t pto) +{ + *entry &= ZPCI_STE_FLAG_MASK; + *entry |= (pto & ZPCI_STE_ADDR_MASK); + *entry |= ZPCI_TABLE_TYPE_SX; +} + +static inline void validate_rt_entry(unsigned long *entry) +{ + *entry &= ~ZPCI_TABLE_VALID_MASK; + *entry &= ~ZPCI_TABLE_OFFSET_MASK; + *entry |= ZPCI_TABLE_VALID; + *entry |= ZPCI_TABLE_LEN_RTX; +} + +static inline void validate_st_entry(unsigned long *entry) +{ + *entry &= ~ZPCI_TABLE_VALID_MASK; + *entry |= ZPCI_TABLE_VALID; +} + +static inline void invalidate_pt_entry(unsigned long *entry) +{ + WARN_ON_ONCE((*entry & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_INVALID); + *entry &= ~ZPCI_PTE_VALID_MASK; + *entry |= ZPCI_PTE_INVALID; +} + +static inline void validate_pt_entry(unsigned long *entry) +{ + WARN_ON_ONCE((*entry & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID); + *entry &= ~ZPCI_PTE_VALID_MASK; + *entry |= ZPCI_PTE_VALID; +} + +static inline void entry_set_protected(unsigned long *entry) +{ + *entry &= ~ZPCI_TABLE_PROT_MASK; + *entry |= ZPCI_TABLE_PROTECTED; +} + +static inline void entry_clr_protected(unsigned long *entry) +{ + *entry &= ~ZPCI_TABLE_PROT_MASK; + *entry |= ZPCI_TABLE_UNPROTECTED; +} + +static inline int reg_entry_isvalid(unsigned long entry) +{ + return (entry & ZPCI_TABLE_VALID_MASK) == ZPCI_TABLE_VALID; +} + +static inline int pt_entry_isvalid(unsigned long entry) +{ + return (entry & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID; +} + +static inline unsigned long *get_rt_sto(unsigned long entry) +{ + if ((entry & ZPCI_TABLE_TYPE_MASK) == ZPCI_TABLE_TYPE_RTX) + return phys_to_virt(entry & ZPCI_RTE_ADDR_MASK); + else + return NULL; +} + +static inline unsigned long *get_st_pto(unsigned long entry) +{ + if ((entry & ZPCI_TABLE_TYPE_MASK) == ZPCI_TABLE_TYPE_SX) + return phys_to_virt(entry & ZPCI_STE_ADDR_MASK); + else + return NULL; +} + +static int __init dma_alloc_cpu_table_caches(void) +{ + dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables", + ZPCI_TABLE_SIZE, + ZPCI_TABLE_ALIGN, + 0, NULL); + if (!dma_region_table_cache) + return -ENOMEM; + + dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables", + ZPCI_PT_SIZE, + ZPCI_PT_ALIGN, + 0, NULL); + if (!dma_page_table_cache) { + kmem_cache_destroy(dma_region_table_cache); + return -ENOMEM; + } + return 0; +} + +static unsigned long *dma_alloc_cpu_table(gfp_t gfp) +{ + unsigned long *table, *entry; + + table = kmem_cache_alloc(dma_region_table_cache, gfp); + if (!table) + return NULL; + + for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++) + *entry = ZPCI_TABLE_INVALID; + return table; +} + +static void dma_free_cpu_table(void *table) +{ + kmem_cache_free(dma_region_table_cache, table); +} + +static void dma_free_page_table(void *table) +{ + kmem_cache_free(dma_page_table_cache, table); +} + +static void dma_free_seg_table(unsigned long entry) +{ + unsigned long *sto = get_rt_sto(entry); + int sx; + + for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++) + if (reg_entry_isvalid(sto[sx])) + dma_free_page_table(get_st_pto(sto[sx])); + + dma_free_cpu_table(sto); +} + +static void dma_cleanup_tables(unsigned long *table) +{ + int rtx; + + if (!table) + return; + + 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); +} + +static unsigned long *dma_alloc_page_table(gfp_t gfp) +{ + unsigned long *table, *entry; + + table = kmem_cache_alloc(dma_page_table_cache, gfp); + if (!table) + return NULL; + + for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++) + *entry = ZPCI_PTE_INVALID; + return table; +} + +static unsigned long *dma_get_seg_table_origin(unsigned long *rtep, gfp_t gfp) +{ + unsigned long old_rte, rte; + unsigned long *sto; + + rte = READ_ONCE(*rtep); + if (reg_entry_isvalid(rte)) { + sto = get_rt_sto(rte); + } else { + sto = dma_alloc_cpu_table(gfp); + if (!sto) + return NULL; + + set_rt_sto(&rte, virt_to_phys(sto)); + validate_rt_entry(&rte); + entry_clr_protected(&rte); + + old_rte = cmpxchg(rtep, ZPCI_TABLE_INVALID, rte); + if (old_rte != ZPCI_TABLE_INVALID) { + /* Somone else was faster, use theirs */ + dma_free_cpu_table(sto); + sto = get_rt_sto(old_rte); + } + } + return sto; +} + +static unsigned long *dma_get_page_table_origin(unsigned long *step, gfp_t gfp) +{ + unsigned long old_ste, ste; + unsigned long *pto; + + ste = READ_ONCE(*step); + if (reg_entry_isvalid(ste)) { + pto = get_st_pto(ste); + } else { + pto = dma_alloc_page_table(gfp); + if (!pto) + return NULL; + set_st_pto(&ste, virt_to_phys(pto)); + validate_st_entry(&ste); + entry_clr_protected(&ste); + + old_ste = cmpxchg(step, ZPCI_TABLE_INVALID, ste); + if (old_ste != ZPCI_TABLE_INVALID) { + /* Somone else was faster, use theirs */ + dma_free_page_table(pto); + pto = get_st_pto(old_ste); + } + } + return pto; +} + +static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr, gfp_t gfp) +{ + unsigned long *sto, *pto; + unsigned int rtx, sx, px; + + rtx = calc_rtx(dma_addr); + sto = dma_get_seg_table_origin(&rto[rtx], gfp); + if (!sto) + return NULL; + + sx = calc_sx(dma_addr); + pto = dma_get_page_table_origin(&sto[sx], gfp); + if (!pto) + return NULL; + + px = calc_px(dma_addr); + return &pto[px]; +} + +static void dma_update_cpu_trans(unsigned long *ptep, phys_addr_t page_addr, int flags) +{ + unsigned long pte; + + pte = READ_ONCE(*ptep); + if (flags & ZPCI_PTE_INVALID) { + invalidate_pt_entry(&pte); + } else { + set_pt_pfaa(&pte, page_addr); + validate_pt_entry(&pte); + } + + if (flags & ZPCI_TABLE_PROTECTED) + entry_set_protected(&pte); + else + entry_clr_protected(&pte); + + xchg(ptep, pte); +} + static struct s390_domain *to_s390_domain(struct iommu_domain *dom) { return container_of(dom, struct s390_domain, domain); @@ -34,6 +318,8 @@ static bool s390_iommu_capable(struct device *dev, enum iommu_cap cap) switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: return true; + case IOMMU_CAP_DEFERRED_FLUSH: + return true; default: return false; } @@ -81,14 +367,13 @@ static void s390_domain_free(struct iommu_domain *domain) call_rcu(&s390_domain->rcu, s390_iommu_rcu_free_domain); } -static void __s390_iommu_detach_device(struct zpci_dev *zdev) +static void s390_iommu_detach_device(struct iommu_domain *domain, + struct device *dev) { - struct s390_domain *s390_domain = zdev->s390_domain; + struct s390_domain *s390_domain = to_s390_domain(domain); + struct zpci_dev *zdev = to_zpci_dev(dev); unsigned long flags; - if (!s390_domain) - return; - spin_lock_irqsave(&s390_domain->list_lock, flags); list_del_rcu(&zdev->iommu_list); spin_unlock_irqrestore(&s390_domain->list_lock, flags); @@ -115,9 +400,7 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, return -EINVAL; if (zdev->s390_domain) - __s390_iommu_detach_device(zdev); - else if (zdev->dma_table) - zpci_dma_exit_device(zdev); + s390_iommu_detach_device(&zdev->s390_domain->domain, dev); cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, virt_to_phys(s390_domain->dma_table), &status); @@ -127,7 +410,6 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, */ if (cc && status != ZPCI_PCI_ST_FUNC_NOT_AVAIL) return -EIO; - zdev->dma_table = s390_domain->dma_table; zdev->dma_table = s390_domain->dma_table; zdev->s390_domain = s390_domain; @@ -139,31 +421,6 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, return 0; } -/* - * Switch control over the IOMMU to S390's internal dma_api ops - */ -static int s390_iommu_platform_attach(struct iommu_domain *platform_domain, - struct device *dev) -{ - struct zpci_dev *zdev = to_zpci_dev(dev); - - if (!zdev->s390_domain) - return 0; - - __s390_iommu_detach_device(zdev); - zpci_dma_init_device(zdev); - return 0; -} - -static struct iommu_domain_ops s390_iommu_platform_ops = { - .attach_dev = s390_iommu_platform_attach, -}; - -static struct iommu_domain s390_iommu_platform_domain = { - .type = IOMMU_DOMAIN_PLATFORM, - .ops = &s390_iommu_platform_ops, -}; - static void s390_iommu_get_resv_regions(struct device *dev, struct list_head *list) { @@ -216,7 +473,7 @@ static void s390_iommu_release_device(struct device *dev) * to the device, but keep it attached to other devices in the group. */ if (zdev) - __s390_iommu_detach_device(zdev); + s390_iommu_detach_device(&zdev->s390_domain->domain, dev); } static int zpci_refresh_all(struct zpci_dev *zdev) @@ -232,6 +489,7 @@ static void s390_iommu_flush_iotlb_all(struct iommu_domain *domain) rcu_read_lock(); list_for_each_entry_rcu(zdev, &s390_domain->devices, iommu_list) { + atomic64_inc(&s390_domain->ctrs.global_rpcits); zpci_refresh_all(zdev); } rcu_read_unlock(); @@ -250,6 +508,7 @@ static void s390_iommu_iotlb_sync(struct iommu_domain *domain, rcu_read_lock(); list_for_each_entry_rcu(zdev, &s390_domain->devices, iommu_list) { + atomic64_inc(&s390_domain->ctrs.sync_rpcits); zpci_refresh_trans((u64)zdev->fh << 32, gather->start, size); } @@ -267,6 +526,7 @@ static int s390_iommu_iotlb_sync_map(struct iommu_domain *domain, list_for_each_entry_rcu(zdev, &s390_domain->devices, iommu_list) { if (!zdev->tlb_refresh) continue; + atomic64_inc(&s390_domain->ctrs.sync_map_rpcits); ret = zpci_refresh_trans((u64)zdev->fh << 32, iova, size); /* @@ -361,16 +621,15 @@ static int s390_iommu_map_pages(struct iommu_domain *domain, if (!IS_ALIGNED(iova | paddr, pgsize)) return -EINVAL; - if (!(prot & IOMMU_READ)) - return -EINVAL; - if (!(prot & IOMMU_WRITE)) flags |= ZPCI_TABLE_PROTECTED; rc = s390_iommu_validate_trans(s390_domain, paddr, iova, - pgcount, flags, gfp); - if (!rc) + pgcount, flags, gfp); + if (!rc) { *mapped = size; + atomic64_add(pgcount, &s390_domain->ctrs.mapped_pages); + } return rc; } @@ -426,12 +685,26 @@ static size_t s390_iommu_unmap_pages(struct iommu_domain *domain, return 0; iommu_iotlb_gather_add_range(gather, iova, size); + atomic64_add(pgcount, &s390_domain->ctrs.unmapped_pages); return size; } +static void s390_iommu_probe_finalize(struct device *dev) +{ + iommu_setup_dma_ops(dev, 0, U64_MAX); +} + +struct zpci_iommu_ctrs *zpci_get_iommu_ctrs(struct zpci_dev *zdev) +{ + if (!zdev || !zdev->s390_domain) + return NULL; + return &zdev->s390_domain->ctrs; +} + int zpci_init_iommu(struct zpci_dev *zdev) { + u64 aperture_size; int rc = 0; rc = iommu_device_sysfs_add(&zdev->iommu_dev, NULL, NULL, @@ -443,6 +716,12 @@ int zpci_init_iommu(struct zpci_dev *zdev) if (rc) goto out_sysfs; + zdev->start_dma = PAGE_ALIGN(zdev->start_dma); + aperture_size = min3(s390_iommu_aperture, + ZPCI_TABLE_SIZE_RT - zdev->start_dma, + zdev->end_dma - zdev->start_dma + 1); + zdev->end_dma = zdev->start_dma + aperture_size - 1; + return 0; out_sysfs: @@ -458,11 +737,50 @@ void zpci_destroy_iommu(struct zpci_dev *zdev) iommu_device_sysfs_remove(&zdev->iommu_dev); } +static int __init s390_iommu_setup(char *str) +{ + if (!strcmp(str, "strict")) { + pr_warn("s390_iommu=strict deprecated; use iommu.strict=1 instead\n"); + iommu_set_dma_strict(); + } + return 1; +} + +__setup("s390_iommu=", s390_iommu_setup); + +static int __init s390_iommu_aperture_setup(char *str) +{ + if (kstrtou32(str, 10, &s390_iommu_aperture_factor)) + s390_iommu_aperture_factor = 1; + return 1; +} + +__setup("s390_iommu_aperture=", s390_iommu_aperture_setup); + +static int __init s390_iommu_init(void) +{ + int rc; + + iommu_dma_forcedac = true; + s390_iommu_aperture = (u64)virt_to_phys(high_memory); + if (!s390_iommu_aperture_factor) + s390_iommu_aperture = ULONG_MAX; + else + s390_iommu_aperture *= s390_iommu_aperture_factor; + + rc = dma_alloc_cpu_table_caches(); + if (rc) + return rc; + + return rc; +} +subsys_initcall(s390_iommu_init); + static const struct iommu_ops s390_iommu_ops = { - .default_domain = &s390_iommu_platform_domain, .capable = s390_iommu_capable, .domain_alloc_paging = s390_domain_alloc_paging, .probe_device = s390_iommu_probe_device, + .probe_finalize = s390_iommu_probe_finalize, .release_device = s390_iommu_release_device, .device_group = generic_device_group, .pgsize_bitmap = SZ_4K, |