diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/include/asm/pci.h | 1 | ||||
| -rw-r--r-- | arch/s390/pci/pci_dma.c | 74 |
2 files changed, 45 insertions, 30 deletions
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h index e4c3e4e04d30..b248694e0024 100644 --- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -157,7 +157,6 @@ struct zpci_dev { /* DMA stuff */ unsigned long *dma_table; - spinlock_t dma_table_lock; int tlb_refresh; spinlock_t iommu_bitmap_lock; diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index dee825ee7305..ea478d11fbd1 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -63,37 +63,55 @@ static void dma_free_page_table(void *table) kmem_cache_free(dma_page_table_cache, table); } -static unsigned long *dma_get_seg_table_origin(unsigned long *entry) +static unsigned long *dma_get_seg_table_origin(unsigned long *rtep) { + unsigned long old_rte, rte; unsigned long *sto; - if (reg_entry_isvalid(*entry)) - sto = get_rt_sto(*entry); - else { + rte = READ_ONCE(*rtep); + if (reg_entry_isvalid(rte)) { + sto = get_rt_sto(rte); + } else { sto = dma_alloc_cpu_table(); if (!sto) return NULL; - set_rt_sto(entry, virt_to_phys(sto)); - validate_rt_entry(entry); - entry_clr_protected(entry); + 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 *entry) +static unsigned long *dma_get_page_table_origin(unsigned long *step) { + unsigned long old_ste, ste; unsigned long *pto; - if (reg_entry_isvalid(*entry)) - pto = get_st_pto(*entry); - else { + ste = READ_ONCE(*step); + if (reg_entry_isvalid(ste)) { + pto = get_st_pto(ste); + } else { pto = dma_alloc_page_table(); if (!pto) return NULL; - set_st_pto(entry, virt_to_phys(pto)); - validate_st_entry(entry); - entry_clr_protected(entry); + 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; } @@ -117,19 +135,24 @@ unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr) return &pto[px]; } -void dma_update_cpu_trans(unsigned long *entry, phys_addr_t page_addr, int flags) +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(entry); + invalidate_pt_entry(&pte); } else { - set_pt_pfaa(entry, page_addr); - validate_pt_entry(entry); + set_pt_pfaa(&pte, page_addr); + validate_pt_entry(&pte); } if (flags & ZPCI_TABLE_PROTECTED) - entry_set_protected(entry); + entry_set_protected(&pte); else - entry_clr_protected(entry); + entry_clr_protected(&pte); + + xchg(ptep, pte); } static int __dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa, @@ -137,18 +160,14 @@ static int __dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa, { unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; phys_addr_t page_addr = (pa & PAGE_MASK); - unsigned long irq_flags; unsigned long *entry; int i, rc = 0; if (!nr_pages) return -EINVAL; - spin_lock_irqsave(&zdev->dma_table_lock, irq_flags); - if (!zdev->dma_table) { - rc = -EINVAL; - goto out_unlock; - } + if (!zdev->dma_table) + return -EINVAL; for (i = 0; i < nr_pages; i++) { entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr); @@ -173,8 +192,6 @@ undo_cpu_trans: dma_update_cpu_trans(entry, page_addr, flags); } } -out_unlock: - spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags); return rc; } @@ -558,7 +575,6 @@ int zpci_dma_init_device(struct zpci_dev *zdev) WARN_ON(zdev->s390_domain); spin_lock_init(&zdev->iommu_bitmap_lock); - spin_lock_init(&zdev->dma_table_lock); zdev->dma_table = dma_alloc_cpu_table(); if (!zdev->dma_table) { |