From fb170fb4c548c6d9fe9f71db946e216abb5c6641 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Fri, 11 Jul 2014 14:19:28 +0800 Subject: [PATCH] iommu/vt-d: Introduce helper functions to make code symmetric for readability Introduce domain_attach_iommu()/domain_detach_iommu() and refine iommu_attach_domain()/iommu_detach_domain() to make code symmetric and improve readability. Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 147 ++++++++++++++++++++---------------- 1 file changed, 80 insertions(+), 67 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 52250b3e58d1..eae9b0d8bc60 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1523,32 +1523,39 @@ static struct dmar_domain *alloc_domain(int flags) return domain; } -static int iommu_attach_domain(struct dmar_domain *domain, - struct intel_iommu *iommu) +static int __iommu_attach_domain(struct dmar_domain *domain, + struct intel_iommu *iommu) { int num; unsigned long ndomains; - unsigned long flags; ndomains = cap_ndoms(iommu->cap); - - spin_lock_irqsave(&iommu->lock, flags); - num = find_first_zero_bit(iommu->domain_ids, ndomains); - if (num >= ndomains) { - spin_unlock_irqrestore(&iommu->lock, flags); - printk(KERN_ERR "IOMMU: no free domain ids\n"); - return -ENOMEM; + if (num < ndomains) { + set_bit(num, iommu->domain_ids); + iommu->domains[num] = domain; + } else { + num = -ENOSPC; } - domain->id = num; - domain->iommu_count++; - set_bit(num, iommu->domain_ids); - set_bit(iommu->seq_id, domain->iommu_bmp); - iommu->domains[num] = domain; + return num; +} + +static int iommu_attach_domain(struct dmar_domain *domain, + struct intel_iommu *iommu) +{ + int num; + unsigned long flags; + + spin_lock_irqsave(&iommu->lock, flags); + num = __iommu_attach_domain(domain, iommu); + if (num < 0) + pr_err("IOMMU: no free domain ids\n"); + else + domain->id = num; spin_unlock_irqrestore(&iommu->lock, flags); - return 0; + return num; } static void iommu_detach_domain(struct dmar_domain *domain, @@ -1558,17 +1565,53 @@ static void iommu_detach_domain(struct dmar_domain *domain, int num, ndomains; spin_lock_irqsave(&iommu->lock, flags); - ndomains = cap_ndoms(iommu->cap); - for_each_set_bit(num, iommu->domain_ids, ndomains) { - if (iommu->domains[num] == domain) { - clear_bit(num, iommu->domain_ids); - iommu->domains[num] = NULL; - break; + if (domain_type_is_vm_or_si(domain)) { + ndomains = cap_ndoms(iommu->cap); + for_each_set_bit(num, iommu->domain_ids, ndomains) { + if (iommu->domains[num] == domain) { + clear_bit(num, iommu->domain_ids); + iommu->domains[num] = NULL; + break; + } } + } else { + clear_bit(domain->id, iommu->domain_ids); + iommu->domains[domain->id] = NULL; } spin_unlock_irqrestore(&iommu->lock, flags); } +static void domain_attach_iommu(struct dmar_domain *domain, + struct intel_iommu *iommu) +{ + unsigned long flags; + + spin_lock_irqsave(&domain->iommu_lock, flags); + if (!test_and_set_bit(iommu->seq_id, domain->iommu_bmp)) { + domain->iommu_count++; + if (domain->iommu_count == 1) + domain->nid = iommu->node; + domain_update_iommu_cap(domain); + } + spin_unlock_irqrestore(&domain->iommu_lock, flags); +} + +static int domain_detach_iommu(struct dmar_domain *domain, + struct intel_iommu *iommu) +{ + unsigned long flags; + int count = INT_MAX; + + spin_lock_irqsave(&domain->iommu_lock, flags); + if (test_and_clear_bit(iommu->seq_id, domain->iommu_bmp)) { + count = --domain->iommu_count; + domain_update_iommu_cap(domain); + } + spin_unlock_irqrestore(&domain->iommu_lock, flags); + + return count; +} + static struct iova_domain reserved_iova_list; static struct lock_class_key reserved_rbtree_key; @@ -1706,9 +1749,7 @@ static void domain_exit(struct dmar_domain *domain) /* clear attached or cached domains */ rcu_read_lock(); for_each_active_iommu(iommu, drhd) - if (domain_type_is_vm(domain) || - test_bit(iommu->seq_id, domain->iommu_bmp)) - iommu_detach_domain(domain, iommu); + iommu_detach_domain(domain, iommu); rcu_read_unlock(); dma_free_pagelist(freelist); @@ -1762,16 +1803,12 @@ static int domain_context_mapping_one(struct dmar_domain *domain, } if (found == 0) { - num = find_first_zero_bit(iommu->domain_ids, ndomains); - if (num >= ndomains) { + id = __iommu_attach_domain(domain, iommu); + if (id < 0) { spin_unlock_irqrestore(&iommu->lock, flags); - printk(KERN_ERR "IOMMU: no free domain ids\n"); + pr_err("IOMMU: no free domain ids\n"); return -EFAULT; } - - set_bit(num, iommu->domain_ids); - iommu->domains[num] = domain; - id = num; } /* Skip top levels of page tables for @@ -1830,14 +1867,8 @@ static int domain_context_mapping_one(struct dmar_domain *domain, iommu_enable_dev_iotlb(info); spin_unlock_irqrestore(&iommu->lock, flags); - spin_lock_irqsave(&domain->iommu_lock, flags); - if (!test_and_set_bit(iommu->seq_id, domain->iommu_bmp)) { - domain->iommu_count++; - if (domain->iommu_count == 1) - domain->nid = iommu->node; - domain_update_iommu_cap(domain); - } - spin_unlock_irqrestore(&domain->iommu_lock, flags); + domain_attach_iommu(domain, iommu); + return 0; } @@ -2085,7 +2116,7 @@ static inline void unlink_domain_info(struct device_domain_info *info) static void domain_remove_dev_info(struct dmar_domain *domain) { struct device_domain_info *info, *tmp; - unsigned long flags, flags2; + unsigned long flags; spin_lock_irqsave(&device_domain_lock, flags); list_for_each_entry_safe(info, tmp, &domain->devices, link) { @@ -2097,16 +2128,7 @@ static void domain_remove_dev_info(struct dmar_domain *domain) if (domain_type_is_vm(domain)) { iommu_detach_dependent_devices(info->iommu, info->dev); - /* clear this iommu in iommu_bmp, update iommu count - * and capabilities - */ - spin_lock_irqsave(&domain->iommu_lock, flags2); - if (test_and_clear_bit(info->iommu->seq_id, - domain->iommu_bmp)) { - domain->iommu_count--; - domain_update_iommu_cap(domain); - } - spin_unlock_irqrestore(&domain->iommu_lock, flags2); + domain_detach_iommu(domain, info->iommu); } free_devinfo_mem(info); @@ -2236,11 +2258,11 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw) if (!domain) return NULL; - if (iommu_attach_domain(domain, iommu)) { + if (iommu_attach_domain(domain, iommu) < 0) { free_domain_mem(domain); return NULL; } - + domain_attach_iommu(domain, iommu); if (domain_init(domain, gaw)) { domain_exit(domain); return NULL; @@ -2413,10 +2435,11 @@ static int __init si_domain_init(int hw) for_each_active_iommu(iommu, drhd) { ret = iommu_attach_domain(si_domain, iommu); - if (ret) { + if (ret < 0) { domain_exit(si_domain); return -EFAULT; } + domain_attach_iommu(si_domain, iommu); } if (md_domain_init(si_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) { @@ -4155,19 +4178,9 @@ static void domain_remove_one_dev_info(struct dmar_domain *domain, spin_unlock_irqrestore(&device_domain_lock, flags); if (found == 0) { - unsigned long tmp_flags; - spin_lock_irqsave(&domain->iommu_lock, tmp_flags); - clear_bit(iommu->seq_id, domain->iommu_bmp); - domain->iommu_count--; - domain_update_iommu_cap(domain); - spin_unlock_irqrestore(&domain->iommu_lock, tmp_flags); - - if (!domain_type_is_vm_or_si(domain)) { - spin_lock_irqsave(&iommu->lock, tmp_flags); - clear_bit(domain->id, iommu->domain_ids); - iommu->domains[domain->id] = NULL; - spin_unlock_irqrestore(&iommu->lock, tmp_flags); - } + domain_detach_iommu(domain, iommu); + if (!domain_type_is_vm_or_si(domain)) + iommu_detach_domain(domain, iommu); } } -- 2.30.2