diff options
Diffstat (limited to 'drivers/iommu/intel/cache.c')
| -rw-r--r-- | drivers/iommu/intel/cache.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/drivers/iommu/intel/cache.c b/drivers/iommu/intel/cache.c new file mode 100644 index 000000000000..e8418cdd8331 --- /dev/null +++ b/drivers/iommu/intel/cache.c @@ -0,0 +1,419 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * cache.c - Intel VT-d cache invalidation + * + * Copyright (C) 2024 Intel Corporation + * + * Author: Lu Baolu <[email protected]> + */ + +#define pr_fmt(fmt) "DMAR: " fmt + +#include <linux/dmar.h> +#include <linux/iommu.h> +#include <linux/memory.h> +#include <linux/pci.h> +#include <linux/spinlock.h> + +#include "iommu.h" +#include "pasid.h" +#include "trace.h" + +/* Check if an existing cache tag can be reused for a new association. */ +static bool cache_tage_match(struct cache_tag *tag, u16 domain_id, + struct intel_iommu *iommu, struct device *dev, + ioasid_t pasid, enum cache_tag_type type) +{ + if (tag->type != type) + return false; + + if (tag->domain_id != domain_id || tag->pasid != pasid) + return false; + + if (type == CACHE_TAG_IOTLB || type == CACHE_TAG_NESTING_IOTLB) + return tag->iommu == iommu; + + if (type == CACHE_TAG_DEVTLB || type == CACHE_TAG_NESTING_DEVTLB) + return tag->dev == dev; + + return false; +} + +/* Assign a cache tag with specified type to domain. */ +static int cache_tag_assign(struct dmar_domain *domain, u16 did, + struct device *dev, ioasid_t pasid, + enum cache_tag_type type) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + struct intel_iommu *iommu = info->iommu; + struct cache_tag *tag, *temp; + unsigned long flags; + + tag = kzalloc(sizeof(*tag), GFP_KERNEL); + if (!tag) + return -ENOMEM; + + tag->type = type; + tag->iommu = iommu; + tag->domain_id = did; + tag->pasid = pasid; + tag->users = 1; + + if (type == CACHE_TAG_DEVTLB || type == CACHE_TAG_NESTING_DEVTLB) + tag->dev = dev; + else + tag->dev = iommu->iommu.dev; + + spin_lock_irqsave(&domain->cache_lock, flags); + list_for_each_entry(temp, &domain->cache_tags, node) { + if (cache_tage_match(temp, did, iommu, dev, pasid, type)) { + temp->users++; + spin_unlock_irqrestore(&domain->cache_lock, flags); + kfree(tag); + trace_cache_tag_assign(temp); + return 0; + } + } + list_add_tail(&tag->node, &domain->cache_tags); + spin_unlock_irqrestore(&domain->cache_lock, flags); + trace_cache_tag_assign(tag); + + return 0; +} + +/* Unassign a cache tag with specified type from domain. */ +static void cache_tag_unassign(struct dmar_domain *domain, u16 did, + struct device *dev, ioasid_t pasid, + enum cache_tag_type type) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + struct intel_iommu *iommu = info->iommu; + struct cache_tag *tag; + unsigned long flags; + + spin_lock_irqsave(&domain->cache_lock, flags); + list_for_each_entry(tag, &domain->cache_tags, node) { + if (cache_tage_match(tag, did, iommu, dev, pasid, type)) { + trace_cache_tag_unassign(tag); + if (--tag->users == 0) { + list_del(&tag->node); + kfree(tag); + } + break; + } + } + spin_unlock_irqrestore(&domain->cache_lock, flags); +} + +static int __cache_tag_assign_domain(struct dmar_domain *domain, u16 did, + struct device *dev, ioasid_t pasid) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + int ret; + + ret = cache_tag_assign(domain, did, dev, pasid, CACHE_TAG_IOTLB); + if (ret || !info->ats_enabled) + return ret; + + ret = cache_tag_assign(domain, did, dev, pasid, CACHE_TAG_DEVTLB); + if (ret) + cache_tag_unassign(domain, did, dev, pasid, CACHE_TAG_IOTLB); + + return ret; +} + +static void __cache_tag_unassign_domain(struct dmar_domain *domain, u16 did, + struct device *dev, ioasid_t pasid) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + + cache_tag_unassign(domain, did, dev, pasid, CACHE_TAG_IOTLB); + + if (info->ats_enabled) + cache_tag_unassign(domain, did, dev, pasid, CACHE_TAG_DEVTLB); +} + +static int __cache_tag_assign_parent_domain(struct dmar_domain *domain, u16 did, + struct device *dev, ioasid_t pasid) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + int ret; + + ret = cache_tag_assign(domain, did, dev, pasid, CACHE_TAG_NESTING_IOTLB); + if (ret || !info->ats_enabled) + return ret; + + ret = cache_tag_assign(domain, did, dev, pasid, CACHE_TAG_NESTING_DEVTLB); + if (ret) + cache_tag_unassign(domain, did, dev, pasid, CACHE_TAG_NESTING_IOTLB); + + return ret; +} + +static void __cache_tag_unassign_parent_domain(struct dmar_domain *domain, u16 did, + struct device *dev, ioasid_t pasid) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + + cache_tag_unassign(domain, did, dev, pasid, CACHE_TAG_NESTING_IOTLB); + + if (info->ats_enabled) + cache_tag_unassign(domain, did, dev, pasid, CACHE_TAG_NESTING_DEVTLB); +} + +static u16 domain_get_id_for_dev(struct dmar_domain *domain, struct device *dev) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + struct intel_iommu *iommu = info->iommu; + + /* + * The driver assigns different domain IDs for all domains except + * the SVA type. + */ + if (domain->domain.type == IOMMU_DOMAIN_SVA) + return FLPT_DEFAULT_DID; + + return domain_id_iommu(domain, iommu); +} + +/* + * Assign cache tags to a domain when it's associated with a device's + * PASID using a specific domain ID. + * + * On success (return value of 0), cache tags are created and added to the + * domain's cache tag list. On failure (negative return value), an error + * code is returned indicating the reason for the failure. + */ +int cache_tag_assign_domain(struct dmar_domain *domain, + struct device *dev, ioasid_t pasid) +{ + u16 did = domain_get_id_for_dev(domain, dev); + int ret; + + ret = __cache_tag_assign_domain(domain, did, dev, pasid); + if (ret || domain->domain.type != IOMMU_DOMAIN_NESTED) + return ret; + + ret = __cache_tag_assign_parent_domain(domain->s2_domain, did, dev, pasid); + if (ret) + __cache_tag_unassign_domain(domain, did, dev, pasid); + + return ret; +} + +/* + * Remove the cache tags associated with a device's PASID when the domain is + * detached from the device. + * + * The cache tags must be previously assigned to the domain by calling the + * assign interface. + */ +void cache_tag_unassign_domain(struct dmar_domain *domain, + struct device *dev, ioasid_t pasid) +{ + u16 did = domain_get_id_for_dev(domain, dev); + + __cache_tag_unassign_domain(domain, did, dev, pasid); + if (domain->domain.type == IOMMU_DOMAIN_NESTED) + __cache_tag_unassign_parent_domain(domain->s2_domain, did, dev, pasid); +} + +static unsigned long calculate_psi_aligned_address(unsigned long start, + unsigned long end, + unsigned long *_pages, + unsigned long *_mask) +{ + unsigned long pages = aligned_nrpages(start, end - start + 1); + unsigned long aligned_pages = __roundup_pow_of_two(pages); + unsigned long bitmask = aligned_pages - 1; + unsigned long mask = ilog2(aligned_pages); + unsigned long pfn = IOVA_PFN(start); + + /* + * PSI masks the low order bits of the base address. If the + * address isn't aligned to the mask, then compute a mask value + * needed to ensure the target range is flushed. + */ + if (unlikely(bitmask & pfn)) { + unsigned long end_pfn = pfn + pages - 1, shared_bits; + + /* + * Since end_pfn <= pfn + bitmask, the only way bits + * higher than bitmask can differ in pfn and end_pfn is + * by carrying. This means after masking out bitmask, + * high bits starting with the first set bit in + * shared_bits are all equal in both pfn and end_pfn. + */ + shared_bits = ~(pfn ^ end_pfn) & ~bitmask; + mask = shared_bits ? __ffs(shared_bits) : BITS_PER_LONG; + } + + *_pages = aligned_pages; + *_mask = mask; + + return ALIGN_DOWN(start, VTD_PAGE_SIZE << mask); +} + +/* + * Invalidates a range of IOVA from @start (inclusive) to @end (inclusive) + * when the memory mappings in the target domain have been modified. + */ +void cache_tag_flush_range(struct dmar_domain *domain, unsigned long start, + unsigned long end, int ih) +{ + unsigned long pages, mask, addr; + struct cache_tag *tag; + unsigned long flags; + + addr = calculate_psi_aligned_address(start, end, &pages, &mask); + + spin_lock_irqsave(&domain->cache_lock, flags); + list_for_each_entry(tag, &domain->cache_tags, node) { + struct intel_iommu *iommu = tag->iommu; + struct device_domain_info *info; + u16 sid; + + switch (tag->type) { + case CACHE_TAG_IOTLB: + case CACHE_TAG_NESTING_IOTLB: + if (domain->use_first_level) { + qi_flush_piotlb(iommu, tag->domain_id, + tag->pasid, addr, pages, ih); + } else { + /* + * Fallback to domain selective flush if no + * PSI support or the size is too big. + */ + if (!cap_pgsel_inv(iommu->cap) || + mask > cap_max_amask_val(iommu->cap)) + iommu->flush.flush_iotlb(iommu, tag->domain_id, + 0, 0, DMA_TLB_DSI_FLUSH); + else + iommu->flush.flush_iotlb(iommu, tag->domain_id, + addr | ih, mask, + DMA_TLB_PSI_FLUSH); + } + break; + case CACHE_TAG_NESTING_DEVTLB: + /* + * Address translation cache in device side caches the + * result of nested translation. There is no easy way + * to identify the exact set of nested translations + * affected by a change in S2. So just flush the entire + * device cache. + */ + addr = 0; + mask = MAX_AGAW_PFN_WIDTH; + fallthrough; + case CACHE_TAG_DEVTLB: + info = dev_iommu_priv_get(tag->dev); + sid = PCI_DEVID(info->bus, info->devfn); + + if (tag->pasid == IOMMU_NO_PASID) + qi_flush_dev_iotlb(iommu, sid, info->pfsid, + info->ats_qdep, addr, mask); + else + qi_flush_dev_iotlb_pasid(iommu, sid, info->pfsid, + tag->pasid, info->ats_qdep, + addr, mask); + + quirk_extra_dev_tlb_flush(info, addr, mask, tag->pasid, info->ats_qdep); + break; + } + + trace_cache_tag_flush_range(tag, start, end, addr, pages, mask); + } + spin_unlock_irqrestore(&domain->cache_lock, flags); +} + +/* + * Invalidates all ranges of IOVA when the memory mappings in the target + * domain have been modified. + */ +void cache_tag_flush_all(struct dmar_domain *domain) +{ + struct cache_tag *tag; + unsigned long flags; + + spin_lock_irqsave(&domain->cache_lock, flags); + list_for_each_entry(tag, &domain->cache_tags, node) { + struct intel_iommu *iommu = tag->iommu; + struct device_domain_info *info; + u16 sid; + + switch (tag->type) { + case CACHE_TAG_IOTLB: + case CACHE_TAG_NESTING_IOTLB: + if (domain->use_first_level) + qi_flush_piotlb(iommu, tag->domain_id, + tag->pasid, 0, -1, 0); + else + iommu->flush.flush_iotlb(iommu, tag->domain_id, + 0, 0, DMA_TLB_DSI_FLUSH); + break; + case CACHE_TAG_DEVTLB: + case CACHE_TAG_NESTING_DEVTLB: + info = dev_iommu_priv_get(tag->dev); + sid = PCI_DEVID(info->bus, info->devfn); + + qi_flush_dev_iotlb(iommu, sid, info->pfsid, info->ats_qdep, + 0, MAX_AGAW_PFN_WIDTH); + quirk_extra_dev_tlb_flush(info, 0, MAX_AGAW_PFN_WIDTH, + IOMMU_NO_PASID, info->ats_qdep); + break; + } + + trace_cache_tag_flush_all(tag); + } + spin_unlock_irqrestore(&domain->cache_lock, flags); +} + +/* + * Invalidate a range of IOVA when new mappings are created in the target + * domain. + * + * - VT-d spec, Section 6.1 Caching Mode: When the CM field is reported as + * Set, any software updates to remapping structures other than first- + * stage mapping requires explicit invalidation of the caches. + * - VT-d spec, Section 6.8 Write Buffer Flushing: For hardware that requires + * write buffer flushing, software must explicitly perform write-buffer + * flushing, if cache invalidation is not required. + */ +void cache_tag_flush_range_np(struct dmar_domain *domain, unsigned long start, + unsigned long end) +{ + unsigned long pages, mask, addr; + struct cache_tag *tag; + unsigned long flags; + + addr = calculate_psi_aligned_address(start, end, &pages, &mask); + + spin_lock_irqsave(&domain->cache_lock, flags); + list_for_each_entry(tag, &domain->cache_tags, node) { + struct intel_iommu *iommu = tag->iommu; + + if (!cap_caching_mode(iommu->cap) || domain->use_first_level) { + iommu_flush_write_buffer(iommu); + continue; + } + + if (tag->type == CACHE_TAG_IOTLB || + tag->type == CACHE_TAG_NESTING_IOTLB) { + /* + * Fallback to domain selective flush if no + * PSI support or the size is too big. + */ + if (!cap_pgsel_inv(iommu->cap) || + mask > cap_max_amask_val(iommu->cap)) + iommu->flush.flush_iotlb(iommu, tag->domain_id, + 0, 0, DMA_TLB_DSI_FLUSH); + else + iommu->flush.flush_iotlb(iommu, tag->domain_id, + addr, mask, + DMA_TLB_PSI_FLUSH); + } + + trace_cache_tag_flush_range_np(tag, start, end, addr, pages, mask); + } + spin_unlock_irqrestore(&domain->cache_lock, flags); +} |