[RFC 6/7] iommu/vt-d: convert the intel iommu driver to the dma-iommu ops api

Tom Murphy
2019-05-04T13:23:22Z

Convert the intel iommu driver to the dma-iommu api to allow us to
remove the iova handling code and the reserved region code

Signed-off-by: Tom Murphy <tmurphy@arista.com>
---
drivers/iommu/Kconfig | 1 +
drivers/iommu/intel-iommu.c | 405 ++----------------------------------
include/linux/intel-iommu.h | 1 -
3 files changed, 20 insertions(+), 387 deletions(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 6f07f3b21816..dfed97f55b6e 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -180,6 +180,7 @@ config INTEL_IOMMU
select IOMMU_IOVA
select NEED_DMA_MAP_STATE
select DMAR_TABLE
+ select IOMMU_DMA
help
DMA remapping (DMAR) devices support enables independent address
translations for Direct Memory Access (DMA) from devices.
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 87622a28b854..980fc4816d72 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -39,6 +39,7 @@
#include <linux/io.h>
#include <linux/iova.h>
#include <linux/iommu.h>
+#include <linux/dma-iommu.h>
#include <linux/intel-iommu.h>
#include <linux/syscore_ops.h>
#include <linux/tboot.h>
@@ -1180,13 +1181,6 @@ static void dma_free_pagelist(struct page *freelist)
}
}

-static void iova_entry_free(unsigned long data)
-{
- struct page *freelist = (struct page *)data;
-
- dma_free_pagelist(freelist);
-}
-
/* iommu handling */
static int iommu_alloc_root_entry(struct intel_iommu *iommu)
{
@@ -1530,16 +1524,14 @@ static inline void __mapping_notify_one(struct intel_iommu *iommu,
iommu_flush_write_buffer(iommu);
}

-static void iommu_flush_iova(struct iova_domain *iovad)
+static void iommu_flush_iova(struct iommu_domain *domain)
{
- struct dmar_domain *domain;
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
int idx;

- domain = container_of(iovad, struct dmar_domain, iovad);
-
- for_each_domain_iommu(idx, domain) {
+ for_each_domain_iommu(idx, dmar_domain) {
struct intel_iommu *iommu = g_iommus[idx];
- u16 did = domain->iommu_did[iommu->seq_id];
+ u16 did = dmar_domain->iommu_did[iommu->seq_id];

iommu->flush.flush_iotlb(iommu, did, 0, 0, DMA_TLB_DSI_FLUSH);

@@ -1804,48 +1796,6 @@ static int domain_detach_iommu(struct dmar_domain *domain,
return count;
}

-static struct iova_domain reserved_iova_list;
-static struct lock_class_key reserved_rbtree_key;
-
-static int dmar_init_reserved_ranges(void)
-{
- struct pci_dev *pdev = NULL;
- struct iova *iova;
- int i;
-
- init_iova_domain(&reserved_iova_list, VTD_PAGE_SIZE, IOVA_START_PFN);
-
- lockdep_set_class(&reserved_iova_list.iova_rbtree_lock,
- &reserved_rbtree_key);
-
- /* IOAPIC ranges shouldn't be accessed by DMA */
- iova = reserve_iova(&reserved_iova_list, IOVA_PFN(IOAPIC_RANGE_START),
- IOVA_PFN(IOAPIC_RANGE_END));
- if (!iova) {
- pr_err("Reserve IOAPIC range failed\n");
- return -ENODEV;
- }
-
- /* Reserve all PCI MMIO to avoid peer-to-peer access */
- for_each_pci_dev(pdev) {
- struct resource *r;
-
- for (i = 0; i < PCI_NUM_RESOURCES; i++) {
- r = &pdev->resource[i];
- if (!r->flags || !(r->flags & IORESOURCE_MEM))
- continue;
- iova = reserve_iova(&reserved_iova_list,
- IOVA_PFN(r->start),
- IOVA_PFN(r->end));
- if (!iova) {
- pci_err(pdev, "Reserve iova for %pR failed\n", r);
- return -ENODEV;
- }
- }
- }
- return 0;
-}
-
static inline int guestwidth_to_adjustwidth(int gaw)
{
int agaw;
@@ -1871,7 +1821,7 @@ static void domain_exit(struct dmar_domain *domain)

/* destroy iovas */
if (domain->domain.type == IOMMU_DOMAIN_DMA)
- put_iova_domain(&domain->iovad);
+ iommu_put_dma_cookie(&domain->domain);

freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw), NULL);

@@ -3213,296 +3163,6 @@ static int __init init_dmars(void)
return ret;
}

-/* This takes a number of _MM_ pages, not VTD pages */
-static unsigned long intel_alloc_iova(struct device *dev,
- struct dmar_domain *domain,
- unsigned long nrpages, uint64_t dma_mask)
-{
- unsigned long iova_pfn;
-
- /* Restrict dma_mask to the width that the iommu can handle */
- dma_mask = min_t(uint64_t, DOMAIN_MAX_ADDR(domain->gaw), dma_mask);
- /* Ensure we reserve the whole size-aligned region */
- nrpages = __roundup_pow_of_two(nrpages);
-
- if (!dmar_forcedac && dma_mask > DMA_BIT_MASK(32)) {
- /*
- * First try to allocate an io virtual address in
- * DMA_BIT_MASK(32) and if that fails then try allocating
- * from higher range
- */
- iova_pfn = alloc_iova_fast(&domain->iovad, nrpages,
- IOVA_PFN(DMA_BIT_MASK(32)), false);
- if (iova_pfn)
- return iova_pfn;
- }
- iova_pfn = alloc_iova_fast(&domain->iovad, nrpages,
- IOVA_PFN(dma_mask), true);
- if (unlikely(!iova_pfn)) {
- dev_err(dev, "Allocating %ld-page iova failed", nrpages);
- return 0;
- }
-
- return iova_pfn;
-}
-
-static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
- size_t size, int dir, u64 dma_mask)
-{
- struct dmar_domain *domain;
- phys_addr_t start_paddr;
- unsigned long iova_pfn;
- int prot = 0;
- int ret;
- struct intel_iommu *iommu;
- unsigned long paddr_pfn = paddr >> PAGE_SHIFT;
-
- BUG_ON(dir == DMA_NONE);
-
- domain = find_domain(dev);
- if (!domain)
- return DMA_MAPPING_ERROR;
-
- iommu = domain_get_iommu(domain);
- size = aligned_nrpages(paddr, size);
-
- iova_pfn = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size), dma_mask);
- if (!iova_pfn)
- goto error;
-
- /*
- * Check if DMAR supports zero-length reads on write only
- * mappings..
- */
- if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL || \
- !cap_zlr(iommu->cap))
- prot |= DMA_PTE_READ;
- if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
- prot |= DMA_PTE_WRITE;
- /*
- * paddr - (paddr + size) might be partial page, we should map the whole
- * page. Note: if two part of one page are separately mapped, we
- * might have two guest_addr mapping to the same host paddr, but this
- * is not a big problem
- */
- ret = domain_pfn_mapping(domain, mm_to_dma_pfn(iova_pfn),
- mm_to_dma_pfn(paddr_pfn), size, prot);
- if (ret)
- goto error;
-
- start_paddr = (phys_addr_t)iova_pfn << PAGE_SHIFT;
- start_paddr += paddr & ~PAGE_MASK;
- return start_paddr;
-
-error:
- if (iova_pfn)
- free_iova_fast(&domain->iovad, iova_pfn, dma_to_mm_pfn(size));
- dev_err(dev, "Device request: %zx@%llx dir %d --- failed\n",
- size, (unsigned long long)paddr, dir);
- return DMA_MAPPING_ERROR;
-}
-
-static dma_addr_t intel_map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size,
- enum dma_data_direction dir,
- unsigned long attrs)
-{
- return __intel_map_single(dev, page_to_phys(page) + offset, size,
- dir, *dev->dma_mask);
-}
-
-static dma_addr_t intel_map_resource(struct device *dev, phys_addr_t phys_addr,
- size_t size, enum dma_data_direction dir,
- unsigned long attrs)
-{
- return __intel_map_single(dev, phys_addr, size, dir, *dev->dma_mask);
-}
-
-static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
-{
- struct dmar_domain *domain;
- unsigned long start_pfn, last_pfn;
- unsigned long nrpages;
- unsigned long iova_pfn;
- struct intel_iommu *iommu;
- struct page *freelist;
-
- domain = find_domain(dev);
- BUG_ON(!domain);
-
- iommu = domain_get_iommu(domain);
-
- iova_pfn = IOVA_PFN(dev_addr);
-
- nrpages = aligned_nrpages(dev_addr, size);
- start_pfn = mm_to_dma_pfn(iova_pfn);
- last_pfn = start_pfn + nrpages - 1;
-
- dev_dbg(dev, "Device unmapping: pfn %lx-%lx\n", start_pfn, last_pfn);
-
- freelist = domain_unmap(domain, start_pfn, last_pfn, NULL);
-
- if (intel_iommu_strict) {
- iommu_flush_iotlb_psi(iommu, domain, start_pfn,
- nrpages, !freelist, 0);
- /* free iova */
- free_iova_fast(&domain->iovad, iova_pfn, dma_to_mm_pfn(nrpages));
- dma_free_pagelist(freelist);
- } else {
- queue_iova(&domain->iovad, iova_pfn, nrpages,
- (unsigned long)freelist);
- /*
- * queue up the release of the unmap to save the 1/6th of the
- * cpu used up by the iotlb flush operation...
- */
- }
-}
-
-static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
- size_t size, enum dma_data_direction dir,
- unsigned long attrs)
-{
- intel_unmap(dev, dev_addr, size);
-}
-
-static void *intel_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t flags,
- unsigned long attrs)
-{
- struct page *page = NULL;
- int order;
-
- size = PAGE_ALIGN(size);
- order = get_order(size);
-
- if (dev->coherent_dma_mask < dma_get_required_mask(dev)) {
- if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
- flags |= GFP_DMA;
- else
- flags |= GFP_DMA32;
- }
-
- if (gfpflags_allow_blocking(flags)) {
- unsigned int count = size >> PAGE_SHIFT;
-
- page = dma_alloc_from_contiguous(dev, count, order,
- flags & __GFP_NOWARN);
- }
-
- if (!page)
- page = alloc_pages(flags, order);
- if (!page)
- return NULL;
- memset(page_address(page), 0, size);
-
- *dma_handle = __intel_map_single(dev, page_to_phys(page), size,
- DMA_BIDIRECTIONAL,
- dev->coherent_dma_mask);
- if (*dma_handle != DMA_MAPPING_ERROR)
- return page_address(page);
- if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
- __free_pages(page, order);
-
- return NULL;
-}
-
-static void intel_free_coherent(struct device *dev, size_t size, void *vaddr,
- dma_addr_t dma_handle, unsigned long attrs)
-{
- int order;
- struct page *page = virt_to_page(vaddr);
-
- size = PAGE_ALIGN(size);
- order = get_order(size);
-
- intel_unmap(dev, dma_handle, size);
- if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
- __free_pages(page, order);
-}
-
-static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist,
- int nelems, enum dma_data_direction dir,
- unsigned long attrs)
-{
- dma_addr_t startaddr = sg_dma_address(sglist) & PAGE_MASK;
- unsigned long nrpages = 0;
- struct scatterlist *sg;
- int i;
-
- for_each_sg(sglist, sg, nelems, i) {
- nrpages += aligned_nrpages(sg_dma_address(sg), sg_dma_len(sg));
- }
-
- intel_unmap(dev, startaddr, nrpages << VTD_PAGE_SHIFT);
-}
-
-static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nelems,
- enum dma_data_direction dir, unsigned long attrs)
-{
- int i;
- struct dmar_domain *domain;
- size_t size = 0;
- int prot = 0;
- unsigned long iova_pfn;
- int ret;
- struct scatterlist *sg;
- unsigned long start_vpfn;
- struct intel_iommu *iommu;
-
- BUG_ON(dir == DMA_NONE);
-
- domain = find_domain(dev);
- if (!domain)
- return 0;
-
- iommu = domain_get_iommu(domain);
-
- for_each_sg(sglist, sg, nelems, i)
- size += aligned_nrpages(sg->offset, sg->length);
-
- iova_pfn = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size),
- *dev->dma_mask);
- if (!iova_pfn) {
- sglist->dma_length = 0;
- return 0;
- }
-
- /*
- * Check if DMAR supports zero-length reads on write only
- * mappings..
- */
- if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL || \
- !cap_zlr(iommu->cap))
- prot |= DMA_PTE_READ;
- if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
- prot |= DMA_PTE_WRITE;
-
- start_vpfn = mm_to_dma_pfn(iova_pfn);
-
- ret = domain_sg_mapping(domain, start_vpfn, sglist, size, prot);
- if (unlikely(ret)) {
- dma_pte_free_pagetable(domain, start_vpfn,
- start_vpfn + size - 1,
- agaw_to_level(domain->agaw) + 1);
- free_iova_fast(&domain->iovad, iova_pfn, dma_to_mm_pfn(size));
- return 0;
- }
-
- return nelems;
-}
-
-static const struct dma_map_ops intel_dma_ops = {
- .alloc = intel_alloc_coherent,
- .free = intel_free_coherent,
- .map_sg = intel_map_sg,
- .unmap_sg = intel_unmap_sg,
- .map_page = intel_map_page,
- .unmap_page = intel_unmap_page,
- .map_resource = intel_map_resource,
- .unmap_resource = intel_unmap_page,
- .dma_supported = dma_direct_supported,
-};
-
static inline int iommu_domain_cache_init(void)
{
int ret = 0;
@@ -4229,7 +3889,7 @@ static void free_all_cpu_cached_iovas(unsigned int cpu)
if (!domain || domain->domain.type != IOMMU_DOMAIN_DMA)
continue;

- free_cpu_cached_iovas(cpu, &domain->iovad);
+ iommu_dma_free_cpu_cached_iovas(cpu, &domain->domain);
}
}
}
@@ -4440,12 +4100,6 @@ int __init intel_iommu_init(void)
if (list_empty(&dmar_atsr_units))
pr_info("No ATSR found\n");

- if (dmar_init_reserved_ranges()) {
- if (force_on)
- panic("tboot: Failed to reserve iommu ranges\n");
- goto out_free_reserved_range;
- }
-
init_no_remapping_devices();

ret = init_dmars();
@@ -4453,7 +4107,7 @@ int __init intel_iommu_init(void)
if (force_on)
panic("tboot: Failed to initialize DMARs\n");
pr_err("Initialization failed\n");
- goto out_free_reserved_range;
+ goto out_free_dmar;
}
up_write(&dmar_global_lock);

@@ -4492,8 +4146,6 @@ int __init intel_iommu_init(void)

return 0;

-out_free_reserved_range:
- put_iova_domain(&reserved_iova_list);
out_free_dmar:
intel_iommu_free_dmars();
up_write(&dmar_global_lock);
@@ -4587,18 +4239,6 @@ static int md_domain_init(struct dmar_domain *domain, int guest_width)
return 0;
}

-static void intel_init_iova_domain(struct dmar_domain *dmar_domain)
-{
- init_iova_domain(&dmar_domain->iovad, VTD_PAGE_SIZE, IOVA_START_PFN);
- copy_reserved_iova(&reserved_iova_list, &dmar_domain->iovad);
-
- if (init_iova_flush_queue(&dmar_domain->iovad, iommu_flush_iova,
- iova_entry_free)) {
- pr_warn("iova flush queue initialization failed\n");
- intel_iommu_strict = 1;
- }
-}
-
static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
{
struct dmar_domain *dmar_domain;
@@ -4620,8 +4260,9 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
return NULL;
}

- if (type == IOMMU_DOMAIN_DMA)
- intel_init_iova_domain(dmar_domain);
+ if (type == IOMMU_DOMAIN_DMA &&
+ iommu_get_dma_cookie(&dmar_domain->domain))
+ return NULL;

domain_update_iommu_cap(dmar_domain);
domain = &dmar_domain->domain;
@@ -4852,9 +4493,11 @@ static bool intel_iommu_capable(enum iommu_cap cap)

static int intel_iommu_add_device(struct device *dev)
{
+ struct dmar_domain *dmar_domain;
+ struct iommu_domain *domain;
struct intel_iommu *iommu;
struct iommu_group *group;
- struct iommu_domain *domain;
+ dma_addr_t base;
u8 bus, devfn;

iommu = device_to_iommu(dev, &bus, &devfn);
@@ -4871,9 +4514,12 @@ static int intel_iommu_add_device(struct device *dev)
if (IS_ERR(group))
return PTR_ERR(group);

+ base = IOVA_START_PFN << VTD_PAGE_SHIFT;
domain = iommu_get_domain_for_dev(dev);
+ dmar_domain = to_dmar_domain(domain);
if (domain->type == IOMMU_DOMAIN_DMA)
- dev->dma_ops = &intel_dma_ops;
+ iommu_setup_dma_ops(dev, base,
+ __DOMAIN_MAX_ADDR(dmar_domain->gaw) - base);

iommu_group_put(group);
return 0;
@@ -5002,19 +4648,6 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sd
return ret;
}

-static void intel_iommu_apply_resv_region(struct device *dev,
- struct iommu_domain *domain,
- struct iommu_resv_region *region)
-{
- struct dmar_domain *dmar_domain = to_dmar_domain(domain);
- unsigned long start, end;
-
- start = IOVA_PFN(region->start);
- end = IOVA_PFN(region->start + region->length - 1);
-
- WARN_ON_ONCE(!reserve_iova(&dmar_domain->iovad, start, end));
-}
-
struct intel_iommu *intel_svm_device_to_iommu(struct device *dev)
{
struct intel_iommu *iommu;
@@ -5050,13 +4683,13 @@ const struct iommu_ops intel_iommu_ops = {
.detach_dev = intel_iommu_detach_device,
.map = intel_iommu_map,
.unmap = intel_iommu_unmap,
+ .flush_iotlb_all = iommu_flush_iova,
.flush_iotlb_range = intel_iommu_flush_iotlb_range,
.iova_to_phys = intel_iommu_iova_to_phys,
.add_device = intel_iommu_add_device,
.remove_device = intel_iommu_remove_device,
.get_resv_regions = intel_iommu_get_resv_regions,
.put_resv_regions = intel_iommu_put_resv_regions,
- .apply_resv_region = intel_iommu_apply_resv_region,
.device_group = pci_device_group,
.def_domain_type = intel_iommu_def_domain_type,
.is_attach_deferred = intel_iommu_is_attach_deferred,
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index fa364de9db18..418073fe26d0 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -492,7 +492,6 @@ struct dmar_domain {

bool has_iotlb_device;
struct list_head devices; /* all devices' list */
- struct iova_domain iovad; /* iova's that belong to this domain */

struct dma_pte *pgd; /* virtual address */
int gaw; /* max guest address width */
--
2.17.1