[RFC 2/7] iommu/vt-d: Remove iova handling code from non-dma ops path

Tom Murphy
2019-05-04T13:23:18Z

There is no reason to keep track of the iovas in the non-dma ops path.
All this code seems to be pointless and can be removed.

Signed-off-by: Tom Murphy <tmurphy@arista.com>
---
drivers/iommu/intel-iommu.c | 94 +++++++++++++------------------------
1 file changed, 33 insertions(+), 61 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 2db1dc47e7e4..77895cd89f29 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1846,11 +1846,6 @@ static int dmar_init_reserved_ranges(void)
return 0;
}

-static void domain_reserve_special_ranges(struct dmar_domain *domain)
-{
- copy_reserved_iova(&reserved_iova_list, &domain->iovad);
-}
-
static inline int guestwidth_to_adjustwidth(int gaw)
{
int agaw;
@@ -1875,7 +1870,8 @@ static void domain_exit(struct dmar_domain *domain)
rcu_read_unlock();

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

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

@@ -2554,19 +2550,9 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
}

static int iommu_domain_identity_map(struct dmar_domain *domain,
- unsigned long long start,
- unsigned long long end)
+ unsigned long first_vpfn,
+ unsigned long last_vpfn)
{
- unsigned long first_vpfn = start >> VTD_PAGE_SHIFT;
- unsigned long last_vpfn = end >> VTD_PAGE_SHIFT;
-
- if (!reserve_iova(&domain->iovad, dma_to_mm_pfn(first_vpfn),
- dma_to_mm_pfn(last_vpfn))) {
- pr_err("Reserving iova failed\n");
- return -ENOMEM;
- }
-
- pr_debug("Mapping reserved region %llx-%llx\n", start, end);
/*
* RMRR range might have overlap with physical memory range,
* clear it first
@@ -2613,7 +2599,8 @@ static int __init si_domain_init(int hw)

for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
ret = iommu_domain_identity_map(si_domain,
- PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
+ mm_to_dma_pfn(start_pfn),
+ mm_to_dma_pfn(end_pfn));
if (ret)
return ret;
}
@@ -4181,58 +4168,37 @@ static int intel_iommu_memory_notifier(struct notifier_block *nb,
unsigned long val, void *v)
{
struct memory_notify *mhp = v;
- unsigned long long start, end;
- unsigned long start_vpfn, last_vpfn;
+ unsigned long start_vpfn = mm_to_dma_pfn(mhp->start_pfn);
+ unsigned long last_vpfn = mm_to_dma_pfn(mhp->start_pfn +
+ mhp->nr_pages - 1);

switch (val) {
case MEM_GOING_ONLINE:
- start = mhp->start_pfn << PAGE_SHIFT;
- end = ((mhp->start_pfn + mhp->nr_pages) << PAGE_SHIFT) - 1;
- if (iommu_domain_identity_map(si_domain, start, end)) {
- pr_warn("Failed to build identity map for [%llx-%llx]\n",
- start, end);
+ if (iommu_domain_identity_map(si_domain, start_vpfn,
+ last_vpfn)) {
+ pr_warn("Failed to build identity map for [%lx-%lx]\n",
+ start_vpfn, last_vpfn);
return NOTIFY_BAD;
}
break;

case MEM_OFFLINE:
case MEM_CANCEL_ONLINE:
- start_vpfn = mm_to_dma_pfn(mhp->start_pfn);
- last_vpfn = mm_to_dma_pfn(mhp->start_pfn + mhp->nr_pages - 1);
- while (start_vpfn <= last_vpfn) {
- struct iova *iova;
+ {
struct dmar_drhd_unit *drhd;
struct intel_iommu *iommu;
struct page *freelist;

- iova = find_iova(&si_domain->iovad, start_vpfn);
- if (iova == NULL) {
- pr_debug("Failed get IOVA for PFN %lx\n",
- start_vpfn);
- break;
- }
-
- iova = split_and_remove_iova(&si_domain->iovad, iova,
- start_vpfn, last_vpfn);
- if (iova == NULL) {
- pr_warn("Failed to split IOVA PFN [%lx-%lx]\n",
- start_vpfn, last_vpfn);
- return NOTIFY_BAD;
- }
-
- freelist = domain_unmap(si_domain, iova->pfn_lo,
- iova->pfn_hi);
+ freelist = domain_unmap(si_domain, start_vpfn,
+ last_vpfn);

rcu_read_lock();
for_each_active_iommu(iommu, drhd)
iommu_flush_iotlb_psi(iommu, si_domain,
- iova->pfn_lo, iova_size(iova),
+ start_vpfn, mhp->nr_pages,
!freelist, 0);
rcu_read_unlock();
dma_free_pagelist(freelist);
-
- start_vpfn = iova->pfn_hi + 1;
- free_iova_mem(iova);
}
break;
}
@@ -4260,8 +4226,9 @@ static void free_all_cpu_cached_iovas(unsigned int cpu)
for (did = 0; did < cap_ndoms(iommu->cap); did++) {
domain = get_iommu_domain(iommu, (u16)did);

- if (!domain)
+ if (!domain || domain->domain.type != IOMMU_DOMAIN_DMA)
continue;
+
free_cpu_cached_iovas(cpu, &domain->iovad);
}
}
@@ -4602,9 +4569,6 @@ static int md_domain_init(struct dmar_domain *domain, int guest_width)
{
int adjust_width;

- init_iova_domain(&domain->iovad, VTD_PAGE_SIZE, IOVA_START_PFN);
- domain_reserve_special_ranges(domain);
-
/* calculate AGAW */
domain->gaw = guest_width;
adjust_width = guestwidth_to_adjustwidth(guest_width);
@@ -4623,6 +4587,18 @@ 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;
@@ -4644,12 +4620,8 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
return NULL;
}

- if (type == IOMMU_DOMAIN_DMA &&
- 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;
- }
+ if (type == IOMMU_DOMAIN_DMA)
+ intel_init_iova_domain(dmar_domain);

domain_update_iommu_cap(dmar_domain);
domain = &dmar_domain->domain;
--
2.17.1