[PATCH RESEND v5 5/5] iova: Add iova_len argument to iova_domain_init_rcaches()

From: John Garry
Date: Mon Apr 04 2022 - 07:33:33 EST


Add max opt argument to iova_domain_init_rcaches(), and use it to set the
rcaches range.

Also fix up all users to set this value (at 0, meaning use default),
including a wrapper for that, iova_domain_init_rcaches_default().

For dma-iommu.c we derive the iova_len argument from the IOMMU group
max opt DMA size.

Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
drivers/iommu/dma-iommu.c | 15 ++++++++++++++-
drivers/iommu/iova.c | 19 ++++++++++++++++---
drivers/vdpa/vdpa_user/iova_domain.c | 4 ++--
include/linux/iova.h | 3 ++-
4 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 42ca42ff1b5d..19f35624611c 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -525,6 +525,8 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
struct iommu_dma_cookie *cookie = domain->iova_cookie;
unsigned long order, base_pfn;
struct iova_domain *iovad;
+ size_t max_opt_dma_size;
+ unsigned long iova_len = 0;
int ret;

if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE)
@@ -560,7 +562,18 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
}

init_iova_domain(iovad, 1UL << order, base_pfn);
- ret = iova_domain_init_rcaches(iovad);
+
+ max_opt_dma_size = iommu_group_get_max_opt_dma_size(dev->iommu_group);
+ if (max_opt_dma_size) {
+ unsigned long shift = __ffs(1UL << order);
+
+ iova_len = roundup_pow_of_two(max_opt_dma_size);
+ iova_len >>= shift;
+ if (!iova_len)
+ iova_len = 1;
+ }
+
+ ret = iova_domain_init_rcaches(iovad, iova_len);
if (ret)
return ret;

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 5c22b9187b79..d65e79e132ee 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -706,12 +706,20 @@ static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn)
mag->pfns[mag->size++] = pfn;
}

-int iova_domain_init_rcaches(struct iova_domain *iovad)
+static unsigned long iova_len_to_rcache_max(unsigned long iova_len)
+{
+ return order_base_2(iova_len) + 1;
+}
+
+int iova_domain_init_rcaches(struct iova_domain *iovad, unsigned long iova_len)
{
unsigned int cpu;
int i, ret;

- iovad->rcache_max_size = 6; /* Arbitrarily high default */
+ if (iova_len)
+ iovad->rcache_max_size = iova_len_to_rcache_max(iova_len);
+ else
+ iovad->rcache_max_size = 6; /* Arbitrarily high default */

iovad->rcaches = kcalloc(iovad->rcache_max_size,
sizeof(struct iova_rcache),
@@ -755,7 +763,12 @@ int iova_domain_init_rcaches(struct iova_domain *iovad)
free_iova_rcaches(iovad);
return ret;
}
-EXPORT_SYMBOL_GPL(iova_domain_init_rcaches);
+
+int iova_domain_init_rcaches_default(struct iova_domain *iovad)
+{
+ return iova_domain_init_rcaches(iovad, 0);
+}
+EXPORT_SYMBOL_GPL(iova_domain_init_rcaches_default);

/*
* Try inserting IOVA range starting with 'iova_pfn' into 'rcache', and
diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c
index 6daa3978d290..3a2acef98a4a 100644
--- a/drivers/vdpa/vdpa_user/iova_domain.c
+++ b/drivers/vdpa/vdpa_user/iova_domain.c
@@ -514,12 +514,12 @@ vduse_domain_create(unsigned long iova_limit, size_t bounce_size)
spin_lock_init(&domain->iotlb_lock);
init_iova_domain(&domain->stream_iovad,
PAGE_SIZE, IOVA_START_PFN);
- ret = iova_domain_init_rcaches(&domain->stream_iovad);
+ ret = iova_domain_init_rcaches_default(&domain->stream_iovad);
if (ret)
goto err_iovad_stream;
init_iova_domain(&domain->consistent_iovad,
PAGE_SIZE, bounce_pfns);
- ret = iova_domain_init_rcaches(&domain->consistent_iovad);
+ ret = iova_domain_init_rcaches_default(&domain->consistent_iovad);
if (ret)
goto err_iovad_consistent;

diff --git a/include/linux/iova.h b/include/linux/iova.h
index 02f7222fa85a..56281434ce0c 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -95,7 +95,8 @@ struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
unsigned long pfn_hi);
void init_iova_domain(struct iova_domain *iovad, unsigned long granule,
unsigned long start_pfn);
-int iova_domain_init_rcaches(struct iova_domain *iovad);
+int iova_domain_init_rcaches(struct iova_domain *iovad, unsigned long iova_len);
+int iova_domain_init_rcaches_default(struct iova_domain *iovad);
struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
void put_iova_domain(struct iova_domain *iovad);
#else
--
2.26.2