iommu: Make IOVA domain low limit flexible
To share the IOVA allocator with other architectures, it needs to
accommodate more general aperture restrictions; move the lower limit
from a compile-time constant to a runtime domain property to allow
IOVA domains with different requirements to co-exist.
Also reword the slightly unclear description of alloc_iova since we're
touching it anyway.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index e758d8e..86f9e82 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -71,6 +71,9 @@
__DOMAIN_MAX_PFN(gaw), (unsigned long)-1))
#define DOMAIN_MAX_ADDR(gaw) (((uint64_t)__DOMAIN_MAX_PFN(gaw)) << VTD_PAGE_SHIFT)
+/* IO virtual address start page frame number */
+#define IOVA_START_PFN (1)
+
#define IOVA_PFN(addr) ((addr) >> PAGE_SHIFT)
#define DMA_32BIT_PFN IOVA_PFN(DMA_BIT_MASK(32))
#define DMA_64BIT_PFN IOVA_PFN(DMA_BIT_MASK(64))
@@ -1632,7 +1635,7 @@
struct iova *iova;
int i;
- init_iova_domain(&reserved_iova_list, DMA_32BIT_PFN);
+ init_iova_domain(&reserved_iova_list, IOVA_START_PFN, DMA_32BIT_PFN);
lockdep_set_class(&reserved_iova_list.iova_rbtree_lock,
&reserved_rbtree_key);
@@ -1690,7 +1693,7 @@
int adjust_width, agaw;
unsigned long sagaw;
- init_iova_domain(&domain->iovad, DMA_32BIT_PFN);
+ init_iova_domain(&domain->iovad, IOVA_START_PFN, DMA_32BIT_PFN);
domain_reserve_special_ranges(domain);
/* calculate AGAW */
@@ -4313,7 +4316,7 @@
{
int adjust_width;
- init_iova_domain(&domain->iovad, DMA_32BIT_PFN);
+ init_iova_domain(&domain->iovad, IOVA_START_PFN, DMA_32BIT_PFN);
domain_reserve_special_ranges(domain);
/* calculate AGAW */
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 520b8c8..a3dbba8 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -55,11 +55,13 @@
}
void
-init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit)
+init_iova_domain(struct iova_domain *iovad, unsigned long start_pfn,
+ unsigned long pfn_32bit)
{
spin_lock_init(&iovad->iova_rbtree_lock);
iovad->rbroot = RB_ROOT;
iovad->cached32_node = NULL;
+ iovad->start_pfn = start_pfn;
iovad->dma_32bit_pfn = pfn_32bit;
}
@@ -162,7 +164,7 @@
if (!curr) {
if (size_aligned)
pad_size = iova_get_pad_size(size, limit_pfn);
- if ((IOVA_START_PFN + size + pad_size) > limit_pfn) {
+ if ((iovad->start_pfn + size + pad_size) > limit_pfn) {
spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
return -ENOMEM;
}
@@ -237,8 +239,8 @@
* @size: - size of page frames to allocate
* @limit_pfn: - max limit address
* @size_aligned: - set if size_aligned address range is required
- * This function allocates an iova in the range limit_pfn to IOVA_START_PFN
- * looking from limit_pfn instead from IOVA_START_PFN. If the size_aligned
+ * This function allocates an iova in the range iovad->start_pfn to limit_pfn,
+ * searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned
* flag is set then the allocated address iova->pfn_lo will be naturally
* aligned on roundup_power_of_two(size).
*/
diff --git a/include/linux/iova.h b/include/linux/iova.h
index ad0507c..591b196 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -16,9 +16,6 @@
#include <linux/rbtree.h>
#include <linux/dma-mapping.h>
-/* IO virtual address start page frame number */
-#define IOVA_START_PFN (1)
-
/* iova structure */
struct iova {
struct rb_node node;
@@ -31,6 +28,7 @@
spinlock_t iova_rbtree_lock; /* Lock to protect update of rbtree */
struct rb_root rbroot; /* iova domain rbtree root */
struct rb_node *cached32_node; /* Save last alloced node */
+ unsigned long start_pfn; /* Lower limit for this domain */
unsigned long dma_32bit_pfn;
};
@@ -52,7 +50,8 @@
struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
unsigned long pfn_hi);
void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to);
-void init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit);
+void init_iova_domain(struct iova_domain *iovad, unsigned long start_pfn,
+ unsigned long pfn_32bit);
struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
void put_iova_domain(struct iova_domain *iovad);
struct iova *split_and_remove_iova(struct iova_domain *iovad,
