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>
This commit is contained in:
Robin Murphy 2015-01-12 17:51:15 +00:00 committed by Joerg Roedel
parent 85b4545629
commit 1b72250076
3 changed files with 15 additions and 11 deletions

View file

@ -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 @@ struct iova_domain {
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 *alloc_iova(struct iova_domain *iovad, unsigned long size,
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,