Commit 1b722500 authored by Robin Murphy's avatar Robin Murphy Committed by Joerg Roedel
Browse files

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: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 85b45456

drivers/iommu/intel-iommu.c

+6 −3
Original line number Diff line number Diff line
@@ -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 @@ static int dmar_init_reserved_ranges(void) 
	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 @@ static int domain_init(struct dmar_domain *domain, int guest_width) 
	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 @@ static int md_domain_init(struct dmar_domain *domain, int guest_width) 
{

	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 */

drivers/iommu/iova.c

+6 −4
Original line number Diff line number Diff line
@@ -55,11 +55,13 @@ void free_iova_mem(struct iova *iova) 
}



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 @@ move_left: 
	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 @@ iova_insert_rbtree(struct rb_root *root, struct iova *iova) 
 * @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).

 */

include/linux/iova.h

+3 −4
Original line number Diff line number Diff line
@@ -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,

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