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Commit 00cd122a authored by Joerg Roedel's avatar Joerg Roedel
Browse files

amd-iommu: handle exlusion ranges and unity mappings in alloc_new_range 



This patch makes sure no reserved addresses are allocated in an dma_ops
domain when the aperture is increased dynamically.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 9cabe89b

arch/x86/kernel/amd_iommu.c

+60 −11
Original line number Diff line number Diff line
@@ -58,6 +58,9 @@ static struct dma_ops_domain *find_protection_domain(u16 devid); 
static u64* alloc_pte(struct protection_domain *dom,

		      unsigned long address, u64

		      **pte_page, gfp_t gfp);

static void dma_ops_reserve_addresses(struct dma_ops_domain *dom,

				      unsigned long start_page,

				      unsigned int pages);



#ifdef CONFIG_AMD_IOMMU_STATS
@@ -620,15 +623,43 @@ static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom, 
 * called with domain->lock held

 */



/*

 * This function checks if there is a PTE for a given dma address. If

 * there is one, it returns the pointer to it.

 */

static u64* fetch_pte(struct protection_domain *domain,

		      unsigned long address)

{

	u64 *pte;



	pte = &domain->pt_root[IOMMU_PTE_L2_INDEX(address)];



	if (!IOMMU_PTE_PRESENT(*pte))

		return NULL;



	pte = IOMMU_PTE_PAGE(*pte);

	pte = &pte[IOMMU_PTE_L1_INDEX(address)];



	if (!IOMMU_PTE_PRESENT(*pte))

		return NULL;



	pte = IOMMU_PTE_PAGE(*pte);

	pte = &pte[IOMMU_PTE_L0_INDEX(address)];



	return pte;

}



/*

 * This function is used to add a new aperture range to an existing

 * aperture in case of dma_ops domain allocation or address allocation

 * failure.

 */

static int alloc_new_range(struct dma_ops_domain *dma_dom,

static int alloc_new_range(struct amd_iommu *iommu,

			   struct dma_ops_domain *dma_dom,

			   bool populate, gfp_t gfp)

{

	int index = dma_dom->aperture_size >> APERTURE_RANGE_SHIFT;

	int i;



	if (index >= APERTURE_MAX_RANGES)

		return -ENOMEM;
@@ -662,6 +693,33 @@ static int alloc_new_range(struct dma_ops_domain *dma_dom, 


	dma_dom->aperture_size += APERTURE_RANGE_SIZE;



	/* Intialize the exclusion range if necessary */

	if (iommu->exclusion_start &&

	    iommu->exclusion_start >= dma_dom->aperture[index]->offset &&

	    iommu->exclusion_start < dma_dom->aperture_size) {

		unsigned long startpage = iommu->exclusion_start >> PAGE_SHIFT;

		int pages = iommu_num_pages(iommu->exclusion_start,

					    iommu->exclusion_length,

					    PAGE_SIZE);

		dma_ops_reserve_addresses(dma_dom, startpage, pages);

	}



	/*

	 * Check for areas already mapped as present in the new aperture

	 * range and mark those pages as reserved in the allocator. Such

	 * mappings may already exist as a result of requested unity

	 * mappings for devices.

	 */

	for (i = dma_dom->aperture[index]->offset;

	     i < dma_dom->aperture_size;

	     i += PAGE_SIZE) {

		u64 *pte = fetch_pte(&dma_dom->domain, i);

		if (!pte || !IOMMU_PTE_PRESENT(*pte))

			continue;



		dma_ops_reserve_addresses(dma_dom, i << PAGE_SHIFT, 1);

	}



	return 0;



out_free:
@@ -911,7 +969,7 @@ static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu, 
	dma_dom->need_flush = false;

	dma_dom->target_dev = 0xffff;



	if (alloc_new_range(dma_dom, true, GFP_KERNEL))

	if (alloc_new_range(iommu, dma_dom, true, GFP_KERNEL))

		goto free_dma_dom;



	/*
@@ -921,15 +979,6 @@ static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu, 
	dma_dom->aperture[0]->bitmap[0] = 1;

	dma_dom->next_address = 0;



	/* Intialize the exclusion range if necessary */

	if (iommu->exclusion_start &&

	    iommu->exclusion_start < dma_dom->aperture_size) {

		unsigned long startpage = iommu->exclusion_start >> PAGE_SHIFT;

		int pages = iommu_num_pages(iommu->exclusion_start,

					    iommu->exclusion_length,

					    PAGE_SIZE);

		dma_ops_reserve_addresses(dma_dom, startpage, pages);

	}



	return dma_dom;