Commit 402e6688 authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
Browse files

iommu/vt-d: Remove intel_iommu::domains 



The "domains" field of the intel_iommu structure keeps the mapping of
domain_id to dmar_domain. This information is not used anywhere. Remove
and cleanup it to avoid unnecessary memory consumption.

Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220214025704.3184654-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20220301020159.633356-2-baolu.lu@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 067e95fc

drivers/iommu/intel/iommu.c

+3 −65
Original line number Diff line number Diff line
@@ -455,36 +455,6 @@ __setup("intel_iommu=", intel_iommu_setup); 
static struct kmem_cache *iommu_domain_cache;

static struct kmem_cache *iommu_devinfo_cache;



static struct dmar_domain* get_iommu_domain(struct intel_iommu *iommu, u16 did)

{

	struct dmar_domain **domains;

	int idx = did >> 8;



	domains = iommu->domains[idx];

	if (!domains)

		return NULL;



	return domains[did & 0xff];

}



static void set_iommu_domain(struct intel_iommu *iommu, u16 did,

			     struct dmar_domain *domain)

{

	struct dmar_domain **domains;

	int idx = did >> 8;



	if (!iommu->domains[idx]) {

		size_t size = 256 * sizeof(struct dmar_domain *);

		iommu->domains[idx] = kzalloc(size, GFP_ATOMIC);

	}



	domains = iommu->domains[idx];

	if (WARN_ON(!domains))

		return;

	else

		domains[did & 0xff] = domain;

}



void *alloc_pgtable_page(int node)

{

	struct page *page;
@@ -1751,8 +1721,7 @@ static void intel_flush_iotlb_all(struct iommu_domain *domain) 
						 DMA_TLB_DSI_FLUSH);



		if (!cap_caching_mode(iommu->cap))

			iommu_flush_dev_iotlb(get_iommu_domain(iommu, did),

					      0, MAX_AGAW_PFN_WIDTH);

			iommu_flush_dev_iotlb(dmar_domain, 0, MAX_AGAW_PFN_WIDTH);

	}

}
@@ -1815,7 +1784,6 @@ static void iommu_disable_translation(struct intel_iommu *iommu) 
static int iommu_init_domains(struct intel_iommu *iommu)

{

	u32 ndomains;

	size_t size;



	ndomains = cap_ndoms(iommu->cap);

	pr_debug("%s: Number of Domains supported <%d>\n",
@@ -1827,24 +1795,6 @@ static int iommu_init_domains(struct intel_iommu *iommu) 
	if (!iommu->domain_ids)

		return -ENOMEM;



	size = (ALIGN(ndomains, 256) >> 8) * sizeof(struct dmar_domain **);

	iommu->domains = kzalloc(size, GFP_KERNEL);



	if (iommu->domains) {

		size = 256 * sizeof(struct dmar_domain *);

		iommu->domains[0] = kzalloc(size, GFP_KERNEL);

	}



	if (!iommu->domains || !iommu->domains[0]) {

		pr_err("%s: Allocating domain array failed\n",

		       iommu->name);

		bitmap_free(iommu->domain_ids);

		kfree(iommu->domains);

		iommu->domain_ids = NULL;

		iommu->domains    = NULL;

		return -ENOMEM;

	}



	/*

	 * If Caching mode is set, then invalid translations are tagged

	 * with domain-id 0, hence we need to pre-allocate it. We also
@@ -1871,7 +1821,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu) 
	struct device_domain_info *info, *tmp;

	unsigned long flags;



	if (!iommu->domains || !iommu->domain_ids)

	if (!iommu->domain_ids)

		return;



	spin_lock_irqsave(&device_domain_lock, flags);
@@ -1892,15 +1842,8 @@ static void disable_dmar_iommu(struct intel_iommu *iommu) 


static void free_dmar_iommu(struct intel_iommu *iommu)

{

	if ((iommu->domains) && (iommu->domain_ids)) {

		int elems = ALIGN(cap_ndoms(iommu->cap), 256) >> 8;

		int i;



		for (i = 0; i < elems; i++)

			kfree(iommu->domains[i]);

		kfree(iommu->domains);

	if (iommu->domain_ids) {

		bitmap_free(iommu->domain_ids);

		iommu->domains = NULL;

		iommu->domain_ids = NULL;

	}
@@ -1978,11 +1921,8 @@ static int domain_attach_iommu(struct dmar_domain *domain, 
		}



		set_bit(num, iommu->domain_ids);

		set_iommu_domain(iommu, num, domain);



		domain->iommu_did[iommu->seq_id] = num;

		domain->nid			 = iommu->node;



		domain_update_iommu_cap(domain);

	}
@@ -2001,8 +1941,6 @@ static void domain_detach_iommu(struct dmar_domain *domain, 
	if (domain->iommu_refcnt[iommu->seq_id] == 0) {

		num = domain->iommu_did[iommu->seq_id];

		clear_bit(num, iommu->domain_ids);

		set_iommu_domain(iommu, num, NULL);



		domain_update_iommu_cap(domain);

		domain->iommu_did[iommu->seq_id] = 0;

	}

include/linux/intel-iommu.h

+0 −1
Original line number Diff line number Diff line
@@ -578,7 +578,6 @@ struct intel_iommu { 


#ifdef CONFIG_INTEL_IOMMU

	unsigned long 	*domain_ids; /* bitmap of domains */

	struct dmar_domain ***domains; /* ptr to domains */

	spinlock_t	lock; /* protect context, domain ids */

	struct root_entry *root_entry; /* virtual address */