diff mbox series

[RFC,2/7] iommu/vt-d: Remove iova handling code from non-dma ops path

Message ID 20190504132327.27041-3-tmurphy@arista.com (mailing list archive)
State RFC
Headers show
Series Convert the Intel iommu driver to the dma-ops api | expand

Commit Message

Tom Murphy May 4, 2019, 1:23 p.m. UTC
There is no reason to keep track of the iovas in the non-dma ops path.
All this code seems to be pointless and can be removed.

Signed-off-by: Tom Murphy <tmurphy@arista.com>
---
 drivers/iommu/intel-iommu.c | 94 +++++++++++++------------------------
 1 file changed, 33 insertions(+), 61 deletions(-)

Comments

Baolu Lu May 5, 2019, 1:19 a.m. UTC | #1
Hi,

On 5/4/19 9:23 PM, Tom Murphy via iommu wrote:
> @@ -4181,58 +4168,37 @@ static int intel_iommu_memory_notifier(struct notifier_block *nb,
>   				       unsigned long val, void *v)
>   {
>   	struct memory_notify *mhp = v;
> -	unsigned long long start, end;
> -	unsigned long start_vpfn, last_vpfn;
> +	unsigned long start_vpfn = mm_to_dma_pfn(mhp->start_pfn);
> +	unsigned long last_vpfn = mm_to_dma_pfn(mhp->start_pfn +
> +			mhp->nr_pages - 1);
>   
>   	switch (val) {
>   	case MEM_GOING_ONLINE:
> -		start = mhp->start_pfn << PAGE_SHIFT;
> -		end = ((mhp->start_pfn + mhp->nr_pages) << PAGE_SHIFT) - 1;
> -		if (iommu_domain_identity_map(si_domain, start, end)) {
> -			pr_warn("Failed to build identity map for [%llx-%llx]\n",
> -				start, end);
> +		if (iommu_domain_identity_map(si_domain, start_vpfn,
> +					last_vpfn)) {
> +			pr_warn("Failed to build identity map for [%lx-%lx]\n",
> +				start_vpfn, last_vpfn);
>   			return NOTIFY_BAD;
>   		}
>   		break;

Actually we don't need to update the si_domain if iommu hardware
supports pass-through mode. This should be made in a separated patch
anyway.

Best regards,
Lu Baolu
Baolu Lu May 5, 2019, 1:22 a.m. UTC | #2
Hi,

On 5/5/19 9:19 AM, Lu Baolu wrote:
> Hi,
> 
> On 5/4/19 9:23 PM, Tom Murphy via iommu wrote:
>> @@ -4181,58 +4168,37 @@ static int intel_iommu_memory_notifier(struct 
>> notifier_block *nb,
>>                          unsigned long val, void *v)
>>   {
>>       struct memory_notify *mhp = v;
>> -    unsigned long long start, end;
>> -    unsigned long start_vpfn, last_vpfn;
>> +    unsigned long start_vpfn = mm_to_dma_pfn(mhp->start_pfn);
>> +    unsigned long last_vpfn = mm_to_dma_pfn(mhp->start_pfn +
>> +            mhp->nr_pages - 1);
>>       switch (val) {
>>       case MEM_GOING_ONLINE:
>> -        start = mhp->start_pfn << PAGE_SHIFT;
>> -        end = ((mhp->start_pfn + mhp->nr_pages) << PAGE_SHIFT) - 1;
>> -        if (iommu_domain_identity_map(si_domain, start, end)) {
>> -            pr_warn("Failed to build identity map for [%llx-%llx]\n",
>> -                start, end);
>> +        if (iommu_domain_identity_map(si_domain, start_vpfn,
>> +                    last_vpfn)) {
>> +            pr_warn("Failed to build identity map for [%lx-%lx]\n",
>> +                start_vpfn, last_vpfn);
>>               return NOTIFY_BAD;
>>           }
>>           break;
> 
> Actually we don't need to update the si_domain if iommu hardware
> supports pass-through mode. This should be made in a separated patch
> anyway.

Oh! please ignore it.

This callback is only registered when hardware doesn't support pass
through mode.

         if (si_domain && !hw_pass_through)
                 register_memory_notifier(&intel_iommu_memory_nb);

Best regards,
Lu Baolu
diff mbox series

Patch

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 2db1dc47e7e4..77895cd89f29 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1846,11 +1846,6 @@  static int dmar_init_reserved_ranges(void)
 	return 0;
 }
 
-static void domain_reserve_special_ranges(struct dmar_domain *domain)
-{
-	copy_reserved_iova(&reserved_iova_list, &domain->iovad);
-}
-
 static inline int guestwidth_to_adjustwidth(int gaw)
 {
 	int agaw;
@@ -1875,7 +1870,8 @@  static void domain_exit(struct dmar_domain *domain)
 	rcu_read_unlock();
 
 	/* destroy iovas */
-	put_iova_domain(&domain->iovad);
+	if (domain->domain.type == IOMMU_DOMAIN_DMA)
+		put_iova_domain(&domain->iovad);
 
 	freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
 
@@ -2554,19 +2550,9 @@  static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 }
 
 static int iommu_domain_identity_map(struct dmar_domain *domain,
-				     unsigned long long start,
-				     unsigned long long end)
+				     unsigned long first_vpfn,
+				     unsigned long last_vpfn)
 {
-	unsigned long first_vpfn = start >> VTD_PAGE_SHIFT;
-	unsigned long last_vpfn = end >> VTD_PAGE_SHIFT;
-
-	if (!reserve_iova(&domain->iovad, dma_to_mm_pfn(first_vpfn),
-			  dma_to_mm_pfn(last_vpfn))) {
-		pr_err("Reserving iova failed\n");
-		return -ENOMEM;
-	}
-
-	pr_debug("Mapping reserved region %llx-%llx\n", start, end);
 	/*
 	 * RMRR range might have overlap with physical memory range,
 	 * clear it first
@@ -2613,7 +2599,8 @@  static int __init si_domain_init(int hw)
 
 		for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
 			ret = iommu_domain_identity_map(si_domain,
-					PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
+					mm_to_dma_pfn(start_pfn),
+					mm_to_dma_pfn(end_pfn));
 			if (ret)
 				return ret;
 		}
@@ -4181,58 +4168,37 @@  static int intel_iommu_memory_notifier(struct notifier_block *nb,
 				       unsigned long val, void *v)
 {
 	struct memory_notify *mhp = v;
-	unsigned long long start, end;
-	unsigned long start_vpfn, last_vpfn;
+	unsigned long start_vpfn = mm_to_dma_pfn(mhp->start_pfn);
+	unsigned long last_vpfn = mm_to_dma_pfn(mhp->start_pfn +
+			mhp->nr_pages - 1);
 
 	switch (val) {
 	case MEM_GOING_ONLINE:
-		start = mhp->start_pfn << PAGE_SHIFT;
-		end = ((mhp->start_pfn + mhp->nr_pages) << PAGE_SHIFT) - 1;
-		if (iommu_domain_identity_map(si_domain, start, end)) {
-			pr_warn("Failed to build identity map for [%llx-%llx]\n",
-				start, end);
+		if (iommu_domain_identity_map(si_domain, start_vpfn,
+					last_vpfn)) {
+			pr_warn("Failed to build identity map for [%lx-%lx]\n",
+				start_vpfn, last_vpfn);
 			return NOTIFY_BAD;
 		}
 		break;
 
 	case MEM_OFFLINE:
 	case MEM_CANCEL_ONLINE:
-		start_vpfn = mm_to_dma_pfn(mhp->start_pfn);
-		last_vpfn = mm_to_dma_pfn(mhp->start_pfn + mhp->nr_pages - 1);
-		while (start_vpfn <= last_vpfn) {
-			struct iova *iova;
+		{
 			struct dmar_drhd_unit *drhd;
 			struct intel_iommu *iommu;
 			struct page *freelist;
 
-			iova = find_iova(&si_domain->iovad, start_vpfn);
-			if (iova == NULL) {
-				pr_debug("Failed get IOVA for PFN %lx\n",
-					 start_vpfn);
-				break;
-			}
-
-			iova = split_and_remove_iova(&si_domain->iovad, iova,
-						     start_vpfn, last_vpfn);
-			if (iova == NULL) {
-				pr_warn("Failed to split IOVA PFN [%lx-%lx]\n",
-					start_vpfn, last_vpfn);
-				return NOTIFY_BAD;
-			}
-
-			freelist = domain_unmap(si_domain, iova->pfn_lo,
-					       iova->pfn_hi);
+			freelist = domain_unmap(si_domain, start_vpfn,
+					last_vpfn);
 
 			rcu_read_lock();
 			for_each_active_iommu(iommu, drhd)
 				iommu_flush_iotlb_psi(iommu, si_domain,
-					iova->pfn_lo, iova_size(iova),
+					start_vpfn, mhp->nr_pages,
 					!freelist, 0);
 			rcu_read_unlock();
 			dma_free_pagelist(freelist);
-
-			start_vpfn = iova->pfn_hi + 1;
-			free_iova_mem(iova);
 		}
 		break;
 	}
@@ -4260,8 +4226,9 @@  static void free_all_cpu_cached_iovas(unsigned int cpu)
 		for (did = 0; did < cap_ndoms(iommu->cap); did++) {
 			domain = get_iommu_domain(iommu, (u16)did);
 
-			if (!domain)
+			if (!domain || domain->domain.type != IOMMU_DOMAIN_DMA)
 				continue;
+
 			free_cpu_cached_iovas(cpu, &domain->iovad);
 		}
 	}
@@ -4602,9 +4569,6 @@  static int md_domain_init(struct dmar_domain *domain, int guest_width)
 {
 	int adjust_width;
 
-	init_iova_domain(&domain->iovad, VTD_PAGE_SIZE, IOVA_START_PFN);
-	domain_reserve_special_ranges(domain);
-
 	/* calculate AGAW */
 	domain->gaw = guest_width;
 	adjust_width = guestwidth_to_adjustwidth(guest_width);
@@ -4623,6 +4587,18 @@  static int md_domain_init(struct dmar_domain *domain, int guest_width)
 	return 0;
 }
 
+static void intel_init_iova_domain(struct dmar_domain *dmar_domain)
+{
+	init_iova_domain(&dmar_domain->iovad, VTD_PAGE_SIZE, IOVA_START_PFN);
+	copy_reserved_iova(&reserved_iova_list, &dmar_domain->iovad);
+
+	if (init_iova_flush_queue(&dmar_domain->iovad, iommu_flush_iova,
+				iova_entry_free)) {
+		pr_warn("iova flush queue initialization failed\n");
+		intel_iommu_strict = 1;
+	}
+}
+
 static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
 {
 	struct dmar_domain *dmar_domain;
@@ -4644,12 +4620,8 @@  static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
 			return NULL;
 		}
 
-		if (type == IOMMU_DOMAIN_DMA &&
-		    init_iova_flush_queue(&dmar_domain->iovad,
-					  iommu_flush_iova, iova_entry_free)) {
-			pr_warn("iova flush queue initialization failed\n");
-			intel_iommu_strict = 1;
-		}
+		if (type == IOMMU_DOMAIN_DMA)
+			intel_init_iova_domain(dmar_domain);
 
 		domain_update_iommu_cap(dmar_domain);
 		domain = &dmar_domain->domain;