Attachment 124216 Details for Bug 96293 – Fix this_cpu_ptr() in intel/iommu

[patch] Fix this_cpu_ptr() in intel/iommu

0001-iommu.patch (text/plain), 4.53 KB, created by Chris Wilson on 2016-05-31 16:25:02 UTC

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Creator: Chris Wilson

Created: 2016-05-31 16:25:02 UTC

Size: 4.53 KB

patch

obsolete

>From c4546a7e594cb3ef662789a17c17fc71e1dc1b99 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Tue, 31 May 2016 17:18:27 +0100
>Subject: [PATCH] iommu
>
>---
> drivers/iommu/iova.c | 33 +++++++++++----------------------
> 1 file changed, 11 insertions(+), 22 deletions(-)
>
>diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
>index ba764a0835d3..a8754d287218 100644
>--- a/drivers/iommu/iova.c
>+++ b/drivers/iommu/iova.c
>@@ -390,6 +390,11 @@ free_iova(struct iova_domain *iovad, unsigned long pfn)
> }
> EXPORT_SYMBOL_GPL(free_iova);
> 
>+static void free_this_cached_iovas(void *info)
>+{
>+	free_cpu_cached_iovas(smp_processor_id(), info);
>+}
>+
> /**
>  * alloc_iova_fast - allocates an iova from rcache
>  * @iovad: - iova domain in question
>@@ -413,15 +418,12 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
> retry:
> 	new_iova = alloc_iova(iovad, size, limit_pfn, true);
> 	if (!new_iova) {
>-		unsigned int cpu;
>-
> 		if (flushed_rcache)
> 			return 0;
> 
> 		/* Try replenishing IOVAs by flushing rcache. */
> 		flushed_rcache = true;
>-		for_each_online_cpu(cpu)
>-			free_cpu_cached_iovas(cpu, iovad);
>+		on_each_cpu(free_this_cached_iovas, iovad, true);
> 		goto retry;
> 	}
> 
>@@ -645,7 +647,6 @@ struct iova_magazine {
> };
> 
> struct iova_cpu_rcache {
>-	spinlock_t lock;
> 	struct iova_magazine *loaded;
> 	struct iova_magazine *prev;
> };
>@@ -727,7 +728,6 @@ static void init_iova_rcaches(struct iova_domain *iovad)
> 			continue;
> 		for_each_possible_cpu(cpu) {
> 			cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
>-			spin_lock_init(&cpu_rcache->lock);
> 			cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL);
> 			cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL);
> 		}
>@@ -747,10 +747,9 @@ static bool __iova_rcache_insert(struct iova_domain *iovad,
> 	struct iova_magazine *mag_to_free = NULL;
> 	struct iova_cpu_rcache *cpu_rcache;
> 	bool can_insert = false;
>-	unsigned long flags;
> 
>+	preempt_disable();
> 	cpu_rcache = this_cpu_ptr(rcache->cpu_rcaches);
>-	spin_lock_irqsave(&cpu_rcache->lock, flags);
> 
> 	if (!iova_magazine_full(cpu_rcache->loaded)) {
> 		can_insert = true;
>@@ -778,7 +777,7 @@ static bool __iova_rcache_insert(struct iova_domain *iovad,
> 	if (can_insert)
> 		iova_magazine_push(cpu_rcache->loaded, iova_pfn);
> 
>-	spin_unlock_irqrestore(&cpu_rcache->lock, flags);
>+	preempt_enable();
> 
> 	if (mag_to_free) {
> 		iova_magazine_free_pfns(mag_to_free, iovad);
>@@ -810,10 +809,9 @@ static unsigned long __iova_rcache_get(struct iova_rcache *rcache,
> 	struct iova_cpu_rcache *cpu_rcache;
> 	unsigned long iova_pfn = 0;
> 	bool has_pfn = false;
>-	unsigned long flags;
> 
>+	preempt_disable();
> 	cpu_rcache = this_cpu_ptr(rcache->cpu_rcaches);
>-	spin_lock_irqsave(&cpu_rcache->lock, flags);
> 
> 	if (!iova_magazine_empty(cpu_rcache->loaded)) {
> 		has_pfn = true;
>@@ -833,7 +831,7 @@ static unsigned long __iova_rcache_get(struct iova_rcache *rcache,
> 	if (has_pfn)
> 		iova_pfn = iova_magazine_pop(cpu_rcache->loaded, limit_pfn);
> 
>-	spin_unlock_irqrestore(&cpu_rcache->lock, flags);
>+	preempt_enable();
> 
> 	return iova_pfn;
> }
>@@ -862,17 +860,11 @@ static void free_cpu_iova_rcache(unsigned int cpu, struct iova_domain *iovad,
> 				 struct iova_rcache *rcache)
> {
> 	struct iova_cpu_rcache *cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
>-	unsigned long flags;
>-
>-	spin_lock_irqsave(&cpu_rcache->lock, flags);
>-
> 	iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
> 	iova_magazine_free(cpu_rcache->loaded);
> 
> 	iova_magazine_free_pfns(cpu_rcache->prev, iovad);
> 	iova_magazine_free(cpu_rcache->prev);
>-
>-	spin_unlock_irqrestore(&cpu_rcache->lock, flags);
> }
> 
> /*
>@@ -887,9 +879,9 @@ static void free_iova_rcaches(struct iova_domain *iovad)
> 
> 	for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
> 		rcache = &iovad->rcaches[i];
>+		spin_lock_irqsave(&rcache->lock, flags);
> 		for_each_possible_cpu(cpu)
> 			free_cpu_iova_rcache(cpu, iovad, rcache);
>-		spin_lock_irqsave(&rcache->lock, flags);
> 		free_percpu(rcache->cpu_rcaches);
> 		for (j = 0; j < rcache->depot_size; ++j) {
> 			iova_magazine_free_pfns(rcache->depot[j], iovad);
>@@ -906,16 +898,13 @@ void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad)
> {
> 	struct iova_cpu_rcache *cpu_rcache;
> 	struct iova_rcache *rcache;
>-	unsigned long flags;
> 	int i;
> 
> 	for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
> 		rcache = &iovad->rcaches[i];
> 		cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
>-		spin_lock_irqsave(&cpu_rcache->lock, flags);
> 		iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
> 		iova_magazine_free_pfns(cpu_rcache->prev, iovad);
>-		spin_unlock_irqrestore(&cpu_rcache->lock, flags);
> 	}
> }
> 
>-- 
>2.8.1
>

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