From: Alexey Kardashevskiy <aik@ozlabs.ru>
To: linuxppc-dev@lists.ozlabs.org
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>,
linux-kernel@vger.kernel.org, Paul Mackerras <paulus@samba.org>,
Anton Blanchard <anton@samba.org>,
David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH] powerpc/vfio: Add missing locks for take/release TCE table ownership
Date: Wed, 26 Jun 2013 15:39:19 +1000 [thread overview]
Message-ID: <1372225159-30187-1-git-send-email-aik@ozlabs.ru> (raw)
VFIO IOMMU driver for sPAPR TCE locks the whole DMA window by setting
ones to iommu_table.it_map. However this was not protected by the locks
which other clients of iommu_table use.
The patch fixes this.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
arch/powerpc/kernel/iommu.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index b20ff17..9f34742 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1076,25 +1076,41 @@ EXPORT_SYMBOL_GPL(iommu_put_tce_user_mode);
int iommu_take_ownership(struct iommu_table *tbl)
{
unsigned long sz = (tbl->it_size + 7) >> 3;
+ int i, ret = 0;
+
+ for (i = 0; i < tbl->nr_pools; i++)
+ spin_lock(&tbl->pools[i].lock);
+ spin_lock(&tbl->large_pool.lock);
if (tbl->it_offset == 0)
clear_bit(0, tbl->it_map);
if (!bitmap_empty(tbl->it_map, tbl->it_size)) {
pr_err("iommu_tce: it_map is not empty");
- return -EBUSY;
+ ret = -EBUSY;
+ goto unlock_exit;
}
memset(tbl->it_map, 0xff, sz);
iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size);
- return 0;
+unlock_exit:
+ spin_unlock(&tbl->large_pool.lock);
+ for (i = 0; i < tbl->nr_pools; i++)
+ spin_unlock(&tbl->pools[i].lock);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(iommu_take_ownership);
void iommu_release_ownership(struct iommu_table *tbl)
{
unsigned long sz = (tbl->it_size + 7) >> 3;
+ int i;
+
+ for (i = 0; i < tbl->nr_pools; i++)
+ spin_lock(&tbl->pools[i].lock);
+ spin_lock(&tbl->large_pool.lock);
iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size);
memset(tbl->it_map, 0, sz);
@@ -1102,6 +1118,11 @@ void iommu_release_ownership(struct iommu_table *tbl)
/* Restore bit#0 set by iommu_init_table() */
if (tbl->it_offset == 0)
set_bit(0, tbl->it_map);
+
+ spin_unlock(&tbl->large_pool.lock);
+ for (i = 0; i < tbl->nr_pools; i++)
+ spin_unlock(&tbl->pools[i].lock);
+
}
EXPORT_SYMBOL_GPL(iommu_release_ownership);
--
1.7.10.4
next reply other threads:[~2013-06-26 5:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-26 5:39 Alexey Kardashevskiy [this message]
2013-06-26 5:49 ` [PATCH] powerpc/vfio: Add missing locks for take/release TCE table ownership Benjamin Herrenschmidt
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