From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: iommu@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org, Joerg Roedel <joro@8bytes.org>,
tglx@linutronix.de,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH 04/10] iommu/amd: split irq_lookup_table out of the amd_iommu_devtable_lock
Date: Fri, 23 Feb 2018 23:27:30 +0100 [thread overview]
Message-ID: <20180223222736.18542-5-bigeasy@linutronix.de> (raw)
In-Reply-To: <20180223222736.18542-1-bigeasy@linutronix.de>
The function get_irq_table() reads/writes irq_lookup_table while holding
the amd_iommu_devtable_lock. It also modifies
amd_iommu_dev_table[].data[2].
set_dte_entry() is using amd_iommu_dev_table[].data[0|1] (under the
domain->lock) so it should be okay. The access to the iommu is
serialized with its own (iommu's) lock.
So split out get_irq_table() out of amd_iommu_devtable_lock's lock. The
new lock is a raw_spin_lock because modify_irte_ga() is called while
desc->lock is held (which is raw).
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
drivers/iommu/amd_iommu.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 958efe311057..72487ac43eef 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -82,6 +82,7 @@
static DEFINE_RWLOCK(amd_iommu_devtable_lock);
static DEFINE_SPINLOCK(pd_bitmap_lock);
+static DEFINE_RAW_SPINLOCK(iommu_table_lock);
/* List of all available dev_data structures */
static LLIST_HEAD(dev_data_list);
@@ -3594,7 +3595,7 @@ static struct irq_remap_table *get_irq_table(u16 devid, bool ioapic)
unsigned long flags;
u16 alias;
- write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+ raw_spin_lock_irqsave(&iommu_table_lock, flags);
iommu = amd_iommu_rlookup_table[devid];
if (!iommu)
@@ -3659,7 +3660,7 @@ static struct irq_remap_table *get_irq_table(u16 devid, bool ioapic)
iommu_completion_wait(iommu);
out_unlock:
- write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+ raw_spin_unlock_irqrestore(&iommu_table_lock, flags);
return table;
}
--
2.16.1
next prev parent reply other threads:[~2018-02-23 22:30 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-23 22:27 iommu/amd: lock splitting & GFP_KERNEL allocation Sebastian Andrzej Siewior
2018-02-23 22:27 ` [PATCH 01/10] iommu/amd: take into account that alloc_dev_data() may return NULL Sebastian Andrzej Siewior
2018-02-23 22:27 ` [PATCH 02/10] iommu/amd: turn dev_data_list into a lock less list Sebastian Andrzej Siewior
2018-02-23 22:27 ` [PATCH 03/10] iommu/amd: split domain id out of amd_iommu_devtable_lock Sebastian Andrzej Siewior
2018-02-23 22:27 ` Sebastian Andrzej Siewior [this message]
2018-03-15 12:54 ` [PATCH 04/10] iommu/amd: split irq_lookup_table out of the amd_iommu_devtable_lock Joerg Roedel
2018-02-23 22:27 ` [PATCH 05/10] iommu/amd: remove the special case from get_irq_table() Sebastian Andrzej Siewior
2018-03-15 12:53 ` Joerg Roedel
2018-03-15 13:01 ` Sebastian Andrzej Siewior
2018-03-15 13:07 ` Joerg Roedel
2018-03-15 14:15 ` Sebastian Andrzej Siewior
2018-03-15 15:19 ` Joerg Roedel
2018-03-15 15:25 ` Sebastian Andrzej Siewior
2018-02-23 22:27 ` [PATCH 06/10] iommu/amd: use `table' instead `irt' as variable name in amd_iommu_update_ga() Sebastian Andrzej Siewior
2018-02-23 22:27 ` [PATCH 07/10] iommu/amd: factor out setting the remap table for a devid Sebastian Andrzej Siewior
2018-02-23 22:27 ` [PATCH 08/10] iommu/amd: drop the lock while allocating new irq remap table Sebastian Andrzej Siewior
2018-03-15 12:58 ` Joerg Roedel
2018-02-23 22:27 ` [PATCH 09/10] iommu/amd: declare irq_remap_table's and amd_iommu's lock as a raw_spin_lock Sebastian Andrzej Siewior
2018-02-23 22:27 ` [PATCH 10/10] iommu/amd: make amd_iommu_devtable_lock a spin_lock Sebastian Andrzej Siewior
2018-03-15 13:01 ` iommu/amd: lock splitting & GFP_KERNEL allocation Joerg Roedel
2018-03-16 20:18 [PATCH 00/10 v2] " Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 04/10] iommu/amd: split irq_lookup_table out of the amd_iommu_devtable_lock Sebastian Andrzej Siewior
2018-03-22 15:22 [PATCH 00/10 v3] iommu/amd: lock splitting & GFP_KERNEL allocation Sebastian Andrzej Siewior
2018-03-22 15:22 ` [PATCH 04/10] iommu/amd: split irq_lookup_table out of the amd_iommu_devtable_lock Sebastian Andrzej Siewior
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180223222736.18542-5-bigeasy@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=iommu@lists.linux-foundation.org \
--cc=joro@8bytes.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).