From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Bjorn Helgaas <helgaas@kernel.org>, linux-pci@vger.kernel.org
Cc: Hari Vyas <hari.vyas@broadcom.com>,
Ray Jui <ray.jui@broadcom.com>,
Srinath Mannam <srinath.mannam@broadcom.com>,
Guenter Roeck <linux@roeck-us.net>, Jens Axboe <axboe@kernel.dk>,
Lukas Wunner <lukas@wunner.de>,
Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
Marta Rybczynska <mrybczyn@kalray.eu>,
Pierre-Yves Kerbrat <pkerbrat@kalray.eu>,
linux-kernel@vger.kernel.org,
Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: [RFC PATCH 4/6] pci: Add a mutex to pci_dev to protect device state
Date: Fri, 17 Aug 2018 14:49:00 +1000 [thread overview]
Message-ID: <20180817044902.31420-5-benh@kernel.crashing.org> (raw)
In-Reply-To: <20180817044902.31420-1-benh@kernel.crashing.org>
This adds a pci_dev mutex which will be used to fix a number
of races related to the various state bits maintained in
that structure.
We call it "state_lock" with similarly named accessors to avoid
confusion with the pci_dev_lock() which uses the device_lock().
This is a low level mutex meant to protect the mapping between
the state fields and the hardware state, for example enabling
disabling, setting/clearing bus master etc...
These operations can happen while the device_lock() is already
held (but don't have to) so a separate mutex is preferable.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
drivers/pci/probe.c | 1 +
include/linux/pci.h | 17 +++++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 440445ac7dfa..3ce287ab6150 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2155,6 +2155,7 @@ struct pci_dev *pci_alloc_dev(struct pci_bus *bus)
INIT_LIST_HEAD(&dev->bus_list);
dev->dev.type = &pci_dev_type;
dev->bus = pci_bus_get(bus);
+ mutex_init(&dev->state_lock);
return dev;
}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index f58bda204f09..0d4fc22df190 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -33,6 +33,7 @@
#include <linux/io.h>
#include <linux/resource_ext.h>
#include <uapi/linux/pci.h>
+#include <linux/mutex.h>
#include <linux/pci_ids.h>
@@ -443,8 +444,24 @@ struct pci_dev {
phys_addr_t rom; /* Physical address if not from BAR */
size_t romlen; /* Length if not from BAR */
char *driver_override; /* Driver name to force a match */
+
+ unsigned long priv_flags; /* Private flags for the PCI driver */
+
+ struct mutex state_lock; /* Protect local state bits */
+
+ /* --- Fields below this line are protected by the state_lock mutex */
};
+static inline void pci_dev_state_lock(struct pci_dev *dev)
+{
+ mutex_lock(&dev->state_lock);
+}
+
+static inline void pci_dev_state_unlock(struct pci_dev *dev)
+{
+ mutex_unlock(&dev->state_lock);
+}
+
static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
{
#ifdef CONFIG_PCI_IOV
--
2.17.1
next prev parent reply other threads:[~2018-08-17 5:50 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-17 4:48 [RFC PATCH 0/6] pci: Rework is_added race fix and address bridge enable races Benjamin Herrenschmidt
2018-08-17 4:48 ` [RFC PATCH 1/6] Revert "PCI: Fix is_added/is_busmaster race condition" Benjamin Herrenschmidt
2018-08-17 4:57 ` Benjamin Herrenschmidt
2018-08-17 15:44 ` Bjorn Helgaas
2018-08-18 3:24 ` Benjamin Herrenschmidt
2018-08-19 2:24 ` Bjorn Helgaas
2018-08-20 2:10 ` Benjamin Herrenschmidt
2018-08-20 6:25 ` Hari Vyas
2018-08-20 11:09 ` Benjamin Herrenschmidt
2018-08-20 11:43 ` Hari Vyas
2018-08-20 7:17 ` Lukas Wunner
2018-08-20 11:12 ` Benjamin Herrenschmidt
2018-08-17 4:48 ` [RFC PATCH 2/6] pci: Set pci_dev->is_added before calling device_add Benjamin Herrenschmidt
2018-08-17 4:57 ` Benjamin Herrenschmidt
2018-08-17 16:25 ` Bjorn Helgaas
2018-08-17 18:15 ` Lukas Wunner
2018-08-18 3:41 ` Benjamin Herrenschmidt
2018-08-18 3:28 ` Benjamin Herrenschmidt
2018-08-17 4:48 ` [RFC PATCH 3/6] pci: Remove priv_flags and use dev->error_state for "disconnected" status Benjamin Herrenschmidt
2018-08-17 5:13 ` [RFC PATCH v2 " Benjamin Herrenschmidt
2018-08-17 4:49 ` Benjamin Herrenschmidt [this message]
2018-08-17 4:49 ` [RFC PATCH 5/6] pci: Protect the enable/disable state of pci_dev using the state mutex Benjamin Herrenschmidt
2018-08-17 8:09 ` Marta Rybczynska
2018-08-17 8:30 ` Benjamin Herrenschmidt
2018-08-17 9:00 ` Hari Vyas
2018-08-17 9:39 ` Benjamin Herrenschmidt
2018-08-17 10:10 ` Hari Vyas
2018-08-17 10:24 ` Benjamin Herrenschmidt
2018-08-17 4:49 ` [RFC PATCH 6/6] pci: Protect is_busmaster using the state lock Benjamin Herrenschmidt
2018-08-17 5:03 ` [RFC PATCH 0/6] pci: Rework is_added race fix and address bridge enable races Benjamin Herrenschmidt
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