From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: kishon@ti.com, lorenzo.pieralisi@arm.com
Cc: kw@linux.com, bhelgaas@google.com, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org, bjorn.andersson@linaro.org,
dmitry.baryshkov@linaro.org,
Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Subject: [PATCH v2] PCI: endpoint: Use blocking notifier instead of atomic
Date: Mon, 28 Feb 2022 11:22:40 +0530 [thread overview]
Message-ID: <20220228055240.24774-1-manivannan.sadhasivam@linaro.org> (raw)
The use of atomic notifier causes sleeping in atomic context bug when
the EPC core functions are used in the notifier chain. This is due to the
use of epc->lock (mutex) in core functions protecting the concurrent use of
EPC.
So switch to blocking notifier for getting rid of the bug as it runs in
non-atomic context and allows sleeping in notifier chain.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
Changes in v2:
* Removed the changes related to non-upstreamed patches
drivers/pci/endpoint/pci-epc-core.c | 6 +++---
include/linux/pci-epc.h | 4 ++--
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 3bc9273d0a08..c4347f472618 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -693,7 +693,7 @@ void pci_epc_linkup(struct pci_epc *epc)
if (!epc || IS_ERR(epc))
return;
- atomic_notifier_call_chain(&epc->notifier, LINK_UP, NULL);
+ blocking_notifier_call_chain(&epc->notifier, LINK_UP, NULL);
}
EXPORT_SYMBOL_GPL(pci_epc_linkup);
@@ -710,7 +710,7 @@ void pci_epc_init_notify(struct pci_epc *epc)
if (!epc || IS_ERR(epc))
return;
- atomic_notifier_call_chain(&epc->notifier, CORE_INIT, NULL);
+ blocking_notifier_call_chain(&epc->notifier, CORE_INIT, NULL);
}
EXPORT_SYMBOL_GPL(pci_epc_init_notify);
@@ -774,7 +774,7 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
mutex_init(&epc->lock);
INIT_LIST_HEAD(&epc->pci_epf);
- ATOMIC_INIT_NOTIFIER_HEAD(&epc->notifier);
+ BLOCKING_INIT_NOTIFIER_HEAD(&epc->notifier);
device_initialize(&epc->dev);
epc->dev.class = pci_epc_class;
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index a48778e1a4ee..04a2e74aed63 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -149,7 +149,7 @@ struct pci_epc {
/* mutex to protect against concurrent access of EP controller */
struct mutex lock;
unsigned long function_num_map;
- struct atomic_notifier_head notifier;
+ struct blocking_notifier_head notifier;
};
/**
@@ -195,7 +195,7 @@ static inline void *epc_get_drvdata(struct pci_epc *epc)
static inline int
pci_epc_register_notifier(struct pci_epc *epc, struct notifier_block *nb)
{
- return atomic_notifier_chain_register(&epc->notifier, nb);
+ return blocking_notifier_chain_register(&epc->notifier, nb);
}
struct pci_epc *
--
2.25.1
next reply other threads:[~2022-02-28 5:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-28 5:52 Manivannan Sadhasivam [this message]
2022-02-28 6:16 ` [PATCH v2] PCI: endpoint: Use blocking notifier instead of atomic Kishon Vijay Abraham I
2022-02-28 6:28 ` Manivannan Sadhasivam
2022-03-09 4:37 ` Kishon Vijay Abraham I
2022-03-23 18:09 ` Manivannan Sadhasivam
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