* [PATCH 1/3] PCI: endpoint: Add 'started' to pci_epc to set whether the controller is started
2020-10-02 4:48 [PATCH 0/3] PCI: endpoint: Add endpoint restart management support Kunihiko Hayashi
@ 2020-10-02 4:48 ` Kunihiko Hayashi
2020-10-02 4:48 ` [PATCH 2/3] PCI: endpoint: Add endpoint restart management Kunihiko Hayashi
2020-10-02 4:48 ` [PATCH 3/3] PCI: uniphier-ep: Add EPC restart management support Kunihiko Hayashi
2 siblings, 0 replies; 4+ messages in thread
From: Kunihiko Hayashi @ 2020-10-02 4:48 UTC (permalink / raw)
To: Lorenzo Pieralisi, Rob Herring, Bjorn Helgaas, Kishon Vijay Abraham I
Cc: linux-pci, linux-arm-kernel, linux-kernel, Masami Hiramatsu,
Jassi Brar, Kunihiko Hayashi
This adds a member 'started' as a boolean value to struct pci_epc to set
whether the controller is started, and also adds a function to get the
value.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---
drivers/pci/endpoint/pci-epc-core.c | 2 ++
include/linux/pci-epc.h | 7 +++++++
2 files changed, 9 insertions(+)
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index cadd3db..155be574 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -148,6 +148,7 @@ void pci_epc_stop(struct pci_epc *epc)
mutex_lock(&epc->lock);
epc->ops->stop(epc);
+ epc->started = false;
mutex_unlock(&epc->lock);
}
EXPORT_SYMBOL_GPL(pci_epc_stop);
@@ -170,6 +171,7 @@ int pci_epc_start(struct pci_epc *epc)
mutex_lock(&epc->lock);
ret = epc->ops->start(epc);
+ epc->started = true;
mutex_unlock(&epc->lock);
return ret;
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index cc66bec..d875d2d 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -107,6 +107,7 @@ struct pci_epc_mem {
* @lock: mutex to protect pci_epc ops
* @function_num_map: bitmap to manage physical function number
* @notifier: used to notify EPF of any EPC events (like linkup)
+ * @started: true if this EPC is started
*/
struct pci_epc {
struct device dev;
@@ -121,6 +122,7 @@ struct pci_epc {
struct mutex lock;
unsigned long function_num_map;
struct atomic_notifier_head notifier;
+ bool started;
};
/**
@@ -167,6 +169,11 @@ pci_epc_register_notifier(struct pci_epc *epc, struct notifier_block *nb)
return atomic_notifier_chain_register(&epc->notifier, nb);
}
+static inline bool pci_epc_is_started(struct pci_epc *epc)
+{
+ return epc->started;
+}
+
struct pci_epc *
__devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
struct module *owner);
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/3] PCI: endpoint: Add endpoint restart management
2020-10-02 4:48 [PATCH 0/3] PCI: endpoint: Add endpoint restart management support Kunihiko Hayashi
2020-10-02 4:48 ` [PATCH 1/3] PCI: endpoint: Add 'started' to pci_epc to set whether the controller is started Kunihiko Hayashi
@ 2020-10-02 4:48 ` Kunihiko Hayashi
2020-10-02 4:48 ` [PATCH 3/3] PCI: uniphier-ep: Add EPC restart management support Kunihiko Hayashi
2 siblings, 0 replies; 4+ messages in thread
From: Kunihiko Hayashi @ 2020-10-02 4:48 UTC (permalink / raw)
To: Lorenzo Pieralisi, Rob Herring, Bjorn Helgaas, Kishon Vijay Abraham I
Cc: linux-pci, linux-arm-kernel, linux-kernel, Masami Hiramatsu,
Jassi Brar, Kunihiko Hayashi
Add new functions to manage recovery of configuration parameters and
restart the controller when asserting bus-reset from root-complex (RC).
This feature is only available if bus-reset (PERST#) line is physically
routed between RC and endpoint and the signal from RC affects endpoint.
This feature works as follows.
- This adds a polling thread, that polls and detects the bus-reset signal,
and recovers configuration parameters for endpoint. The polling period
is fixed at EPC_RESTART_POLL_PERIOD_MS.
- After the endpoint controller starts and the user sets configuration
parameters using sysfs or function drivers, once RC asserts bus-reset
and endpoint can receive it, the endpoint controller will also reset
and initialize configuration parameters.
- If the thread detects bus-reset signal, the thread stops the controller,
unbinds it, quickly binds it and restart it. The configuration
paremters are restored to the user's values.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---
drivers/pci/endpoint/Kconfig | 9 +++
drivers/pci/endpoint/Makefile | 1 +
drivers/pci/endpoint/pci-epc-restart.c | 114 +++++++++++++++++++++++++++++++++
include/linux/pci-epc.h | 15 +++++
4 files changed, 139 insertions(+)
create mode 100644 drivers/pci/endpoint/pci-epc-restart.c
diff --git a/drivers/pci/endpoint/Kconfig b/drivers/pci/endpoint/Kconfig
index 17bbdc9..016c82a 100644
--- a/drivers/pci/endpoint/Kconfig
+++ b/drivers/pci/endpoint/Kconfig
@@ -28,6 +28,15 @@ config PCI_ENDPOINT_CONFIGFS
configure the endpoint function and used to bind the
function with a endpoint controller.
+config PCI_ENDPOINT_RESTART
+ bool "PCI Endpoint Restart Management Support"
+ depends on PCI_ENDPOINT
+ help
+ Enable restart management functions, which detects bus-reset
+ from root complex, and recover endpoint configuration.
+ This is only available if bus-reset line is physically routed
+ between root complex and endpoint.
+
source "drivers/pci/endpoint/functions/Kconfig"
endmenu
diff --git a/drivers/pci/endpoint/Makefile b/drivers/pci/endpoint/Makefile
index 95b2fe4..7301aea 100644
--- a/drivers/pci/endpoint/Makefile
+++ b/drivers/pci/endpoint/Makefile
@@ -4,5 +4,6 @@
#
obj-$(CONFIG_PCI_ENDPOINT_CONFIGFS) += pci-ep-cfs.o
+obj-$(CONFIG_PCI_ENDPOINT_RESTART) += pci-epc-restart.o
obj-$(CONFIG_PCI_ENDPOINT) += pci-epc-core.o pci-epf-core.o\
pci-epc-mem.o functions/
diff --git a/drivers/pci/endpoint/pci-epc-restart.c b/drivers/pci/endpoint/pci-epc-restart.c
new file mode 100644
index 0000000..ab956be
--- /dev/null
+++ b/drivers/pci/endpoint/pci-epc-restart.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * PCI Endpoint Controller Restart Management
+ *
+ * Copyright (C) 2019-2020 Socionext Inc.
+ * Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
+ */
+
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+
+#define EPC_RESTART_POLL_PERIOD_MS 80
+
+static int pci_epc_restart_thread(void *dev_id)
+{
+ struct pci_epc *epc = dev_id;
+ struct pci_epf *epf;
+ int ret = 0;
+
+ dev_info(&epc->dev, "[epc-restart] thread start\n");
+
+ while (!kthread_should_stop()) {
+ if (epc->restart_poll) {
+ /* call polling function */
+ ret = epc->restart_poll(epc->restart_poll_data);
+ if (!ret) {
+ msleep(EPC_RESTART_POLL_PERIOD_MS);
+ continue;
+ } else if (ret < 0) {
+ break;
+ }
+ } else {
+ /* wait for interrupt */
+ ret = wait_for_completion_interruptible(&epc->restart_comp);
+ if (ret <= 0)
+ break;
+ }
+
+ if (!pci_epc_is_started(epc))
+ continue;
+
+ /*
+ * After stop linkup, call unbind() once and call bind() again.
+ * to reload config parameters to the controller.
+ */
+ pci_epc_stop(epc);
+ list_for_each_entry(epf, &epc->pci_epf, list) {
+ pci_epf_unbind(epf);
+ pci_epf_bind(epf);
+ }
+ pci_epc_start(epc);
+
+ dev_info(&epc->dev, "[epc-restart] assert\n");
+ }
+
+ dev_info(&epc->dev, "[epc-restart] thread exit\n");
+
+ return ret;
+}
+
+/**
+ * pci_epc_restart_init() - initialize epc-restart thread
+ * @epc: the EPC device
+ */
+int pci_epc_restart_init(struct pci_epc *epc)
+{
+ init_completion(&epc->restart_comp);
+
+ epc->restart_task = kthread_run(pci_epc_restart_thread, epc,
+ "pci-epc-restart");
+ if (IS_ERR(epc->restart_task))
+ return PTR_ERR(epc->restart_task);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_epc_restart_init);
+
+/**
+ * pci_epc_restart_cleanup() - clean up epc-restart thread
+ * @epc: the EPC device
+ */
+void pci_epc_restart_cleanup(struct pci_epc *epc)
+{
+ if (epc->restart_task)
+ kthread_stop(epc->restart_task);
+}
+EXPORT_SYMBOL_GPL(pci_epc_restart_cleanup);
+
+/**
+ * pci_epc_restart_notify() - notify to epc-restart thread
+ * @epc: the EPC device
+ */
+void pci_epc_restart_notify(struct pci_epc *epc)
+{
+ complete(&epc->restart_comp);
+}
+EXPORT_SYMBOL_GPL(pci_epc_restart_notify);
+
+/**
+ * pci_epc_restart_register_poll_func() - register polling method for restart thread
+ * @epc: the EPC device
+ * @func: polling function
+ * @data: data for polling function
+ */
+void pci_epc_restart_register_poll_func(struct pci_epc *epc, bool (*func)(void *),
+ void *data)
+{
+ epc->restart_poll = func;
+ epc->restart_poll_data = data;
+}
+EXPORT_SYMBOL_GPL(pci_epc_restart_register_poll_func);
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index d875d2d..a50c8c8 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -108,6 +108,10 @@ struct pci_epc_mem {
* @function_num_map: bitmap to manage physical function number
* @notifier: used to notify EPF of any EPC events (like linkup)
* @started: true if this EPC is started
+ * @restart_task: pointer to task for restart thread
+ * @restart_comp: completion object for receiving reset interrupts from RC
+ * @restart_poll: function to poll reset detection from RC
+ * @restart_poll_data: an argument that restart_poll function gets
*/
struct pci_epc {
struct device dev;
@@ -123,6 +127,11 @@ struct pci_epc {
unsigned long function_num_map;
struct atomic_notifier_head notifier;
bool started;
+ /* for epc-restart */
+ struct task_struct *restart_task;
+ struct completion restart_comp;
+ bool (*restart_poll)(void *func);
+ void *restart_poll_data;
};
/**
@@ -223,4 +232,10 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
phys_addr_t *phys_addr, size_t size);
void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
void __iomem *virt_addr, size_t size);
+int pci_epc_restart_init(struct pci_epc *epc);
+void pci_epc_restart_cleanup(struct pci_epc *epc);
+void pci_epc_restart_notify(struct pci_epc *epc);
+void pci_epc_restart_register_poll_func(struct pci_epc *epc,
+ bool (*func)(void *), void *data);
+
#endif /* __LINUX_PCI_EPC_H */
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 3/3] PCI: uniphier-ep: Add EPC restart management support
2020-10-02 4:48 [PATCH 0/3] PCI: endpoint: Add endpoint restart management support Kunihiko Hayashi
2020-10-02 4:48 ` [PATCH 1/3] PCI: endpoint: Add 'started' to pci_epc to set whether the controller is started Kunihiko Hayashi
2020-10-02 4:48 ` [PATCH 2/3] PCI: endpoint: Add endpoint restart management Kunihiko Hayashi
@ 2020-10-02 4:48 ` Kunihiko Hayashi
2 siblings, 0 replies; 4+ messages in thread
From: Kunihiko Hayashi @ 2020-10-02 4:48 UTC (permalink / raw)
To: Lorenzo Pieralisi, Rob Herring, Bjorn Helgaas, Kishon Vijay Abraham I
Cc: linux-pci, linux-arm-kernel, linux-kernel, Masami Hiramatsu,
Jassi Brar, Kunihiko Hayashi
Set the polling function and call the init function to enable EPC restart
management. The polling function detects that the bus-reset signal is a
rising edge.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---
drivers/pci/controller/dwc/Kconfig | 1 +
drivers/pci/controller/dwc/pcie-uniphier-ep.c | 34 +++++++++++++++++++++++++--
2 files changed, 33 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index bc04986..4932095 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -296,6 +296,7 @@ config PCIE_UNIPHIER_EP
depends on OF && HAS_IOMEM
depends on PCI_ENDPOINT
select PCIE_DW_EP
+ select PCI_ENDPOINT_RESTART
help
Say Y here if you want PCIe endpoint controller support on
UniPhier SoCs. This driver supports Pro5 SoC.
diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
index 1483559..bd187b1 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
@@ -26,6 +26,7 @@
#define PCL_RSTCTRL_PIPE3 BIT(0)
#define PCL_RSTCTRL1 0x0020
+#define PCL_RSTCTRL_PERST_MON BIT(16)
#define PCL_RSTCTRL_PERST BIT(0)
#define PCL_RSTCTRL2 0x0024
@@ -60,6 +61,7 @@ struct uniphier_pcie_ep_priv {
struct clk *clk, *clk_gio;
struct reset_control *rst, *rst_gio;
struct phy *phy;
+ bool bus_reset_status;
const struct pci_epc_features *features;
};
@@ -218,6 +220,23 @@ static const struct dw_pcie_ep_ops uniphier_pcie_ep_ops = {
.get_features = uniphier_pcie_get_features,
};
+static bool uniphier_pcie_ep_poll_reset(void *data)
+{
+ struct uniphier_pcie_ep_priv *priv = data;
+ bool ret, status;
+
+ if (!priv)
+ return false;
+
+ status = !(readl(priv->base + PCL_RSTCTRL1) & PCL_RSTCTRL_PERST_MON);
+
+ /* return true if the rising edge of bus reset is detected */
+ ret = !!(status == false && priv->bus_reset_status == true);
+ priv->bus_reset_status = status;
+
+ return ret;
+}
+
static int uniphier_add_pcie_ep(struct uniphier_pcie_ep_priv *priv,
struct platform_device *pdev)
{
@@ -241,10 +260,21 @@ static int uniphier_add_pcie_ep(struct uniphier_pcie_ep_priv *priv,
ep->addr_size = resource_size(res);
ret = dw_pcie_ep_init(ep);
- if (ret)
+ if (ret) {
dev_err(dev, "Failed to initialize endpoint (%d)\n", ret);
+ return ret;
+ }
- return ret;
+ /* Set up epc-restart thread */
+ pci_epc_restart_register_poll_func(ep->epc,
+ uniphier_pcie_ep_poll_reset, priv);
+ /* With call of poll_reset() directly, initialize internal state */
+ uniphier_pcie_ep_poll_reset(priv);
+ ret = pci_epc_restart_init(ep->epc);
+ if (ret)
+ dev_err(dev, "Failed to initialize epc-restart (%d)\n", ret);
+
+ return 0;
}
static int uniphier_pcie_ep_enable(struct uniphier_pcie_ep_priv *priv)
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread