From 50b52fdee050745935d92e7026373edea2647e60 Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 4 Feb 2014 18:31:11 -0800 Subject: PCI: pciehp: Add hotplug_lock to serialize hotplug events Today it is there is no protection around pciehp_enable_slot() and pciehp_disable_slot() to ensure that they complete before another hot-plug operation can be done on that particular slot. This patch introduces the slot->hotplug_lock to ensure that any hotplug operations (add / remove) complete before another hotplug event can begin processing on that particular slot. Signed-off-by: Rajat Jain Signed-off-by: Rajat Jain Signed-off-by: Guenter Roeck Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp.h | 1 + drivers/pci/hotplug/pciehp_core.c | 7 ++++++- drivers/pci/hotplug/pciehp_ctrl.c | 17 +++++++++++++++-- drivers/pci/hotplug/pciehp_hpc.c | 1 + 4 files changed, 23 insertions(+), 3 deletions(-) diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index d8d033619a77..8a66866b8cf1 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -76,6 +76,7 @@ struct slot { struct hotplug_slot *hotplug_slot; struct delayed_work work; /* work for button event */ struct mutex lock; + struct mutex hotplug_lock; struct workqueue_struct *wq; }; diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index 53b58debc288..23b4bde8aad3 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -283,8 +283,11 @@ static int pciehp_probe(struct pcie_device *dev) slot = ctrl->slot; pciehp_get_adapter_status(slot, &occupied); pciehp_get_power_status(slot, &poweron); - if (occupied && pciehp_force) + if (occupied && pciehp_force) { + mutex_lock(&slot->hotplug_lock); pciehp_enable_slot(slot); + mutex_unlock(&slot->hotplug_lock); + } /* If empty slot's power status is on, turn power off */ if (!occupied && poweron && POWER_CTRL(ctrl)) pciehp_power_off_slot(slot); @@ -328,10 +331,12 @@ static int pciehp_resume (struct pcie_device *dev) /* Check if slot is occupied */ pciehp_get_adapter_status(slot, &status); + mutex_lock(&slot->hotplug_lock); if (status) pciehp_enable_slot(slot); else pciehp_disable_slot(slot); + mutex_unlock(&slot->hotplug_lock); return 0; } #endif /* PM */ diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index 3e40ec0f7da1..fec99a164d93 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -293,6 +293,7 @@ static void pciehp_power_thread(struct work_struct *work) struct power_work_info *info = container_of(work, struct power_work_info, work); struct slot *p_slot = info->p_slot; + int ret; switch (info->req) { case DISABLE_REQ: @@ -300,7 +301,9 @@ static void pciehp_power_thread(struct work_struct *work) "Disabling domain:bus:device=%04x:%02x:00\n", pci_domain_nr(p_slot->ctrl->pcie->port->subordinate), p_slot->ctrl->pcie->port->subordinate->number); + mutex_lock(&p_slot->hotplug_lock); pciehp_disable_slot(p_slot); + mutex_unlock(&p_slot->hotplug_lock); mutex_lock(&p_slot->lock); p_slot->state = STATIC_STATE; mutex_unlock(&p_slot->lock); @@ -310,7 +313,10 @@ static void pciehp_power_thread(struct work_struct *work) "Enabling domain:bus:device=%04x:%02x:00\n", pci_domain_nr(p_slot->ctrl->pcie->port->subordinate), p_slot->ctrl->pcie->port->subordinate->number); - if (pciehp_enable_slot(p_slot)) + mutex_lock(&p_slot->hotplug_lock); + ret = pciehp_enable_slot(p_slot); + mutex_unlock(&p_slot->hotplug_lock); + if (ret) pciehp_green_led_off(p_slot); mutex_lock(&p_slot->lock); p_slot->state = STATIC_STATE; @@ -546,6 +552,9 @@ static void interrupt_event_handler(struct work_struct *work) kfree(info); } +/* + * Note: This function must be called with slot->hotplug_lock held + */ int pciehp_enable_slot(struct slot *p_slot) { u8 getstatus = 0; @@ -584,7 +593,9 @@ int pciehp_enable_slot(struct slot *p_slot) return rc; } - +/* + * Note: This function must be called with slot->hotplug_lock held + */ int pciehp_disable_slot(struct slot *p_slot) { u8 getstatus = 0; @@ -617,7 +628,9 @@ int pciehp_sysfs_enable_slot(struct slot *p_slot) case STATIC_STATE: p_slot->state = POWERON_STATE; mutex_unlock(&p_slot->lock); + mutex_lock(&p_slot->hotplug_lock); retval = pciehp_enable_slot(p_slot); + mutex_unlock(&p_slot->hotplug_lock); mutex_lock(&p_slot->lock); p_slot->state = STATIC_STATE; break; diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 6433e73aa2df..da4b0204b4f7 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -686,6 +686,7 @@ static int pcie_init_slot(struct controller *ctrl) slot->ctrl = ctrl; mutex_init(&slot->lock); + mutex_init(&slot->hotplug_lock); INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work); ctrl->slot = slot; return 0; -- cgit v1.2.3-55-g7522