From 4703389f7df70518cc4ea584f3e64cb11f28aa7c Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 4 Feb 2014 18:28:43 -0800 Subject: [PATCH 01/11] PCI: pciehp: Make check_link_active() non-static check_link_active() functionality needs to be used by subsequent patches (that introduce link state change based hotplug). Thus make the function non-static, and rename it to pciehp_check_link_active() so as to be consistent with other non-static functions. 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_hpc.c | 6 +++--- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index 88b37cad4b35..f9524592da0f 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -153,6 +153,7 @@ void pciehp_green_led_on(struct slot *slot); void pciehp_green_led_off(struct slot *slot); void pciehp_green_led_blink(struct slot *slot); int pciehp_check_link_status(struct controller *ctrl); +bool pciehp_check_link_active(struct controller *ctrl); void pciehp_release_ctrl(struct controller *ctrl); int pciehp_reset_slot(struct slot *slot, int probe); diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 14acfccb7670..aed6ab43cc13 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -206,7 +206,7 @@ static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask) mutex_unlock(&ctrl->ctrl_lock); } -static bool check_link_active(struct controller *ctrl) +bool pciehp_check_link_active(struct controller *ctrl) { struct pci_dev *pdev = ctrl_dev(ctrl); u16 lnk_status; @@ -225,12 +225,12 @@ static void __pcie_wait_link_active(struct controller *ctrl, bool active) { int timeout = 1000; - if (check_link_active(ctrl) == active) + if (pciehp_check_link_active(ctrl) == active) return; while (timeout > 0) { msleep(10); timeout -= 10; - if (check_link_active(ctrl) == active) + if (pciehp_check_link_active(ctrl) == active) return; } ctrl_dbg(ctrl, "Data Link Layer Link Active not %s in 1000 msec\n", From e48f1b67f668762003e8888eccd7acb71109e874 Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 4 Feb 2014 18:29:10 -0800 Subject: [PATCH 02/11] PCI: pciehp: Use link change notifications for hot-plug and removal A lot of systems do not have the fancy buttons and LEDs, and instead want to rely only on the Link state change events to drive the hotplug and removal state machinery. (http://www.spinics.net/lists/hotplug/msg05802.html) This patch adds support for that functionality. Here are the details about the patch itself: * Define and use interrupt events for linkup / linkdown. * Make the pcie_isr() also look at link events, and direct control to corresponding (new) link state change handler function. * Introduce the functions to handle link-up and link-down events and queue the add / removal work in the slot->wq to be processed by pciehp_power_thread() As a side note, this patch also fixes the bug https://bugzilla.kernel.org/show_bug.cgi?id=65521 "pciehp ignores Data Link Layer State Changed bit." 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 | 3 ++ drivers/pci/hotplug/pciehp_ctrl.c | 88 +++++++++++++++++++++++++++++++ drivers/pci/hotplug/pciehp_hpc.c | 6 ++- 3 files changed, 96 insertions(+), 1 deletion(-) diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index f9524592da0f..d8d033619a77 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -109,6 +109,8 @@ struct controller { #define INT_BUTTON_PRESS 7 #define INT_BUTTON_RELEASE 8 #define INT_BUTTON_CANCEL 9 +#define INT_LINK_UP 10 +#define INT_LINK_DOWN 11 #define STATIC_STATE 0 #define BLINKINGON_STATE 1 @@ -132,6 +134,7 @@ u8 pciehp_handle_attention_button(struct slot *p_slot); u8 pciehp_handle_switch_change(struct slot *p_slot); u8 pciehp_handle_presence_change(struct slot *p_slot); u8 pciehp_handle_power_fault(struct slot *p_slot); +void pciehp_handle_linkstate_change(struct slot *p_slot); int pciehp_configure_device(struct slot *p_slot); int pciehp_unconfigure_device(struct slot *p_slot); void pciehp_queue_pushbutton_work(struct work_struct *work); diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index 50628487597d..56082842b265 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -150,6 +150,27 @@ u8 pciehp_handle_power_fault(struct slot *p_slot) return 1; } +void pciehp_handle_linkstate_change(struct slot *p_slot) +{ + u32 event_type; + struct controller *ctrl = p_slot->ctrl; + + /* Link Status Change */ + ctrl_dbg(ctrl, "Data Link Layer State change\n"); + + if (pciehp_check_link_active(ctrl)) { + ctrl_info(ctrl, "slot(%s): Link Up event\n", + slot_name(p_slot)); + event_type = INT_LINK_UP; + } else { + ctrl_info(ctrl, "slot(%s): Link Down event\n", + slot_name(p_slot)); + event_type = INT_LINK_DOWN; + } + + queue_interrupt_event(p_slot, event_type); +} + /* The following routines constitute the bulk of the hotplug controller logic */ @@ -415,6 +436,69 @@ static void handle_surprise_event(struct slot *p_slot) queue_work(p_slot->wq, &info->work); } +/* + * Note: This function must be called with slot->lock held + */ +static void handle_link_event(struct slot *p_slot, u32 event) +{ + struct controller *ctrl = p_slot->ctrl; + struct power_work_info *info; + + info = kmalloc(sizeof(*info), GFP_KERNEL); + if (!info) { + ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n", + __func__); + return; + } + info->p_slot = p_slot; + INIT_WORK(&info->work, pciehp_power_thread); + + switch (p_slot->state) { + case BLINKINGON_STATE: + case BLINKINGOFF_STATE: + cancel_delayed_work(&p_slot->work); + /* Fall through */ + case STATIC_STATE: + p_slot->state = event == INT_LINK_UP ? + POWERON_STATE : POWEROFF_STATE; + queue_work(p_slot->wq, &info->work); + break; + case POWERON_STATE: + if (event == INT_LINK_UP) { + ctrl_info(ctrl, + "Link Up event ignored on slot(%s): already powering on\n", + slot_name(p_slot)); + kfree(info); + } else { + ctrl_info(ctrl, + "Link Down event queued on slot(%s): currently getting powered on\n", + slot_name(p_slot)); + p_slot->state = POWEROFF_STATE; + queue_work(p_slot->wq, &info->work); + } + break; + case POWEROFF_STATE: + if (event == INT_LINK_UP) { + ctrl_info(ctrl, + "Link Up event queued on slot(%s): currently getting powered off\n", + slot_name(p_slot)); + p_slot->state = POWERON_STATE; + queue_work(p_slot->wq, &info->work); + } else { + ctrl_info(ctrl, + "Link Down event ignored on slot(%s): already powering off\n", + slot_name(p_slot)); + kfree(info); + } + break; + default: + ctrl_err(ctrl, "Not a valid state on slot(%s)\n", + slot_name(p_slot)); + kfree(info); + break; + } +} + static void interrupt_event_handler(struct work_struct *work) { struct event_info *info = container_of(work, struct event_info, work); @@ -439,6 +523,10 @@ static void interrupt_event_handler(struct work_struct *work) ctrl_dbg(ctrl, "Surprise Removal\n"); handle_surprise_event(p_slot); break; + case INT_LINK_UP: + case INT_LINK_DOWN: + handle_link_event(p_slot, info->event_type); + break; default: break; } diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index aed6ab43cc13..b413dce8f194 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -540,7 +540,7 @@ static irqreturn_t pcie_isr(int irq, void *dev_id) detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | - PCI_EXP_SLTSTA_CC); + PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); detected &= ~intr_loc; intr_loc |= detected; if (!intr_loc) @@ -579,6 +579,10 @@ static irqreturn_t pcie_isr(int irq, void *dev_id) ctrl->power_fault_detected = 1; pciehp_handle_power_fault(slot); } + + if (intr_loc & PCI_EXP_SLTSTA_DLLSC) + pciehp_handle_linkstate_change(slot); + return IRQ_HANDLED; } From 4f854f2a2a4414248f82239e8d86b98489a1cf40 Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 4 Feb 2014 18:29:23 -0800 Subject: [PATCH 03/11] PCI: pciehp: Enable link state change notifications Enable the Link state notifications unconditionally. Enable the presence detection notification only if attention button is absent. This was discussed at this thread: https://lkml.kernel.org/r/529E5C0E.80903@gmail.com Signed-off-by: Rajat Jain Signed-off-by: Rajat Jain Signed-off-by: Guenter Roeck Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_hpc.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index b413dce8f194..245a3cb5d2f3 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -600,9 +600,17 @@ void pcie_enable_notification(struct controller *ctrl) * when it is cleared in the interrupt service routine, and * next power fault detected interrupt was notified again. */ - cmd = PCI_EXP_SLTCTL_PDCE; + + /* + * Always enable link events: thus link-up and link-down shall + * always be treated as hotplug and unplug respectively. Enable + * presence detect only if Attention Button is not present. + */ + cmd = PCI_EXP_SLTCTL_DLLSCE; if (ATTN_BUTTN(ctrl)) cmd |= PCI_EXP_SLTCTL_ABPE; + else + cmd |= PCI_EXP_SLTCTL_PDCE; if (MRL_SENS(ctrl)) cmd |= PCI_EXP_SLTCTL_MRLSCE; if (!pciehp_poll_mode) @@ -610,7 +618,8 @@ void pcie_enable_notification(struct controller *ctrl) mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE | PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE | - PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE); + PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE | + PCI_EXP_SLTCTL_DLLSCE); pcie_write_cmd(ctrl, cmd, mask); } From b1811d2455f32754cc3d8725bf2e961c5eda2a72 Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 4 Feb 2014 18:30:04 -0800 Subject: [PATCH 04/11] PCI: pciehp: Don't disable the link permanently during removal We need future link up events for hot-add, thus don't disable the link permanently during device removal. Also, remove the static functions that are now left unused. This reverts part of 2debd9289997 ("PCI: pciehp: Disable/enable link during slot power off/on"). This was discussed at the URL below, where it was revealed that it was done for a bug in a PCIe repeater chip on that particular platform. Link: https://lkml.kernel.org/r/CAErSpo72KZ-a2OSQLWoK71GCgwBt676XZdGt4tEYm-6UYnLmPw@mail.gmail.com Signed-off-by: Rajat Jain Signed-off-by: Rajat Jain Signed-off-by: Guenter Roeck Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_hpc.c | 18 ------------------ 1 file changed, 18 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 245a3cb5d2f3..15ca3a1cad8d 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -242,11 +242,6 @@ static void pcie_wait_link_active(struct controller *ctrl) __pcie_wait_link_active(ctrl, true); } -static void pcie_wait_link_not_active(struct controller *ctrl) -{ - __pcie_wait_link_active(ctrl, false); -} - static bool pci_bus_check_dev(struct pci_bus *bus, int devfn) { u32 l; @@ -332,11 +327,6 @@ static int pciehp_link_enable(struct controller *ctrl) return __pciehp_link_set(ctrl, true); } -static int pciehp_link_disable(struct controller *ctrl) -{ - return __pciehp_link_set(ctrl, false); -} - void pciehp_get_attention_status(struct slot *slot, u8 *status) { struct controller *ctrl = slot->ctrl; @@ -508,14 +498,6 @@ void pciehp_power_off_slot(struct slot * slot) { struct controller *ctrl = slot->ctrl; - /* Disable the link at first */ - pciehp_link_disable(ctrl); - /* wait the link is down */ - if (ctrl->link_active_reporting) - pcie_wait_link_not_active(ctrl); - else - msleep(1000); - pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC); ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__, pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, From 02e93a8a7c1dcecc1a33ea762a0c041cbb6a0a66 Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 4 Feb 2014 18:30:21 -0800 Subject: [PATCH 05/11] PCI: pciehp: Don't check adapter or latch status while disabling It does not make much sense to refuse to disable a slot if an adapter is not present or the latch is open. If an adapter is not present, it provides an even better reason to disable the device slot. This is specially a problem for link state hot-plug, because some ports use in band mechanism for presence detection. Thus when link goes down, presence detect also goes down. We _want_ that the removal should take place in such case. Thus remove the checks for adapter and latch in pciehp_disable_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_ctrl.c | 18 ------------------ 1 file changed, 18 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index 56082842b265..b418e3b09aa4 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -582,24 +582,6 @@ int pciehp_disable_slot(struct slot *p_slot) if (!p_slot->ctrl) return 1; - if (!HP_SUPR_RM(p_slot->ctrl)) { - pciehp_get_adapter_status(p_slot, &getstatus); - if (!getstatus) { - ctrl_info(ctrl, "No adapter on slot(%s)\n", - slot_name(p_slot)); - return -ENODEV; - } - } - - if (MRL_SENS(p_slot->ctrl)) { - pciehp_get_latch_status(p_slot, &getstatus); - if (getstatus) { - ctrl_info(ctrl, "Latch open on slot(%s)\n", - slot_name(p_slot)); - return -ENODEV; - } - } - if (POWER_CTRL(p_slot->ctrl)) { pciehp_get_power_status(p_slot, &getstatus); if (!getstatus) { From 06a8d89af551b6151fa2289dd8660647ea9d2faa Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 4 Feb 2014 18:30:40 -0800 Subject: [PATCH 06/11] PCI: pciehp: Disable link notification across slot reset Disable the link notification (in addition to presence detect notifications) across the slot reset since the reset could flap the link, and we don't want to treat it as hot unplug followed by a hotplug. Signed-off-by: Rajat Jain Signed-off-by: Rajat Jain Signed-off-by: Guenter Roeck Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_hpc.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 15ca3a1cad8d..6433e73aa2df 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -619,33 +619,37 @@ static void pcie_disable_notification(struct controller *ctrl) /* * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary - * bus reset of the bridge, but if the slot supports surprise removal we need - * to disable presence detection around the bus reset and clear any spurious + * bus reset of the bridge, but if the slot supports surprise removal (or + * link state change based hotplug), we need to disable presence detection + * (or link state notifications) around the bus reset and clear any spurious * events after. */ int pciehp_reset_slot(struct slot *slot, int probe) { struct controller *ctrl = slot->ctrl; struct pci_dev *pdev = ctrl_dev(ctrl); + u16 stat_mask = 0, ctrl_mask = 0; if (probe) return 0; - if (HP_SUPR_RM(ctrl)) { - pcie_write_cmd(ctrl, 0, PCI_EXP_SLTCTL_PDCE); - if (pciehp_poll_mode) - del_timer_sync(&ctrl->poll_timer); + if (HP_SUPR_RM(ctrl) && !ATTN_BUTTN(ctrl)) { + ctrl_mask |= PCI_EXP_SLTCTL_PDCE; + stat_mask |= PCI_EXP_SLTSTA_PDC; } + ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE; + stat_mask |= PCI_EXP_SLTSTA_DLLSC; + + pcie_write_cmd(ctrl, 0, ctrl_mask); + if (pciehp_poll_mode) + del_timer_sync(&ctrl->poll_timer); pci_reset_bridge_secondary_bus(ctrl->pcie->port); - if (HP_SUPR_RM(ctrl)) { - pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, - PCI_EXP_SLTSTA_PDC); - pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PDCE, PCI_EXP_SLTCTL_PDCE); - if (pciehp_poll_mode) - int_poll_timeout(ctrl->poll_timer.data); - } + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask); + pcie_write_cmd(ctrl, ctrl_mask, ctrl_mask); + if (pciehp_poll_mode) + int_poll_timeout(ctrl->poll_timer.data); return 0; } From c4f2f5e4981073a5aa0739f93b6733060cd37648 Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 4 Feb 2014 18:30:56 -0800 Subject: [PATCH 07/11] PCI: pciehp: Ensure very fast hotplug events are also processed Today, this is how all the hotplug and unplug events work: Hotplug / Removal needs to be done => Set slot->state (protected by slot->lock) to either POWERON_STATE (for enabling) or POWEROFF_STATE (for disabling). => Submit the work item for pciehp_power_thread() to slot->wq. Problem: There is a problem if the hotplug events can happen fast enough that they do not give SW enough time to add or remove the new devices. => Assume: Event for unplug comes (e.g. surprise removal). But before the pciehp_power_thread() work item was executed, the card was replaced by another card, causing surprise hotplug event. => What goes wrong: => The hot-removal event sets slot->state to POWEROFF_STATE, and schedules the pciehp_power_thread(). => The hot-add event sets slot->state to POWERON_STATE, and schedules the pciehp_power_thread(). => Now the pciehp_power_thread() is scheduled twice, and on both occasions it will find POWERON_STATE and will try to add the devices on the slot, and will fail complaining that the devices already exist. => Why this is a problem: If the device was replaced between the hot removal and hot-add, then we should unload the old driver and reload the new one. This does not happen today. The kernel or the driver is not even aware that the device was replaced. The problem is that the pciehp_power_thread() only looks at the slot->state which would only contain the *latest* state - not the actual event (add / remove) that was the intent of the IRQ handler who submitted the work. What this patch does: => Hotplug events pass on an actual request (for addition or removal) to pciehp_power_thread() which is local to that work item submission. => pciehp_power_thread() does not need to look at slote->state and hence no locks needed in that. => Essentially this results in all the hotplug and unplug events "replayed" by pciehp_power_thread(). Signed-off-by: Rajat Jain Signed-off-by: Rajat Jain Signed-off-by: Guenter Roeck Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_ctrl.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index b418e3b09aa4..3e40ec0f7da1 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -276,6 +276,9 @@ static int remove_board(struct slot *p_slot) struct power_work_info { struct slot *p_slot; struct work_struct work; + unsigned int req; +#define DISABLE_REQ 0 +#define ENABLE_REQ 1 }; /** @@ -291,10 +294,8 @@ static void pciehp_power_thread(struct work_struct *work) container_of(work, struct power_work_info, work); struct slot *p_slot = info->p_slot; - mutex_lock(&p_slot->lock); - switch (p_slot->state) { - case POWEROFF_STATE: - mutex_unlock(&p_slot->lock); + switch (info->req) { + case DISABLE_REQ: ctrl_dbg(p_slot->ctrl, "Disabling domain:bus:device=%04x:%02x:00\n", pci_domain_nr(p_slot->ctrl->pcie->port->subordinate), @@ -302,18 +303,22 @@ static void pciehp_power_thread(struct work_struct *work) pciehp_disable_slot(p_slot); mutex_lock(&p_slot->lock); p_slot->state = STATIC_STATE; - break; - case POWERON_STATE: mutex_unlock(&p_slot->lock); + break; + case ENABLE_REQ: + ctrl_dbg(p_slot->ctrl, + "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)) pciehp_green_led_off(p_slot); mutex_lock(&p_slot->lock); p_slot->state = STATIC_STATE; + mutex_unlock(&p_slot->lock); break; default: break; } - mutex_unlock(&p_slot->lock); kfree(info); } @@ -336,9 +341,11 @@ void pciehp_queue_pushbutton_work(struct work_struct *work) switch (p_slot->state) { case BLINKINGOFF_STATE: p_slot->state = POWEROFF_STATE; + info->req = DISABLE_REQ; break; case BLINKINGON_STATE: p_slot->state = POWERON_STATE; + info->req = ENABLE_REQ; break; default: kfree(info); @@ -428,10 +435,13 @@ static void handle_surprise_event(struct slot *p_slot) INIT_WORK(&info->work, pciehp_power_thread); pciehp_get_adapter_status(p_slot, &getstatus); - if (!getstatus) + if (!getstatus) { p_slot->state = POWEROFF_STATE; - else + info->req = DISABLE_REQ; + } else { p_slot->state = POWERON_STATE; + info->req = ENABLE_REQ; + } queue_work(p_slot->wq, &info->work); } @@ -451,6 +461,7 @@ static void handle_link_event(struct slot *p_slot, u32 event) return; } info->p_slot = p_slot; + info->req = event == INT_LINK_UP ? ENABLE_REQ : DISABLE_REQ; INIT_WORK(&info->work, pciehp_power_thread); switch (p_slot->state) { From 50b52fdee050745935d92e7026373edea2647e60 Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 4 Feb 2014 18:31:11 -0800 Subject: [PATCH 08/11] 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; From 50277c8b06d56f2345e1a0693db46db29fc6d063 Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Tue, 11 Feb 2014 17:36:51 -0700 Subject: [PATCH 09/11] PCI: pciehp: Don't turn slot off when hot-added device already exists If we found device already exists during hot add device, we should leave it, not turn the slot off. Signed-off-by: Yijing Wang Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_ctrl.c | 3 ++- drivers/pci/hotplug/pciehp_pci.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index fec99a164d93..b4a4ac150e61 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -233,7 +233,8 @@ static int board_added(struct slot *p_slot) if (retval) { ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n", pci_domain_nr(parent), parent->number); - goto err_exit; + if (retval != -EEXIST) + goto err_exit; } pciehp_green_led_on(p_slot); diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c index b07d7cc2d697..1b533060ce65 100644 --- a/drivers/pci/hotplug/pciehp_pci.c +++ b/drivers/pci/hotplug/pciehp_pci.c @@ -50,7 +50,7 @@ int pciehp_configure_device(struct slot *p_slot) "at %04x:%02x:00, cannot hot-add\n", pci_name(dev), pci_domain_nr(parent), parent->number); pci_dev_put(dev); - ret = -EINVAL; + ret = -EEXIST; goto out; } From 2b3940b60626ac4932fa048cc74f2a872cc4bfb4 Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 18 Feb 2014 18:53:19 -0800 Subject: [PATCH 10/11] PCI: pciehp: Remove a non-existent card, regardless of "surprise" capability In case a card is physically yanked out, it should immediately be removed, regardless of the "surprise" capability bit. Thus: - Always handle the physical removal - regardless of the "surprise" bit. - Don't use "surprise" capability when making decisions about enabling presence detect notifications. - Reword the comments to indicate the intent. Signed-off-by: Rajat Jain Signed-off-by: Rajat Jain Signed-off-by: Guenter Roeck Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_ctrl.c | 9 ++++++++- drivers/pci/hotplug/pciehp_hpc.c | 9 +++++---- 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index b4a4ac150e61..0c2e524a1cf0 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -535,9 +535,16 @@ static void interrupt_event_handler(struct work_struct *work) pciehp_green_led_off(p_slot); break; case INT_PRESENCE_ON: - case INT_PRESENCE_OFF: if (!HP_SUPR_RM(ctrl)) break; + ctrl_dbg(ctrl, "Surprise Insertion\n"); + handle_surprise_event(p_slot); + break; + case INT_PRESENCE_OFF: + /* + * Regardless of surprise capability, we need to + * definitely remove a card that has been pulled out! + */ ctrl_dbg(ctrl, "Surprise Removal\n"); handle_surprise_event(p_slot); break; diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index da4b0204b4f7..d7d058fa19a4 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -619,9 +619,10 @@ static void pcie_disable_notification(struct controller *ctrl) /* * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary - * bus reset of the bridge, but if the slot supports surprise removal (or - * link state change based hotplug), we need to disable presence detection - * (or link state notifications) around the bus reset and clear any spurious + * bus reset of the bridge, but at the same time we want to ensure that it is + * not seen as a hot-unplug, followed by the hot-plug of the device. Thus, + * disable link state notification and presence detection change notification + * momentarily, if we see that they could interfere. Also, clear any spurious * events after. */ int pciehp_reset_slot(struct slot *slot, int probe) @@ -633,7 +634,7 @@ int pciehp_reset_slot(struct slot *slot, int probe) if (probe) return 0; - if (HP_SUPR_RM(ctrl) && !ATTN_BUTTN(ctrl)) { + if (!ATTN_BUTTN(ctrl)) { ctrl_mask |= PCI_EXP_SLTCTL_PDCE; stat_mask |= PCI_EXP_SLTSTA_PDC; } From 9cad7f582055513fe13a93fee3ddb213656a6a5d Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 11 Feb 2014 15:26:29 -0700 Subject: [PATCH 11/11] PCI: pciehp: Cleanup whitespace Minor whitespace cleanup; no functional change. Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_acpi.c | 1 + drivers/pci/hotplug/pciehp_core.c | 1 + drivers/pci/hotplug/pciehp_ctrl.c | 9 ++++----- 3 files changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_acpi.c b/drivers/pci/hotplug/pciehp_acpi.c index eddddd447d0d..20fea57d2149 100644 --- a/drivers/pci/hotplug/pciehp_acpi.c +++ b/drivers/pci/hotplug/pciehp_acpi.c @@ -112,6 +112,7 @@ static struct pcie_port_service_driver __initdata dummy_driver = { static int __init select_detection_mode(void) { struct dummy_slot *slot, *tmp; + if (pcie_port_service_register(&dummy_driver)) return PCIEHP_DETECT_ACPI; pcie_port_service_unregister(&dummy_driver); diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index 23b4bde8aad3..0e0a2fff20a3 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -108,6 +108,7 @@ static int init_slot(struct controller *ctrl) ops = kzalloc(sizeof(*ops), GFP_KERNEL); if (!ops) goto out; + ops->enable_slot = enable_slot; ops->disable_slot = disable_slot; ops->get_power_status = get_power_status; diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index 0c2e524a1cf0..c75e6a678dcc 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -399,11 +399,10 @@ static void handle_button_press_event(struct slot *p_slot) */ ctrl_info(ctrl, "Button cancel on Slot(%s)\n", slot_name(p_slot)); cancel_delayed_work(&p_slot->work); - if (p_slot->state == BLINKINGOFF_STATE) { + if (p_slot->state == BLINKINGOFF_STATE) pciehp_green_led_on(p_slot); - } else { + else pciehp_green_led_off(p_slot); - } pciehp_set_attention_status(p_slot, 0); ctrl_info(ctrl, "PCI slot #%s - action canceled " "due to button press\n", slot_name(p_slot)); @@ -595,9 +594,9 @@ int pciehp_enable_slot(struct slot *p_slot) pciehp_get_latch_status(p_slot, &getstatus); rc = board_added(p_slot); - if (rc) { + if (rc) pciehp_get_latch_status(p_slot, &getstatus); - } + return rc; }