pciehp: Let user control LED status
PATCH v4 1/1 pciehp: Let user control LED status
This patch adds a new flag to the pci_dev structure instructing pciehp to not interpret PCIe slot LED indicators. The pciehp driver will instead allow all LED control from the user by setting the slot control indicators as the user requested through sysfs. This is preparing for domain devices that repurpose these control bits for non-standard use.
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v3 -> v4:
Fixing symbol usage by generating patch from the tree that compiles correctly.
drivers/pci/hotplug/pciehp.h | 5 +++++ drivers/pci/hotplug/pciehp_core.c | 3 +++ drivers/pci/hotplug/pciehp_hpc.c | 27 +++++++++++++++++++++++++++ include/linux/pci.h | 1 + 4 files changed, 36 insertions(+)
drivers/pci/hotplug/pciehp.h +5 -0
@@ -152,6 +152,11 @@ bool pciehp_check_link_active(struct controller *ctrl);void pciehp_release_ctrl (struct controller *ctrl);int pciehp_reset_slot (struct slot *slot,int probe); +int pciehp_set_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 status); +int pciehp_get_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 *status); +static inline const char *slot_name (struct slot *slot) {return hotplug_slot_name (slot->hotplug_slot);
drivers/pci/hotplug/pciehp_core.c +3 -0
@@ -113,6 +113,9 @@ static int init_slot(struct controller *ctrl)if (ATTN_LED (ctrl)) { ops->get_attention_status = get_attention_status; ops->set_attention_status = set_attention_status; + }else if (ctrl->pcie->port->user_leds) { + ops->get_attention_status = pciehp_get_raw_attention_status; + ops->set_attention_status = pciehp_set_raw_attention_status; }/* register this slot with the hotplug pci core */
drivers/pci/hotplug/pciehp_hpc.c +27 -0
@@ -355,6 +355,18 @@ static int pciehp_link_enable(struct controller *ctrl)return __pciehp_link_set (ctrl, true); } +int pciehp_get_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 *status) +{ +struct slot *slot = hotplug_slot->private; +struct pci_dev *pdev =ctrl_dev (slot->ctrl); +u16 slot_ctrl; + +pcie_capability_read_word (pdev,PCI_EXP_SLTCTL , &slot_ctrl); + *status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC |PCI_EXP_SLTCTL_PIC )) >>6 ; +return 0 ; +} +void pciehp_get_attention_status (struct slot *slot,u8 *status) {struct controller *ctrl = slot->ctrl;
@@ -431,6 +443,17 @@ int pciehp_query_power_fault(struct slot *slot)return !!(slot_status &PCI_EXP_SLTSTA_PFD ); } +int pciehp_set_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 status) +{ +struct slot *slot = hotplug_slot->private; +struct controller *ctrl = slot->ctrl; + +pcie_write_cmd_nowait (ctrl, status <<6 , +PCI_EXP_SLTCTL_AIC |PCI_EXP_SLTCTL_PIC ); +return 0 ; +} +void pciehp_set_attention_status (struct slot *slot,u8 value) {struct controller *ctrl = slot->ctrl;
@@ -804,6 +827,10 @@ struct controller *pcie_init(struct pcie_device *dev) } ctrl->pcie = dev;pcie_capability_read_dword (pdev,PCI_EXP_SLTCAP , &slot_cap); + +if (pdev->user_leds) + slot_cap &= ~(PCI_EXP_SLTCAP_AIP |PCI_EXP_SLTCAP_PIP ); + ctrl->slot_cap = slot_cap;mutex_init (&ctrl->ctrl_lock);init_waitqueue_head (&ctrl->queue);
include/linux/pci.h +1 -0
@@ -308,6 +308,7 @@ struct pci_dev {powered on/off by the corresponding bridge */ unsigned int ignore_hotplug:1; /* Ignore hotplug events */ + unsigned int user_leds:1; /* User excluse LED SlotCtl */unsigned int d3_delay;/* D3->D0 transition time in ms */ unsigned int d3cold_delay;/* D3cold->D0 transition time in ms */
Signature · 1 line
2.7.2
Bjorn Helgaas
AppliedQuoted 7 lines · Keith Busch
This patch adds a new flag to the
pci_devstructure instructing pciehp to not interpret PCIe slot LED indicators. The pciehp driver will instead allow all LED control from the user by setting the slot control indicators as the user requested through sysfs. This is preparing for domain devices that repurpose these control bits for non-standard use.Signed-off-by Keith Busch <[email protected]>
I applied this with a few minor tweaks to pci/hotplug for v4.9, thanks! The tweaks are:
- s/pciehp_set_raw_attention_status/pciehp_set_raw_indicator_status/ and s/pciehp_get_raw_attention_status/pciehp_get_raw_indicator_status/ because we're now talking to *both* Attention and Power Indicators, not just the Attention Indicator.
- s/user_leds/hotplug_user_indicators/ to use spec terminology ("indicator") and to put it in a "hotplug" group in pci_dev.
- Expand changelog to the following to highlight the fact that we're adding user control of the Power Indicator, which didn't exist before:
PCI: pciehp: Allow exclusive userspace control of indicators
PCIe hotplug supports optional Attention and Power Indicators, which are used internally by pciehp. Users can't control the Power Indicator, but they can control the Attention Indicator by writing to a sysfs "attention" file.
The Slot Control register has two bits for each indicator, and the PCIe spec defines the encodings for each as (Reserved/On/Blinking/Off). For sysfs "attention" writes, pciehp_set_attention_status() maps into these encodings, so the only useful write values are 0 (Off), 1 (On), and 2 (Blinking).
However, some platforms use all four bits for platform-specific indicators, and they need to allow direct user control of them while preventing pciehp from using them at all.
Add a "hotplug_user_indicators" flag to the pci_dev structure. When set, pciehp does not use either the Attention Indicator or the Power Indicator, and the low four bits (values 0x0 - 0xf) of sysfs "attention" write values are written directly to the Attention Indicator Control and Power Indicator Control fields.
Let me know if any of these are problematic. Obviously I don't have a way to test and make sure I didn't break something.
Quoted 113 lines
---
v3 -> v4:Fixing symbol usage by generating patch from the tree that compiles correctly.
drivers/pci/hotplug/pciehp.h | 5 +++++ drivers/pci/hotplug/pciehp_core.c | 3 +++ drivers/pci/hotplug/pciehp_hpc.c | 27 +++++++++++++++++++++++++++ include/linux/pci.h | 1 + 4 files changed, 36 insertions(+)drivers/pci/hotplug/pciehp.h +5
-0@@ -152,6 +152,11 @@ bool pciehp_check_link_active(struct controller *ctrl);void pciehp_release_ctrl (struct controller *ctrl);int pciehp_reset_slot (struct slot *slot,int probe); +int pciehp_set_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 status); +int pciehp_get_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 *status); +static inline const char *slot_name (struct slot *slot) {return hotplug_slot_name (slot->hotplug_slot);drivers/pci/hotplug/pciehp_core.c +3
-0@@ -113,6 +113,9 @@ static int init_slot(struct controller *ctrl)if (ATTN_LED (ctrl)) { ops->get_attention_status = get_attention_status; ops->set_attention_status = set_attention_status; + }else if (ctrl->pcie->port->user_leds) { + ops->get_attention_status = pciehp_get_raw_attention_status; + ops->set_attention_status = pciehp_set_raw_attention_status; }/* register this slot with the hotplug pci core */ drivers/pci/hotplug/pciehp_hpc.c +27
-0@@ -355,6 +355,18 @@ static int pciehp_link_enable(struct controller *ctrl)return __pciehp_link_set (ctrl, true); } +int pciehp_get_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 *status) +{ +struct slot *slot = hotplug_slot->private; +struct pci_dev *pdev =ctrl_dev (slot->ctrl); +u16 slot_ctrl; + +pcie_capability_read_word (pdev,PCI_EXP_SLTCTL , &slot_ctrl); + *status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC |PCI_EXP_SLTCTL_PIC )) >>6 ; +return 0 ; +} +void pciehp_get_attention_status (struct slot *slot,u8 *status) {struct controller *ctrl = slot->ctrl;@@ -431,6 +443,17 @@ int pciehp_query_power_fault(struct slot *slot)return !!(slot_status &PCI_EXP_SLTSTA_PFD ); } +int pciehp_set_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 status) +{ +struct slot *slot = hotplug_slot->private; +struct controller *ctrl = slot->ctrl; + +pcie_write_cmd_nowait (ctrl, status <<6 , +PCI_EXP_SLTCTL_AIC |PCI_EXP_SLTCTL_PIC ); +return 0 ; +} +void pciehp_set_attention_status (struct slot *slot,u8 value) {struct controller *ctrl = slot->ctrl;@@ -804,6 +827,10 @@ struct controller *pcie_init(struct pcie_device *dev) } ctrl->pcie = dev;pcie_capability_read_dword (pdev,PCI_EXP_SLTCAP , &slot_cap); + +if (pdev->user_leds) + slot_cap &= ~(PCI_EXP_SLTCAP_AIP |PCI_EXP_SLTCAP_PIP ); + ctrl->slot_cap = slot_cap;mutex_init (&ctrl->ctrl_lock);init_waitqueue_head (&ctrl->queue);include/linux/pci.h +1
-0@@ -308,6 +308,7 @@ struct pci_dev {powered on/off by the corresponding bridge */ unsigned int ignore_hotplug:1; /* Ignore hotplug events */ + unsigned int user_leds:1; /* User excluse LED SlotCtl */unsigned int d3_delay;/* D3->D0 transition time in ms */ unsigned int d3cold_delay;/* D3cold->D0 transition time in ms */ Signature · 6 lines
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Quoted 7 lines · Keith Busch
This patch adds a new flag to the
pci_devstructure instructing pciehp to not interpret PCIe slot LED indicators. The pciehp driver will instead allow all LED control from the user by setting the slot control indicators as the user requested through sysfs. This is preparing for domain devices that repurpose these control bits for non-standard use.Signed-off-by Keith Busch <[email protected]>
BTW, I think this turned out really well. It's small and clean and I think it's safe in terms of races and so on. Thanks a lot for pushing on this!
Quoted 113 lines
---
v3 -> v4:Fixing symbol usage by generating patch from the tree that compiles correctly.
drivers/pci/hotplug/pciehp.h | 5 +++++ drivers/pci/hotplug/pciehp_core.c | 3 +++ drivers/pci/hotplug/pciehp_hpc.c | 27 +++++++++++++++++++++++++++ include/linux/pci.h | 1 + 4 files changed, 36 insertions(+)drivers/pci/hotplug/pciehp.h +5
-0@@ -152,6 +152,11 @@ bool pciehp_check_link_active(struct controller *ctrl);void pciehp_release_ctrl (struct controller *ctrl);int pciehp_reset_slot (struct slot *slot,int probe); +int pciehp_set_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 status); +int pciehp_get_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 *status); +static inline const char *slot_name (struct slot *slot) {return hotplug_slot_name (slot->hotplug_slot);drivers/pci/hotplug/pciehp_core.c +3
-0@@ -113,6 +113,9 @@ static int init_slot(struct controller *ctrl)if (ATTN_LED (ctrl)) { ops->get_attention_status = get_attention_status; ops->set_attention_status = set_attention_status; + }else if (ctrl->pcie->port->user_leds) { + ops->get_attention_status = pciehp_get_raw_attention_status; + ops->set_attention_status = pciehp_set_raw_attention_status; }/* register this slot with the hotplug pci core */ drivers/pci/hotplug/pciehp_hpc.c +27
-0@@ -355,6 +355,18 @@ static int pciehp_link_enable(struct controller *ctrl)return __pciehp_link_set (ctrl, true); } +int pciehp_get_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 *status) +{ +struct slot *slot = hotplug_slot->private; +struct pci_dev *pdev =ctrl_dev (slot->ctrl); +u16 slot_ctrl; + +pcie_capability_read_word (pdev,PCI_EXP_SLTCTL , &slot_ctrl); + *status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC |PCI_EXP_SLTCTL_PIC )) >>6 ; +return 0 ; +} +void pciehp_get_attention_status (struct slot *slot,u8 *status) {struct controller *ctrl = slot->ctrl;@@ -431,6 +443,17 @@ int pciehp_query_power_fault(struct slot *slot)return !!(slot_status &PCI_EXP_SLTSTA_PFD ); } +int pciehp_set_raw_attention_status (struct hotplug_slot *hotplug_slot, +u8 status) +{ +struct slot *slot = hotplug_slot->private; +struct controller *ctrl = slot->ctrl; + +pcie_write_cmd_nowait (ctrl, status <<6 , +PCI_EXP_SLTCTL_AIC |PCI_EXP_SLTCTL_PIC ); +return 0 ; +} +void pciehp_set_attention_status (struct slot *slot,u8 value) {struct controller *ctrl = slot->ctrl;@@ -804,6 +827,10 @@ struct controller *pcie_init(struct pcie_device *dev) } ctrl->pcie = dev;pcie_capability_read_dword (pdev,PCI_EXP_SLTCAP , &slot_cap); + +if (pdev->user_leds) + slot_cap &= ~(PCI_EXP_SLTCAP_AIP |PCI_EXP_SLTCAP_PIP ); + ctrl->slot_cap = slot_cap;mutex_init (&ctrl->ctrl_lock);init_waitqueue_head (&ctrl->queue);include/linux/pci.h +1
-0@@ -308,6 +308,7 @@ struct pci_dev {powered on/off by the corresponding bridge */ unsigned int ignore_hotplug:1; /* Ignore hotplug events */ + unsigned int user_leds:1; /* User excluse LED SlotCtl */unsigned int d3_delay;/* D3->D0 transition time in ms */ unsigned int d3cold_delay;/* D3cold->D0 transition time in ms */ Signature · 6 lines
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