linux-stable/include/linux/pci-aspm.h

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/*
* aspm.h
*
* PCI Express ASPM defines and function prototypes
*
* Copyright (C) 2007 Intel Corp.
* Zhang Yanmin (yanmin.zhang@intel.com)
* Shaohua Li (shaohua.li@intel.com)
*
* For more information, please consult the following manuals (look at
* http://www.pcisig.com/ for how to get them):
*
* PCI Express Specification
*/
#ifndef LINUX_ASPM_H
#define LINUX_ASPM_H
#include <linux/pci.h>
#define PCIE_LINK_STATE_L0S 1
#define PCIE_LINK_STATE_L1 2
#define PCIE_LINK_STATE_CLKPM 4
#ifdef CONFIG_PCIEASPM
extern void pcie_aspm_init_link_state(struct pci_dev *pdev);
extern void pcie_aspm_exit_link_state(struct pci_dev *pdev);
extern void pcie_aspm_pm_state_change(struct pci_dev *pdev);
PCI: PCIe links may not get configured for ASPM under POWERSAVE mode v3 -> v2: Moved ASPM enabling logic to pci_set_power_state() v2 -> v1: Preserved the logic in pci_raw_set_power_state() : Added ASPM enabling logic after scanning Root Bridge : http://marc.info/?l=linux-pci&m=130046996216391&w=2 v1 : http://marc.info/?l=linux-pci&m=130013164703283&w=2 The assumption made in commit 41cd766b065970ff6f6c89dd1cf55fa706c84a3d (PCI: Don't enable aspm before drivers have had a chance to veto it) that pci_enable_device() will result in re-configuring ASPM when aspm_policy is POWERSAVE is no longer valid. This is due to commit 97c145f7c87453cec90e91238fba5fe2c1561b32 (PCI: read current power state at enable time) which resets dev->current_state to D0. Due to this the call to pcie_aspm_pm_state_change() is never made. Note the equality check (below) that returns early: ./drivers/pci/pci.c: pci_raw_set_pci_power_state() 546 /* Check if we're already there */ 547 if (dev->current_state == state) 548 return 0; Therefore OSPM never configures the PCIe links for ASPM to turn them "on". Fix it by configuring ASPM from the pci_enable_device() code path. This also allows a driver such as the e1000e networking driver a chance to disable ASPM (L0s, L1), if need be, prior to enabling the device. A driver may perform this action if the device is known to mis-behave wrt ASPM. Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-03-21 03:29:08 +00:00
extern void pcie_aspm_powersave_config_link(struct pci_dev *pdev);
extern void pci_disable_link_state(struct pci_dev *pdev, int state);
PCI/e1000e: Add and use pci_disable_link_state_locked() Need to use it in _e1000e_disable_aspm. This routine is used for error recovery, where the pci_bus_sem is already held, and we don't want pci_disable_link_state to try to take it again. So add a locked variant for use in cases like this. Found lock up: [ 2374.654557] kworker/32:1 D ffff881027f6b0f0 0 6075 2 0x00000000 [ 2374.654816] ffff88503f099a68 0000000000000046 ffff88503f098000 0000000000004000 [ 2374.654837] 00000000001d1ec0 ffff88503f099fd8 00000000001d1ec0 ffff88503f099fd8 [ 2374.654860] 0000000000004000 00000000001d1ec0 ffff88503dcc8000 ffff88503f090000 [ 2374.654880] Call Trace: [ 2374.654898] [<ffffffff810b1302>] ? __lock_acquired+0x3a/0x224 [ 2374.654914] [<ffffffff81c2b59c>] ? _raw_spin_unlock_irq+0x30/0x36 [ 2374.654925] [<ffffffff810b069d>] ? trace_hardirqs_on_caller+0x1f/0x178 [ 2374.654936] [<ffffffff81c2ab24>] rwsem_down_failed_common+0xd3/0x103 [ 2374.654945] [<ffffffff810b158f>] ? __lock_contended+0x3a/0x2a2 [ 2374.654955] [<ffffffff81c2ab7b>] rwsem_down_read_failed+0x12/0x14 [ 2374.654967] [<ffffffff813371e4>] call_rwsem_down_read_failed+0x14/0x30 [ 2374.654981] [<ffffffff8135df20>] ? pci_disable_link_state+0x5f/0xf5 [ 2374.654990] [<ffffffff81c2a0e6>] ? down_read+0x7e/0x91 [ 2374.654999] [<ffffffff8135df20>] ? pci_disable_link_state+0x5f/0xf5 [ 2374.655008] [<ffffffff8135df20>] pci_disable_link_state+0x5f/0xf5 [ 2374.655024] [<ffffffff81661796>] e1000e_disable_aspm+0x55/0x5a [ 2374.655037] [<ffffffff816677eb>] e1000_io_slot_reset+0x59/0xea [ 2374.655048] [<ffffffff8135fe0d>] ? report_mmio_enabled+0x5d/0x5d [ 2374.655057] [<ffffffff8135fe3b>] report_slot_reset+0x2e/0x5d [ 2374.655072] [<ffffffff8135369e>] pci_walk_bus+0x8a/0xb7 [ 2374.655081] [<ffffffff8135fe0d>] ? report_mmio_enabled+0x5d/0x5d [ 2374.655091] [<ffffffff813603be>] broadcast_error_message+0xa4/0xb2 [ 2374.655101] [<ffffffff81352c71>] ? pci_bus_read_config_dword+0x72/0x80 [ 2374.655110] [<ffffffff813606df>] do_recovery+0x9e/0xf9 [ 2374.655120] [<ffffffff81360786>] handle_error_source+0x4c/0x51 [ 2374.655129] [<ffffffff81360974>] aer_isr_one_error+0x1e9/0x21a [ 2374.655138] [<ffffffff81360a6c>] aer_isr+0xc7/0xcc [ 2374.655147] [<ffffffff813609a5>] ? aer_isr_one_error+0x21a/0x21a [ 2374.655159] [<ffffffff81096d9f>] process_one_work+0x237/0x3ec [ 2374.655168] [<ffffffff81096d10>] ? process_one_work+0x1a8/0x3ec [ 2374.655178] [<ffffffff8109728d>] worker_thread+0x17c/0x240 [ 2374.655186] [<ffffffff810b0803>] ? trace_hardirqs_on+0xd/0xf [ 2374.655196] [<ffffffff81097111>] ? manage_workers+0xab/0xab [ 2374.655209] [<ffffffff8109c8ed>] kthread+0xa0/0xa8 [ 2374.655223] [<ffffffff81c332d4>] kernel_thread_helper+0x4/0x10 [ 2374.655232] [<ffffffff81c2b880>] ? retint_restore_args+0xe/0xe [ 2374.655243] [<ffffffff8109c84d>] ? __init_kthread_worker+0x5b/0x5b [ 2374.655252] [<ffffffff81c332d0>] ? gs_change+0xb/0xb when aer happens, pci_walk_bus already have down_read(&pci_bus_sem)... then report_slot_reset ==> e1000_io_slot_reset ==> e1000e_disable_aspm ==> pci_disable_link_state... We can not use pci_disable_link_state, and it will try to hold pci_bus_sem again. Try to have __pci_disable_link_state that will not need to hold pci_bus_sem. -v2: change name to pci_disable_link_state_locked() according to Jesse. [jbarnes: make sure new function is exported for modules] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-05-13 00:11:47 +00:00
extern void pci_disable_link_state_locked(struct pci_dev *pdev, int state);
extern void pcie_clear_aspm(struct pci_bus *bus);
extern void pcie_no_aspm(void);
#else
static inline void pcie_aspm_init_link_state(struct pci_dev *pdev)
{
}
static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev)
{
}
static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev)
{
}
PCI: PCIe links may not get configured for ASPM under POWERSAVE mode v3 -> v2: Moved ASPM enabling logic to pci_set_power_state() v2 -> v1: Preserved the logic in pci_raw_set_power_state() : Added ASPM enabling logic after scanning Root Bridge : http://marc.info/?l=linux-pci&m=130046996216391&w=2 v1 : http://marc.info/?l=linux-pci&m=130013164703283&w=2 The assumption made in commit 41cd766b065970ff6f6c89dd1cf55fa706c84a3d (PCI: Don't enable aspm before drivers have had a chance to veto it) that pci_enable_device() will result in re-configuring ASPM when aspm_policy is POWERSAVE is no longer valid. This is due to commit 97c145f7c87453cec90e91238fba5fe2c1561b32 (PCI: read current power state at enable time) which resets dev->current_state to D0. Due to this the call to pcie_aspm_pm_state_change() is never made. Note the equality check (below) that returns early: ./drivers/pci/pci.c: pci_raw_set_pci_power_state() 546 /* Check if we're already there */ 547 if (dev->current_state == state) 548 return 0; Therefore OSPM never configures the PCIe links for ASPM to turn them "on". Fix it by configuring ASPM from the pci_enable_device() code path. This also allows a driver such as the e1000e networking driver a chance to disable ASPM (L0s, L1), if need be, prior to enabling the device. A driver may perform this action if the device is known to mis-behave wrt ASPM. Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-03-21 03:29:08 +00:00
static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
{
}
static inline void pci_disable_link_state(struct pci_dev *pdev, int state)
{
}
static inline void pcie_clear_aspm(struct pci_bus *bus)
{
}
static inline void pcie_no_aspm(void)
{
}
#endif
#ifdef CONFIG_PCIEASPM_DEBUG /* this depends on CONFIG_PCIEASPM */
extern void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev);
extern void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev);
#else
static inline void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev)
{
}
static inline void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
{
}
#endif
#endif /* LINUX_ASPM_H */