From: Rafael J. Wysocki <rjw@xxxxxxx>
PCI: Simplify PCI device PM code
If the offset of PCI device's PM capability in its configuration space and the
mask of states that the device supports PME# from are cached in the
corresponding struct pci_dev, the PCI device PM code can be simplified quite
a bit.
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
drivers/pci/pci.c | 88 ++++++++++++++++++-----------------------------
include/linux/pci.h | 4 ++
include/linux/pci_regs.h | 1
3 files changed, 39 insertions(+), 54 deletions(-)
Index: linux-next/include/linux/pci.h
===================================================================
--- linux-next.orig/include/linux/pci.h
+++ linux-next/include/linux/pci.h
@@ -177,6 +177,10 @@ struct pci_dev {
pci_power_t current_state; /* Current operating state. In ACPI-speak,
this is D0-D3, D0 being fully functional,
and D3 being off. */
+ int pm_cap; /* PM capability offset in the
+ configuration space */
+ unsigned int pme_data:5; /* Bitmask of states from which PME#
+ can be generated */
#ifdef CONFIG_PCIEASPM
struct pcie_link_state *link_state; /* ASPM link state. */
Index: linux-next/drivers/pci/pci.c
===================================================================
--- linux-next.orig/drivers/pci/pci.c
+++ linux-next/drivers/pci/pci.c
@@ -419,7 +419,6 @@ static inline int platform_pci_sleep_wak
* pci_raw_set_power_state - Use PCI PM registers to set the power state of
* given PCI device
* @dev: PCI device to handle.
- * @pm: PCI PM capability offset of the device.
* @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
*
* RETURN VALUE:
@@ -430,12 +429,12 @@ static inline int platform_pci_sleep_wak
* 0 if device's power state has been successfully changed.
*/
static int
-pci_raw_set_power_state(struct pci_dev *dev, int pm, pci_power_t state)
+pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
{
u16 pmcsr, pmc;
bool need_restore = false;
- if (!pm)
+ if (!dev->pm_cap)
return -EIO;
if (state < PCI_D0 || state > PCI_D3hot)
@@ -455,7 +454,7 @@ pci_raw_set_power_state(struct pci_dev *
return -EINVAL;
}
- pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
+ pci_read_config_word(dev, dev->pm_cap + PCI_PM_PMC, &pmc);
if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
printk(KERN_ERR
@@ -469,7 +468,7 @@ pci_raw_set_power_state(struct pci_dev *
|| (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2)))
return -EIO;
- pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+ pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
/* If we're (effectively) in D3, force entire word to 0.
* This doesn't affect PME_Status, disables PME_En, and
@@ -493,7 +492,7 @@ pci_raw_set_power_state(struct pci_dev *
}
/* enter specified state */
- pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
+ pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
/* Mandatory power management transition delays */
/* see PCI PM 1.1 5.6.1 table 18 */
@@ -529,14 +528,13 @@ pci_raw_set_power_state(struct pci_dev *
* pci_update_current_state - Read PCI power state of given device from its
* PCI PM registers and cache it
* @dev: PCI device to handle.
- * @pm: PCI PM capability offset of the device.
*/
-static void pci_update_current_state(struct pci_dev *dev, int pm)
+static void pci_update_current_state(struct pci_dev *dev)
{
- if (pm) {
+ if (dev->pm_cap) {
u16 pmcsr;
- pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+ pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
}
}
@@ -558,7 +556,7 @@ static void pci_update_current_state(str
*/
int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
{
- int pm, error;
+ int error;
/* bound the state we're entering */
if (state > PCI_D3hot)
@@ -573,9 +571,6 @@ int pci_set_power_state(struct pci_dev *
*/
return 0;
- /* Find PCI PM capability in the list */
- pm = pci_find_capability(dev, PCI_CAP_ID_PM);
-
if (state == PCI_D0 && platform_pci_power_manageable(dev)) {
/*
* Allow the platform to change the state, for example via ACPI
@@ -583,16 +578,16 @@ int pci_set_power_state(struct pci_dev *
*/
int ret = platform_pci_set_power_state(dev, PCI_D0);
if (!ret)
- pci_update_current_state(dev, pm);
+ pci_update_current_state(dev);
}
- error = pci_raw_set_power_state(dev, pm, state);
+ error = pci_raw_set_power_state(dev, state);
if (state > PCI_D0 && platform_pci_power_manageable(dev)) {
/* Allow the platform to finalize the transition */
int ret = platform_pci_set_power_state(dev, state);
if (!ret) {
- pci_update_current_state(dev, pm);
+ pci_update_current_state(dev);
error = 0;
}
}
@@ -1051,48 +1046,40 @@ int pci_set_pcie_reset_state(struct pci_
/**
* pci_pme_capable - check the capability of PCI device to generate PME#
* @dev: PCI device to handle.
- * @pm: PCI PM capability offset of the device.
* @state: PCI state from which device will issue PME#.
*/
-static bool pci_pme_capable(struct pci_dev *dev, int pm, pci_power_t state)
+static bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
{
u16 pmc;
- if (!pm)
+ if (!dev->pm_cap)
return false;
- /* Check device's ability to generate PME# from given state */
- pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
-
- pmc &= PCI_PM_CAP_PME_MASK;
- pmc >>= ffs(PCI_PM_CAP_PME_MASK) - 1; /* First bit of mask */
-
- return !!(pmc & (1 << state));
+ return !!(dev->pme_data & (1 << state));
}
/**
* pci_pme_active - enable or disable PCI device's PME# function
* @dev: PCI device to handle.
- * @pm: PCI PM capability offset of the device.
* @enable: 'true' to enable PME# generation; 'false' to disable it.
*
* The caller must verify that the device is capable of generating PME# before
* calling this function with @enable equal to 'true'.
*/
-static void pci_pme_active(struct pci_dev *dev, int pm, bool enable)
+static void pci_pme_active(struct pci_dev *dev, bool enable)
{
u16 pmcsr;
- if (!pm)
+ if (!dev->pm_cap)
return;
- pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+ pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
/* Clear PME_Status by writing 1 to it and enable PME# */
pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
if (!enable)
pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
- pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
+ pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
}
/**
@@ -1118,7 +1105,6 @@ static void pci_pme_active(struct pci_de
*/
int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
{
- int pm;
int error = 0;
if (!device_may_wakeup(&dev->dev))
@@ -1131,9 +1117,8 @@ int pci_enable_wake(struct pci_dev *dev,
* We are going to enable/disable the generation of PME# even if the
* platform claims to have handled the device as requested.
*/
- pm = pci_find_capability(dev, PCI_CAP_ID_PM);
- if (!enable || pci_pme_capable(dev, pm, state)) {
- pci_pme_active(dev, pm, enable);
+ if (!enable || pci_pme_capable(dev, state)) {
+ pci_pme_active(dev, enable);
if (enable)
return 0;
}
@@ -1156,7 +1141,6 @@ int pci_enable_wake(struct pci_dev *dev,
int pci_prepare_to_sleep(struct pci_dev *dev)
{
pci_power_t target_state = PCI_D3hot;
- int pm = pci_find_capability(dev, PCI_CAP_ID_PM);
int error;
if (platform_pci_power_manageable(dev)) {
@@ -1184,23 +1168,14 @@ int pci_prepare_to_sleep(struct pci_dev
* wake-up events, make it the target state and enable device
* to generate PME#.
*/
- u16 pmc;
-
- if (!pm)
+ if (!dev->pm_cap)
return -EIO;
- pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
- if (pmc & PCI_PM_CAP_PME_MASK) {
- if (!(pmc & PCI_PM_CAP_PME_D3)) {
- /* Device cannot generate PME# from D3_hot */
- if (pmc & PCI_PM_CAP_PME_D2)
- target_state = PCI_D2;
- else if (pmc & PCI_PM_CAP_PME_D1)
- target_state = PCI_D1;
- else
- target_state = PCI_D0;
- }
- pci_pme_active(dev, pm, true);
+ if (dev->pme_data) {
+ while (target_state
+ && !(dev->pme_data & (1 << target_state)))
+ target_state--;
+ pci_pme_active(dev, true);
}
}
@@ -1236,11 +1211,13 @@ void pci_pm_init(struct pci_dev *dev)
/* find PCI PM capability in list */
pm = pci_find_capability(dev, PCI_CAP_ID_PM);
+ dev->pm_cap = pm;
if (!pm)
return;
/* Check device's ability to generate PME# */
pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
- if (pmc & PCI_PM_CAP_PME_MASK) {
+ pmc &= PCI_PM_CAP_PME_MASK;
+ if (pmc) {
printk(KERN_INFO "PCI: Device %s supports PME# from"
"%s%s%s%s%s\n", pci_name(dev),
(pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
@@ -1248,10 +1225,13 @@ void pci_pm_init(struct pci_dev *dev)
(pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
(pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
(pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
+ dev->pme_data = pmc >> PCI_PM_CAP_PME_SHIFT;
/* Mak device's PM flags reflect the wake-up capability */
device_init_wakeup(&dev->dev, true);
/* Disable the PME# generation functionality */
- pci_pme_active(dev, pm, false);
+ pci_pme_active(dev, false);
+ } else {
+ dev->pme_data = 0;
}
}
Index: linux-next/include/linux/pci_regs.h
===================================================================
--- linux-next.orig/include/linux/pci_regs.h
+++ linux-next/include/linux/pci_regs.h
@@ -231,6 +231,7 @@
#define PCI_PM_CAP_PME_D2 0x2000 /* PME# from D2 */
#define PCI_PM_CAP_PME_D3 0x4000 /* PME# from D3 (hot) */
#define PCI_PM_CAP_PME_D3cold 0x8000 /* PME# from D3 (cold) */
+#define PCI_PM_CAP_PME_SHIFT 11 /* Start of the PME Mask in PMC */
#define PCI_PM_CTRL 4 /* PM control and status register */
#define PCI_PM_CTRL_STATE_MASK 0x0003 /* Current power state (D0 to D3) */
#define PCI_PM_CTRL_NO_SOFT_RESET 0x0004 /* No reset for D3hot->D0 */
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