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PCI ASPM: cleanup initialization
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Clean up ASPM initialization by refactoring some functionality, renaming
functions, and moving things around.

Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
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Kenji Kaneshige authored and Jesse Barnes committed Jun 18, 2009
1 parent 5aa6358 commit 8d349ac
Showing 1 changed file with 75 additions and 67 deletions.
142 changes: 75 additions & 67 deletions drivers/pci/pcie/aspm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -126,7 +126,7 @@ static void pcie_set_clock_pm(struct pcie_link_state *link, int enable)
link->clkpm_enabled = !!enable;
}

static void pcie_check_clock_pm(struct pcie_link_state *link, int blacklist)
static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
{
int pos, capable = 1, enabled = 1;
u32 reg32;
Expand All @@ -151,13 +151,7 @@ static void pcie_check_clock_pm(struct pcie_link_state *link, int blacklist)
}
link->clkpm_enabled = enabled;
link->clkpm_default = enabled;
if (!blacklist) {
link->clkpm_capable = capable;
pcie_set_clock_pm(link, policy_to_clkpm_state(link));
} else {
link->clkpm_capable = 0;
pcie_set_clock_pm(link, 0);
}
link->clkpm_capable = (blacklist) ? 0 : capable;
}

static bool pcie_aspm_downstream_has_switch(struct pcie_link_state *link)
Expand Down Expand Up @@ -314,12 +308,23 @@ static void pcie_aspm_get_cap_device(struct pci_dev *pdev, u32 *state,
*enabled = reg16 & (PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1);
}

static void pcie_aspm_cap_init(struct pcie_link_state *link)
static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
{
u32 support, l0s, l1, enabled;
struct pci_dev *child, *parent = link->pdev;
struct pci_bus *linkbus = parent->subordinate;

if (blacklist) {
/* Set support state to 0, so we will disable ASPM later */
link->aspm_support = 0;
link->aspm_default = 0;
link->aspm_enabled = PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1;
return;
}

/* Configure common clock before checking latencies */
pcie_aspm_configure_common_clock(link);

/* upstream component states */
pcie_aspm_get_cap_device(parent, &support, &l0s, &l1, &enabled);
link->aspm_support = support;
Expand Down Expand Up @@ -590,87 +595,90 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev)
return 0;
}

static struct pcie_link_state *pcie_aspm_setup_link_state(struct pci_dev *pdev)
{
struct pcie_link_state *link;
int blacklist = !!pcie_aspm_sanity_check(pdev);

link = kzalloc(sizeof(*link), GFP_KERNEL);
if (!link)
return NULL;
INIT_LIST_HEAD(&link->sibling);
INIT_LIST_HEAD(&link->children);
INIT_LIST_HEAD(&link->link);
link->pdev = pdev;
link->has_switch = pcie_aspm_downstream_has_switch(link);
if (pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM) {
struct pcie_link_state *parent;
parent = pdev->bus->parent->self->link_state;
if (!parent) {
kfree(link);
return NULL;
}
link->parent = parent;
list_add(&link->link, &parent->children);
}
list_add(&link->sibling, &link_list);

pdev->link_state = link;

/* Check ASPM capability */
pcie_aspm_cap_init(link, blacklist);

/* Check Clock PM capability */
pcie_clkpm_cap_init(link, blacklist);

return link;
}

/*
* pcie_aspm_init_link_state: Initiate PCI express link state.
* It is called after the pcie and its children devices are scaned.
* @pdev: the root port or switch downstream port
*/
void pcie_aspm_init_link_state(struct pci_dev *pdev)
{
unsigned int state;
struct pcie_link_state *link_state;
int error = 0;
int blacklist;
u32 state;
struct pcie_link_state *link;

if (aspm_disabled || !pdev->is_pcie || pdev->link_state)
return;
if (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
return;

/* VIA has a strange chipset, root port is under a bridge */
if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT &&
pdev->bus->self)
pdev->bus->self)
return;

down_read(&pci_bus_sem);
if (list_empty(&pdev->subordinate->devices))
goto out;

blacklist = !!pcie_aspm_sanity_check(pdev);

mutex_lock(&aspm_lock);

link_state = kzalloc(sizeof(*link_state), GFP_KERNEL);
if (!link_state)
goto unlock_out;

INIT_LIST_HEAD(&link_state->children);
INIT_LIST_HEAD(&link_state->link);
if (pdev->bus->self) {/* this is a switch */
struct pcie_link_state *parent_link_state;

parent_link_state = pdev->bus->parent->self->link_state;
if (!parent_link_state) {
kfree(link_state);
goto unlock_out;
}
list_add(&link_state->link, &parent_link_state->children);
link_state->parent = parent_link_state;
}
link_state->pdev = pdev;
link_state->has_switch = pcie_aspm_downstream_has_switch(link_state);
pdev->link_state = link_state;

if (!blacklist) {
pcie_aspm_configure_common_clock(link_state);
pcie_aspm_cap_init(link_state);
link = pcie_aspm_setup_link_state(pdev);
if (!link)
goto unlock;
/*
* Setup initial ASPM state
*
* If link has switch, delay the link config. The leaf link
* initialization will config the whole hierarchy. But we must
* make sure BIOS doesn't set unsupported link state.
*/
if (link->has_switch) {
state = pcie_aspm_check_state(link, link->aspm_default);
__pcie_aspm_config_link(link, state);
} else {
link_state->aspm_enabled =
(PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1);
link_state->aspm_default = 0;
/* Set support state to 0, so we will disable ASPM later */
link_state->aspm_support = 0;
state = policy_to_aspm_state(link);
__pcie_aspm_configure_link_state(link, state);
}

list_add(&link_state->sibling, &link_list);

if (link_state->has_switch) {
/*
* If link has switch, delay the link config. The leaf link
* initialization will config the whole hierarchy. but we must
* make sure BIOS doesn't set unsupported link state
**/
state = pcie_aspm_check_state(link_state,
link_state->aspm_default);
__pcie_aspm_config_link(link_state, state);
} else
__pcie_aspm_configure_link_state(link_state,
policy_to_aspm_state(link_state));

pcie_check_clock_pm(link_state, blacklist);

unlock_out:
if (error)
free_link_state(link_state);
/* Setup initial Clock PM state */
state = (link->clkpm_capable) ? policy_to_clkpm_state(link) : 0;
pcie_set_clock_pm(link, state);
unlock:
mutex_unlock(&aspm_lock);
out:
up_read(&pci_bus_sem);
Expand Down

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