Platform firmware may not be able to access config space to program
ASPM. For instance, devices behind Intel VMD are not configured by the
BIOS.
So add a helper to let drivers have an option to enable ASPM.
Signed-off-by: Kai-Heng Feng <kai.heng.f...@canonical.com>
---
drivers/pci/pcie/aspm.c | 73 ++++++++++++++++++++++++++++++-----------
include/linux/pci.h | 7 ++++
2 files changed, 60 insertions(+), 20 deletions(-)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 253c30cc1967..b5ac6a99e016 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1080,6 +1080,58 @@ static struct pcie_link_state *pcie_aspm_get_link(struct
pci_dev *pdev)
return bridge->link_state;
}
+static u32 pcie_aspm_convert_state(int state)
+{
+ u32 aspm = 0;
+
+ if (state & PCIE_LINK_STATE_L0S)
+ aspm |= ASPM_STATE_L0S;
+ if (state & PCIE_LINK_STATE_L1)
+ /* L1 PM substates require L1 */
+ aspm |= ASPM_STATE_L1 | ASPM_STATE_L1SS;
+ if (state & PCIE_LINK_STATE_L1_1)
+ aspm |= ASPM_STATE_L1_1;
+ if (state & PCIE_LINK_STATE_L1_2)
+ aspm |= ASPM_STATE_L1_2;
+ if (state & PCIE_LINK_STATE_L1_1_PCIPM)
+ aspm |= ASPM_STATE_L1_1_PCIPM;
+ if (state & PCIE_LINK_STATE_L1_2_PCIPM)
+ aspm |= ASPM_STATE_L1_2_PCIPM;
+
+ return aspm;
+}
+
+static void pci_set_link_state(struct pci_dev *pdev, bool enable, int state)
+{
+ struct pcie_link_state *link = pcie_aspm_get_link(pdev);
+
+ mutex_lock(&aspm_lock);
+ if (enable)
+ link->aspm_default = pcie_aspm_convert_state(state);
+ else
+ link->aspm_disable = pcie_aspm_convert_state(state);
+ pcie_config_aspm_link(link, policy_to_aspm_state(link));
+
+ if (state & PCIE_LINK_STATE_CLKPM) {
+ link->clkpm_default = enable;
+ link->clkpm_disable = !enable;
+ }
+ pcie_set_clkpm(link, policy_to_clkpm_state(link));
+ mutex_unlock(&aspm_lock);
+}
+
+int pci_enable_link_state(struct pci_dev *pdev, int state)
+{
+ struct pcie_link_state *link = pcie_aspm_get_link(pdev);
+
+ if (!link)
+ return -EINVAL;
+
+ pci_set_link_state(pdev, true, state);
+ return 0;
+}
+EXPORT_SYMBOL(pci_enable_link_state);
+
static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
{
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
@@ -1101,26 +1153,7 @@ static int __pci_disable_link_state(struct pci_dev
*pdev, int state, bool sem)
if (sem)
down_read(&pci_bus_sem);
- mutex_lock(&aspm_lock);
- if (state & PCIE_LINK_STATE_L0S)
- link->aspm_disable |= ASPM_STATE_L0S;
- if (state & PCIE_LINK_STATE_L1)
- /* L1 PM substates require L1 */
- link->aspm_disable |= ASPM_STATE_L1 | ASPM_STATE_L1SS;
- if (state & PCIE_LINK_STATE_L1_1)
- link->aspm_disable |= ASPM_STATE_L1_1;
- if (state & PCIE_LINK_STATE_L1_2)
- link->aspm_disable |= ASPM_STATE_L1_2;
- if (state & PCIE_LINK_STATE_L1_1_PCIPM)
- link->aspm_disable |= ASPM_STATE_L1_1_PCIPM;
- if (state & PCIE_LINK_STATE_L1_2_PCIPM)
- link->aspm_disable |= ASPM_STATE_L1_2_PCIPM;
- pcie_config_aspm_link(link, policy_to_aspm_state(link));
-
- if (state & PCIE_LINK_STATE_CLKPM)
- link->clkpm_disable = 1;
- pcie_set_clkpm(link, policy_to_clkpm_state(link));
- mutex_unlock(&aspm_lock);
+ pci_set_link_state(pdev, false, state);
if (sem)
up_read(&pci_bus_sem);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 835530605c0d..a6a7830ec258 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1568,14 +1568,21 @@ extern bool pcie_ports_native;
#define PCIE_LINK_STATE_L1_2 BIT(4)
#define PCIE_LINK_STATE_L1_1_PCIPM BIT(5)
#define PCIE_LINK_STATE_L1_2_PCIPM BIT(6)
+#define PCIE_LINK_STATE_ALL (PCIE_LINK_STATE_L0S |
PCIE_LINK_STATE_L1 |\
+ PCIE_LINK_STATE_CLKPM |
PCIE_LINK_STATE_L1_1 |\
+ PCIE_LINK_STATE_L1_2 |
PCIE_LINK_STATE_L1_1_PCIPM |\
+ PCIE_LINK_STATE_L1_2_PCIPM)
#ifdef CONFIG_PCIEASPM
+int pci_enable_link_state(struct pci_dev *pdev, int state);
int pci_disable_link_state(struct pci_dev *pdev, int state);
int pci_disable_link_state_locked(struct pci_dev *pdev, int state);
void pcie_no_aspm(void);
bool pcie_aspm_support_enabled(void);
bool pcie_aspm_enabled(struct pci_dev *pdev);
#else
+static inline int pci_enable_link_state(struct pci_dev *pdev, int state)
+{ return 0; }
static inline int pci_disable_link_state(struct pci_dev *pdev, int state)
{ return 0; }
static inline int pci_disable_link_state_locked(struct pci_dev *pdev, int
state)
--
2.17.1
