[RFC PATCH v1 1/4] [PCI/ASPM:] Remove struct pcie_link_state.clkpm_default

Saheed O. Bolarinwa
2021-09-29T00:44:17Z

From: "Bolarinwa O. Saheed" <refactormyself@gmail.com>

The clkpm_default member of the struct pcie_link_state stores the
value of the default clkpm state as it is in the BIOS.

This patch:
- Removes clkpm_default from struct pcie_link_state
- Creates pcie_get_clkpm_state() which return the clkpm state
obtained the BIOS
- Replaces references to clkpm_default with call to
pcie_get_clkpm_state()

Signed-off-by: Bolarinwa O. Saheed <refactormyself@gmail.com>
---
drivers/pci/pcie/aspm.c | 37 +++++++++++++++++++++++++++----------
1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 013a47f587ce..c23da9a4e2fb 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -63,7 +63,6 @@ struct pcie_link_state {
/* Clock PM state */
u32 clkpm_capable:1; /* Clock PM capable? */
u32 clkpm_enabled:1; /* Current Clock PM state */
- u32 clkpm_default:1; /* Default Clock PM state by BIOS */
u32 clkpm_disable:1; /* Clock PM disabled */

/* Exit latencies */
@@ -123,6 +122,30 @@ static int policy_to_aspm_state(struct pcie_link_state *link)
return 0;
}

+static int pcie_get_clkpm_state(struct pci_dev *pdev)
+{
+ int enabled = 1;
+ u32 reg32;
+ u16 reg16;
+ struct pci_dev *child;
+ struct pci_bus *linkbus = pdev->subordinate;
+
+ /* All functions should have the same clkpm state, take the worst */
+ list_for_each_entry(child, &linkbus->devices, bus_list) {
+ pcie_capability_read_dword(child, PCI_EXP_LNKCAP, &reg32);
+ if (!(reg32 & PCI_EXP_LNKCAP_CLKPM)) {
+ enabled = 0;
+ break;
+ }
+
+ pcie_capability_read_word(child, PCI_EXP_LNKCTL, &reg16);
+ if (!(reg16 & PCI_EXP_LNKCTL_CLKREQ_EN))
+ enabled = 0;
+ }
+
+ return enabled;
+}
+
static int policy_to_clkpm_state(struct pcie_link_state *link)
{
switch (aspm_policy) {
@@ -134,7 +157,7 @@ static int policy_to_clkpm_state(struct pcie_link_state *link)
/* Enable Clock PM */
return 1;
case POLICY_DEFAULT:
- return link->clkpm_default;
+ return pcie_get_clkpm_state(link->pdev);
}
return 0;
}
@@ -168,9 +191,8 @@ static void pcie_set_clkpm(struct pcie_link_state *link, int enable)

static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
{
- int capable = 1, enabled = 1;
+ int capable = 1;
u32 reg32;
- u16 reg16;
struct pci_dev *child;
struct pci_bus *linkbus = link->pdev->subordinate;

@@ -179,15 +201,10 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
pcie_capability_read_dword(child, PCI_EXP_LNKCAP, &reg32);
if (!(reg32 & PCI_EXP_LNKCAP_CLKPM)) {
capable = 0;
- enabled = 0;
break;
}
- pcie_capability_read_word(child, PCI_EXP_LNKCTL, &reg16);
- if (!(reg16 & PCI_EXP_LNKCTL_CLKREQ_EN))
- enabled = 0;
}
- link->clkpm_enabled = enabled;
- link->clkpm_default = enabled;
+ link->clkpm_enabled = pcie_get_clkpm_state(link->pdev);
link->clkpm_capable = capable;
link->clkpm_disable = blacklist ? 1 : 0;
}
--
2.20.1