[RFC PATCH v1 3/6] PCI/ASPM: Extract the calculation of link->aspm_enabled

From: Saheed O. Bolarinwa
Date: Sat Nov 06 2021 - 13:54:10 EST


Inside pcie_aspm_init_cap() the initial enabled state is read
from the firmware and calculated. It is stored in
struct pcie_link_state->aspm_enabled and also backed up in
struct pcie_link_state->aspm_default. pcie_aspm_init_cap() can
be simplified by isolation this calculation.

Extract the calculation of struct pcie_link_state->aspm_enabled
into aspm_calc_enabled_states().

Signed-off-by: Saheed O. Bolarinwa <refactormyself@xxxxxxxxx>
---
drivers/pci/pcie/aspm.c | 66 ++++++++++++++++++++++++-----------------
1 file changed, 38 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 23441a32f604..5e8613cb5db6 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -591,13 +591,47 @@ static u32 aspm_calc_init_linkcap(u32 up_lnkcap, u32 dwn_lnkcap,
return link_cap;
}

+static u32 aspm_calc_enabled_states(struct pcie_link_state *link,
+ u32 up_l1ss_cap, u32 dwn_l1ss_cap)
+{
+ struct pci_dev *child = link->downstream, *parent = link->pdev;
+ u16 parent_lnkctl, child_lnkctl;
+ u32 aspm_enabled = 0, parent_l1ss_ctl1 = 0, child_l1ss_ctl1 = 0;
+
+ pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &parent_lnkctl);
+ pcie_capability_read_word(child, PCI_EXP_LNKCTL, &child_lnkctl);
+
+ if (child_lnkctl & PCI_EXP_LNKCTL_ASPM_L0S)
+ aspm_enabled |= ASPM_STATE_L0S_UP;
+ if (parent_lnkctl & PCI_EXP_LNKCTL_ASPM_L0S)
+ aspm_enabled |= ASPM_STATE_L0S_DW;
+ if (parent_lnkctl & child_lnkctl & PCI_EXP_LNKCTL_ASPM_L1)
+ aspm_enabled |= ASPM_STATE_L1;
+
+ if (up_l1ss_cap)
+ pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ &parent_l1ss_ctl1);
+ if (dwn_l1ss_cap)
+ pci_read_config_dword(child, child->l1ss + PCI_L1SS_CTL1,
+ &child_l1ss_ctl1);
+
+ if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_1)
+ aspm_enabled |= ASPM_STATE_L1_1;
+ if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_2)
+ aspm_enabled |= ASPM_STATE_L1_2;
+ if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_1)
+ aspm_enabled |= ASPM_STATE_L1_1_PCIPM;
+ if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_2)
+ aspm_enabled |= ASPM_STATE_L1_2_PCIPM;
+
+ return aspm_enabled;
+}
+
static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
{
struct pci_dev *child = link->downstream, *parent = link->pdev;
u32 parent_lnkcap, child_lnkcap;
- u16 parent_lnkctl, child_lnkctl;
u32 parent_l1ss_cap, child_l1ss_cap;
- u32 parent_l1ss_ctl1 = 0, child_l1ss_ctl1 = 0;
struct pci_bus *linkbus = parent->subordinate;

if (blacklist) {
@@ -627,41 +661,17 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
*/
pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &parent_lnkcap);
pcie_capability_read_dword(child, PCI_EXP_LNKCAP, &child_lnkcap);
- pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &parent_lnkctl);
- pcie_capability_read_word(child, PCI_EXP_LNKCTL, &child_lnkctl);

- /* Setup L0s state */
- if (child_lnkctl & PCI_EXP_LNKCTL_ASPM_L0S)
- link->aspm_enabled |= ASPM_STATE_L0S_UP;
- if (parent_lnkctl & PCI_EXP_LNKCTL_ASPM_L0S)
- link->aspm_enabled |= ASPM_STATE_L0S_DW;
link->latency_up.l0s = calc_l0s_latency(parent_lnkcap);
link->latency_dw.l0s = calc_l0s_latency(child_lnkcap);
-
- /* Setup L1 state */
- if (parent_lnkctl & child_lnkctl & PCI_EXP_LNKCTL_ASPM_L1)
- link->aspm_enabled |= ASPM_STATE_L1;
link->latency_up.l1 = calc_l1_latency(parent_lnkcap);
link->latency_dw.l1 = calc_l1_latency(child_lnkcap);

/* Setup L1 substate */
aspm_calc_both_l1ss_caps(link, &parent_l1ss_cap, &child_l1ss_cap);

- if (parent_l1ss_cap)
- pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
- &parent_l1ss_ctl1);
- if (child_l1ss_cap)
- pci_read_config_dword(child, child->l1ss + PCI_L1SS_CTL1,
- &child_l1ss_ctl1);
-
- if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_1)
- link->aspm_enabled |= ASPM_STATE_L1_1;
- if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_2)
- link->aspm_enabled |= ASPM_STATE_L1_2;
- if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_1)
- link->aspm_enabled |= ASPM_STATE_L1_1_PCIPM;
- if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_2)
- link->aspm_enabled |= ASPM_STATE_L1_2_PCIPM;
+ link->aspm_enabled = aspm_calc_enabled_states(link, parent_l1ss_cap,
+ child_l1ss_cap);

/* Save default state */
link->aspm_default = link->aspm_enabled;
--
2.20.1