PCI/ASPM: Remove struct aspm_register_info.l1ss_cap_ptr

Save the L1 Substates Capability pointer in struct pci_dev.  Then we don't
have to keep track of it in the struct aspm_register_info and struct
pcie_link_state, which makes the code easier to read.  No functional change
intended.

[bhelgaas: split to a separate patch]
Link: https://lore.kernel.org/r/20201015193039.12585-8-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index fd6e597..7731626 100644 (file)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -77,8 +77,6 @@ struct pcie_link_state {
 
        /* L1 PM Substate info */
        struct {
-               u32 up_cap_ptr;         /* L1SS cap ptr in upstream dev */
-               u32 dw_cap_ptr;         /* L1SS cap ptr in downstream dev */
                u32 ctl1;               /* value to be programmed in ctl1 */
                u32 ctl2;               /* value to be programmed in ctl2 */
        } l1ss;
@@ -386,7 +384,6 @@ static void encode_l12_threshold(u32 threshold_us, u32 *scale, u32 *value)
 
 struct aspm_register_info {
        /* L1 substates */
-       u32 l1ss_cap_ptr;
        u32 l1ss_cap;
        u32 l1ss_ctl1;
        u32 l1ss_ctl2;
@@ -397,19 +394,20 @@ static void pcie_get_aspm_reg(struct pci_dev *pdev,
 {
        /* Read L1 PM substate capabilities */
        info->l1ss_cap = info->l1ss_ctl1 = info->l1ss_ctl2 = 0;
-       info->l1ss_cap_ptr = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_L1SS);
-       if (!info->l1ss_cap_ptr)
+
+       if (!pdev->l1ss)
                return;
-       pci_read_config_dword(pdev, info->l1ss_cap_ptr + PCI_L1SS_CAP,
+
+       pci_read_config_dword(pdev, pdev->l1ss + PCI_L1SS_CAP,
                              &info->l1ss_cap);
        if (!(info->l1ss_cap & PCI_L1SS_CAP_L1_PM_SS)) {
                info->l1ss_cap = 0;
                return;
        }
 
-       pci_read_config_dword(pdev, info->l1ss_cap_ptr + PCI_L1SS_CTL1,
+       pci_read_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1,
                              &info->l1ss_ctl1);
-       pci_read_config_dword(pdev, info->l1ss_cap_ptr + PCI_L1SS_CTL2,
+       pci_read_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL2,
                              &info->l1ss_ctl2);
 }
 
@@ -494,8 +492,6 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link,
        u32 val1, val2, scale1, scale2;
        u32 t_common_mode, t_power_on, l1_2_threshold, scale, value;
 
-       link->l1ss.up_cap_ptr = upreg->l1ss_cap_ptr;
-       link->l1ss.dw_cap_ptr = dwreg->l1ss_cap_ptr;
        link->l1ss.ctl1 = link->l1ss.ctl2 = 0;
 
        if (!(link->aspm_support & ASPM_STATE_L1_2_MASK))
@@ -664,8 +660,6 @@ static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
 {
        u32 val, enable_req;
        struct pci_dev *child = link->downstream, *parent = link->pdev;
-       u32 up_cap_ptr = link->l1ss.up_cap_ptr;
-       u32 dw_cap_ptr = link->l1ss.dw_cap_ptr;
 
        enable_req = (link->aspm_enabled ^ state) & state;
 
@@ -683,9 +677,9 @@ static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
         */
 
        /* Disable all L1 substates */
-       pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1,
+       pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
                                PCI_L1SS_CTL1_L1SS_MASK, 0);
-       pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1,
+       pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
                                PCI_L1SS_CTL1_L1SS_MASK, 0);
        /*
         * If needed, disable L1, and it gets enabled later
@@ -701,22 +695,22 @@ static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
        if (enable_req & ASPM_STATE_L1_2_MASK) {
 
                /* Program T_POWER_ON times in both ports */
-               pci_write_config_dword(parent, up_cap_ptr + PCI_L1SS_CTL2,
+               pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2,
                                       link->l1ss.ctl2);
-               pci_write_config_dword(child, dw_cap_ptr + PCI_L1SS_CTL2,
+               pci_write_config_dword(child, child->l1ss + PCI_L1SS_CTL2,
                                       link->l1ss.ctl2);
 
                /* Program Common_Mode_Restore_Time in upstream device */
-               pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1,
+               pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
                                        PCI_L1SS_CTL1_CM_RESTORE_TIME,
                                        link->l1ss.ctl1);
 
                /* Program LTR_L1.2_THRESHOLD time in both ports */
-               pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1,
+               pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
                                        PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
                                        PCI_L1SS_CTL1_LTR_L12_TH_SCALE,
                                        link->l1ss.ctl1);
-               pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1,
+               pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
                                        PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
                                        PCI_L1SS_CTL1_LTR_L12_TH_SCALE,
                                        link->l1ss.ctl1);
@@ -733,9 +727,9 @@ static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
                val |= PCI_L1SS_CTL1_PCIPM_L1_2;
 
        /* Enable what we need to enable */
-       pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1,
+       pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
                                PCI_L1SS_CTL1_L1SS_MASK, val);
-       pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1,
+       pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
                                PCI_L1SS_CTL1_L1SS_MASK, val);
 }
 

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 03d3712..06f6bbc 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2106,6 +2106,9 @@ static void pci_configure_ltr(struct pci_dev *dev)
        if (!pci_is_pcie(dev))
                return;
 
+       /* Read L1 PM substate capabilities */
+       dev->l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS);
+
        pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap);
        if (!(cap & PCI_EXP_DEVCAP2_LTR))
                return;

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8355306..c5288cd 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -380,6 +380,7 @@ struct pci_dev {
        struct pcie_link_state  *link_state;    /* ASPM link state */
        unsigned int    ltr_path:1;     /* Latency Tolerance Reporting
                                           supported from root to here */
+       int             l1ss;           /* L1SS Capability pointer */
 #endif
        unsigned int    eetlp_prefix_path:1;    /* End-to-End TLP Prefix */