[Linux-kernel-mentees] [RFC PATCH v5 11/23] PCI: Rework and Rename aspm_calc_l1ss_info()

Saheed O. Bolarinwa refactormyself at gmail.com
Sat Aug 22 20:03:46 UTC 2020


The value of l1ss_cap_ptr can nw be obtained directly from struct
pci_dev, it is no useful to cache it. So, aspm_calc_l1ss_info()
will only be computing the values of ctl1 and ctl2.

 - Rename aspm_calc_l1ss_info() to aspm_calc_l1ss_ctl_values().
 - Rework the function to take a pci_dev and values' pointer.
 - Remove caching of pdev->l1ss_cap_ptr
 - Change calls to aspm_calc_l1ss_info() into new function.
 - Access pdev->l1ss_cap_ptr directly
 - No more reference to struct pcie_link_state.l1ss, so remove it.

Signed-off-by: Saheed O. Bolarinwa <refactormyself at gmail.com>
---
 drivers/pci/pcie/aspm.c | 43 ++++++++++++++---------------------------
 1 file changed, 15 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 89f3f3a6d007..4cff11dc8d83 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -74,14 +74,6 @@ struct pcie_link_state {
 	 * has one slot under it, so at most there are 8 functions.
 	 */
 	struct aspm_latency acceptable[8];
-
-	/* 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;
 };
 
 static int aspm_disabled, aspm_force;
@@ -444,17 +436,15 @@ static struct pci_dev *pci_function_0(struct pci_bus *linkbus)
 }
 
 /* Calculate L1.2 PM substate timing parameters */
-static void aspm_calc_l1ss_info(struct pcie_link_state *link)
+static void aspm_calc_l1ss_ctl_values(struct pci_dev *pdev,
+						u32 *ctl1, u32 *ctl2)
 {
+	struct pcie_link_state *link = pdev->link_state;
 	u32 val1, val2, scale1, scale2;
 	u32 t_common_mode, t_power_on, l1_2_threshold, scale, value;
 	struct pci_dev *dw_pdev = link->downstream;
 	struct pci_dev *up_pdev = link->pdev;
 
-	link->l1ss.up_cap_ptr = up_pdev->l1ss_cap_ptr;
-	link->l1ss.dw_cap_ptr = dw_pdev->l1ss_cap_ptr;
-	link->l1ss.ctl1 = link->l1ss.ctl2 = 0;
-
 	if (!(link->aspm_support & ASPM_STATE_L1_2_MASK))
 		return;
 
@@ -471,10 +461,10 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link)
 
 	if (calc_l1ss_pwron(up_pdev, scale1, val1) >
 	    calc_l1ss_pwron(dw_pdev, scale2, val2)) {
-		link->l1ss.ctl2 |= scale1 | (val1 << 3);
+		*ctl2 |= scale1 | (val1 << 3);
 		t_power_on = calc_l1ss_pwron(up_pdev, scale1, val1);
 	} else {
-		link->l1ss.ctl2 |= scale2 | (val2 << 3);
+		*ctl2 |= scale2 | (val2 << 3);
 		t_power_on = calc_l1ss_pwron(dw_pdev, scale2, val2);
 	}
 
@@ -490,7 +480,7 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link)
 	 */
 	l1_2_threshold = 2 + 4 + t_common_mode + t_power_on;
 	encode_l12_threshold(l1_2_threshold, &scale, &value);
-	link->l1ss.ctl1 |= t_common_mode << 8 | scale << 29 | value << 16;
+	*ctl1 |= t_common_mode << 8 | scale << 29 | value << 16;
 }
 
 static u32 get_aspm_enable(struct pci_dev *pdev)
@@ -620,13 +610,13 @@ static void pci_clear_and_set_dword(struct pci_dev *pdev, int pos,
 /* Configure the ASPM L1 substates */
 static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
 {
-	u32 val, enable_req;
+	u32 val, enable_req, ctl1, ctl2;
 	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;
+	int up_cap_ptr = parent->l1ss_cap_ptr;
+	int dw_cap_ptr = child->l1ss_cap_ptr;
 
 	enable_req = (parent->aspm_enabled ^ state) & state;
-	aspm_calc_l1ss_info(link);
+	aspm_calc_l1ss_ctl_values(parent, &ctl1, &ctl2);
 
 	/*
 	 * Here are the rules specified in the PCIe spec for enabling L1SS:
@@ -661,24 +651,21 @@ static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
 
 		/* Program T_POWER_ON times in both ports */
 		pci_write_config_dword(parent, up_cap_ptr + PCI_L1SS_CTL2,
-				       link->l1ss.ctl2);
+				       ctl2);
 		pci_write_config_dword(child, dw_cap_ptr + PCI_L1SS_CTL2,
-				       link->l1ss.ctl2);
+				       ctl2);
 
 		/* Program Common_Mode_Restore_Time in upstream device */
 		pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1,
-					PCI_L1SS_CTL1_CM_RESTORE_TIME,
-					link->l1ss.ctl1);
+					PCI_L1SS_CTL1_CM_RESTORE_TIME, ctl1);
 
 		/* Program LTR_L1.2_THRESHOLD time in both ports */
 		pci_clear_and_set_dword(parent,	up_cap_ptr + PCI_L1SS_CTL1,
 					PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
-					PCI_L1SS_CTL1_LTR_L12_TH_SCALE,
-					link->l1ss.ctl1);
+					PCI_L1SS_CTL1_LTR_L12_TH_SCALE, ctl1);
 		pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1,
 					PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
-					PCI_L1SS_CTL1_LTR_L12_TH_SCALE,
-					link->l1ss.ctl1);
+					PCI_L1SS_CTL1_LTR_L12_TH_SCALE, ctl1);
 	}
 
 	val = 0;
-- 
2.18.4



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