From: Vidya Sagar <vidyas@nvidia.com>
To: <bhelgaas@google.com>, <lorenzo.pieralisi@arm.com>,
<refactormyself@gmail.com>, <kw@linux.com>, <rajatja@google.com>,
<kenny@panix.com>, <kai.heng.feng@canonical.com>,
<abhsahu@nvidia.com>, <sagupta@nvidia.com>
Cc: <treding@nvidia.com>, <jonathanh@nvidia.com>,
<linux-pci@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<kthota@nvidia.com>, <mmaddireddy@nvidia.com>,
<vidyas@nvidia.com>, <sagar.tv@gmail.com>
Subject: [PATCH V4 1/2] PCI/ASPM: Refactor ASPM L1SS control register programming
Date: Tue, 13 Sep 2022 18:48:21 +0530 [thread overview]
Message-ID: <20220913131822.16557-2-vidyas@nvidia.com> (raw)
In-Reply-To: <20220913131822.16557-1-vidyas@nvidia.com>
Refactor the code to extract the command code out to program
Control Registers-1 & 2 of L1 Sub-States capability to a new function
aspm_program_l1ss() and call it for both parent and child devices.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V4:
* New patch in this series
drivers/pci/pcie/aspm.c | 63 +++++++++++++++++++----------------------
1 file changed, 29 insertions(+), 34 deletions(-)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index a8aec190986c..ecbe3af4188d 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -455,6 +455,31 @@ static void pci_clear_and_set_dword(struct pci_dev *pdev, int pos,
pci_write_config_dword(pdev, pos, val);
}
+static void aspm_program_l1ss(struct pci_dev *dev, u32 ctl1, u32 ctl2)
+{
+ u16 l1ss = dev->l1ss;
+ u32 l1_2_enable;
+
+ /*
+ * Per PCIe r6.0, sec 5.5.4, T_POWER_ON in PCI_L1SS_CTL2 must be
+ * programmed prior to setting the L1.2 enable bits in PCI_L1SS_CTL1.
+ */
+ pci_write_config_dword(dev, l1ss + PCI_L1SS_CTL2, ctl2);
+
+ /*
+ * In addition, Common_Mode_Restore_Time and LTR_L1.2_THRESHOLD in
+ * PCI_L1SS_CTL1 must be programmed *before* setting the L1.2
+ * enable bits, even though they're all in PCI_L1SS_CTL1.
+ */
+ l1_2_enable = ctl1 & PCI_L1SS_CTL1_L1_2_MASK;
+ ctl1 &= ~PCI_L1SS_CTL1_L1_2_MASK;
+
+ pci_write_config_dword(dev, l1ss + PCI_L1SS_CTL1, ctl1);
+ if (l1_2_enable)
+ pci_write_config_dword(dev, l1ss + PCI_L1SS_CTL1,
+ ctl1 | l1_2_enable);
+}
+
/* Calculate L1.2 PM substate timing parameters */
static void aspm_calc_l1ss_info(struct pcie_link_state *link,
u32 parent_l1ss_cap, u32 child_l1ss_cap)
@@ -464,7 +489,6 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link,
u32 t_common_mode, t_power_on, l1_2_threshold, scale, value;
u32 ctl1 = 0, ctl2 = 0;
u32 pctl1, pctl2, cctl1, cctl2;
- u32 pl1_2_enables, cl1_2_enables;
if (!(link->aspm_support & ASPM_STATE_L1_2_MASK))
return;
@@ -513,39 +537,10 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link,
ctl2 == pctl2 && ctl2 == cctl2)
return;
- /* Disable L1.2 while updating. See PCIe r5.0, sec 5.5.4, 7.8.3.3 */
- pl1_2_enables = pctl1 & PCI_L1SS_CTL1_L1_2_MASK;
- cl1_2_enables = cctl1 & PCI_L1SS_CTL1_L1_2_MASK;
-
- if (pl1_2_enables || cl1_2_enables) {
- pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_L1_2_MASK, 0);
- pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_L1_2_MASK, 0);
- }
-
- /* Program T_POWER_ON times in both ports */
- pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, ctl2);
- pci_write_config_dword(child, child->l1ss + PCI_L1SS_CTL2, ctl2);
-
- /* Program Common_Mode_Restore_Time in upstream device */
- pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_CM_RESTORE_TIME, ctl1);
-
- /* Program LTR_L1.2_THRESHOLD time in both ports */
- 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, 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, ctl1);
-
- if (pl1_2_enables || cl1_2_enables) {
- pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1, 0,
- pl1_2_enables);
- pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1, 0,
- cl1_2_enables);
- }
+ aspm_program_l1ss(parent,
+ ctl1 | (pctl1 & PCI_L1SS_CTL1_L1_2_MASK), ctl2);
+ aspm_program_l1ss(child,
+ ctl1 | (cctl1 & PCI_L1SS_CTL1_L1_2_MASK), ctl2);
}
static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
--
2.17.1
next prev parent reply other threads:[~2022-09-13 13:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-13 13:18 [PATCH V4 0/2] PCI/ASPM: Save/restore L1SS Capability for suspend/resume Vidya Sagar
2022-09-13 13:18 ` Vidya Sagar [this message]
2022-09-29 22:00 ` [PATCH V4 1/2] PCI/ASPM: Refactor ASPM L1SS control register programming Bjorn Helgaas
2022-10-03 6:42 ` Vidya Sagar
2022-10-05 2:35 ` Bjorn Helgaas
2022-10-09 5:44 ` Vidya Sagar
2022-09-13 13:18 ` [PATCH V4 2/2] PCI/ASPM: Save/restore L1SS Capability for suspend/resume Vidya Sagar
2022-09-13 17:17 ` [PATCH V4 0/2] " Bjorn Helgaas
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