Received-SPF: pass (google.com: domain of linux-kernel+bounces-42014-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
From: "David E. Box" <david.e.box@linux.intel.com>
To: mika.westerberg@linux.intel.com,
	david.e.box@linux.intel.com,
	ilpo.jarvinen@linux.intel.com,
	bhelgaas@google.com,
	rjw@rjwysocki.net
Cc: tasev.stefanoska@skynet.be,
	enriquezmark36@gmail.com,
	kernel@witt.link,
	wse@tuxedocomputers.com,
	vidyas@nvidia.com,
	kai.heng.feng@canonical.com,
	sathyanarayanan.kuppuswamy@linux.intel.com,
	ricky_wu@realtek.com,
	mario.limonciello@amd.com,
	linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 4/5] PCI: Move pci_save/restore_ltr_state() to aspm.c
Date: Sun, 28 Jan 2024 15:32:11 -0800
Message-Id: <20240128233212.1139663-5-david.e.box@linux.intel.com>
In-Reply-To: <20240128233212.1139663-1-david.e.box@linux.intel.com>
References: <20240128233212.1139663-1-david.e.box@linux.intel.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

Since the LTR Capability is linked with ASPM and only enabled when
CONFIG_PCIEASPM is set, move the save/restore code to aspm.c

Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
---
 drivers/pci/pci.c       | 40 ----------------------------------------
 drivers/pci/pci.h       |  2 ++
 drivers/pci/pcie/aspm.c | 40 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 40 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0a8613e77dab..61e56e040510 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1636,46 +1636,6 @@ static void pci_restore_pcix_state(struct pci_dev *dev)
 	pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
 }
 
-static void pci_save_ltr_state(struct pci_dev *dev)
-{
-	int ltr;
-	struct pci_cap_saved_state *save_state;
-	u32 *cap;
-
-	if (!pci_is_pcie(dev))
-		return;
-
-	ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
-	if (!ltr)
-		return;
-
-	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
-	if (!save_state) {
-		pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n");
-		return;
-	}
-
-	/* Some broken devices only support dword access to LTR */
-	cap = &save_state->cap.data[0];
-	pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap);
-}
-
-static void pci_restore_ltr_state(struct pci_dev *dev)
-{
-	struct pci_cap_saved_state *save_state;
-	int ltr;
-	u32 *cap;
-
-	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
-	ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
-	if (!save_state || !ltr)
-		return;
-
-	/* Some broken devices only support dword access to LTR */
-	cap = &save_state->cap.data[0];
-	pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap);
-}
-
 /**
  * pci_save_state - save the PCI configuration space of a device before
  *		    suspending
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 7b14cdbe2e69..98f54b48f013 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -100,6 +100,8 @@ void pci_bridge_d3_update(struct pci_dev *dev);
 void pci_aspm_get_l1ss(struct pci_dev *pdev);
 void pci_save_aspm_state(struct pci_dev *pdev);
 void pci_restore_aspm_state(struct pci_dev *pdev);
+void pci_save_ltr_state(struct pci_dev *dev);
+void pci_restore_ltr_state(struct pci_dev *dev);
 int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type);
 
 static inline void pci_wakeup_event(struct pci_dev *dev)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 3185058e9c41..f7712d8453a4 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -155,6 +155,46 @@ void pci_restore_aspm_state(struct pci_dev *pdev)
 	pcie_capability_set_word(pdev, PCI_EXP_LNKCTL, val);
 }
 
+void pci_save_ltr_state(struct pci_dev *dev)
+{
+	int ltr;
+	struct pci_cap_saved_state *save_state;
+	u32 *cap;
+
+	if (!pci_is_pcie(dev))
+		return;
+
+	ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
+	if (!ltr)
+		return;
+
+	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
+	if (!save_state) {
+		pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n");
+		return;
+	}
+
+	/* Some broken devices only support dword access to LTR */
+	cap = &save_state->cap.data[0];
+	pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap);
+}
+
+void pci_restore_ltr_state(struct pci_dev *dev)
+{
+	struct pci_cap_saved_state *save_state;
+	int ltr;
+	u32 *cap;
+
+	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
+	ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
+	if (!save_state || !ltr)
+		return;
+
+	/* Some broken devices only support dword access to LTR */
+	cap = &save_state->cap.data[0];
+	pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap);
+}
+
 #ifdef CONFIG_PCIEASPM
 
 #ifdef MODULE_PARAM_PREFIX
-- 
2.34.1