[J/K/Unstable/OEM-5.17/OEM-6.0] [PATCH 06/10] UBUNTU: SAUCE: PCI/PTM: Preserve RsvdP bits in PTM Control register

[Kai-Heng Feng]

From: Bjorn Helgaas <bhelgaas at google.com>

BugLink: https://bugs.launchpad.net/bugs/1988797

Even though only the low 16 bits of PTM Control are currently defined, the
register is 32 bits wide and the unused bits are RsvdP ("Reserved and
Preserved"), so software must preserve the values of those bits when
writing the register.

Update PTM Control reads and writes to use 32-bit accesses and preserve the
reserved bits on writes.

Link: https://lore.kernel.org/r/20220909202505.314195-7-helgaas@kernel.org
Tested-by: Rajvi Jingar <rajvi.jingar at linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy at linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg at linux.intel.com>
(cherry picked from commit 2b89c22f2434b931b3cf22298ac5f5ec089e9ad1 git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git pci/pm)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 drivers/pci/pcie/ptm.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
index fc296b352fe23..5b8598b222b01 100644
--- a/drivers/pci/pcie/ptm.c
+++ b/drivers/pci/pcie/ptm.c
@@ -12,14 +12,14 @@
 static void __pci_disable_ptm(struct pci_dev *dev)
 {
 	u16 ptm = dev->ptm_cap;
-	u16 ctrl;
+	u32 ctrl;
 
 	if (!ptm)
 		return;
 
-	pci_read_config_word(dev, ptm + PCI_PTM_CTRL, &ctrl);
+	pci_read_config_dword(dev, ptm + PCI_PTM_CTRL, &ctrl);
 	ctrl &= ~(PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT);
-	pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl);
+	pci_write_config_dword(dev, ptm + PCI_PTM_CTRL, ctrl);
 }
 
 /**
@@ -41,7 +41,7 @@ void pci_save_ptm_state(struct pci_dev *dev)
 {
 	u16 ptm = dev->ptm_cap;
 	struct pci_cap_saved_state *save_state;
-	u16 *cap;
+	u32 *cap;
 
 	if (!ptm)
 		return;
@@ -50,15 +50,15 @@ void pci_save_ptm_state(struct pci_dev *dev)
 	if (!save_state)
 		return;
 
-	cap = (u16 *)&save_state->cap.data[0];
-	pci_read_config_word(dev, ptm + PCI_PTM_CTRL, cap);
+	cap = (u32 *)&save_state->cap.data[0];
+	pci_read_config_dword(dev, ptm + PCI_PTM_CTRL, cap);
 }
 
 void pci_restore_ptm_state(struct pci_dev *dev)
 {
 	u16 ptm = dev->ptm_cap;
 	struct pci_cap_saved_state *save_state;
-	u16 *cap;
+	u32 *cap;
 
 	if (!ptm)
 		return;
@@ -67,8 +67,8 @@ void pci_restore_ptm_state(struct pci_dev *dev)
 	if (!save_state)
 		return;
 
-	cap = (u16 *)&save_state->cap.data[0];
-	pci_write_config_word(dev, ptm + PCI_PTM_CTRL, *cap);
+	cap = (u32 *)&save_state->cap.data[0];
+	pci_write_config_dword(dev, ptm + PCI_PTM_CTRL, *cap);
 }
 
 /*
@@ -112,7 +112,7 @@ void pci_ptm_init(struct pci_dev *dev)
 		return;
 
 	dev->ptm_cap = ptm;
-	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_PTM, sizeof(u16));
+	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_PTM, sizeof(u32));
 
 	pci_read_config_dword(dev, ptm + PCI_PTM_CAP, &cap);
 	dev->ptm_granularity = (cap & PCI_PTM_GRANULARITY_MASK) >> 8;
@@ -170,7 +170,10 @@ static int __pci_enable_ptm(struct pci_dev *dev)
 			return -EINVAL;
 	}
 
-	ctrl = PCI_PTM_CTRL_ENABLE;
+	pci_read_config_dword(dev, ptm + PCI_PTM_CTRL, &ctrl);
+
+	ctrl |= PCI_PTM_CTRL_ENABLE;
+	ctrl &= ~PCI_PTM_GRANULARITY_MASK;
 	ctrl |= dev->ptm_granularity << 8;
 	if (dev->ptm_root)
 		ctrl |= PCI_PTM_CTRL_ROOT;
-- 
2.37.2