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PCI/PTM: Preserve RsvdP bits in PTM Control register

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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@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This commit is contained in:
Bjorn Helgaas 2022-09-09 15:25:02 -05:00
parent 91b12b2a10
commit 2b89c22f24
1 changed files with 14 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
drivers/pci/pcie/ptm.c
View File

@ -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;