Commit a47126ec authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

PCI/PTM: Cache PTM Capability offset 

Cache the PTM Capability offset instead of searching for it every time we
enable/disable PTM or save/restore PTM state.  No functional change
intended.

Link: https://lore.kernel.org/r/20220909202505.314195-2-helgaas@kernel.org


Tested-by: default avatarRajvi Jingar <rajvi.jingar@linux.intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
parent 568035b0

drivers/pci/pcie/ptm.c

+17 −24
Original line number Diff line number Diff line
@@ -31,13 +31,9 @@ static void pci_ptm_info(struct pci_dev *dev) 


void pci_disable_ptm(struct pci_dev *dev)

{

	int ptm;

	u16 ptm = dev->ptm_cap;

	u16 ctrl;



	if (!pci_is_pcie(dev))

		return;



	ptm = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);

	if (!ptm)

		return;
@@ -48,14 +44,10 @@ void pci_disable_ptm(struct pci_dev *dev) 


void pci_save_ptm_state(struct pci_dev *dev)

{

	int ptm;

	u16 ptm = dev->ptm_cap;

	struct pci_cap_saved_state *save_state;

	u16 *cap;



	if (!pci_is_pcie(dev))

		return;



	ptm = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);

	if (!ptm)

		return;
@@ -69,16 +61,15 @@ void pci_save_ptm_state(struct pci_dev *dev) 


void pci_restore_ptm_state(struct pci_dev *dev)

{

	u16 ptm = dev->ptm_cap;

	struct pci_cap_saved_state *save_state;

	int ptm;

	u16 *cap;



	if (!pci_is_pcie(dev))

	if (!ptm)

		return;



	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_PTM);

	ptm = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);

	if (!save_state || !ptm)

	if (!save_state)

		return;



	cap = (u16 *)&save_state->cap.data[0];
@@ -87,7 +78,7 @@ void pci_restore_ptm_state(struct pci_dev *dev) 


void pci_ptm_init(struct pci_dev *dev)

{

	int pos;

	u16 ptm;

	u32 cap, ctrl;

	u8 local_clock;

	struct pci_dev *ups;
@@ -117,13 +108,14 @@ void pci_ptm_init(struct pci_dev *dev) 
		return;

	}



	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);

	if (!pos)

	ptm = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);

	if (!ptm)

		return;



	dev->ptm_cap = ptm;

	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_PTM, sizeof(u16));



	pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);

	pci_read_config_dword(dev, ptm + PCI_PTM_CAP, &cap);

	local_clock = (cap & PCI_PTM_GRANULARITY_MASK) >> 8;



	/*
@@ -148,7 +140,7 @@ void pci_ptm_init(struct pci_dev *dev) 
	}



	ctrl |= dev->ptm_granularity << 8;

	pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl);

	pci_write_config_dword(dev, ptm + PCI_PTM_CTRL, ctrl);

	dev->ptm_enabled = 1;



	pci_ptm_info(dev);
@@ -156,18 +148,19 @@ void pci_ptm_init(struct pci_dev *dev) 


int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)

{

	int pos;

	u16 ptm;

	u32 cap, ctrl;

	struct pci_dev *ups;



	if (!pci_is_pcie(dev))

		return -EINVAL;



	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);

	if (!pos)

	ptm = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);

	if (!ptm)

		return -EINVAL;



	pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);

	dev->ptm_cap = ptm;

	pci_read_config_dword(dev, ptm + PCI_PTM_CAP, &cap);

	if (!(cap & PCI_PTM_CAP_REQ))

		return -EINVAL;
@@ -192,7 +185,7 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) 


	ctrl = PCI_PTM_CTRL_ENABLE;

	ctrl |= dev->ptm_granularity << 8;

	pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl);

	pci_write_config_dword(dev, ptm + PCI_PTM_CTRL, ctrl);

	dev->ptm_enabled = 1;



	pci_ptm_info(dev);

include/linux/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -475,6 +475,7 @@ struct pci_dev { 
	unsigned int	broken_cmd_compl:1;	/* No compl for some cmds */

#endif

#ifdef CONFIG_PCIE_PTM

	u16		ptm_cap;		/* PTM Capability */

	unsigned int	ptm_root:1;

	unsigned int	ptm_enabled:1;

	u8		ptm_granularity;