From: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
My philosophy is unused code is dead code. And dead code is subject to bit
rot and is a likely source of bugs. Use it or lose it.
This reverts 51c2e0a7e5bc ("PCI: add latency tolerance reporting
enable/disable support"), removing these interfaces:
pci_enable_ltr()
pci_disable_ltr()
pci_set_ltr()
[bhelgaas: split to separate patch, also remove prototypes from pci.h]
Signed-off-by: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
CC: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
---
drivers/pci/pci.c | 123 ---------------------------------------------------
include/linux/pci.h | 4 --
2 files changed, 127 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 33120d156668..020f672deabb 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2223,129 +2223,6 @@ void pci_disable_obff(struct pci_dev *dev)
}
EXPORT_SYMBOL(pci_disable_obff);
-/**
- * pci_ltr_supported - check whether a device supports LTR
- * @dev: PCI device
- *
- * RETURNS:
- * True if @dev supports latency tolerance reporting, false otherwise.
- */
-static bool pci_ltr_supported(struct pci_dev *dev)
-{
- u32 cap;
-
- pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap);
-
- return cap & PCI_EXP_DEVCAP2_LTR;
-}
-
-/**
- * pci_enable_ltr - enable latency tolerance reporting
- * @dev: PCI device
- *
- * Enable LTR on @dev if possible, which means enabling it first on
- * upstream ports.
- *
- * RETURNS:
- * Zero on success, errno on failure.
- */
-int pci_enable_ltr(struct pci_dev *dev)
-{
- int ret;
-
- /* Only primary function can enable/disable LTR */
- if (PCI_FUNC(dev->devfn) != 0)
- return -EINVAL;
-
- if (!pci_ltr_supported(dev))
- return -ENOTSUPP;
-
- /* Enable upstream ports first */
- if (dev->bus->self) {
- ret = pci_enable_ltr(dev->bus->self);
- if (ret)
- return ret;
- }
-
- return pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
- PCI_EXP_DEVCTL2_LTR_EN);
-}
-EXPORT_SYMBOL(pci_enable_ltr);
-
-/**
- * pci_disable_ltr - disable latency tolerance reporting
- * @dev: PCI device
- */
-void pci_disable_ltr(struct pci_dev *dev)
-{
- /* Only primary function can enable/disable LTR */
- if (PCI_FUNC(dev->devfn) != 0)
- return;
-
- if (!pci_ltr_supported(dev))
- return;
-
- pcie_capability_clear_word(dev, PCI_EXP_DEVCTL2,
- PCI_EXP_DEVCTL2_LTR_EN);
-}
-EXPORT_SYMBOL(pci_disable_ltr);
-
-static int __pci_ltr_scale(int *val)
-{
- int scale = 0;
-
- while (*val > 1023) {
- *val = (*val + 31) / 32;
- scale++;
- }
- return scale;
-}
-
-/**
- * pci_set_ltr - set LTR latency values
- * @dev: PCI device
- * @snoop_lat_ns: snoop latency in nanoseconds
- * @nosnoop_lat_ns: nosnoop latency in nanoseconds
- *
- * Figure out the scale and set the LTR values accordingly.
- */
-int pci_set_ltr(struct pci_dev *dev, int snoop_lat_ns, int nosnoop_lat_ns)
-{
- int pos, ret, snoop_scale, nosnoop_scale;
- u16 val;
-
- if (!pci_ltr_supported(dev))
- return -ENOTSUPP;
-
- snoop_scale = __pci_ltr_scale(&snoop_lat_ns);
- nosnoop_scale = __pci_ltr_scale(&nosnoop_lat_ns);
-
- if (snoop_lat_ns > PCI_LTR_VALUE_MASK ||
- nosnoop_lat_ns > PCI_LTR_VALUE_MASK)
- return -EINVAL;
-
- if ((snoop_scale > (PCI_LTR_SCALE_MASK >> PCI_LTR_SCALE_SHIFT)) ||
- (nosnoop_scale > (PCI_LTR_SCALE_MASK >> PCI_LTR_SCALE_SHIFT)))
- return -EINVAL;
-
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
- if (!pos)
- return -ENOTSUPP;
-
- val = (snoop_scale << PCI_LTR_SCALE_SHIFT) | snoop_lat_ns;
- ret = pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, val);
- if (ret != 4)
- return -EIO;
-
- val = (nosnoop_scale << PCI_LTR_SCALE_SHIFT) | nosnoop_lat_ns;
- ret = pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, val);
- if (ret != 4)
- return -EIO;
-
- return 0;
-}
-EXPORT_SYMBOL(pci_set_ltr);
-
static int pci_acs_enable;
/**
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 1084a15175e0..ee26454746ba 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1009,10 +1009,6 @@ enum pci_obff_signal_type {
int pci_enable_obff(struct pci_dev *dev, enum pci_obff_signal_type);
void pci_disable_obff(struct pci_dev *dev);
-int pci_enable_ltr(struct pci_dev *dev);
-void pci_disable_ltr(struct pci_dev *dev);
-int pci_set_ltr(struct pci_dev *dev, int snoop_lat_ns, int nosnoop_lat_ns);
-
/* For use by arch with custom probe code */
void set_pcie_port_type(struct pci_dev *pdev);
void set_pcie_hotplug_bridge(struct pci_dev *pdev);
--
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