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PCI: iproc: Hard-code PCIe capability offset instead of searching

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We know where the PCIe capability lives in the host bridge's config space;
in fact, we already hard-coded the offset of the Link Control 2 register.

The hard-coded Link Control 2 offset was 0xdc.  Link Control 2 is at offset
0x30 into the PCIe capability, so the capability itself must be at
0xdc - 0x30 = 0xac.

Hard-code the PCIe capability offset, which means we don't have to search
for it and we can use the standard definitions for registers within the
capability.

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Bjorn Helgaas 2016-10-06 13:36:07 -05:00
parent 6d76833c52
commit e3a1698b1e
1 changed files with 5 additions and 6 deletions
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11
drivers/pci/host/pcie-iproc.c
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@ -63,6 +63,8 @@
#define OARR_SIZE_CFG_SHIFT 1
#define OARR_SIZE_CFG BIT(OARR_SIZE_CFG_SHIFT)
#define PCI_EXP_CAP 0xac
#define MAX_NUM_OB_WINDOWS 2
#define IPROC_PCIE_REG_INVALID 0xffff
@ -261,7 +263,7 @@ static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
struct device *dev = pcie->dev;
u8 hdr_type;
u32 link_ctrl, class, val;
u16 pos, link_status;
u16 pos = PCI_EXP_CAP, link_status;
bool link_is_active = false;
/*
@ -294,30 +296,27 @@ static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
pci_bus_write_config_dword(bus, 0, PCI_BRIDGE_CTRL_REG_OFFSET, class);
/* check link status to see if link is active */
pos = pci_bus_find_capability(bus, 0, PCI_CAP_ID_EXP);
pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA, &link_status);
if (link_status & PCI_EXP_LNKSTA_NLW)
link_is_active = true;
if (!link_is_active) {
/* try GEN 1 link speed */
#define PCI_LINK_STATUS_CTRL_2_OFFSET 0x0dc
#define PCI_TARGET_LINK_SPEED_MASK 0xf
#define PCI_TARGET_LINK_SPEED_GEN2 0x2
#define PCI_TARGET_LINK_SPEED_GEN1 0x1
pci_bus_read_config_dword(bus, 0,
PCI_LINK_STATUS_CTRL_2_OFFSET,
pos + PCI_EXP_LNKCTL2,
&link_ctrl);
if ((link_ctrl & PCI_TARGET_LINK_SPEED_MASK) ==
PCI_TARGET_LINK_SPEED_GEN2) {
link_ctrl &= ~PCI_TARGET_LINK_SPEED_MASK;
link_ctrl |= PCI_TARGET_LINK_SPEED_GEN1;
pci_bus_write_config_dword(bus, 0,
PCI_LINK_STATUS_CTRL_2_OFFSET,
pos + PCI_EXP_LNKCTL2,
link_ctrl);
msleep(100);
pos = pci_bus_find_capability(bus, 0, PCI_CAP_ID_EXP);
pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA,
&link_status);
if (link_status & PCI_EXP_LNKSTA_NLW)