[PATCH 1/4] Add pci_obff_supported() function.

From: Xudong Hao
Date: Fri Jun 08 2012 - 04:02:49 EST


Add pci_obff_supported() function and use it by obff relative function.

Signed-off-by: Xudong Hao <xudong.hao@xxxxxxxxx>
---
drivers/pci/pci.c | 30 ++++++++++++++++++++++++------
1 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 447e834..a70093b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -39,6 +39,7 @@ EXPORT_SYMBOL(pci_pci_problems);

unsigned int pci_pm_d3_delay;

+static bool pci_obff_supported(struct pci_dev *dev);
static void pci_pme_list_scan(struct work_struct *work);

static LIST_HEAD(pci_pme_list);
@@ -2071,6 +2072,27 @@ void pci_disable_ido(struct pci_dev *dev, unsigned long type)
EXPORT_SYMBOL(pci_disable_ido);

/**
+ * pci_obff_supported - check whether a device supports OBFF
+ * @dev: PCI device
+ *
+ * RETURNS:
+ * True if @dev supports optimized buffer flush/fill, false otherwise.
+ */
+static bool pci_obff_supported(struct pci_dev *dev)
+{
+ int pos;
+ u32 cap;
+
+ pos = pci_pcie_cap(dev);
+ if (!pos)
+ return false;
+
+ pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
+
+ return cap & PCI_EXP_OBFF_MASK;
+}
+
+/**
* pci_enable_obff - enable optimized buffer flush/fill
* @dev: PCI device
* @type: type of signaling to use
@@ -2096,17 +2118,13 @@ int pci_enable_obff(struct pci_dev *dev, enum pci_obff_signal_type type)
u16 ctrl;
int ret;

- if (!pci_is_pcie(dev))
+ if (!pci_obff_supported(dev))
return -ENOTSUPP;

pos = pci_pcie_cap(dev);
if (!pos)
return -ENOTSUPP;

- pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
- if (!(cap & PCI_EXP_OBFF_MASK))
- return -ENOTSUPP; /* no OBFF support at all */
-
/* Make sure the topology supports OBFF as well */
if (dev->bus) {
ret = pci_enable_obff(dev->bus->self, type);
@@ -2149,7 +2167,7 @@ void pci_disable_obff(struct pci_dev *dev)
int pos;
u16 ctrl;

- if (!pci_is_pcie(dev))
+ if (!pci_obff_supported(dev))
return;

pos = pci_pcie_cap(dev);
--
1.5.5

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