lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

PCI: Add pci_clear_master() as opposite of pci_set_master()

Browse Source 
During an online device reset it may be useful to disable bus-mastering.
pci_disable_device() does that, and far more besides, so is not suitable
for an online reset.

Add pci_clear_master() which does just this.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
Ben Hutchings
2008-12-23 03:08:29 +00:00
committed by Jesse Barnes
parent b8d9cb2a22
commit 6a479079c0
3 changed files with 31 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/pci/pci.c
View File

@@ -1667,6 +1667,22 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
((1 << 6) - 1), res_name);
}
static void __pci_set_master(struct pci_dev *dev, bool enable)
{
u16 old_cmd, cmd;
pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
if (enable)
cmd = old_cmd | PCI_COMMAND_MASTER;
else
cmd = old_cmd & ~PCI_COMMAND_MASTER;
if (cmd != old_cmd) {
dev_dbg(&dev->dev, "%s bus mastering\n",
enable ? "enabling" : "disabling");
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
dev->is_busmaster = enable;
}
/**
* pci_set_master - enables bus-mastering for device dev
@@ -1675,21 +1691,21 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
* Enables bus-mastering on the device and calls pcibios_set_master()
* to do the needed arch specific settings.
*/
void
pci_set_master(struct pci_dev *dev)
void pci_set_master(struct pci_dev *dev)
{
u16 cmd;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (! (cmd & PCI_COMMAND_MASTER)) {
dev_dbg(&dev->dev, "enabling bus mastering\n");
cmd |= PCI_COMMAND_MASTER;
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
dev->is_busmaster = 1;
__pci_set_master(dev, true);
pcibios_set_master(dev);
}
/**
* pci_clear_master - disables bus-mastering for device dev
* @dev: the PCI device to disable
*/
void pci_clear_master(struct pci_dev *dev)
{
__pci_set_master(dev, false);
}
#ifdef PCI_DISABLE_MWI
int pci_set_mwi(struct pci_dev *dev)
{
@@ -2346,6 +2362,7 @@ EXPORT_SYMBOL(pci_release_selected_regions);
EXPORT_SYMBOL(pci_request_selected_regions);
EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
EXPORT_SYMBOL(pci_set_master);
EXPORT_SYMBOL(pci_clear_master);
EXPORT_SYMBOL(pci_set_mwi);
EXPORT_SYMBOL(pci_try_set_mwi);
EXPORT_SYMBOL(pci_clear_mwi);