This patch adds boot option to align MMIO resource for a device.
The alignment is a bigger value between the PAGE_SIZE and the
resource size.
The boot option can be used as:
pci=align-mmio=0000:01:02.3
'[0000:]01:02.3' is the domain, bus, device and function number
of the device.
Cc: Alex Chiang <achiang@xxxxxx>
Cc: Grant Grundler <grundler@xxxxxxxxxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <matthew@xxxxxx>
Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
Cc: Roland Dreier <rdreier@xxxxxxxxx>
Signed-off-by: Yu Zhao <yu.zhao@xxxxxxxxx>
---
arch/x86/pci/common.c | 37 +++++++++++++++++++++++++++++++++++++
drivers/pci/pci.c | 20 ++++++++++++++++++--
include/linux/pci.h | 1 +
3 files changed, 56 insertions(+), 2 deletions(-)
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 06e1ce0..3c5d230 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -139,6 +139,7 @@ static void __devinit pcibios_fixup_device_resources(struct pci_dev *dev)
static char *pci_assign_pio;
static char *pci_assign_mmio;
+static char *pci_align_mmio;
static int pcibios_bus_resource_needs_fixup(struct pci_bus *bus)
{
@@ -192,6 +193,36 @@ static void __devinit pcibios_fixup_bus_resources(struct pci_bus *bus)
}
}
+int pcibios_resource_alignment(struct pci_dev *dev, int resno)
+{
+ int domain, busnr, slot, func;
+ char *str = pci_align_mmio;
+
+ if (dev->resource[resno].flags & IORESOURCE_IO)
+ return 0;
+
+ while (str && *str) {
+ if (sscanf(str, "%04x:%02x:%02x.%d",
+ &domain, &busnr, &slot, &func) != 4) {
+ if (sscanf(str, "%02x:%02x.%d",
+ &busnr, &slot, &func) != 3)
+ break;
+ domain = 0;
+ }
+
+ if (pci_domain_nr(dev->bus) == domain &&
+ dev->bus->number == busnr &&
+ dev->devfn == PCI_DEVFN(slot, func))
+ return PAGE_SIZE;
+
+ str = strchr(str, ';');
+ if (str)
+ str++;
+ }
+
+ return 0;
+}
+
int pcibios_resource_needs_fixup(struct pci_dev *dev, int resno)
{
struct pci_bus *bus;
@@ -200,6 +231,9 @@ int pcibios_resource_needs_fixup(struct pci_dev *dev, int resno)
if (pcibios_bus_resource_needs_fixup(bus))
return 1;
+ if (pcibios_resource_alignment(dev, resno))
+ return 1;
+
return 0;
}
@@ -592,6 +626,9 @@ char * __devinit pcibios_setup(char *str)
} else if (!strncmp(str, "assign-mmio=", 12)) {
pci_assign_mmio = str + 12;
return NULL;
+ } else if (!strncmp(str, "align-mmio=", 11)) {
+ pci_align_mmio = str + 11;
+ return NULL;
}
return str;
}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b02167a..11ecd6f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1015,6 +1015,20 @@ int __attribute__ ((weak)) pcibios_set_pcie_reset_state(struct pci_dev *dev,
}
/**
+ * pcibios_resource_alignment - get resource alignment requirement
+ * @dev: the PCI device
+ * @resno: resource number
+ *
+ * Queries the resource alignment from PCI low level code. Returns positive
+ * if there is alignment requirement of the resource, or 0 otherwise.
+ */
+int __attribute__ ((weak)) pcibios_resource_alignment(struct pci_dev *dev,
+ int resno)
+{
+ return 0;
+}
+
+/**
* pci_set_pcie_reset_state - set reset state for device dev
* @dev: the PCI-E device reset
* @state: Reset state to enter into
@@ -1913,12 +1927,14 @@ int pci_select_bars(struct pci_dev *dev, unsigned long flags)
*/
int pci_resource_alignment(struct pci_dev *dev, int resno)
{
- resource_size_t align;
+ resource_size_t align, bios_align;
struct resource *res = dev->resource + resno;
+ bios_align = pcibios_resource_alignment(dev, resno);
+
align = resource_alignment(res);
if (align)
- return align;
+ return align > bios_align ? align : bios_align;
dev_err(&dev->dev, "alignment: invalid resource #%d\n", resno);
return 0;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 2ada2b6..6ac69af 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1121,6 +1121,7 @@ int pcibios_add_platform_entries(struct pci_dev *dev);
void pcibios_disable_device(struct pci_dev *dev);
int pcibios_set_pcie_reset_state(struct pci_dev *dev,
enum pcie_reset_state state);
+int pcibios_resource_alignment(struct pci_dev *dev, int resno);
#ifdef CONFIG_PCI_MMCONFIG
extern void __init pci_mmcfg_early_init(void);
--
1.5.6.4
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
