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authorTimur Tabi <timur@freescale.com>2011-10-31 17:06:35 -0500
committerKumar Gala <galak@kernel.crashing.org>2011-11-24 02:01:41 -0600
commit895d603f945baf7d1680b7657561212890e3a803 (patch)
treea403a4c1b186768b276eb2aceefd9b7ec862e3c1 /arch
parentdb9c1870918b08e6cc947c3008fd5aacfc9d6567 (diff)
downloadblackbird-obmc-linux-895d603f945baf7d1680b7657561212890e3a803.tar.gz
blackbird-obmc-linux-895d603f945baf7d1680b7657561212890e3a803.zip
powerpc/fsl_msi: add support for the fsl, msi property in PCI nodes
On Freescale parts with multiple MSI controllers, the controllers are combined into one "pool" of interrupts. Whenever a device requests an MSI interrupt, the next available interrupt from the pool is selected, regardless of which MSI controller the interrupt is from. This works because each PCI bus has an ATMU to all of CCSR, so any PCI device can access any MSI interrupt register. The fsl,msi property is used to specify that a given PCI bus should only use a specific MSI device. This is necessary, for example, with the Freescale hypervisor, because the MSI devices are assigned to specific partitions. Ideally, we'd like to be able to assign MSI devices to PCI busses within the MSI or PCI layers. However, there does not appear to be a mechanism to do that. Whenever the MSI layer wants to allocate an MSI interrupt to a PCI device, it just calls arch_setup_msi_irqs(). It would be nice if we could register an MSI device with a specific PCI bus. So instead we remember the phandles of each MSI device, and we use that to limit our search for an available interrupt. Whenever we are asked to allocate a new interrupt for a PCI device, we check the fsl,msi property of the PCI bus for that device. If it exists, then as we are looping over all MSI devices, we skip the ones that don't have a matching phandle. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/sysdev/fsl_msi.c39
-rw-r--r--arch/powerpc/sysdev/fsl_msi.h3
2 files changed, 42 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index e5c344d336ea..89548e07ddeb 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -148,14 +148,47 @@ static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
{
+ struct pci_controller *hose = pci_bus_to_host(pdev->bus);
+ struct device_node *np;
+ phandle phandle = 0;
int rc, hwirq = -ENOMEM;
unsigned int virq;
struct msi_desc *entry;
struct msi_msg msg;
struct fsl_msi *msi_data;
+ /*
+ * If the PCI node has an fsl,msi property, then we need to use it
+ * to find the specific MSI.
+ */
+ np = of_parse_phandle(hose->dn, "fsl,msi", 0);
+ if (np) {
+ if (of_device_is_compatible(np, "fsl,mpic-msi"))
+ phandle = np->phandle;
+ else {
+ dev_err(&pdev->dev, "node %s has an invalid fsl,msi"
+ " phandle\n", hose->dn->full_name);
+ return -EINVAL;
+ }
+ }
+
list_for_each_entry(entry, &pdev->msi_list, list) {
+ /*
+ * Loop over all the MSI devices until we find one that has an
+ * available interrupt.
+ */
list_for_each_entry(msi_data, &msi_head, list) {
+ /*
+ * If the PCI node has an fsl,msi property, then we
+ * restrict our search to the corresponding MSI node.
+ * The simplest way is to skip over MSI nodes with the
+ * wrong phandle. Under the Freescale hypervisor, this
+ * has the additional benefit of skipping over MSI
+ * nodes that are not mapped in the PAMU.
+ */
+ if (phandle && (phandle != msi_data->phandle))
+ continue;
+
hwirq = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
if (hwirq >= 0)
break;
@@ -370,6 +403,12 @@ static int __devinit fsl_of_msi_probe(struct platform_device *dev)
msi->msiir_offset = features->msiir_offset + (res.start & 0xfffff);
+ /*
+ * Remember the phandle, so that we can match with any PCI nodes
+ * that have an "fsl,msi" property.
+ */
+ msi->phandle = dev->dev.of_node->phandle;
+
rc = fsl_msi_init_allocator(msi);
if (rc) {
dev_err(&dev->dev, "Error allocating MSI bitmap\n");
diff --git a/arch/powerpc/sysdev/fsl_msi.h b/arch/powerpc/sysdev/fsl_msi.h
index 1313abbc5200..b5d25ba51311 100644
--- a/arch/powerpc/sysdev/fsl_msi.h
+++ b/arch/powerpc/sysdev/fsl_msi.h
@@ -13,6 +13,7 @@
#ifndef _POWERPC_SYSDEV_FSL_MSI_H
#define _POWERPC_SYSDEV_FSL_MSI_H
+#include <linux/of.h>
#include <asm/msi_bitmap.h>
#define NR_MSI_REG 8
@@ -36,6 +37,8 @@ struct fsl_msi {
struct msi_bitmap bitmap;
struct list_head list; /* support multiple MSI banks */
+
+ phandle phandle;
};
#endif /* _POWERPC_SYSDEV_FSL_MSI_H */
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