Re: [PATCH 2/2] PCI: Add support for Enhanced Allocation devices
From: Yinghai Lu <yinghai@kernel.org>
Date: 2015-09-01 23:14:12
Also in:
linux-pci, lkml
On Thu, Aug 20, 2015 at 9:59 AM, Sean O. Stalley [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Add support for devices using Enhanced Allocation entries instead of BARs. This patch allows the kernel to parse the EA Extended Capability structure in PCI configspace and claim the BAR-equivalent resources. Signed-off-by: Sean O. Stalley <redacted> --- drivers/pci/pci.c | 219 ++++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/pci/pci.h | 1 + drivers/pci/probe.c | 3 + 3 files changed, 223 insertions(+)diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 0008c95..c8217a8 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c
...
+
+/* Read an Enhanced Allocation (EA) entry */
+static int pci_ea_read(struct pci_dev *dev, int offset)
+{...
+ res->name = pci_name(dev);
+ res->start = start;
+ res->end = end;
+ res->flags = flags;
+
+ pci_ea_claim_resource(dev, res);
+
+out:
+ return offset + ent_size;
+}
+
+/* Enhanced Allocation Initalization */
+void pci_ea_init(struct pci_dev *dev)
+{...
+
+ for (i = 0; i < num_ent; ++i) {
+ /* parse each EA entry */
+ dev_dbg(&dev->dev, "%s: parsing entry %i...\n", __func__, i);
+ offset = pci_ea_read(dev, offset);
+ }
+}
+
static void pci_add_saved_cap(struct pci_dev *pci_dev,
struct pci_cap_saved_state *new_cap)
{quoted hunk ↗ jump to hunk
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index cefd636..4cadf35 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c@@ -1522,6 +1522,9 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) static void pci_init_capabilities(struct pci_dev *dev) { + /* Enhanced Allocation */ + pci_ea_init(dev); + /* MSI/MSI-X list */ pci_msi_init_pci_dev(dev);
Should not call pci_ea_claim_resource() that early. For x86 and other arches, we call pcibios_resource_survey/pcibios_allocate_bus_resouce/pcibios_allocate_resources quite late. Yinghai