From: "Sean O. Stalley" <sean.stalley@xxxxxxxxx>
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 <sean.stalley@xxxxxxxxx>
[david.daney@xxxxxxxxxx: Add more support/checking for Entry Properties,
allow EA behind bridges, rewrite some error messages.]
Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
---
drivers/pci/pci.c | 177 ++++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/pci/pci.h | 1 +
drivers/pci/probe.c | 3 +
3 files changed, 181 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6a9a111..f1f6308 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2148,6 +2148,183 @@ void pci_pm_init(struct pci_dev *dev)
}
}
+static unsigned long pci_ea_set_flags(struct pci_dev *dev, u8 prop)
+{
+ unsigned long flags = IORESOURCE_PCI_FIXED;
+
+ switch (prop) {
+ case PCI_EA_P_MEM:
+ case PCI_EA_P_VF_MEM:
+ flags |= IORESOURCE_MEM;
+ break;
+ case PCI_EA_P_MEM_PREFETCH:
+ case PCI_EA_P_VF_MEM_PREFETCH:
+ flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
+ break;
+ case PCI_EA_P_IO:
+ flags |= IORESOURCE_IO;
+ break;
+ default:
+ return 0;
+ }
+
+ return flags;
+}
+
+static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei,
+ u8 prop)
+{
+ if (bei <= PCI_EA_BEI_BAR5 && prop <= PCI_EA_P_IO)
+ return &dev->resource[bei];
+ else if (bei == PCI_EA_BEI_ROM)
+ return &dev->resource[PCI_ROM_RESOURCE];
+ else
+ return NULL;
+}
+
+/* Read an Enhanced Allocation (EA) entry */
+static int pci_ea_read(struct pci_dev *dev, int offset)
+{
+ struct resource *res;
+ int ent_offset = offset;
+ int ent_size;
+ resource_size_t start;
+ resource_size_t end;
+ unsigned long flags;
+ u32 dw0;
+ u32 base;
+ u32 max_offset;
+ u8 prop;
+ bool support_64 = (sizeof(resource_size_t) >= 8);
+
+ pci_read_config_dword(dev, ent_offset, &dw0);
+ ent_offset += 4;
+
+ /* Entry size field indicates DWORDs after 1st */
+ ent_size = ((dw0 & PCI_EA_ES) + 1) << 2;
+
+ if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */
+ goto out;
+
+ prop = PCI_EA_PP(dw0);
+ /*
+ * If the Property is in the reserved range, try the Secondary
+ * Property instead.
+ */
+ if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED)
+ prop = PCI_EA_SP(dw0);
+ if (prop > PCI_EA_P_BRIDGE_IO)
+ goto out;
+
+ res = pci_ea_get_resource(dev, PCI_EA_BEI(dw0), prop);
+ if (!res) {
+ dev_err(&dev->dev, "Unsupported EA entry BEI: %u\n",
+ PCI_EA_BEI(dw0));
+ goto out;
+ }
+
+ flags = pci_ea_set_flags(dev, prop);
+ if (!flags) {
+ dev_err(&dev->dev, "Unsupported EA properties: %u\n", prop);
+ goto out;
+ }
+
+ /* Read Base */
+ pci_read_config_dword(dev, ent_offset, &base);
+ start = (base & PCI_EA_FIELD_MASK);
+ ent_offset += 4;
+
+ /* Read MaxOffset */
+ pci_read_config_dword(dev, ent_offset, &max_offset);
+ ent_offset += 4;
+
+ /* Read Base MSBs (if 64-bit entry) */
+ if (base & PCI_EA_IS_64) {
+ u32 base_upper;
+
+ pci_read_config_dword(dev, ent_offset, &base_upper);
+ ent_offset += 4;
+
+ flags |= IORESOURCE_MEM_64;
+
+ /* entry starts above 32-bit boundary, can't use */
+ if (!support_64 && base_upper)
+ goto out;
+
+ if (support_64)
+ start |= ((u64)base_upper << 32);
+ }
+
+ end = start + (max_offset | 0x03);
+
+ /* Read MaxOffset MSBs (if 64-bit entry) */
+ if (max_offset & PCI_EA_IS_64) {
+ u32 max_offset_upper;
+
+ pci_read_config_dword(dev, ent_offset, &max_offset_upper);
+ ent_offset += 4;
+
+ flags |= IORESOURCE_MEM_64;
+
+ /* entry too big, can't use */
+ if (!support_64 && max_offset_upper)
+ goto out;
+
+ if (support_64)
+ end += ((u64)max_offset_upper << 32);
+ }
+
+ if (end < start) {
+ dev_err(&dev->dev, "EA Entry crosses address boundary\n");
+ goto out;
+ }
+
+ if (ent_size != ent_offset - offset) {
+ dev_err(&dev->dev,
+ "EA Entry Size (%d) does not match length read (%d)\n",
+ ent_size, ent_offset - offset);
+ goto out;
+ }
+
+ res->name = pci_name(dev);
+ res->start = start;
+ res->end = end;
+ res->flags = flags;
+ dev_printk(KERN_DEBUG, &dev->dev, "EA - BEI %2u, Prop 0x%02x: %pR\n",
+ PCI_EA_BEI(dw0), prop, res);
+out:
+ return offset + ent_size;
+}
+
+/* Enhanced Allocation Initalization */
+void pci_ea_init(struct pci_dev *dev)
+{
+ int ea;
+ u8 num_ent;
+ int offset;
+ int i;
+
+ /* find PCI EA capability in list */
+ ea = pci_find_capability(dev, PCI_CAP_ID_EA);
+ if (!ea)
+ return;
+
+ /* determine the number of entries */
+ pci_bus_read_config_byte(dev->bus, dev->devfn, ea + PCI_EA_NUM_ENT,
+ &num_ent);
+ num_ent &= PCI_EA_NUM_ENT_MASK;
+
+ offset = ea + PCI_EA_FIRST_ENT;
+
+ /* Skip DWORD 2 for type 1 functions */
+ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
+ offset += 4;
+
+ /* parse each EA entry */
+ for (i = 0; i < num_ent; ++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)
{
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 24ba9dc..a160733 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -78,6 +78,7 @@ bool pci_dev_keep_suspended(struct pci_dev *dev);
void pci_config_pm_runtime_get(struct pci_dev *dev);
void pci_config_pm_runtime_put(struct pci_dev *dev);
void pci_pm_init(struct pci_dev *dev);
+void pci_ea_init(struct pci_dev *dev);
void pci_allocate_cap_save_buffers(struct pci_dev *dev);
void pci_free_cap_save_buffers(struct pci_dev *dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 8361d27..4c4af78 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1597,6 +1597,9 @@ 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);
--
1.9.1
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