PCI Enhanced Allocation is a new method of allocating MMIO & IO
resources for PCI devices & bridges. It can be used instead
of the traditional PCI method of using BARs.
EA entries are hardware-initialized to a fixed address.
Unlike BARs, regions described by EA are cannot be moved.
Because of this, only devices which are permanently connected to
the PCI bus can use EA. A removable PCI card must not use EA.
This patchset adds support for using EA entries instead of BARs.
The Enhanced Allocation ECN is publicly available here:
https://www.pcisig.com/specifications/conventional/ECN_Enhanced_Allocation_23_Oct_2014_Final.pdf
Sean O. Stalley (2):
PCI: Add Enhanced Allocation register entries
PCI: Add parsing of Enhanced Allocation entries
drivers/pci/pci.c | 219 ++++++++++++++++++++++++++++++++++++++++++
drivers/pci/pci.h | 1 +
drivers/pci/probe.c | 3 +
include/uapi/linux/pci_regs.h | 40 +++++++-
4 files changed, 262 insertions(+), 1 deletion(-)
--
1.9.1
Add registers defined in PCI-SIG's Enhanced allocation ECN.
Signed-off-by: Sean O. Stalley <[email protected]>
---
include/uapi/linux/pci_regs.h | 40 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 39 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index 413417f..084ce98 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -216,7 +216,8 @@
#define PCI_CAP_ID_MSIX 0x11 /* MSI-X */
#define PCI_CAP_ID_SATA 0x12 /* SATA Data/Index Conf. */
#define PCI_CAP_ID_AF 0x13 /* PCI Advanced Features */
-#define PCI_CAP_ID_MAX PCI_CAP_ID_AF
+#define PCI_CAP_ID_EA 0x14 /* PCI Enhanced Allocation */
+#define PCI_CAP_ID_MAX PCI_CAP_ID_EA
#define PCI_CAP_LIST_NEXT 1 /* Next capability in the list */
#define PCI_CAP_FLAGS 2 /* Capability defined flags (16 bits) */
#define PCI_CAP_SIZEOF 4
@@ -353,6 +354,43 @@
#define PCI_AF_STATUS_TP 0x01
#define PCI_CAP_AF_SIZEOF 6 /* size of AF registers */
+/* PCI Enhanced Allocation registers */
+
+#define PCI_EA_NUM_ENT 2 /* Number of Capability Entries */
+#define PCI_EA_NUM_ENT_MASK 0x3f /* Num Entries Mask */
+#define PCI_EA_FIRST_ENT 4 /* First EA Entry in List */
+#define PCI_EA_FIRST_ENT_BRIDGE 8 /* First EA Entry for Bridges */
+#define PCI_EA_ES 0x7 /* Entry Size */
+#define PCI_EA_BEI(x) (((x) >> 4) & 0xf) /* BAR Equivalent Indicator */
+/* 0-5 map to BARs 0-5 respectively */
+#define PCI_EA_BEI_BRIDGE 6 /* Resource behind bridge */
+#define PCI_EA_BEI_ENI 7 /* Equivalent Not Indicated */
+#define PCI_EA_BEI_ROM 8 /* Expansion ROM */
+/* 9-14 map to VF BARs 0-5 respectively */
+#define PCI_EA_BEI_RESERVED 15 /* Reserved - Treat like ENI */
+
+#define PCI_EA_PP(x) (((x) >> 8) & 0xff) /* Primary Properties */
+#define PCI_EA_SP(x) (((x) >> 16) & 0xff) /* Secondary Properties */
+#define PCI_EA_P_MEM 0x00 /* Non-Prefetch Memory */
+#define PCI_EA_P_MEM_PREFETCH 0x01 /* Prefetchable Memory */
+#define PCI_EA_P_IO 0x02 /* I/O Space */
+#define PCI_EA_P_VIRT_MEM_PREFETCH 0x03 /* VF Prefetchable Memory */
+#define PCI_EA_P_VIRT_MEM 0x04 /* VF Non-Prefetch Memory */
+#define PCI_EA_P_BRIDGE_MEM 0x05 /* Bridge Non-Prefetch Memory */
+#define PCI_EA_P_BRIDGE_MEM_PREFETCH 0x06 /* Bridge Prefetchable Memory */
+#define PCI_EA_P_BRIDGE_IO 0x07 /* Bridge I/O Space */
+/* 0x08-0xfc reserved */
+#define PCI_EA_P_MEM_RESERVED 0xfd /* Reserved Memory */
+#define PCI_EA_P_IO_RESERVED 0xfe /* Reserved I/O Space */
+#define PCI_EA_P_UNAVAILABLE 0xff /* Entry Unavailable */
+#define PCI_EA_WRITEABLE BIT(30) /* Writable, 1 = RW, 0 = HwInit */
+#define PCI_EA_ENABLE BIT(31) /* Enable for this entry */
+#define PCI_EA_BASE 4 /* Base Address Offset */
+#define PCI_EA_MAX_OFFSET 8 /* MaxOffset (resource length) */
+/* bit 0 is reserved */
+#define PCI_EA_IS_64 BIT(1) /* 64-bit field flag */
+#define PCI_EA_FIELD_MASK 0xfffffffc /* For Base & Max Offset */
+
/* PCI-X registers (Type 0 (non-bridge) devices) */
#define PCI_X_CMD 2 /* Modes & Features */
--
1.9.1
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 <[email protected]>
---
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
@@ -2134,6 +2134,225 @@ 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:
+ flags |= IORESOURCE_MEM;
+ break;
+ case PCI_EA_P_MEM_PREFETCH:
+ flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
+ break;
+ case PCI_EA_P_IO:
+ flags |= IORESOURCE_IO;
+ break;
+ default:
+ dev_warn(&dev->dev, "%s: Property type %x not supported\n",
+ __func__, prop);
+ return 0;
+ }
+
+ return flags;
+}
+
+static struct resource *pci_ea_get_parent_resource(struct pci_dev *dev,
+ struct resource *res)
+{
+ struct resource *parent;
+
+ parent = pci_find_parent_resource(dev, res);
+ if (parent)
+ return parent;
+
+ /* for resources not claimed by a bridge */
+ if (res->flags & IORESOURCE_MEM)
+ return &iomem_resource;
+
+ if (res->flags & IORESOURCE_IO)
+ return &ioport_resource;
+
+ return NULL;
+}
+
+/* claim the memory for this device in the proper location */
+static void pci_ea_claim_resource(struct pci_dev *dev, struct resource *res)
+{
+ struct resource *parent;
+ struct resource *conflict;
+
+ parent = pci_ea_get_parent_resource(dev, res);
+ if (!parent) {
+ dev_warn(&dev->dev, "can't find parent resource for EA entry %s %pR\n",
+ res->name, res);
+ return;
+ }
+
+ /* claim the appropriate resource */
+ conflict = request_resource_conflict(parent, res);
+ if (conflict) {
+ dev_warn(&dev->dev, "can't claim EA entry %s %pR: address conflict with %s %pR\n",
+ res->name, res, conflict->name, conflict);
+ }
+}
+
+static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei)
+{
+ if (bei <= PCI_STD_RESOURCE_END)
+ 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;
+ 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)) {
+ dev_err(&dev->dev, "%s: Entry not enabled\n", __func__);
+ goto out;
+ }
+
+ res = pci_ea_get_resource(dev, PCI_EA_BEI(dw0));
+ if (!res) {
+ dev_err(&dev->dev, "%s: Unsupported EA entry BEI\n", __func__);
+ goto out;
+ }
+
+ flags = pci_ea_set_flags(dev, PCI_EA_PP(dw0));
+ if (!flags)
+ flags = pci_ea_set_flags(dev, PCI_EA_SP(dw0));
+ if (!flags) {
+ dev_err(&dev->dev, "%s: Entry EA properties not supported\n",
+ __func__);
+ 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);
+ }
+
+ dev_dbg(&dev->dev, "%s: start = %pa\n", __func__, &start);
+
+ 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);
+ }
+
+ dev_dbg(&dev->dev, "%s: end = %pa\n", __func__, &end);
+
+ 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 does not match length read\n"
+ "(Entry Size:%u Length Read:%u)\n",
+ ent_size, ent_offset - offset);
+ goto out;
+ }
+
+ 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)
+{
+ 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;
+
+ dev_dbg(&dev->dev, "%s: capability found!\n", __func__);
+
+ /* 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;
+ /* TODO: Support fixed bus numbers */
+
+ 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)
{
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 4ff0ff1..92fbef0 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -76,6 +76,7 @@ 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 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);
--
1.9.1