pci: implement Enhanced Allocation support

Some PCI devices have their base addresses not defined in the BARs,
but instead have them defined in Enhanced Allocation structures.

Add support for these Enhanced Allocation structures, taken directly
from the Linux Kernel.

Motivation for adding this is the LS1028a SoC which uses Enhanced
Allocation for the Ethernet Subsystem which comes as an integrated
Endpoint Root Complex.

Link: https://lore.barebox.org/20231219125630.3684-6-s.hauer@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 48 insertions, 1 deletions

diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index 631f218229..8d71914f75 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -219,7 +219,8 @@
 #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
@@ -355,6 +356,52 @@
 #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		0x00000007 /* Entry Size */
+#define  PCI_EA_BEI		0x000000f0 /* BAR Equivalent Indicator */
+
+/* EA fixed Secondary and Subordinate bus numbers for Bridge */
+#define PCI_EA_SEC_BUS_MASK	0xff
+#define PCI_EA_SUB_BUS_MASK	0xff00
+#define PCI_EA_SUB_BUS_SHIFT	8
+
+/* 0-5 map to BARs 0-5 respectively */
+#define   PCI_EA_BEI_BAR0		0
+#define   PCI_EA_BEI_BAR5		5
+#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_VF_BAR0		9
+#define   PCI_EA_BEI_VF_BAR5		14
+#define   PCI_EA_BEI_RESERVED		15	/* Reserved - Treat like ENI */
+#define  PCI_EA_PP		0x0000ff00	/* Primary Properties */
+#define  PCI_EA_SP		0x00ff0000	/* 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_VF_MEM_PREFETCH	0x03	/* VF Prefetchable Memory */
+#define   PCI_EA_P_VF_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_WRITABLE	0x40000000	/* Writable: 1 = RW, 0 = HwInit */
+#define  PCI_EA_ENABLE		0x80000000	/* 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		0x00000002	/* 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 */