[efi] Use address offset as reported by EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL

Retrieve the address windows and translation offsets for the
appropriate PCI root bridge and use them to adjust the PCI BAR address
prior to calling ioremap().

Originally-implemented-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

3 files changed, 206 insertions, 14 deletions

diff --git a/src/include/ipxe/acpi.h b/src/include/ipxe/acpi.h
index 78f4025..e41bd28 100644
--- a/src/include/ipxe/acpi.h
+++ b/src/include/ipxe/acpi.h
@@ -19,6 +19,138 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/api.h>
 #include <config/general.h>
 
+/** An ACPI small resource descriptor header */
+struct acpi_small_resource {
+	/** Tag byte */
+	uint8_t tag;
+} __attribute__ (( packed ));
+
+/** ACPI small resource length mask */
+#define ACPI_SMALL_LEN_MASK 0x03
+
+/** An ACPI end resource descriptor */
+#define ACPI_END_RESOURCE 0x78
+
+/** An ACPI end resource descriptor */
+struct acpi_end_resource {
+	/** Header */
+	struct acpi_small_resource hdr;
+	/** Checksum */
+	uint8_t checksum;
+} __attribute__ (( packed ));
+
+/** An ACPI large resource descriptor header */
+struct acpi_large_resource {
+	/** Tag byte */
+	uint8_t tag;
+	/** Length of data items */
+	uint16_t len;
+} __attribute__ (( packed ));
+
+/** ACPI large resource flag */
+#define ACPI_LARGE 0x80
+
+/** An ACPI QWORD address space resource descriptor */
+#define ACPI_QWORD_ADDRESS_SPACE_RESOURCE 0x8a
+
+/** An ACPI QWORD address space resource descriptor */
+struct acpi_qword_address_space_resource {
+	/** Header */
+	struct acpi_large_resource hdr;
+	/** Resource type */
+	uint8_t type;
+	/** General flags */
+	uint8_t general;
+	/** Type-specific flags */
+	uint8_t specific;
+	/** Granularity */
+	uint64_t granularity;
+	/** Minimum address */
+	uint64_t min;
+	/** Maximum address */
+	uint64_t max;
+	/** Translation offset */
+	uint64_t offset;
+	/** Length */
+	uint64_t len;
+} __attribute__ (( packed ));
+
+/** A memory address space type */
+#define ACPI_ADDRESS_TYPE_MEM 0x00
+
+/** An ACPI resource descriptor */
+union acpi_resource {
+	/** Tag byte */
+	uint8_t tag;
+	/** Small resource descriptor */
+	struct acpi_small_resource small;
+	/** End resource descriptor */
+	struct acpi_end_resource end;
+	/** Large resource descriptor */
+	struct acpi_large_resource large;
+	/** QWORD address space resource descriptor */
+	struct acpi_qword_address_space_resource qword;
+};
+
+/**
+ * Get ACPI resource tag
+ *
+ * @v res		ACPI resource descriptor
+ * @ret tag		Resource tag
+ */
+static inline unsigned int acpi_resource_tag ( union acpi_resource *res ) {
+
+	return ( ( res->tag & ACPI_LARGE ) ?
+		 res->tag : ( res->tag & ~ACPI_SMALL_LEN_MASK ) );
+}
+
+/**
+ * Get length of ACPI small resource descriptor
+ *
+ * @v res		Small resource descriptor
+ * @ret len		Length of descriptor
+ */
+static inline size_t acpi_small_len ( struct acpi_small_resource *res ) {
+
+	return ( sizeof ( *res ) + ( res->tag & ACPI_SMALL_LEN_MASK ) );
+}
+
+/**
+ * Get length of ACPI large resource descriptor
+ *
+ * @v res		Large resource descriptor
+ * @ret len		Length of descriptor
+ */
+static inline size_t acpi_large_len ( struct acpi_large_resource *res ) {
+
+	return ( sizeof ( *res ) + le16_to_cpu ( res->len ) );
+}
+
+/**
+ * Get length of ACPI resource descriptor
+ *
+ * @v res		ACPI resource descriptor
+ * @ret len		Length of descriptor
+ */
+static inline size_t acpi_resource_len ( union acpi_resource *res ) {
+
+	return ( ( res->tag & ACPI_LARGE ) ?
+		 acpi_large_len ( &res->large ) :
+		 acpi_small_len ( &res->small ) );
+}
+
+/**
+ * Get next ACPI resource descriptor
+ *
+ * @v res		ACPI resource descriptor
+ * @ret next		Next ACPI resource descriptor
+ */
+static inline union acpi_resource *
+acpi_resource_next ( union acpi_resource *res ) {
+
+	return ( ( ( void * ) res ) + acpi_resource_len ( res ) );
+}
+
 /**
  * An ACPI description header
  *
diff --git a/src/include/ipxe/efi/efi_pci_api.h b/src/include/ipxe/efi/efi_pci_api.h
index df28cef..887d5ee 100644
--- a/src/include/ipxe/efi/efi_pci_api.h
+++ b/src/include/ipxe/efi/efi_pci_api.h
@@ -148,17 +148,4 @@ PCIAPI_INLINE ( efi, pci_write_config_dword ) ( struct pci_device *pci,
 			      value );
 }
 
-/**
- * Map PCI bus address as an I/O address
- *
- * @v bus_addr		PCI bus address
- * @v len		Length of region
- * @ret io_addr		I/O address, or NULL on error
- */
-static inline __always_inline void *
-PCIAPI_INLINE ( efi, pci_ioremap ) ( struct pci_device *pci __unused,
-				     unsigned long bus_addr, size_t len ) {
-	return ioremap ( bus_addr, len );
-}
-
 #endif /* _IPXE_EFI_PCI_API_H */
diff --git a/src/interface/efi/efi_pci.c b/src/interface/efi/efi_pci.c
index 6a92909..93a3738 100644
--- a/src/interface/efi/efi_pci.c
+++ b/src/interface/efi/efi_pci.c
@@ -26,6 +26,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <stdlib.h>
 #include <errno.h>
 #include <ipxe/pci.h>
+#include <ipxe/acpi.h>
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/efi_pci.h>
 #include <ipxe/efi/efi_driver.h>
@@ -224,6 +225,78 @@ int efipci_write ( struct pci_device *pci, unsigned long location,
 	return rc;
 }
 
+/**
+ * Map PCI bus address as an I/O address
+ *
+ * @v bus_addr		PCI bus address
+ * @v len		Length of region
+ * @ret io_addr		I/O address, or NULL on error
+ */
+void * efipci_ioremap ( struct pci_device *pci, unsigned long bus_addr,
+			size_t len ) {
+	union {
+		union acpi_resource *res;
+		void *raw;
+	} u;
+	EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL *root;
+	EFI_HANDLE handle;
+	unsigned int tag;
+	uint64_t offset;
+	uint64_t start;
+	uint64_t end;
+	void *io_addr = NULL;
+	EFI_STATUS efirc;
+	int rc;
+
+	/* Open root bridge */
+	if ( ( rc = efipci_root_open ( pci, &handle, &root ) ) != 0 )
+		goto err_root;
+
+	/* Get ACPI resource descriptors */
+	if ( ( efirc = root->Configuration ( root, &u.raw ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( pci, "EFIPCI " PCI_FMT " cannot get configuration: "
+		       "%s\n", PCI_ARGS ( pci ), strerror ( rc ) );
+		goto err_config;
+	}
+
+	/* Parse resource descriptors */
+	for ( ; ( ( tag = acpi_resource_tag ( u.res ) ) != ACPI_END_RESOURCE ) ;
+	      u.res = acpi_resource_next ( u.res ) ) {
+
+		/* Ignore anything other than an address space descriptor */
+		if ( tag != ACPI_QWORD_ADDRESS_SPACE_RESOURCE )
+			continue;
+
+		/* Ignore descriptors that do not cover this memory range */
+		if ( u.res->qword.type != ACPI_ADDRESS_TYPE_MEM )
+			continue;
+		offset = le64_to_cpu ( u.res->qword.offset );
+		start = ( offset + le64_to_cpu ( u.res->qword.min ) );
+		end = ( start + le64_to_cpu ( u.res->qword.len ) );
+		if ( ( bus_addr < start ) || ( ( bus_addr + len ) > end ) )
+			continue;
+
+		/* Use this address space descriptor */
+		DBGC2 ( pci, "EFIPCI " PCI_FMT " %08lx+%zx -> ",
+			PCI_ARGS ( pci ), bus_addr, len );
+		bus_addr -= offset;
+		DBGC2 ( pci, "%08lx\n", bus_addr );
+		io_addr = ioremap ( bus_addr, len );
+		break;
+	}
+	if ( ! io_addr ) {
+		DBGC ( pci, "EFIPCI " PCI_FMT " %08lx+%zx is not within "
+		       "root bridge address space\n",
+		       PCI_ARGS ( pci ), bus_addr, len );
+	}
+
+ err_config:
+	efipci_root_close ( handle );
+ err_root:
+	return io_addr;
+}
+
 PROVIDE_PCIAPI_INLINE ( efi, pci_num_bus );
 PROVIDE_PCIAPI_INLINE ( efi, pci_read_config_byte );
 PROVIDE_PCIAPI_INLINE ( efi, pci_read_config_word );
@@ -231,7 +304,7 @@ PROVIDE_PCIAPI_INLINE ( efi, pci_read_config_dword );
 PROVIDE_PCIAPI_INLINE ( efi, pci_write_config_byte );
 PROVIDE_PCIAPI_INLINE ( efi, pci_write_config_word );
 PROVIDE_PCIAPI_INLINE ( efi, pci_write_config_dword );
-PROVIDE_PCIAPI_INLINE ( efi, pci_ioremap );
+PROVIDE_PCIAPI ( efi, pci_ioremap, efipci_ioremap );
 
 /******************************************************************************
  *