--- /dev/null
+/*
+ * Copyright (C) 2022 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <errno.h>
+#include <ipxe/uaccess.h>
+#include <ipxe/ecam.h>
+
+/** @file
+ *
+ * PCI Enhanced Configuration Access Mechanism (ECAM)
+ *
+ */
+
+/** Cached mapped ECAM allocation */
+static struct ecam_mapping ecam;
+
+/**
+ * Find lowest ECAM allocation not below a given PCI bus:dev.fn address
+ *
+ * @v busdevfn PCI bus:dev.fn address
+ * @v range PCI device address range to fill in
+ * @v alloc ECAM allocation to fill in, or NULL
+ * @ret rc Return status code
+ */
+static int ecam_find ( uint32_t busdevfn, struct pci_range *range,
+ struct ecam_allocation *alloc ) {
+ struct ecam_allocation tmp;
+ unsigned int best = 0;
+ unsigned int offset;
+ unsigned int count;
+ unsigned int index;
+ userptr_t mcfg;
+ uint32_t length;
+ uint32_t start;
+
+ /* Return empty range on error */
+ range->count = 0;
+
+ /* Locate MCFG table */
+ mcfg = acpi_table ( ECAM_SIGNATURE, 0 );
+ if ( ! mcfg ) {
+ DBGC ( &ecam, "ECAM found no MCFG table\n" );
+ return -ENOTSUP;
+ }
+
+ /* Get length of table */
+ copy_from_user ( &length, mcfg,
+ offsetof ( struct ecam_table, acpi.length ),
+ sizeof ( length ) );
+
+ /* Iterate over allocations */
+ for ( offset = offsetof ( struct ecam_table, alloc ) ;
+ ( offset + sizeof ( tmp ) ) <= le32_to_cpu ( length ) ;
+ offset += sizeof ( tmp ) ) {
+
+ /* Read allocation */
+ copy_from_user ( &tmp, mcfg, offset, sizeof ( tmp ) );
+ DBGC2 ( &ecam, "ECAM %04x:[%02x-%02x] has base %08llx\n",
+ le16_to_cpu ( tmp.segment ), tmp.start, tmp.end,
+ ( ( unsigned long long ) le64_to_cpu ( tmp.base ) ) );
+ start = PCI_BUSDEVFN ( le16_to_cpu ( tmp.segment ),
+ tmp.start, 0, 0 );
+ count = PCI_BUSDEVFN ( 0, ( tmp.end - tmp.start + 1 ), 0, 0 );
+
+ /* Check for a matching or new closest allocation */
+ index = ( busdevfn - start );
+ if ( ( index < count ) || ( index > best ) ) {
+ if ( alloc )
+ memcpy ( alloc, &tmp, sizeof ( *alloc ) );
+ range->start = start;
+ range->count = count;
+ best = index;
+ }
+
+ /* Stop if this range contains the target bus:dev.fn address */
+ if ( index < count )
+ return 0;
+ }
+
+ return ( best ? 0 : -ENOENT );
+}
+
+/**
+ * Find next PCI bus:dev.fn address range in system
+ *
+ * @v busdevfn Starting PCI bus:dev.fn address
+ * @v range PCI bus:dev.fn address range to fill in
+ */
+static void ecam_discover ( uint32_t busdevfn, struct pci_range *range ) {
+
+ /* Find new range, if any */
+ ecam_find ( busdevfn, range, NULL );
+}
+
+/**
+ * Access configuration space for PCI device
+ *
+ * @v pci PCI device
+ * @ret rc Return status code
+ */
+static int ecam_access ( struct pci_device *pci ) {
+ uint64_t base;
+ size_t len;
+ int rc;
+
+ /* Reuse mapping if possible */
+ if ( ( pci->busdevfn - ecam.range.start ) < ecam.range.count )
+ return 0;
+
+ /* Clear any existing mapping */
+ if ( ecam.regs ) {
+ iounmap ( ecam.regs );
+ ecam.regs = NULL;
+ }
+
+ /* Find allocation for this PCI device */
+ if ( ( rc = ecam_find ( pci->busdevfn, &ecam.range,
+ &ecam.alloc ) ) != 0 ) {
+ DBGC ( &ecam, "ECAM found no allocation for " PCI_FMT ": %s\n",
+ PCI_ARGS ( pci ), strerror ( rc ) );
+ goto err_find;
+ }
+ if ( ecam.range.start > pci->busdevfn ) {
+ DBGC ( &ecam, "ECAM found no allocation for " PCI_FMT "\n",
+ PCI_ARGS ( pci ) );
+ goto err_find;
+ }
+
+ /* Map configuration space for this allocation */
+ base = le64_to_cpu ( ecam.alloc.base );
+ len = ( ecam.range.count * ECAM_SIZE );
+ ecam.regs = ioremap ( base, len );
+ if ( ! ecam.regs ) {
+ DBGC ( &ecam, "ECAM %04x:[%02x-%02x] could not map "
+ "[%08llx,%08llx)\n", le16_to_cpu ( ecam.alloc.segment ),
+ ecam.alloc.start, ecam.alloc.end, base, ( base + len ) );
+ rc = -ENODEV;
+ goto err_ioremap;
+ }
+
+ /* Populate cached mapping */
+ DBGC ( &ecam, "ECAM %04x:[%02x-%02x] mapped [%08llx,%08llx) -> %p\n",
+ le16_to_cpu ( ecam.alloc.segment ), ecam.alloc.start,
+ ecam.alloc.end, base, ( base + len ), ecam.regs );
+ return 0;
+
+ iounmap ( ecam.regs );
+ err_ioremap:
+ err_find:
+ ecam.range.count = 0;
+ return rc;
+}
+
+/**
+ * Read from PCI configuration space
+ *
+ * @v pci PCI device
+ * @v location Offset and length within PCI configuration space
+ * @v value Value read
+ * @ret rc Return status code
+ */
+int ecam_read ( struct pci_device *pci, unsigned int location, void *value ) {
+ unsigned int where = ECAM_WHERE ( location );
+ unsigned int len = ECAM_LEN ( location );
+ unsigned int index;
+ void *addr;
+ int rc;
+
+ /* Return all-ones on error */
+ memset ( value, 0xff, len );
+
+ /* Access configuration space */
+ if ( ( rc = ecam_access ( pci ) ) != 0 )
+ return rc;
+
+ /* Read from address */
+ index = ( pci->busdevfn - ecam.range.start );
+ addr = ( ecam.regs + ( index * ECAM_SIZE ) + where );
+ switch ( len ) {
+ case 4:
+ *( ( uint32_t *) value ) = readl ( addr );
+ break;
+ case 2:
+ *( ( uint16_t *) value ) = readw ( addr );
+ break;
+ case 1:
+ *( ( uint8_t *) value ) = readb ( addr );
+ break;
+ default:
+ assert ( 0 );
+ }
+
+ return 0;
+}
+
+/**
+ * Write to PCI configuration space
+ *
+ * @v pci PCI device
+ * @v location Offset and length within PCI configuration space
+ * @v value Value to write
+ * @ret rc Return status code
+ */
+int ecam_write ( struct pci_device *pci, unsigned int location,
+ unsigned long value ) {
+ unsigned int where = ECAM_WHERE ( location );
+ unsigned int len = ECAM_LEN ( location );
+ unsigned int index;
+ void *addr;
+ int rc;
+
+ /* Access configuration space */
+ if ( ( rc = ecam_access ( pci ) ) != 0 )
+ return rc;
+
+ /* Read from address */
+ index = ( pci->busdevfn - ecam.range.start );
+ addr = ( ecam.regs + ( index * ECAM_SIZE ) + where );
+ switch ( len ) {
+ case 4:
+ writel ( value, addr );
+ break;
+ case 2:
+ writew ( value, addr );
+ break;
+ case 1:
+ writeb ( value, addr );
+ break;
+ default:
+ assert ( 0 );
+ }
+
+ return 0;
+}
+
+PROVIDE_PCIAPI ( ecam, pci_discover, ecam_discover );
+PROVIDE_PCIAPI_INLINE ( ecam, pci_read_config_byte );
+PROVIDE_PCIAPI_INLINE ( ecam, pci_read_config_word );
+PROVIDE_PCIAPI_INLINE ( ecam, pci_read_config_dword );
+PROVIDE_PCIAPI_INLINE ( ecam, pci_write_config_byte );
+PROVIDE_PCIAPI_INLINE ( ecam, pci_write_config_word );
+PROVIDE_PCIAPI_INLINE ( ecam, pci_write_config_dword );
+PROVIDE_PCIAPI_INLINE ( ecam, pci_ioremap );
--- /dev/null
+#ifndef _IPXE_ECAM_IO_H
+#define _IPXE_ECAM_IO_H
+
+/** @file
+ *
+ * PCI I/O API for Enhanced Configuration Access Mechanism (ECAM)
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+
+#ifdef PCIAPI_ECAM
+#define PCIAPI_PREFIX_ecam
+#else
+#define PCIAPI_PREFIX_ecam __ecam_
+#endif
+
+struct pci_device;
+
+/** Construct ECAM location */
+#define ECAM_LOC( where, len ) ( ( (len) << 16 ) | where )
+
+/** Extract offset from ECAM location */
+#define ECAM_WHERE( location ) ( (location) & 0xffff )
+
+/** Extract length from ECAM location */
+#define ECAM_LEN( location ) ( (location) >> 16 )
+
+extern int ecam_read ( struct pci_device *pci, unsigned int location,
+ void *value );
+extern int ecam_write ( struct pci_device *pci, unsigned int location,
+ unsigned long value );
+
+/**
+ * Read byte from PCI configuration space via ECAM
+ *
+ * @v pci PCI device
+ * @v where Location within PCI configuration space
+ * @v value Value read
+ * @ret rc Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( ecam, pci_read_config_byte ) ( struct pci_device *pci,
+ unsigned int where,
+ uint8_t *value ) {
+ return ecam_read ( pci, ECAM_LOC ( where, sizeof ( *value ) ), value );
+}
+
+/**
+ * Read word from PCI configuration space via ECAM
+ *
+ * @v pci PCI device
+ * @v where Location within PCI configuration space
+ * @v value Value read
+ * @ret rc Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( ecam, pci_read_config_word ) ( struct pci_device *pci,
+ unsigned int where,
+ uint16_t *value ) {
+ return ecam_read ( pci, ECAM_LOC ( where, sizeof ( *value ) ), value );
+}
+
+/**
+ * Read dword from PCI configuration space via ECAM
+ *
+ * @v pci PCI device
+ * @v where Location within PCI configuration space
+ * @v value Value read
+ * @ret rc Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( ecam, pci_read_config_dword ) ( struct pci_device *pci,
+ unsigned int where,
+ uint32_t *value ) {
+ return ecam_read ( pci, ECAM_LOC ( where, sizeof ( *value ) ), value );
+}
+
+/**
+ * Write byte to PCI configuration space via ECAM
+ *
+ * @v pci PCI device
+ * @v where Location within PCI configuration space
+ * @v value Value to be written
+ * @ret rc Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( ecam, pci_write_config_byte ) ( struct pci_device *pci,
+ unsigned int where,
+ uint8_t value ) {
+ return ecam_write ( pci, ECAM_LOC ( where, sizeof ( value ) ), value );
+}
+
+/**
+ * Write word to PCI configuration space via ECAM
+ *
+ * @v pci PCI device
+ * @v where Location within PCI configuration space
+ * @v value Value to be written
+ * @ret rc Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( ecam, pci_write_config_word ) ( struct pci_device *pci,
+ unsigned int where,
+ uint16_t value ) {
+ return ecam_write ( pci, ECAM_LOC ( where, sizeof ( value ) ), value );
+}
+
+/**
+ * Write dword to PCI configuration space via ECAM
+ *
+ * @v pci PCI device
+ * @v where Location within PCI configuration space
+ * @v value Value to be written
+ * @ret rc Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( ecam, pci_write_config_dword ) ( struct pci_device *pci,
+ unsigned int where,
+ uint32_t value ) {
+ return ecam_write ( pci, ECAM_LOC ( where, sizeof ( value ) ), 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 ( ecam, pci_ioremap ) ( struct pci_device *pci __unused,
+ unsigned long bus_addr, size_t len ) {
+ return ioremap ( bus_addr, len );
+}
+
+#endif /* _IPXE_ECAM_IO_H */
projects / thirdparty / ipxe.git / commitdiff
