[pci] Add support for reading and writing PCI Vital Product Data (VPD)

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 386 insertions, 0 deletions

diff --git a/src/drivers/bus/pcivpd.c b/src/drivers/bus/pcivpd.c
new file mode 100644
index 00000000..1f7d832b
--- /dev/null
+++ b/src/drivers/bus/pcivpd.c
@@ -0,0 +1,386 @@
+/*
+ * Copyright (C) 2010 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <unistd.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <ipxe/pci.h>
+#include <ipxe/isapnp.h>
+#include <ipxe/pcivpd.h>
+
+/** @file
+ *
+ * PCI Vital Product Data
+ *
+ */
+
+/**
+ * Initialise PCI Vital Product Data
+ *
+ * @v vpd		PCI VPD
+ * @v pci		PCI device
+ * @ret rc		Return status code
+ */
+int pci_vpd_init ( struct pci_vpd *vpd, struct pci_device *pci ) {
+
+	/* Initialise structure */
+	vpd->pci = pci;
+	pci_vpd_invalidate_cache ( vpd );
+
+	/* Locate VPD capability */
+	vpd->cap = pci_find_capability ( pci, PCI_CAP_ID_VPD );
+	if ( ! vpd->cap ) {
+		DBGC ( vpd, PCI_FMT " does not support VPD\n",
+		       PCI_ARGS ( pci ) );
+		return -ENOTTY;
+	}
+
+	DBGC ( vpd, PCI_FMT " VPD is at offset %02x\n",
+	       PCI_ARGS ( pci ), vpd->cap );
+	return 0;
+}
+
+/**
+ * Read one dword of PCI Vital Product Data
+ *
+ * @v vpd		PCI VPD
+ * @v address		Address to read
+ * @ret data		Read data
+ * @ret rc		Return status code
+ */
+static int pci_vpd_read_dword ( struct pci_vpd *vpd, int address,
+				uint32_t *data ) {
+	struct pci_device *pci = vpd->pci;
+	unsigned int cap = vpd->cap;
+	unsigned int retries;
+	uint16_t flag;
+
+	/* Return cached value, if present */
+	if ( pci_vpd_cache_is_valid ( vpd ) &&
+	     ( vpd->cache.address == address ) ) {
+		*data = vpd->cache.data;
+		return 0;
+	}
+
+	/* Initiate read */
+	pci_write_config_word ( pci, ( cap + PCI_VPD_ADDRESS ), address );
+
+	/* Wait for read to complete */
+	for ( retries = 0 ; retries < PCI_VPD_MAX_WAIT_MS ; retries++ ) {
+
+		/* Check if data is ready */
+		pci_read_config_word ( pci, ( cap + PCI_VPD_ADDRESS ), &flag );
+		if ( flag & PCI_VPD_FLAG ) {
+
+			/* Read data */
+			pci_read_config_dword ( pci, ( cap + PCI_VPD_DATA ),
+						data );
+			DBGC2 ( vpd, PCI_FMT " VPD %04x => %08x\n",
+				PCI_ARGS ( pci ), address, htonl ( *data ) );
+
+			/* Populate cache */
+			vpd->cache.address = address;
+			vpd->cache.data = *data;
+
+			return 0;
+		}
+
+		/* Wait 1ms before retrying */
+		mdelay ( 1 );
+	}
+
+	DBGC ( vpd, PCI_FMT " VPD %04x read via %02x timed out\n",
+	       PCI_ARGS ( pci ), address, cap );
+	return -ETIMEDOUT;
+}
+
+/**
+ * Write one dword of PCI Vital Product Data
+ *
+ * @v vpd		PCI VPD
+ * @v address		Address to write
+ * @v data		Data to write
+ * @ret rc		Return status code
+ */
+static int pci_vpd_write_dword ( struct pci_vpd *vpd, int address,
+				 uint32_t data ) {
+	struct pci_device *pci = vpd->pci;
+	unsigned int cap = vpd->cap;
+	unsigned int retries;
+	uint16_t flag;
+
+	/* Invalidate cache */
+	pci_vpd_invalidate_cache ( vpd );
+
+	DBGC2 ( vpd, PCI_FMT " VPD %04x <= %08x\n",
+		PCI_ARGS ( pci ), address, htonl ( data ) );
+
+	/* Write data */
+	pci_write_config_dword ( pci, ( cap + PCI_VPD_DATA ), data );
+
+	/* Initiate write */
+	pci_write_config_word ( pci, ( cap + PCI_VPD_ADDRESS ),
+				( address | PCI_VPD_FLAG ) );
+
+	/* Wait for write to complete */
+	for ( retries = 0 ; retries < PCI_VPD_MAX_WAIT_MS ; retries++ ) {
+
+		/* Check if write has completed */
+		pci_read_config_word ( pci, ( cap + PCI_VPD_ADDRESS ), &flag );
+		if ( ! ( flag & PCI_VPD_FLAG ) )
+			return 0;
+
+		/* Wait 1ms before retrying */
+		mdelay ( 1 );
+	}
+
+	DBGC ( vpd, PCI_FMT " VPD %04x write via %02x timed out\n",
+	       PCI_ARGS ( pci ), address, cap );
+	return -ETIMEDOUT;
+}
+
+/**
+ * Read PCI VPD
+ *
+ * @v vpd		PCI VPD
+ * @v address		Starting address
+ * @v buf		Data buffer
+ * @v len		Length of data buffer
+ * @ret rc		Return status code
+ */
+int pci_vpd_read ( struct pci_vpd *vpd, unsigned int address, void *buf,
+		   size_t len ) {
+	uint8_t *bytes = buf;
+	uint32_t data;
+	size_t skip_len;
+	unsigned int i;
+	int rc;
+
+	/* Calculate length to skip at start of data */
+	skip_len = ( address & 0x03 );
+
+	/* Read data, a dword at a time */
+	for ( address &= ~0x03 ; len ; address += 4 ) {
+
+		/* Read whole dword */
+		if ( ( rc = pci_vpd_read_dword ( vpd, address, &data ) ) != 0 )
+			return rc;
+
+		/* Copy data to buffer */
+		for ( i = 4 ; i ; i-- ) {
+			if ( skip_len ) {
+				skip_len--;
+			} else if ( len ) {
+				*(bytes++) = data;
+				len--;
+			}
+			data = ( ( data << 24 ) | ( data >> 8 ) );
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * Write PCI VPD
+ *
+ * @v vpd		PCI VPD
+ * @v address		Starting address
+ * @v buf		Data buffer
+ * @v len		Length of data buffer
+ * @ret rc		Return status code
+ */
+int pci_vpd_write ( struct pci_vpd *vpd, unsigned int address, const void *buf,
+		    size_t len ) {
+	const uint8_t *bytes = buf;
+	uint32_t data;
+	size_t skip_len;
+	unsigned int i;
+	int rc;
+
+	/* Calculate length to skip at start of data */
+	skip_len = ( address & 0x03 );
+
+	/* Write data, a dword at a time */
+	for ( address &= ~0x03 ; len ; address += 4 ) {
+
+		/* Read existing dword, if necessary */
+		if ( skip_len || ( len <= 0x03 ) ) {
+			if ( ( rc = pci_vpd_read_dword ( vpd, address,
+							 &data ) ) != 0 )
+				return rc;
+		}
+
+		/* Copy data from buffer */
+		for ( i = 4 ; i ; i-- ) {
+			if ( skip_len ) {
+				skip_len--;
+			} else if ( len ) {
+				data = ( ( data & ~0xff ) | *(bytes++) );
+				len--;
+			}
+			data = ( ( data << 24 ) | ( data >> 8 ) );
+		}
+
+		/* Write whole dword */
+		if ( ( rc = pci_vpd_write_dword ( vpd, address, data ) ) != 0 )
+			return rc;
+	}
+	return 0;
+}
+
+/**
+ * Dump PCI VPD region (for debugging)
+ *
+ * @v vpd		PCI VPD
+ * @v address		Starting address
+ * @v len		Length of data
+ */
+static void pci_vpd_dump ( struct pci_vpd *vpd, unsigned int address,
+			   size_t len ) {
+	int rc;
+
+	/* Do nothing in non-debug builds */
+	if ( ! DBG_LOG )
+		return;
+
+	/* Read data */
+	{
+		char buf[len];
+		if ( ( rc = pci_vpd_read ( vpd, address, buf,
+					   sizeof ( buf ) ) ) != 0 )
+			return;
+		DBGC_HDA ( vpd, address, buf, sizeof ( buf ) );
+	}
+}
+
+/**
+ * Locate PCI VPD tag
+ *
+ * @v vpd		PCI VPD
+ * @v tag		ISAPnP tag
+ * @ret address		Address of tag body
+ * @ret len		Length of tag body
+ * @ret rc		Return status code
+ */
+static int pci_vpd_find_tag ( struct pci_vpd *vpd, unsigned int tag,
+			      unsigned int *address, size_t *len ) {
+	uint8_t read_tag;
+	uint16_t read_len;
+	int rc;
+
+	/* Scan through tags looking for a match */
+	*address = 0;
+	do {
+		/* Read tag byte */
+		if ( ( rc = pci_vpd_read ( vpd, (*address)++, &read_tag,
+					   sizeof ( read_tag ) ) ) != 0 )
+			return rc;
+
+		/* Extract tag and length */
+		if ( ISAPNP_IS_LARGE_TAG ( read_tag ) ) {
+			if ( ( rc = pci_vpd_read ( vpd, *address, &read_len,
+						   sizeof ( read_len ) ) ) != 0)
+				return rc;
+			*address += sizeof ( read_len );
+			read_len = le16_to_cpu ( read_len );
+			read_tag = ISAPNP_LARGE_TAG_NAME ( read_tag );
+		} else {
+			read_len = ISAPNP_SMALL_TAG_LEN ( read_tag );
+			read_tag = ISAPNP_SMALL_TAG_NAME ( read_tag );
+		}
+
+		/* Check for tag match */
+		if ( tag == read_tag ) {
+			*len = read_len;
+			DBGC ( vpd, PCI_FMT " VPD tag %02x is at "
+			       "[%04x,%04zx)\n", PCI_ARGS ( vpd->pci ), tag,
+			       *address, ( *address + *len ) );
+			return 0;
+		}
+
+		/* Move to next tag */
+		*address += read_len;
+
+	} while ( read_tag != ISAPNP_TAG_END );
+
+	DBGC ( vpd, PCI_FMT " VPD tag %02x not found\n",
+	       PCI_ARGS ( vpd->pci ), tag );
+	return -ENOENT;
+}
+
+/**
+ * Locate PCI VPD field
+ *
+ * @v vpd		PCI VPD
+ * @v field		VPD field descriptor
+ * @ret address		Address of field body
+ * @ret len		Length of field body
+ * @ret rc		Return status code
+ */
+int pci_vpd_find ( struct pci_vpd *vpd, unsigned int field,
+		   unsigned int *address, size_t *len ) {
+	struct pci_vpd_field read_field;
+	int rc;
+
+	/* Locate containing tag */
+	if ( ( rc = pci_vpd_find_tag ( vpd, PCI_VPD_TAG ( field ),
+				       address, len ) ) != 0 )
+		return rc;
+
+	/* Return immediately if we are searching for a whole-tag field */
+	if ( ! PCI_VPD_KEYWORD ( field ) ) {
+		pci_vpd_dump ( vpd, *address, *len );
+		return 0;
+	}
+
+	/* Scan through fields looking for a match */
+	while ( *len >= sizeof ( read_field ) ) {
+
+		/* Read field header */
+		if ( ( rc = pci_vpd_read ( vpd, *address, &read_field,
+					   sizeof ( read_field ) ) ) != 0 )
+			return rc;
+		*address += sizeof ( read_field );
+		*len -= sizeof ( read_field );
+
+		/* Check for keyword match */
+		if ( read_field.keyword == PCI_VPD_KEYWORD ( field ) ) {
+			*len = read_field.len;
+			DBGC ( vpd, PCI_FMT " VPD field " PCI_VPD_FIELD_FMT
+			       " is at [%04x,%04zx)\n", PCI_ARGS ( vpd->pci ),
+			       PCI_VPD_FIELD_ARGS ( field ),
+			       *address, ( *address + *len ) );
+			pci_vpd_dump ( vpd, *address, *len );
+			return 0;
+		}
+
+		/* Move to next field */
+		if ( read_field.len > *len )
+			break;
+		*address += read_field.len;
+		*len -= read_field.len;
+	}
+
+	DBGC ( vpd, PCI_FMT " VPD field " PCI_VPD_FIELD_FMT " not found\n",
+	       PCI_ARGS ( vpd->pci ), PCI_VPD_FIELD_ARGS ( field ) );
+	return -ENOENT;
+}