2002-09-27 21:25:50

by Matt Domsch

[permalink] [raw]
Subject: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

x86 systems suffer from a disconnect between what BIOS believes is the
boot disk, and what Linux thinks BIOS thinks is the boot disk. BIOS
Enhanced Disk Device Services (EDD) 3.0 provides the ability for disk
adapter BIOSs to tell the OS what it believes is the boot disk. While
this isn't widely implemented in BIOSs yet, it's time that Linux
received support to be ready as BIOSs with this feature do become
available.

EDD works by providing the bus (PCI, PCI-X, ISA, InfiniBand, PCI
Express, or HyperTransport) location (e.g. PCI 02:01.0) and interface
(ATAPI, ATA, SCSI, USB, 1394, FibreChannel, I2O, RAID, SATA) location
(e.g. SCSI ID 5 LUN 0) information for each BIOS int13 device.

The patch below creates CONFIG_EDD, that when defined, makes the
calls to retrieve and store this information. It then exports it via
driverfs.

.
|-- bus
| `-- system
| |-- devices
| | |-- int13_dev80 -> ../../../root/bios/int13_dev80
| | |-- int13_dev81 -> ../../../root/bios/int13_dev81
| `-- drivers
| |-- edd
`-- root
|-- bios
| |-- int13_dev80
| | |-- host_bus
| | |-- info
| | |-- interface
| | |-- name
| | `-- power
| |-- int13_dev81
| | |-- host_bus
| | |-- info
| | |-- interface
| | |-- name
| | `-- power
| |-- name
| `-- power


(Yes, the system bus isn't the right place for them to go, but it must
go on some bus, and eventually it will get moved to a better place.)

The 'info' file contains the full set of information returned by BIOS
with extra error reporting. This exists for vendor BIOS debugging purposes.

The 'host-bus' file contains the PCI (or ISA, HyperTransport, ...)
identifying information, as BIOS knows it.

The 'interface' file contains the SCSI (or IDE, USB, ...) identifying
information, as BIOS knows it.


$ cat int13_dev80/host_bus
PCI 02:01.0 channel: 0
$ cat int13_dev80/interface
SCSI id: 0 lun: 0
$ cat int13_dev80/info
80 30 01 00 .0..
1e 00 09 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
3a b9 8b 08 00 00 00 00 00 02 ff ff ff ff be dd :...............
2c 00 00 00 50 43 49 00 53 43 53 49 00 00 00 00 ,...PCI.SCSI....
02 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 28 .........(
version: 3.0
Extensions:
Fixed disk access
Info Flags:
dma_boundry_error_transparent
write_verify
num_default_cylinders: 0
num_default_heads: 0
sectors_per_track: 0
number_of_sectors: 88bb93a
PCI 02:01.0 channel: 0
SCSI id: 0 lun: 0

Warning: Spec violation. Key should be 0xBEDD, is 0xDDBE

$ cat int13_dev81/host_bus
PCI 04:00.0 channel: 0
$ cat int13_dev81/interface
SCSI id: 0 lun: 0
$ cat int13_dev81/info
81 30 01 00 .0..
1e 00 09 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 c0 3a 05 00 00 00 00 00 02 ff ff ff ff dd be ..:.............
2c 00 00 00 50 43 49 20 53 43 53 49 20 20 20 20 ,...PCI SCSI
04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 87 ..........
version: 3.0
Extensions:
Fixed disk access
Info Flags:
dma_boundry_error_transparent
write_verify
num_default_cylinders: 0
num_default_heads: 0
sectors_per_track: 0
number_of_sectors: 53ac000
PCI 04:00.0 channel: 0
SCSI id: 0 lun: 0


In the above case, BIOS int13 device 80 (the boot disk) believes it is
on PCI 02:01.0, SCSI bus 0, ID 0 LUN 0 (in this case it's an Adaptec
39160 add-in card). Likewise, device 81 believes it's at PCI 04:00.0,
channel 0, ID 0, LUN 0 (a Dell PERC3/QC card). The Adaptec BIOS has
some cleanup work to do yet, The PERC3/QC BIOS has made the required
changes to fully support EDD now.

At most 6 BIOS devices are reported, as that fills the space that's
left in the empty_zero_page. In general you only care about device
80h, though for software RAID1 knowing what 81h is might be useful also.

The major changes implemented in this patch:
arch/i386/boot/setup.S - int13 real mode calls store results in empty_zero_page
arch/i386/kernel/setup.c - copy results from empty_zero_page to local storage
arch/i386/kernel/edd.c - export results via driverfs

If you use this, please send reports of success/failure, and the
adapter types and BIOS versions, to [email protected]. I'm keeping a
tally at http://domsch.com/linux/edd30/results.html.


Documentation/i386/zero-page.txt | 2
arch/i386/Config.help | 10
arch/i386/boot/setup.S | 46 +++
arch/i386/config.in | 4
arch/i386/defconfig | 1
arch/i386/kernel/Makefile | 1
arch/i386/kernel/edd.c | 522 +++++++++++++++++++++++++++++++++++++++
arch/i386/kernel/i386_ksyms.c | 6
arch/i386/kernel/setup.c | 20 +
include/asm-i386/edd.h | 162 ++++++++++++
include/asm-i386/setup.h | 2
11 files changed, 776 insertions(+)


Patch against BK-current:
http://domsch.com/linux/edd30/edd-driverfs-3.patch
http://domsch.com/linux/edd30/edd-driverfs-3.patch.sign

BK:
http://mdomsch.bkbits.net/linux-2.5-edd

Future work includes exporting a symlink from the EDD device to the
actual disk device in driverfs. I'll continue working with Patrick
Mochel, Greg KH, and the appropriate subsystem maintainers on the
details needed to make this work well.

Feedback appreciated. I'd like to see this included before the 2.5
feature freeze if at all possible.

Thanks,
Matt

--
Matt Domsch
Sr. Software Engineer, Lead Engineer, Architect
Dell Linux Solutions http://www.dell.com/linux
Linux on Dell mailing lists @ http://lists.us.dell.com


diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/Documentation/i386/zero-page.txt linux-2.5-edd/Documentation/i386/zero-page.txt
--- linux-2.5/Documentation/i386/zero-page.txt Tue Sep 10 11:41:37 2002
+++ linux-2.5-edd/Documentation/i386/zero-page.txt Fri Sep 27 15:53:05 2002
@@ -31,6 +31,7 @@

0x1e0 unsigned long ALT_MEM_K, alternative mem check, in Kb
0x1e8 char number of entries in E820MAP (below)
+0x1e9 unsigned char number of entries in EDDBUF (below)
0x1f1 char size of setup.S, number of sectors
0x1f2 unsigned short MOUNT_ROOT_RDONLY (if !=0)
0x1f4 unsigned short size of compressed kernel-part in the
@@ -66,6 +67,7 @@
0x220 4 bytes (setup.S)
0x224 unsigned short setup.S heap end pointer
0x2d0 - 0x600 E820MAP
+0x600 - 0x7D4 EDDBUF (setup.S)

0x800 string, 2K max COMMAND_LINE, the kernel commandline as
copied using CL_OFFSET.
diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/arch/i386/Config.help linux-2.5-edd/arch/i386/Config.help
--- linux-2.5/arch/i386/Config.help Thu Sep 26 21:44:44 2002
+++ linux-2.5-edd/arch/i386/Config.help Fri Sep 27 15:53:06 2002
@@ -981,3 +981,13 @@
absence of features.

For more information take a look at Documentation/swsusp.txt.
+
+CONFIG_EDD
+ Say Y or M here if you want to enable BIOS Enhanced Disk Device
+ Services real mode BIOS calls to determine which disk
+ BIOS tries boot from. This feature creates a /proc/edd directory
+ and files for each BIOS device detected.
+
+ This option is experimental, and most disk controller BIOS
+ vendors do not yet implement this feature.
+
diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/arch/i386/boot/setup.S linux-2.5-edd/arch/i386/boot/setup.S
--- linux-2.5/arch/i386/boot/setup.S Tue Sep 10 11:41:39 2002
+++ linux-2.5-edd/arch/i386/boot/setup.S Fri Sep 27 15:53:06 2002
@@ -44,6 +44,8 @@
*
* New A20 code ported from SYSLINUX by H. Peter Anvin. AMD Elan bugfixes
* by Robert Schwebel, December 2001 <[email protected]>
+ *
+ * BIOS EDD support September 2002 by Matt Domsch <[email protected]>
*
*/

@@ -53,6 +55,7 @@
#include <linux/compile.h>
#include <asm/boot.h>
#include <asm/e820.h>
+#include <asm/edd.h>
#include <asm/page.h>

/* Signature words to ensure LILO loaded us right */
@@ -541,6 +544,49 @@
no_32_apm_bios:
andw $0xfffd, (76) # remove 32 bit support bit
done_apm_bios:
+#endif
+
+#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
+# Do the BIOS EDD calls
+# This code is sensitive to the size of the structs in edd.h
+edd_start:
+ # %ds points to the bootsector
+ # result buffer for fn48
+ movw $EDDBUF+EDDEXTSIZE, %si # in ds:si, fn41 results
+ # kept just before that
+ movb $0, (EDDNR) # zero value at EDDNR
+ movb $0x80, %dl # BIOS device 0x80
+
+edd_check_ext:
+ movb $0x41, %ah # Function 41
+ movw $0x55aa, %bx # magic
+ int $0x13 # make the call
+ jc edd_done # no more BIOS devices
+
+ cmpw $0xAA55, %bx # is magic right?
+ jne edd_next # nope, next...
+
+ movb %dl, %ds:-4(%si) # store device number
+ movb %ah, %ds:-3(%si) # store version
+ movw %cx, %ds:-2(%si) # store extensions
+ incb (EDDNR) # note that we stored something
+
+edd_get_device_params:
+ movw $EDDPARMSIZE, %ds:(%si) # put size
+ movb $0x48, %ah # Function 48
+ int $0x13 # make the call
+ # Don't check for fail return
+ # it doesn't matter.
+ movw %si, %ax # increment si
+ addw $EDDPARMSIZE+EDDEXTSIZE, %ax
+ movw %ax, %si
+
+edd_next:
+ incb %dl # increment to next device
+ cmpb $EDDMAXNR, (EDDNR) # Out of space?
+ jb edd_check_ext # keep looping
+
+edd_done:
#endif

# Now we want to move to protected mode ...
diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/arch/i386/config.in linux-2.5-edd/arch/i386/config.in
--- linux-2.5/arch/i386/config.in Thu Sep 26 21:44:44 2002
+++ linux-2.5-edd/arch/i386/config.in Fri Sep 27 15:53:06 2002
@@ -198,6 +198,10 @@
tristate '/dev/cpu/*/msr - Model-specific register support' CONFIG_X86_MSR
tristate '/dev/cpu/*/cpuid - CPU information support' CONFIG_X86_CPUID

+if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
+ tristate 'BIOS Enhanced Disk Device calls determine boot disk (EXPERIMENTAL)' CONFIG_EDD
+fi
+
choice 'High Memory Support' \
"off CONFIG_NOHIGHMEM \
4GB CONFIG_HIGHMEM4G \
diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/arch/i386/defconfig linux-2.5-edd/arch/i386/defconfig
--- linux-2.5/arch/i386/defconfig Thu Sep 26 21:44:44 2002
+++ linux-2.5-edd/arch/i386/defconfig Fri Sep 27 15:53:06 2002
@@ -70,6 +70,7 @@
# CONFIG_MICROCODE is not set
# CONFIG_X86_MSR is not set
# CONFIG_X86_CPUID is not set
+# CONFIG_EDD is not set
CONFIG_NOHIGHMEM=y
# CONFIG_HIGHMEM4G is not set
# CONFIG_HIGHMEM64G is not set
diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/arch/i386/kernel/Makefile linux-2.5-edd/arch/i386/kernel/Makefile
--- linux-2.5/arch/i386/kernel/Makefile Fri Sep 20 13:11:58 2002
+++ linux-2.5-edd/arch/i386/kernel/Makefile Wed Sep 25 11:15:18 2002
@@ -26,6 +26,7 @@
obj-$(CONFIG_X86_IO_APIC) += io_apic.o
obj-$(CONFIG_SOFTWARE_SUSPEND) += suspend.o
obj-$(CONFIG_X86_NUMAQ) += numaq.o
+obj-$(CONFIG_EDD) += edd.o

EXTRA_AFLAGS := -traditional

diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/arch/i386/kernel/edd.c linux-2.5-edd/arch/i386/kernel/edd.c
--- linux-2.5/arch/i386/kernel/edd.c Wed Dec 31 18:00:00 1969
+++ linux-2.5-edd/arch/i386/kernel/edd.c Fri Sep 27 15:53:06 2002
@@ -0,0 +1,522 @@
+/*
+ * BIOS Enhanced Disk Device Services
+ * conformant to T13 Committee, Project D1572 http://www.t13.org
+ *
+ * Copyright (C) 2002 Dell Computer Corporation <[email protected]>
+ *
+ * This code takes information provided by BIOS EDD calls
+ * made in setup.S, copied to safe structures in setup.c,
+ * and presents it in driverfs.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2.0 as published by
+ * the Free Software Foundation
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/stat.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/limits.h>
+#include <linux/driverfs_fs.h>
+#include <linux/device.h>
+#include <asm/edd.h>
+
+MODULE_AUTHOR("Matt Domsch <[email protected]>");
+MODULE_DESCRIPTION("driver model interface to BIOS EDD information");
+MODULE_LICENSE("GPL");
+
+#define EDD_VERSION "0.04 2002-Sep-27"
+
+static struct device *edd_devices[EDDMAXNR];
+static struct device bios_device = {
+ .name = "BIOS devices",
+ .bus_id = "bios",
+ .dir = {
+ .mode = (S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO),
+ },
+};
+
+/*
+ * FIXME - this uses system_bus_type because
+ * platform_bus_type isn't exported (yet) and
+ * it'll likely wind up in named bus type yet
+*/
+
+static struct device_driver edd_driver = {
+ .name = "edd",
+ .bus = &system_bus_type,
+ .dir = {
+ .mode = (S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO),
+ }
+};
+
+/*
+ * EDD devices are exactly struct device.
+ * EDD device attributes are exactly struct device_attribute
+ */
+
+#define EDD_DEVICE_ATTR(_name,_mode,_show) \
+struct device_attribute edd_attr_##_name = { \
+ .attr = {.name = __stringify(_name), .mode = _mode }, \
+ .show = _show, \
+};
+
+#define to_edd_attr(_attr) container_of(_attr,struct device_attribute,attr)
+#define to_edd_device(_dir) container_of(_dir,struct device,dir)
+
+static ssize_t
+edd_attr_show(struct driver_dir_entry * dir, struct attribute * attr,
+ char * buf, size_t count, loff_t off)
+{
+ struct device * dev = to_edd_device(dir);
+ struct device_attribute * edd_attr = to_edd_attr(attr);
+ ssize_t ret = 0;
+
+ if (edd_attr->show)
+ ret = edd_attr->show(dev,buf,count,off);
+ return ret;
+}
+
+static struct driverfs_ops edd_attr_ops = {
+ .show = edd_attr_show,
+};
+
+static int
+edd_dump_raw_data(char *b, void *data, int length)
+{
+ char *orig_b = b;
+ char buffer1[80], buffer2[80], *b1, *b2, c;
+ unsigned char *p = data;
+ unsigned long column=0;
+ int length_printed = 0;
+ const char maxcolumn = 16;
+ while (length_printed < length) {
+ b1 = buffer1;
+ b2 = buffer2;
+ for (column = 0;
+ column < maxcolumn && length_printed < length;
+ column ++) {
+ b1 += sprintf(b1, "%02x ",(unsigned char) *p);
+ if (*p < 32 || *p > 126) c = '.';
+ else c = *p;
+ b2 += sprintf(b2, "%c", c);
+ p++;
+ length_printed++;
+ }
+ /* pad out the line */
+ for (; column < maxcolumn; column++)
+ {
+ b1 += sprintf(b1, " ");
+ b2 += sprintf(b2, " ");
+ }
+
+ b += sprintf(b, "%s\t%s\n", buffer1, buffer2);
+ }
+ return (b - orig_b);
+}
+
+/**
+ * __edd_unparse_interface()
+ *
+ * Returns: number of bytes written, or 0 on failure
+ */
+static ssize_t
+__edd_unparse_host_bus(struct device *dev, char *buf, size_t count, loff_t off)
+{
+ struct edd_info *edd=dev_get_drvdata(dev);
+ char *p = buf;
+ int i;
+ for (i=0; i<4; i++) {
+ if (isprint(edd->params.host_bus_type[i])) {
+ p += sprintf(p, "%c", edd->params.host_bus_type[i]);
+ } else {
+ p += sprintf(p, " ");
+ }
+ }
+
+ if (!strncmp(edd->params.host_bus_type, "ISA", 3)) {
+ p += sprintf(p, "\tbase_address: %x\n",
+ edd->params.interface_path.isa.base_address);
+ } else if (!strncmp(edd->params.host_bus_type, "PCIX", 4) ||
+ !strncmp(edd->params.host_bus_type, "PCI", 3)) {
+ p += sprintf(p,
+ "\t%02x:%02x.%01x channel: %x\n",
+ edd->params.interface_path.pci.bus,
+ edd->params.interface_path.pci.slot,
+ edd->params.interface_path.pci.function,
+ edd->params.interface_path.pci.channel);
+ } else if (!strncmp(edd->params.host_bus_type, "IBND", 4) ||
+ !strncmp(edd->params.host_bus_type, "XPRS", 4) ||
+ !strncmp(edd->params.host_bus_type, "HTPT", 4)) {
+ p += sprintf(p,
+ "\tTBD: %llx\n",
+ edd->params.interface_path.ibnd.reserved);
+
+ }
+ else {
+ p += sprintf(p, "\tunknown: %llx\n",
+ edd->params.interface_path.unknown.reserved);
+ }
+ return (p - buf);
+}
+
+/**
+ * edd_show_host_bus() - returns interface path to user space
+ *
+ * Returns: number of bytes written, or 0 on failure
+ */
+static ssize_t
+edd_show_host_bus(struct device *dev, char *buf, size_t count, loff_t off)
+{
+ struct edd_info *edd=dev_get_drvdata(dev);
+ uint8_t c=0;
+ int i, nonzero_path=0;
+ if (!dev || !edd || !buf || off) {
+ return 0;
+ }
+
+ if (! (edd->params.key == 0xBEDD || edd->params.key == 0xDDBE)) {
+ return 0;
+ }
+
+ for (i=30; i<=73; i++) {
+ c = *(((uint8_t *)edd)+i+4);
+ if (c) {
+ nonzero_path++;
+ break;
+ }
+ }
+ if (!nonzero_path) {
+ return 0;
+ }
+ return __edd_unparse_host_bus(dev, buf, count, off);
+}
+
+/**
+ * __edd_unparse_interface()
+ *
+ * Returns: number of bytes written, or 0 on failure
+ */
+static ssize_t
+__edd_unparse_interface(struct device *dev, char *buf, size_t count, loff_t off)
+{
+ struct edd_info *edd=dev_get_drvdata(dev);
+ char *p = buf;
+ int i;
+
+ for (i=0; i<8; i++) {
+ if (isprint(edd->params.interface_type[i])) {
+ p += sprintf(p, "%c", edd->params.interface_type[i]);
+ } else {
+ p += sprintf(p, " ");
+ }
+ }
+ if (!strncmp(edd->params.interface_type, "ATAPI", 5)) {
+ p += sprintf(p, "\tdevice: %x lun: %x\n",
+ edd->params.device_path.atapi.device,
+ edd->params.device_path.atapi.lun);
+ } else if (!strncmp(edd->params.interface_type, "ATA", 3)) {
+ p += sprintf(p, "\tdevice: %x\n",
+ edd->params.device_path.ata.device);
+ } else if (!strncmp(edd->params.interface_type, "SCSI", 4)) {
+ p += sprintf(p, "\tid: %x lun: %llx\n",
+ edd->params.device_path.scsi.id,
+ edd->params.device_path.scsi.lun);
+ } else if (!strncmp(edd->params.interface_type, "USB", 3)) {
+ p += sprintf(p, "\tserial_number: %llx\n",
+ edd->params.device_path.usb.serial_number);
+ } else if (!strncmp(edd->params.interface_type, "1394", 4)) {
+ p += sprintf(p, "\teui: %llx\n",
+ edd->params.device_path.i1394.eui);
+ } else if (!strncmp(edd->params.interface_type, "FIBRE", 5)) {
+ p += sprintf(p, "\twwid: %llx lun: %llx\n",
+ edd->params.device_path.fibre.wwid,
+ edd->params.device_path.fibre.lun);
+ } else if (!strncmp(edd->params.interface_type, "I2O", 3)) {
+ p += sprintf(p, "\tidentity_tag: %llx\n",
+ edd->params.device_path.i2o.identity_tag);
+ } else if (!strncmp(edd->params.interface_type, "RAID", 4)) {
+ p += sprintf(p, "\tidentity_tag: %x\n",
+ edd->params.device_path.raid.array_number);
+ } else if (!strncmp(edd->params.interface_type, "SATA", 4)) {
+ p += sprintf(p, "\tdevice: %x\n",
+ edd->params.device_path.sata.device);
+ } else {
+ p += sprintf(p, "\tunknown: %llx %llx\n",
+ edd->params.device_path.unknown.reserved1,
+ edd->params.device_path.unknown.reserved2);
+ }
+
+ return (p - buf);
+}
+
+/**
+ * edd_show_interface()
+ *
+ * Returns: number of bytes written, or 0 on failure
+ */
+static ssize_t
+edd_show_interface(struct device *dev, char *buf, size_t count, loff_t off)
+{
+ struct edd_info *edd=dev_get_drvdata(dev);
+ uint8_t c=0;
+ int i, nonzero_path=0;
+ if (!dev || !edd || !buf || off) {
+ return 0;
+ }
+
+ if (! (edd->params.key == 0xBEDD || edd->params.key == 0xDDBE)) {
+ return 0;
+ }
+
+ for (i=30; i<=73; i++) {
+ c = *(((uint8_t *)edd)+i+4);
+ if (c) {
+ nonzero_path++;
+ break;
+ }
+ }
+ if (!nonzero_path) {
+ return 0;
+ }
+ return __edd_unparse_interface(dev, buf, count, off);
+}
+
+/**
+ * edd_info_show() - unparses EDD information, returned to user-space
+ *
+ * Rather verbose compared to show_host_bus or show_interface
+ * Returns: number of bytes written, or 0 on failure
+ */
+static ssize_t
+edd_info_show(struct device *dev, char *buf, size_t count, loff_t off)
+{
+ struct edd_info *edd=dev_get_drvdata(dev);
+ int i, warn_padding=0, nonzero_path=0, warn_key=0, warn_checksum=0;
+ uint8_t checksum=0, c=0;
+ char *p = buf;
+ if (!dev || !edd || !buf || off) {
+ return 0;
+ }
+
+ p += edd_dump_raw_data(p, edd, 4);
+ p += edd_dump_raw_data(p, ((char *)edd)+4, sizeof(*edd)-4);
+
+ p += sprintf(p, "version: ");
+ switch (edd->version) {
+ case 0x0:
+ p += sprintf(p, "unsupported\n");
+ case 0x21:
+ p += sprintf(p, "1.1\n");
+ break;
+ case 0x30:
+ p += sprintf(p, "3.0\n");
+ break;
+ default:
+ p += sprintf(p, "(unknown version %xh)\n",
+ edd->version);
+ break;
+ }
+
+ p += sprintf(p, "Extensions:\n");
+ if (edd->interface_support & EDD_EXT_FIXED_DISK_ACCESS) {
+ p += sprintf(p, "\tFixed disk access\n");
+ }
+ if (edd->interface_support & EDD_EXT_DEVICE_LOCKING_AND_EJECTING) {
+ p += sprintf(p, "\tDevice locking and ejecting\n");
+ }
+ if (edd->interface_support & EDD_EXT_ENHANCED_DISK_DRIVE_SUPPORT) {
+ p += sprintf(p, "\tEnhanced Disk Drive support\n");
+ }
+ if (edd->interface_support & EDD_EXT_64BIT_EXTENSIONS) {
+ p += sprintf(p, "\t64-bit extensions\n");
+ }
+
+ p += sprintf(p, "Info Flags:\n");
+ if (edd->params.info_flags & EDD_INFO_DMA_BOUNDRY_ERROR_TRANSPARENT)
+ p += sprintf(p, "\tdma_boundry_error_transparent\n");
+ if (edd->params.info_flags & EDD_INFO_GEOMETRY_VALID)
+ p += sprintf(p, "\tgeometry_valid\n");
+ if (edd->params.info_flags & EDD_INFO_REMOVABLE)
+ p += sprintf(p, "\tremovable\n");
+ if (edd->params.info_flags & EDD_INFO_WRITE_VERIFY)
+ p += sprintf(p, "\twrite_verify\n");
+ if (edd->params.info_flags & EDD_INFO_MEDIA_CHANGE_NOTIFICATION)
+ p += sprintf(p, "\tmedia_change_notification\n");
+ if (edd->params.info_flags & EDD_INFO_LOCKABLE)
+ p += sprintf(p, "\tlockable\n");
+ if (edd->params.info_flags & EDD_INFO_NO_MEDIA_PRESENT)
+ p += sprintf(p, "\tno_media_present\n");
+ if (edd->params.info_flags & EDD_INFO_USE_INT13_FN50)
+ p += sprintf(p, "\tuse_int13_fn50\n");
+
+ p += sprintf(p, "num_default_cylinders: %x\n",
+ edd->params.num_default_cylinders);
+ p += sprintf(p, "num_default_heads: %x\n", edd->params.num_default_heads);
+ p += sprintf(p, "sectors_per_track: %x\n", edd->params.sectors_per_track);
+ p += sprintf(p, "number_of_sectors: %llx\n",
+ edd->params.number_of_sectors);
+
+ /* Spec violation here. Adaptec AIC7899 returns 0xDDBE
+ here, when it should be (per spec) 0xBEDD.
+ */
+ if (edd->params.key == 0xDDBE) {
+ warn_key=1;
+ }
+
+ if (! (edd->params.key == 0xBEDD || edd->params.key == 0xDDBE)) {
+ return (p - buf);
+ }
+
+ for (i=30; i<=73; i++) {
+ c = *(((uint8_t *)edd)+i+4);
+ if (c) nonzero_path++;
+ checksum += c;
+ }
+ if (checksum) {
+ warn_checksum=1;
+ if (!nonzero_path) {
+ p += sprintf(p, "Warning: Spec violation. Device Path checksum invalid (0x%02x should be 0x00).\n", checksum);
+
+ return (p - buf);
+ }
+ }
+
+ p += __edd_unparse_host_bus (dev, p, count - (p - buf), off);
+ p += __edd_unparse_interface(dev, p, count - (p - buf), off);
+
+ p += sprintf(p, "\n");
+ if (warn_key) {
+ p += sprintf(p, "Warning: Spec violation. Key should be 0xBEDD, is 0xDDBE\n");
+ }
+ if (warn_padding) {
+ p += sprintf(p, "Warning: Spec violation. Padding should be 0x20, is 0x00\n");
+ }
+ if (warn_checksum) {
+ p += sprintf(p, "Warning: Spec violation. Device Path checksum invalid (0x%02x should be 0x00).\n", checksum);
+ }
+
+ return (p - buf);
+}
+
+static EDD_DEVICE_ATTR(info,0444,edd_info_show);
+static EDD_DEVICE_ATTR(interface,0444,edd_show_interface);
+static EDD_DEVICE_ATTR(host_bus,0444,edd_show_host_bus);
+
+static struct device_attribute * def_attrs[] = {
+ &edd_attr_info,
+ &edd_attr_interface,
+ &edd_attr_host_bus,
+ NULL,
+};
+
+static int
+edd_create_file(struct device *dev, struct device_attribute * attr)
+{
+ return device_create_file(dev, attr);
+}
+
+static int edd_populate_dir(struct device * dev)
+{
+ struct device_attribute * attr;
+ int i;
+ int error = 0;
+
+ for (i = 0; (attr = def_attrs[i]); i++) {
+ if ((error = edd_create_file(dev,attr))) {
+ break;
+ }
+ }
+ return error;
+}
+
+static int edd_device_register(struct device *dev, int i)
+{
+ int error;
+
+ if (!dev) return 1;
+ memset(dev, 0, sizeof(*dev));
+ dev_set_drvdata(dev, &edd[i]);
+ dev->driver = &edd_driver;
+ dev->bus = dev->driver->bus;
+ dev->parent = &bios_device;
+ dev->dir.ops = &edd_attr_ops;
+ snprintf(dev->name, DEVICE_NAME_SIZE, "BIOS int 13h device %02xh", edd[i].device);
+ snprintf(dev->bus_id, BUS_ID_SIZE, "int13_dev%02x", edd[i].device);
+ dev->dir.name = dev->name;
+
+ error = device_register(dev);
+ if (error) return error;
+
+ error = edd_populate_dir(dev);
+ return error;
+}
+
+/**
+ * edd_init() - creates driverfs edd/{device num}/ tree
+ *
+ * This assumes that eddnr and edd were
+ * assigned in setup.c already.
+ */
+static int __init
+edd_init(void)
+{
+ unsigned int i;
+ int rc;
+
+ printk(KERN_INFO "BIOS EDD facility v%s, %d devices found\n",
+ EDD_VERSION, eddnr);
+
+ if (!eddnr) {
+ printk(KERN_INFO "EDD information not available.\n");
+ return 1;
+ }
+
+ rc = device_register(&bios_device);
+ if (rc) return rc;
+
+ rc = driver_register(&edd_driver);
+ if (rc) {
+ put_device(&bios_device);
+ return rc;
+ }
+
+ for (i=0; i<eddnr && i<EDDMAXNR; i++) {
+ edd_devices[i] = kmalloc(sizeof(*edd_devices[i]), GFP_KERNEL);
+ if (edd_devices[i]) {
+ edd_device_register(edd_devices[i], i);
+ }
+ }
+
+ return 0;
+}
+
+
+static void __exit
+edd_exit(void)
+{
+ int i;
+
+ for (i=0; i<eddnr && i<EDDMAXNR; i++) {
+ if (edd_devices[i]) {
+ put_device(edd_devices[i]);
+ kfree(edd_devices[i]);
+ }
+ }
+ put_driver(&edd_driver);
+ put_device(&bios_device);
+}
+
+late_initcall(edd_init);
+module_exit(edd_exit);
diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/arch/i386/kernel/i386_ksyms.c linux-2.5-edd/arch/i386/kernel/i386_ksyms.c
--- linux-2.5/arch/i386/kernel/i386_ksyms.c Thu Sep 26 21:44:44 2002
+++ linux-2.5-edd/arch/i386/kernel/i386_ksyms.c Fri Sep 27 15:53:06 2002
@@ -29,6 +29,7 @@
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
+#include <asm/edd.h>

extern void dump_thread(struct pt_regs *, struct user *);
extern spinlock_t rtc_lock;
@@ -177,3 +178,8 @@
EXPORT_SYMBOL(is_sony_vaio_laptop);

EXPORT_SYMBOL(__PAGE_KERNEL);
+
+#ifdef CONFIG_EDD_MODULE
+EXPORT_SYMBOL(edd);
+EXPORT_SYMBOL(eddnr);
+#endif
diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/arch/i386/kernel/setup.c linux-2.5-edd/arch/i386/kernel/setup.c
--- linux-2.5/arch/i386/kernel/setup.c Fri Sep 20 13:11:58 2002
+++ linux-2.5-edd/arch/i386/kernel/setup.c Fri Sep 27 15:53:06 2002
@@ -36,6 +36,7 @@
#include <linux/highmem.h>
#include <asm/e820.h>
#include <asm/mpspec.h>
+#include <asm/edd.h>
#include <asm/setup.h>
#include <asm/arch_hooks.h>
#include "setup_arch_pre.h"
@@ -466,6 +467,24 @@
return 0;
}

+#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
+unsigned char eddnr;
+struct edd_info edd[EDDNR];
+/**
+ * copy_edd() - Copy the BIOS EDD information into a safe place.
+ *
+ */
+static inline void copy_edd(void)
+{
+ eddnr = EDD_NR;
+ memcpy(edd, EDD_BUF, sizeof(edd));
+}
+#else
+static inline void copy_edd(void)
+{
+}
+#endif
+
/*
* Do NOT EVER look at the BIOS memory size location.
* It does not work on many machines.
@@ -843,6 +862,7 @@
#endif
ARCH_SETUP
setup_memory_region();
+ copy_edd();

if (!MOUNT_ROOT_RDONLY)
root_mountflags &= ~MS_RDONLY;
diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/include/asm-i386/edd.h linux-2.5-edd/include/asm-i386/edd.h
--- linux-2.5/include/asm-i386/edd.h Wed Dec 31 18:00:00 1969
+++ linux-2.5-edd/include/asm-i386/edd.h Fri Sep 27 15:53:27 2002
@@ -0,0 +1,162 @@
+/*
+ * linux/include/asm-i386/edd.h
+ * by Matt Domsch <[email protected]>
+ * Copyright 2002 Dell Computer Corporation
+ *
+ * structures and definitions for the int 13, ax={41,48}h
+ * BIOS Enhanced Disk Device Services
+ * This is based on the T13 group document D1572 Revision 0 (August 14 2002)
+ * available at http://www.t13.org/docs2002/d1572r0.pdf. It is
+ * very similar to D1484 Revision 3 http://www.t13.org/docs2002/d1484r3.pdf
+ *
+ * In a nutshell, arch/i386/boot/setup.S populates a scratch table
+ * in the empty_zero_block that contains a list of BIOS-enumerated
+ * boot devices.
+ * In arch/i386/kernel/setup.c, this information is
+ * transferred into the edd structure, and in arch/i386/kernel/edd.c, that
+ * information is used to identify BIOS boot disk. The code in setup.S
+ * is very sensitive to the size of these structures.
+ *
+ */
+#ifndef _ASM_I386_EDD_H
+#define _ASM_I386_EDD_H
+
+#define EDDNR 0x1e9 /* addr of number of edd_info structs at EDDBUF
+ in empty_zero_block - treat this as 1 byte */
+#define EDDBUF 0x600 /* addr of edd_info structs in empty_zero_block */
+#define EDDMAXNR 6 /* number of edd_info structs starting at EDDBUF */
+#define EDDEXTSIZE 4 /* change these if you muck with the structures */
+#define EDDPARMSIZE 74
+
+#define EDD_EXT_FIXED_DISK_ACCESS (1 << 0)
+#define EDD_EXT_DEVICE_LOCKING_AND_EJECTING (1 << 1)
+#define EDD_EXT_ENHANCED_DISK_DRIVE_SUPPORT (1 << 2)
+#define EDD_EXT_64BIT_EXTENSIONS (1 << 3)
+
+#define EDD_INFO_DMA_BOUNDRY_ERROR_TRANSPARENT (1 << 0)
+#define EDD_INFO_GEOMETRY_VALID (1 << 1)
+#define EDD_INFO_REMOVABLE (1 << 2)
+#define EDD_INFO_WRITE_VERIFY (1 << 3)
+#define EDD_INFO_MEDIA_CHANGE_NOTIFICATION (1 << 4)
+#define EDD_INFO_LOCKABLE (1 << 5)
+#define EDD_INFO_NO_MEDIA_PRESENT (1 << 6)
+#define EDD_INFO_USE_INT13_FN50 (1 << 7)
+
+
+
+#ifndef __ASSEMBLY__
+
+struct edd_device_params {
+ u16 length;
+ u16 info_flags;
+ u32 num_default_cylinders;
+ u32 num_default_heads;
+ u32 sectors_per_track;
+ u64 number_of_sectors;
+ u16 bytes_per_sector;
+ u32 dpte_ptr; /* 0xFFFFFFFF for our purposes */
+ u16 key; /* = 0xBEDD */
+ u8 device_path_info_length; /* = 44 */
+ u8 reserved2;
+ u16 reserved3;
+ u8 host_bus_type[4];
+ u8 interface_type[8];
+ union {
+ struct {
+ u16 base_address;
+ u16 reserved1;
+ u32 reserved2;
+ } __attribute__((packed)) isa;
+ struct {
+ u8 bus;
+ u8 slot;
+ u8 function;
+ u8 channel;
+ u32 reserved;
+ } __attribute__((packed)) pci;
+ /* pcix is same as pci */
+ struct {
+ u64 reserved;
+ } __attribute__((packed)) ibnd;
+ struct {
+ u64 reserved;
+ } __attribute__((packed)) xprs;
+ struct {
+ u64 reserved;
+ } __attribute__((packed)) htpt;
+ struct {
+ u64 reserved;
+ } __attribute__((packed)) unknown;
+ } interface_path;
+ union {
+ struct {
+ u8 device;
+ u8 reserved1;
+ u16 reserved2;
+ u32 reserved3;
+ u64 reserved4;
+ } __attribute__((packed)) ata;
+ struct {
+ u8 device;
+ u8 lun;
+ u8 reserved1;
+ u8 reserved2;
+ u32 reserved3;
+ u64 reserved4;
+ } __attribute__((packed)) atapi;
+ struct {
+ u16 id;
+ u64 lun;
+ u16 reserved1;
+ u32 reserved2;
+ } __attribute__((packed)) scsi;
+ struct {
+ u64 serial_number;
+ u64 reserved;
+ } __attribute__((packed)) usb;
+ struct {
+ u64 eui;
+ u64 reserved;
+ } __attribute__((packed)) i1394;
+ struct {
+ u64 wwid;
+ u64 lun;
+ } __attribute__((packed)) fibre;
+ struct {
+ u64 identity_tag;
+ u64 reserved;
+ } __attribute__((packed)) i2o;
+ struct {
+ u32 array_number;
+ u32 reserved1;
+ u64 reserved2;
+ } __attribute((packed)) raid;
+ struct {
+ u8 device;
+ u8 reserved1;
+ u16 reserved2;
+ u32 reserved3;
+ u64 reserved4;
+ } __attribute__((packed)) sata;
+ struct {
+ u64 reserved1;
+ u64 reserved2;
+ } __attribute__((packed)) unknown;
+ } device_path;
+ u8 reserved4;
+ u8 checksum;
+} __attribute__((packed));
+
+struct edd_info {
+ u8 device;
+ u8 version;
+ u16 interface_support;
+ struct edd_device_params params;
+} __attribute__((packed));
+
+extern struct edd_info edd[EDDNR];
+extern unsigned char eddnr;
+#endif/*!__ASSEMBLY__*/
+
+#endif /* _ASM_I386_EDD_H */
+
diff -Nur --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet linux-2.5/include/asm-i386/setup.h linux-2.5-edd/include/asm-i386/setup.h
--- linux-2.5/include/asm-i386/setup.h Tue Sep 10 11:42:10 2002
+++ linux-2.5-edd/include/asm-i386/setup.h Fri Sep 27 15:53:27 2002
@@ -37,6 +37,8 @@
#define KERNEL_START (*(unsigned long *) (PARAM+0x214))
#define INITRD_START (*(unsigned long *) (PARAM+0x218))
#define INITRD_SIZE (*(unsigned long *) (PARAM+0x21c))
+#define EDD_NR (*(unsigned char *) (PARAM+EDDNR))
+#define EDD_BUF ((struct edd_info *) (PARAM+EDDBUF))
#define COMMAND_LINE ((char *) (PARAM+2048))
#define COMMAND_LINE_SIZE 256



2002-09-27 22:30:04

by Greg KH

[permalink] [raw]
Subject: Re: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

Looks nice, just a few minor comments:

> $ cat int13_dev80/host_bus
> PCI 02:01.0 channel: 0
> $ cat int13_dev80/interface
> SCSI id: 0 lun: 0
> $ cat int13_dev80/info
> 80 30 01 00 .0..
> 1e 00 09 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 3a b9 8b 08 00 00 00 00 00 02 ff ff ff ff be dd :...............
> 2c 00 00 00 50 43 49 00 53 43 53 49 00 00 00 00 ,...PCI.SCSI....
> 02 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 00 00 00 00 00 00 00 00 00 28 .........(
> version: 3.0
> Extensions:
> Fixed disk access
> Info Flags:
> dma_boundry_error_transparent
> write_verify
> num_default_cylinders: 0
> num_default_heads: 0
> sectors_per_track: 0
> number_of_sectors: 88bb93a
> PCI 02:01.0 channel: 0
> SCSI id: 0 lun: 0
>
> Warning: Spec violation. Key should be 0xBEDD, is 0xDDBE
>

Don't you already get the PCI and SCSI lines in the info file, from the
host_bus and interface files?

And that's a nice way to export binary data through a text file :)

Any way to split out the fields as individual files (version,
extensions, info_flags, num_default_cylinders, and so on)?

> @@ -981,3 +981,13 @@
> absence of features.
>
> For more information take a look at Documentation/swsusp.txt.
> +
> +CONFIG_EDD
> + Say Y or M here if you want to enable BIOS Enhanced Disk Device
> + Services real mode BIOS calls to determine which disk
> + BIOS tries boot from. This feature creates a /proc/edd directory
> + and files for each BIOS device detected.

You should fix up this wording as you aren't doing anything in the /proc
fs anymore :)

thanks,

greg k-h

2002-09-29 16:03:58

by Dave Jones

[permalink] [raw]
Subject: Re: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

On Fri, Sep 27, 2002 at 04:30:29PM -0500, Matt Domsch wrote:
> arch/i386/kernel/edd.c | 522 +++++++++++++++++++++++++++++++++++++++
> arch/i386/kernel/i386_ksyms.c | 6
> arch/i386/kernel/setup.c | 20 +

Something that's been bothering me for a while, has been the
proliferation of 'driver' type things appearing in arch/i386/kernel/
My initial thought was to move the various CPU related 'drivers'
(msr,cpuid,bluesmoke,microcode) to arch/i386/cpu/ [1]
but I'm now wondering if an arch/i386/driver/ would be a better alternative.

Opinions?

Dave

[1] also a more natural home for things like cpufreq if/when it gets integrated.
--
| Dave Jones. http://www.codemonkey.org.uk
| SuSE Labs

2002-09-29 16:14:43

by Zwane Mwaikambo

[permalink] [raw]
Subject: Re: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

On Sun, 29 Sep 2002, Dave Jones wrote:

> On Fri, Sep 27, 2002 at 04:30:29PM -0500, Matt Domsch wrote:
> > arch/i386/kernel/edd.c | 522 +++++++++++++++++++++++++++++++++++++++
> > arch/i386/kernel/i386_ksyms.c | 6
> > arch/i386/kernel/setup.c | 20 +
>
> Something that's been bothering me for a while, has been the
> proliferation of 'driver' type things appearing in arch/i386/kernel/
> My initial thought was to move the various CPU related 'drivers'
> (msr,cpuid,bluesmoke,microcode) to arch/i386/cpu/ [1]
> but I'm now wondering if an arch/i386/driver/ would be a better alternative.
>
> Opinions?

Then again, drivers/char has some x86 specific drivers too (e.g. RNGs),
perhaps it really should get dumped in drivers/

Zwane
--
function.linuxpower.ca

2002-09-29 16:34:22

by Alan Cox

[permalink] [raw]
Subject: Re: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

On Sun, 2002-09-29 at 17:11, Dave Jones wrote:
> On Fri, Sep 27, 2002 at 04:30:29PM -0500, Matt Domsch wrote:
> > arch/i386/kernel/edd.c | 522 +++++++++++++++++++++++++++++++++++++++
> > arch/i386/kernel/i386_ksyms.c | 6
> > arch/i386/kernel/setup.c | 20 +
>
> Something that's been bothering me for a while, has been the
> proliferation of 'driver' type things appearing in arch/i386/kernel/
> My initial thought was to move the various CPU related 'drivers'
> (msr,cpuid,bluesmoke,microcode) to arch/i386/cpu/ [1]
> but I'm now wondering if an arch/i386/driver/ would be a better alternative.
>
> Opinions?

Thats even more prevalent in things like the unmerged bits of the mips
tree. A lot of embedded processors have on chip everything - eg look at
the cirrus logic ARM chips or the Etrax.

The extra people use arch/foo/drivers



2002-09-29 18:15:25

by Kai Germaschewski

[permalink] [raw]
Subject: Re: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

On Sun, 29 Sep 2002, Dave Jones wrote:

> On Fri, Sep 27, 2002 at 04:30:29PM -0500, Matt Domsch wrote:
> > arch/i386/kernel/edd.c | 522 +++++++++++++++++++++++++++++++++++++++
> > arch/i386/kernel/i386_ksyms.c | 6
> > arch/i386/kernel/setup.c | 20 +
>
> Something that's been bothering me for a while, has been the
> proliferation of 'driver' type things appearing in arch/i386/kernel/
> My initial thought was to move the various CPU related 'drivers'
> (msr,cpuid,bluesmoke,microcode) to arch/i386/cpu/ [1]
> but I'm now wondering if an arch/i386/driver/ would be a better alternative.

Let me add that there are currently two places where arch specific drivers
appear, eg:

arch/{cris,um}/drivers/
and
drivers/{s390,macintosh,acorn}/

I think it'd be nice to decide on one way or the other. The first place
has the advantage of putting all arch-specific stuff into one place, the
second one makes it (IMO) cleaner to share drivers between e.g. s390 and
s390x, or possibly i386/x86_64 in the future.

--Kai


2002-09-29 18:22:42

by Russell King

[permalink] [raw]
Subject: Re: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

On Sun, Sep 29, 2002 at 01:20:44PM -0500, Kai Germaschewski wrote:
> Let me add that there are currently two places where arch specific drivers
> appear, eg:
>
> arch/{cris,um}/drivers/
> and
> drivers/{s390,macintosh,acorn}/
>
> I think it'd be nice to decide on one way or the other. The first place
> has the advantage of putting all arch-specific stuff into one place, the
> second one makes it (IMO) cleaner to share drivers between e.g. s390 and
> s390x, or possibly i386/x86_64 in the future.

The ARM port used to have arch/arm/drivers/{block,char,net,sound} but
this was decried by _other_ people in the ARM community to be too
painful, and I was literally hounded into moving them into drivers.

I don't want to go back to arch/arm/drivers now, thanks.

--
Russell King ([email protected]) The developer of ARM Linux
http://www.arm.linux.org.uk/personal/aboutme.html

2002-09-29 18:44:33

by Dave Jones

[permalink] [raw]
Subject: Re: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

On Sun, Sep 29, 2002 at 07:27:58PM +0100, Russell King wrote:

> The ARM port used to have arch/arm/drivers/{block,char,net,sound} but
> this was decried by _other_ people in the ARM community to be too
> painful, and I was literally hounded into moving them into drivers.
>
> I don't want to go back to arch/arm/drivers now, thanks.

Out of curiousity, why was this considered painful ?
Not that I change my original proposition of disinfecting
arch/i386/kernel/ Rather than proposing to set a standard
for all arch's to conform to, I had the sole intention of
trying to cut down some of the growth in that dir by factoring
out the more common things (which were CPU drivers)

Dave

--
| Dave Jones. http://www.codemonkey.org.uk
| SuSE Labs

2002-09-30 04:27:04

by Matt Domsch

[permalink] [raw]
Subject: RE: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

> drivers/{s390,macintosh,acorn}/
> makes it (IMO) cleaner to share drivers between
> e.g. s390 and s390x, or possibly i386/x86_64 in the future.

The i386 EDD "driver" could probably be shared with x86-64, I hadn't thought
about it before. Likewise the IA64 efivars driver *may* eventually be
shared with x86 or others if Intel's plans come to fruition. So I'd vote
for something in drivers/ rather than arch/ for such shareable modules. I'm
open to moving each of these if told where the "right" place should be.
Neither are char or block drivers, so those don't make sense - purely
driverfs/proc interfaces. Nor are they "bus" drivers ala ide or scsi.
drivers/misc is empty and I think people want to keep it that way...

Some ideas for these:
drivers/i386
drivers/efi

Thoughts?

Thanks,
Matt

--
Matt Domsch
Sr. Software Engineer, Lead Engineer, Architect
Dell Linux Solutions http://www.dell.com/linux
Linux on Dell mailing lists @ http://lists.us.dell.com

2002-10-01 01:48:29

by Patrick Mochel

[permalink] [raw]
Subject: Re: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling


> |-- bus
> | `-- system
> | |-- devices
> | | |-- int13_dev80 -> ../../../root/bios/int13_dev80
> | | |-- int13_dev81 -> ../../../root/bios/int13_dev81
> | `-- drivers
> | |-- edd
> `-- root
> |-- bios
> | |-- int13_dev80
> | | |-- host_bus
> | | |-- info
> | | |-- interface
> | | |-- name
> | | `-- power
> | |-- int13_dev81
> | | |-- host_bus
> | | |-- info
> | | |-- interface
> | | |-- name
> | | `-- power
> | |-- name
> | `-- power
>
>
> (Yes, the system bus isn't the right place for them to go, but it must
> go on some bus, and eventually it will get moved to a better place.)

[ Sorry, I didn't get this out earlier, but you're just too damn fast with
your resubmissions.. ;)]

Don't use struct device for the firmware objects. They're not really
devices; they're another type of entity that has some sort of magic
ia32 voodoo relationship with real devices.

I recently converted ACPI to abandon the notion that the namespace objects
were real devices. In doing so, I gave them their own top-level directory
in driverfs. Don't do this. That's only a temporary solution until I
create a 'firmware' or 'platform' directory for all of you people to live.

> The 'info' file contains the full set of information returned by BIOS
> with extra error reporting. This exists for vendor BIOS debugging purposes.
>
> The 'host-bus' file contains the PCI (or ISA, HyperTransport, ...)
> identifying information, as BIOS knows it.
>
> The 'interface' file contains the SCSI (or IDE, USB, ...) identifying
> information, as BIOS knows it.
>
>
> $ cat int13_dev80/host_bus
> PCI 02:01.0 channel: 0

How about a symlink to the bus's directory? Or the PCI device that is the
controller?

> $ cat int13_dev80/interface
> SCSI id: 0 lun: 0

And, a symlink to the device itself? I liked it better the way you had it
before :)

> $ cat int13_dev80/info
> 80 30 01 00 .0..
> 1e 00 09 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 3a b9 8b 08 00 00 00 00 00 02 ff ff ff ff be dd :...............
> 2c 00 00 00 50 43 49 00 53 43 53 49 00 00 00 00 ,...PCI.SCSI....
> 02 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 00 00 00 00 00 00 00 00 00 28 .........(
> version: 3.0
> Extensions:
> Fixed disk access
> Info Flags:
> dma_boundry_error_transparent
> write_verify
> num_default_cylinders: 0
> num_default_heads: 0
> sectors_per_track: 0
> number_of_sectors: 88bb93a
> PCI 02:01.0 channel: 0
> SCSI id: 0 lun: 0

Ugh. Drop the ascii-fying hexdump for one. I'd also strongly encourage you
to split the data in 'info' to separate files.

-pat

2002-10-01 03:32:18

by Matt Domsch

[permalink] [raw]
Subject: RE: [RFC][PATCH] x86 BIOS Enhanced Disk Device (EDD) polling

Pat, thanks for the feedback and changes, I appreciate it!

> Don't use struct device for the firmware objects. They're not really
> devices; they're another type of entity that has some sort of magic
> ia32 voodoo relationship with real devices.

Ahh, yes, it's not the right abstraction, just the easiest for this pass.
I'll look at how ACPI does it and make my own object type. I was wondering
how to get rid of the superfluous 'power' attribute I didn't need...

> > $ cat int13_dev80/host_bus
> > PCI 02:01.0 channel: 0
>
> How about a symlink to the bus's directory? Or the PCI device
> that is the controller?

Ok.

> > $ cat int13_dev80/interface
> > SCSI id: 0 lun: 0
>
> And, a symlink to the device itself? I liked it better the
> way you had it before :)

Can I have both? :-) (I hadn't implemented the symlink before, just faked
it, but I definitely want a symlink, needed the stuff exported to do it
right - thanks!}

> Ugh. Drop the ascii-fying hexdump for one.

I've been over this with Greg privately. I moved it to raw_data, separate,
but there. I know of only one BIOS that implements the spec right, and that
is pre-release, because I could say "see, here's what you're returning, it's
wrong these 4 ways..." in a language the BIOS guys understand - the raw
hexdump of the return struct. This will be critical to getting the changes
required to be useful ubiquitous.

> I'd also strongly encourage you to
> split the data in 'info' to separate files.

Yep, done, with tests such that if the attribute is invalid or for some
reason shouldn't exist, it doesn't get created. The default* files for
example - if the bios puts 0s there, they don't get made. Likewise if the
PCI / SCSI info isn't given by bios, those don't get made either.

Here's my tree now.
.
|-- bus
| `-- system
| |-- devices
| | |-- int13_dev80 -> ../../../root/bios/int13_dev80
| | |-- int13_dev81 -> ../../../root/bios/int13_dev81
| `-- drivers
| |-- edd
`-- root
|-- bios
| |-- int13_dev80
| | |-- default_cylinders
| | |-- default_heads
| | |-- default_sectors_per_track
| | |-- raw_data
| | |-- extensions
| | |-- host_bus
| | |-- info_flags
| | |-- interface
| | |-- name
| | |-- power
| | |-- sectors
| | `-- version
| |-- name
| `-- power

$ cat default_cylinders
0x0

$ cat default_heads
0x0

$ cat default_sectors_per_track
0x0

$ cat raw_data
int 13h fn 48h return struct:

1e 00 09 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
3a b9 8b 08 00 00 00 00 00 02 ff ff ff ff be dd :...............
2c 00 00 00 50 43 49 00 53 43 53 49 00 00 00 00 ,...PCI.SCSI....
02 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 28 .........(

Warning: Spec violation. Key should be 0xBEDD, is 0xDDBE
Warning: Spec violation. Padding should be 0x20, is 0x00.

$ cat extensions
Fixed disk access

$ cat host_bus
PCI 02:01.0 channel: 0

$ cat info_flags
DMA boundry error transparent
write verify

$ cat interface
SCSI id: 0 lun: 0

$ cat name
BIOS int 13h device 80h

$ cat power
0

$ cat sectors
0x88bb93a

$ cat version
0x30


I may try walking the disk class device list for matches rather than the
individual bus type lists - would be slightly faster and possibly less
intrusive. That's a helpful abstraction for me.

My current stuff is in BK at http://mdomsch.bkbits.net/linux-2.5-edd.

Thanks,
Matt

--
Matt Domsch
Sr. Software Engineer, Lead Engineer, Architect
Dell Linux Solutions http://www.dell.com/linux
Linux on Dell mailing lists @ http://lists.us.dell.com
#1 US Linux Server provider for 2001 and Q1/2002! (IDC May 2002)