lkml.org 
[lkml]   [2001]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] PCI bus speed cmdline
Martin (et al),

We spoke a while back about a 'pcispeed=' command line param to set the PCI
busspeed values (for later querying, if needed). Attached is my patch to
implement the feature we agreed upon. It is against linux-2.4.6.

Please let me know if there is any problem that would make this not
suitable for general inclusion in the kernel.

Tim

--
Tim Hockin
Systems Software Engineer
Sun Microsystems, Cobalt Server Appliances
thockin@sun.comdiff -ruN dist-2.4.6/drivers/pci/pci.c cobalt-2.4.6/drivers/pci/pci.c
--- dist-2.4.6/drivers/pci/pci.c Mon Jul 2 14:42:53 2001
+++ cobalt-2.4.6/drivers/pci/pci.c Mon Jul 9 11:04:01 2001
@@ -20,6 +20,7 @@
#include <linux/ioport.h>
#include <linux/spinlock.h>
#include <linux/pm.h>
+#include <linux/ctype.h>
#include <linux/kmod.h> /* for hotplug_path */
#include <linux/bitops.h>

@@ -37,6 +38,8 @@
LIST_HEAD(pci_root_buses);
LIST_HEAD(pci_devices);

+static int get_bus_speed(struct pci_bus *bus);
+
/**
* pci_find_slot - locate PCI device from a given PCI slot
* @bus: number of PCI bus on which desired PCI device resides
@@ -1047,6 +1050,7 @@
child->number = child->secondary = busnr;
child->primary = parent->secondary;
child->subordinate = 0xff;
+ child->bus_speed = get_bus_speed(child);

/* Set up default resource pointers.. */
for (i = 0; i < 4; i++)
@@ -1358,6 +1373,7 @@
list_add_tail(&b->node, &pci_root_buses);

b->number = b->secondary = bus;
+ b->bus_speed = get_bus_speed(b);
b->resource[0] = &ioport_resource;
b->resource[1] = &iomem_resource;
return b;
@@ -1910,7 +1926,67 @@
return 1;
}

+#define MAX_OVERRIDES 256
+static int pci_speed_overrides[MAX_OVERRIDES] __initdata;
+
+static int __init get_bus_speed(struct pci_bus *bus)
+{
+ if (!bus) {
+ return -1;
+ }
+
+ if (pci_speed_overrides[bus->number]) {
+ return pci_speed_overrides[bus->number];
+ } else {
+ /* printk("PCI: assuming 33 MHz for bus %d\n", bus->number); */
+ return 33;
+ }
+}
+
+/* handle pcispeed=0:33,1:66 parameter (speed=0 means unknown) */
+static int __init pci_speed_setup(char *str)
+{
+ while (str) {
+ char *k = strchr(str, ',');
+ if (k) {
+ *k++ = '\0';
+ }
+
+ if (*str) {
+ int bus;
+ int speed;
+ char *endp;
+
+ if (!isdigit(*str)) {
+ printk("PCI: bad bus number for "
+ "pcispeed parameter\n");
+ str = k;
+ continue;
+ }
+ bus = simple_strtoul(str, &endp, 0);
+
+ if (!*endp || !isdigit(*(++endp))) {
+ printk("PCI: bad speed for "
+ "pcispeed parameter\n");
+ str = k;
+ continue;
+ }
+ speed = simple_strtoul(endp, NULL, 0);
+ pci_speed_overrides[bus] = speed;
+ printk("PCI: setting bus %d speed to %d MHz\n",
+ bus, speed);
+
+ str = k;
+ } else {
+ break;
+ }
+ }
+ return 1;
+}
+
__setup("pci=", pci_setup);
+__setup("pcispeed=", pci_speed_setup);
+

EXPORT_SYMBOL(pci_read_config_byte);
EXPORT_SYMBOL(pci_read_config_word);
diff -ruN dist-2.4.6/include/linux/pci.h cobalt-2.4.6/include/linux/pci.h
--- dist-2.4.6/include/linux/pci.h Tue Jul 3 15:43:41 2001
+++ cobalt-2.4.6/include/linux/pci.h Mon Jul 9 15:55:48 2001
@@ -420,6 +420,7 @@
unsigned char primary; /* number of primary bridge */
unsigned char secondary; /* number of secondary bridge */
unsigned char subordinate; /* max number of subordinate buses */
+ int bus_speed; /* the speed of this PCI segment */

char name[48];
unsigned short vendor;
\
 
 \ /
  Last update: 2005-03-22 12:56    [W:0.026 / U:1.324 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site