Re: [PATCH] ACPI: Unneccessary to scan the PCI bus already scanned.

Yinghai Lu
2008-03-03T10:01:17Z

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On Mon, Mar 3, 2008 at 12:30 AM, Yinghai Lu <yhlu.kernel@gmail.com> wrote:
> that regression is caused by:
>
> commit 08f1c192c3c32797068bfe97738babb3295bbf42
> Author: Muli Ben-Yehuda <muli@il.ibm.com>
> Date: Sun Jul 22 00:23:39 2007 +0300
>
> x86-64: introduce struct pci_sysdata to facilitate sharing of ->sysdata
>
> This patch introduces struct pci_sysdata to x86 and x86-64, and
> converts the existing two users (NUMA, Calgary) to use it.
>
> This lays the groundwork for having other users of sysdata, such as
> the PCI domains work.
>
> The Calgary bits are tested, the NUMA bits just look ok.
>
> Signed-off-by: Jeff Garzik <jeff@garzik.org>
> Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
>
> that replace pcibios_scan_root by pci_scan_bus_parented...
> - bus = pcibios_scan_root(busnum);
> + sd->node = -1;
> +
> + pxm = acpi_get_pxm(device->handle);
> +#ifdef CONFIG_ACPI_NUMA
> + if (pxm >= 0)
>
> + sd->node = pxm_to_node(pxm);
> +#endif
> +
> + bus = pci_scan_bus_parented(NULL, busnum, &pci_root_ops, sd);
>
> and in pcibios_scan_root we have
>
> struct pci_bus *bus = NULL;
> struct pci_sysdata *sd;
>
> dmi_check_system(pciprobe_dmi_table);
>
> while ((bus = pci_find_next_bus(bus)) != NULL) {
> if (bus->number == busnum) {
> /* Already scanned */
> return bus;
> }
> }
>

Ingo,

Yakui's patch should be applied for 2.6.25, and 2.6.23 stable, and
2.6.24 stable.

also please use attached patch to replace the one patch in x86.git#
testing. old one can not be applied after Yakui's patch.

YH

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[-- Type: text/x-patch; name=get_mp_bus_early_v2.patch, Size: 12386 bytes --]

x86: get mp_bus_to_node early v2

current on amd k8 system with multi ht chain, the numa_node of pci devices under
/sys/devices/pci0000:80/* always 0, even that chain is on node 1 or 2 or 3.

workaround: pcibus_to_node(bus) is used when we want to get node that pci_device is on.

In struct device, we already have numa_node member. and we could use dev_to_node()
/set_dev_node() to get and set numa_node in the device.
set_dev_node is called in pci_device_add() with pcibus_to_node(bus). and
pcibus_to_node use bus->sysdata for nodeid.

the problem is when pci_add_device is called, bus->sysdata is not assigned
correct nodeid yet. the result will be numa_node always is 0.

pcibios_scan_root and pci_scan_root could take sysdata. So we need to get
mp_bus_to_node mapping before these two are called. and get_mp_bus_to_node
could get correct node for sysdata in root bus.

in scanning of root bus, all child bus will take parent bus sysdata. So all
pci_device->dev.numa_node will be assigned correctly automatically.

later we could use dev_to_node(&pci_dev->dev) to get numa_node, and we could also
could make other bus specific device get the correct numa_node too.

this is one update version to pci_sysdata and jeff's pci_domain patch.
and duplicated scan bus fix patch

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>

Index: linux-2.6/arch/x86/pci/Makefile_32
===================================================================
--- linux-2.6.orig/arch/x86/pci/Makefile_32
+++ linux-2.6/arch/x86/pci/Makefile_32
@@ -10,5 +10,6 @@ pci-y += legacy.o irq.o

pci-$(CONFIG_X86_VISWS) := visws.o fixup.o
pci-$(CONFIG_X86_NUMAQ) := numa.o irq.o
+pci-$(CONFIG_NUMA) += mp_bus_to_node.o

obj-y += $(pci-y) common.o early.o
Index: linux-2.6/arch/x86/pci/common.c
===================================================================
--- linux-2.6.orig/arch/x86/pci/common.c
+++ linux-2.6/arch/x86/pci/common.c
@@ -396,9 +396,14 @@ struct pci_bus * __devinit pcibios_scan_
return NULL;
}

+ sd->node = get_mp_bus_to_node(busnum);
+
printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busnum);
+ bus = pci_scan_bus_parented(NULL, busnum, &pci_root_ops, sd);
+ if (!bus)
+ kfree(sd);

- return pci_scan_bus_parented(NULL, busnum, &pci_root_ops, sd);
+ return bus;
}

extern u8 pci_cache_line_size;
@@ -541,7 +546,7 @@ void pcibios_disable_device (struct pci_
pcibios_disable_irq(dev);
}

-struct pci_bus *__devinit pci_scan_bus_with_sysdata(int busno)
+struct pci_bus *pci_scan_bus_on_node(int busno, struct pci_ops *ops, int node)
{
struct pci_bus *bus = NULL;
struct pci_sysdata *sd;
@@ -556,10 +561,15 @@ struct pci_bus *__devinit pci_scan_bus_w
printk(KERN_ERR "PCI: OOM, skipping PCI bus %02x\n", busno);
return NULL;
}
- sd->node = -1;
- bus = pci_scan_bus(busno, &pci_root_ops, sd);
+ sd->node = node;
+ bus = pci_scan_bus(busno, ops, sd);
if (!bus)
kfree(sd);

return bus;
}
+
+struct pci_bus *pci_scan_bus_with_sysdata(int busno)
+{
+ return pci_scan_bus_on_node(busno, &pci_root_ops, -1);
+}
Index: linux-2.6/arch/x86/pci/irq.c
===================================================================
--- linux-2.6.orig/arch/x86/pci/irq.c
+++ linux-2.6/arch/x86/pci/irq.c
@@ -136,9 +136,11 @@ static void __init pirq_peer_trick(void)
busmap[e->bus] = 1;
}
for(i = 1; i < 256; i++) {
+ int node;
if (!busmap[i] || pci_find_bus(0, i))
continue;
- if (pci_scan_bus_with_sysdata(i))
+ node = get_mp_bus_to_node(i);
+ if (pci_scan_bus_on_node(i, &pci_root_ops, node))
printk(KERN_INFO "PCI: Discovered primary peer "
"bus %02x [IRQ]\n", i);
}
Index: linux-2.6/arch/x86/pci/k8-bus_64.c
===================================================================
--- linux-2.6.orig/arch/x86/pci/k8-bus_64.c
+++ linux-2.6/arch/x86/pci/k8-bus_64.c
@@ -1,7 +1,9 @@
#include <linux/init.h>
#include <linux/pci.h>
+#include <asm/pci-direct.h>
#include <asm/mpspec.h>
#include <linux/cpumask.h>
+#include <linux/topology.h>

/*
* This discovers the pcibus <-> node mapping on AMD K8.
@@ -20,64 +22,96 @@
#define SUBORDINATE_LDT_BUS_NUMBER(dword) ((dword >> 16) & 0xFF)
#define PCI_DEVICE_ID_K8HTCONFIG 0x1100

+#define BUS_NR 256
+
+static int mp_bus_to_node[BUS_NR];
+
+void set_mp_bus_to_node(int busnum, int node)
+{
+ if (busnum >= 0 && busnum < BUS_NR)
+ mp_bus_to_node[busnum] = node;
+}
+
+int get_mp_bus_to_node(int busnum)
+{
+ int node = -1;
+
+ if (busnum < 0 || busnum > (BUS_NR - 1))
+ return node;
+
+ node = mp_bus_to_node[busnum];
+
+ /*
+ * let numa_node_id to decide it later in dma_alloc_pages
+ * if there is no ram on that node
+ */
+ if (node != -1 && !node_online(node))
+ node = -1;
+
+ return node;
+}
+
/**
- * fill_mp_bus_to_cpumask()
+ * early_fill_mp_bus_to_node()
+ * called before pcibios_scan_root and pci_scan_bus
* fills the mp_bus_to_cpumask array based according to the LDT Bus Number
* Registers found in the K8 northbridge
*/
__init static int
-fill_mp_bus_to_cpumask(void)
+early_fill_mp_bus_to_node(void)
{
- struct pci_dev *nb_dev = NULL;
int i, j;
+ unsigned slot;
u32 ldtbus, nid;
+ u32 id;
static int lbnr[3] = {
LDT_BUS_NUMBER_REGISTER_0,
LDT_BUS_NUMBER_REGISTER_1,
LDT_BUS_NUMBER_REGISTER_2
};

- while ((nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
- PCI_DEVICE_ID_K8HTCONFIG, nb_dev))) {
- pci_read_config_dword(nb_dev, NODE_ID_REGISTER, &nid);
+ for (i = 0; i < BUS_NR; i++)
+ mp_bus_to_node[i] = -1;
+
+ if (!early_pci_allowed())
+ return -1;
+
+ for (slot = 0x18; slot < 0x20; slot++) {
+ id = read_pci_config(0, slot, 0, PCI_VENDOR_ID);
+ if (id != (PCI_VENDOR_ID_AMD | (PCI_DEVICE_ID_K8HTCONFIG<<16)))
+ break;
+ nid = read_pci_config(0, slot, 0, NODE_ID_REGISTER);

for (i = 0; i < NR_LDT_BUS_NUMBER_REGISTERS; i++) {
- pci_read_config_dword(nb_dev, lbnr[i], &ldtbus);
+ ldtbus = read_pci_config(0, slot, 0, lbnr[i]);
/*
* if there are no busses hanging off of the current
* ldt link then both the secondary and subordinate
* bus number fields are set to 0.
- *
+ *
* RED-PEN
* This is slightly broken because it assumes
- * HT node IDs == Linux node ids, which is not always
+ * HT node IDs == Linux node ids, which is not always
* true. However it is probably mostly true.
*/
if (!(SECONDARY_LDT_BUS_NUMBER(ldtbus) == 0
&& SUBORDINATE_LDT_BUS_NUMBER(ldtbus) == 0)) {
for (j = SECONDARY_LDT_BUS_NUMBER(ldtbus);
j <= SUBORDINATE_LDT_BUS_NUMBER(ldtbus);
- j++) {
- struct pci_bus *bus;
- struct pci_sysdata *sd;
-
- long node = NODE_ID(nid);
- /* Algorithm a bit dumb, but
- it shouldn't matter here */
- bus = pci_find_bus(0, j);
- if (!bus)
- continue;
- if (!node_online(node))
- node = 0;
-
- sd = bus->sysdata;
- sd->node = node;
- }
+ j++) {
+ int node = NODE_ID(nid);
+ mp_bus_to_node[j] = (unsigned char)node;
+ }
}
}
}

+ for (i = 0; i < BUS_NR; i++) {
+ int node = mp_bus_to_node[i];
+ if (node >= 0)
+ printk(KERN_DEBUG "bus: %02x to node: %02x\n", i, node);
+ }
return 0;
}

-fs_initcall(fill_mp_bus_to_cpumask);
+postcore_initcall(early_fill_mp_bus_to_node);
Index: linux-2.6/arch/x86/pci/legacy.c
===================================================================
--- linux-2.6.orig/arch/x86/pci/legacy.c
+++ linux-2.6/arch/x86/pci/legacy.c
@@ -12,6 +12,7 @@
static void __devinit pcibios_fixup_peer_bridges(void)
{
int n, devfn;
+ long node;

if (pcibios_last_bus <= 0 || pcibios_last_bus >= 0xff)
return;
@@ -21,12 +22,13 @@ static void __devinit pcibios_fixup_peer
u32 l;
if (pci_find_bus(0, n))
continue;
+ node = get_mp_bus_to_node(n);
for (devfn = 0; devfn < 256; devfn += 8) {
if (!raw_pci_read(0, n, devfn, PCI_VENDOR_ID, 2, &l) &&
l != 0x0000 && l != 0xffff) {
DBG("Found device at %02x:%02x [%04x]\n", n, devfn, l);
printk(KERN_INFO "PCI: Discovered peer bus %02x\n", n);
- pci_scan_bus_with_sysdata(n);
+ pci_scan_bus_on_node(n, &pci_root_ops, node);
break;
}
}
Index: linux-2.6/arch/x86/pci/mp_bus_to_node.c
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86/pci/mp_bus_to_node.c
@@ -0,0 +1,23 @@
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/topology.h>
+
+#define BUS_NR 256
+
+static unsigned char mp_bus_to_node[BUS_NR];
+
+void set_mp_bus_to_node(int busnum, int node)
+{
+ if (busnum >= 0 && busnum < BUS_NR)
+ mp_bus_to_node[busnum] = (unsigned char) node;
+}
+
+int get_mp_bus_to_node(int busnum)
+{
+ int node;
+
+ if (busnum < 0 || busnum > (BUS_NR - 1))
+ return 0;
+ node = mp_bus_to_node[busnum];
+ return node;
+}
Index: linux-2.6/include/asm-x86/pci.h
===================================================================
--- linux-2.6.orig/include/asm-x86/pci.h
+++ linux-2.6/include/asm-x86/pci.h
@@ -20,6 +20,8 @@ struct pci_sysdata {
};

/* scan a bus after allocating a pci_sysdata for it */
+extern struct pci_bus *pci_scan_bus_on_node(int busno, struct pci_ops *ops,
+ int node);
extern struct pci_bus *pci_scan_bus_with_sysdata(int busno);

static inline int pci_domain_nr(struct pci_bus *bus)
Index: linux-2.6/include/asm-x86/topology.h
===================================================================
--- linux-2.6.orig/include/asm-x86/topology.h
+++ linux-2.6/include/asm-x86/topology.h
@@ -165,8 +165,19 @@ extern int __node_distance(int, int);
#define node_distance(a, b) __node_distance(a, b)
#endif

+int get_mp_bus_to_node(int busnum);
+void set_mp_bus_to_node(int busnum, int node);
+
#else /* CONFIG_NUMA */

+static inline int get_mp_bus_to_node(int busnum)
+{
+ return 0;
+}
+static inline void set_mp_bus_to_node(int busnum, int node)
+{
+}
+
#include <asm-generic/topology.h>

#endif
Index: linux-2.6/arch/x86/pci/acpi.c
===================================================================
--- linux-2.6.orig/arch/x86/pci/acpi.c
+++ linux-2.6/arch/x86/pci/acpi.c
@@ -191,7 +191,10 @@ struct pci_bus * __devinit pci_acpi_scan
{
struct pci_bus *bus;
struct pci_sysdata *sd;
+ int node;
+#ifdef CONFIG_ACPI_NUMA
int pxm;
+#endif

dmi_check_system(acpi_pciprobe_dmi_table);

@@ -201,54 +204,52 @@ struct pci_bus * __devinit pci_acpi_scan
return NULL;
}

- /* Allocate per-root-bus (not per bus) arch-specific data.
- * TODO: leak; this memory is never freed.
- * It's arguable whether it's worth the trouble to care.
- */
- sd = kzalloc(sizeof(*sd), GFP_KERNEL);
- if (!sd) {
- printk(KERN_ERR "PCI: OOM, not probing PCI bus %02x\n", busnum);
- return NULL;
- }
-
- sd->domain = domain;
- sd->node = -1;
-
- pxm = acpi_get_pxm(device->handle);
+ node = -1;
#ifdef CONFIG_ACPI_NUMA
+ pxm = acpi_get_pxm(device->handle);
if (pxm >= 0)
- sd->node = pxm_to_node(pxm);
+ node = pxm_to_node(pxm);
+ if (node != -1)
+ set_mp_bus_to_node(busnum, node);
+ else
+ node = get_mp_bus_to_node(busnum);
#endif
- /*
- * Maybe the desired pci bus has been already scanned. In such case
- * it is unnecessary to scan the pci bus with the given domain,busnum.
- */
+
bus = pci_find_bus(domain, busnum);
if (bus) {
- /*
- * If the desired bus exits, the content of bus->sysdata will
- * be replaced by sd.
+ /* already scanned ?*/
+ bus->sysdata->node = node;
+ } else {
+ /* Allocate per-root-bus (not per bus) arch-specific data.
+ * TODO: leak; this memory is never freed.
+ * It's arguable whether it's worth the trouble to care.
*/
- memcpy(bus->sysdata, sd, sizeof(*sd));
- kfree(sd);
- } else
- bus = pci_scan_bus_parented(NULL, busnum, &pci_root_ops, sd);
+ sd = kzalloc(sizeof(*sd), GFP_KERNEL);
+ if (!sd) {
+ printk(KERN_ERR "PCI: OOM, not probing PCI bus %02x\n",
+ busnum);
+ return NULL;
+ }

- if (!bus)
- kfree(sd);
+ sd->domain = domain;
+ sd->node = node;
+
+ bus = pci_scan_bus_parented(NULL, busnum, &pci_root_ops, sd);
+ if (!bus)
+ kfree(sd);
+ }

#ifdef CONFIG_ACPI_NUMA
- if (bus != NULL) {
+ if (bus) {
if (pxm >= 0) {
- printk("bus %d -> pxm %d -> node %d\n",
- busnum, pxm, pxm_to_node(pxm));
+ printk(KERN_DEBUG "bus %02x -> pxm %d -> node %d\n",
+ busnum, pxm, node);
}
}
#endif

if (bus && (pci_probe & PCI_USE__CRS))
get_current_resources(device, busnum, bus);
-
return bus;
}