Patchworkβ [1/2] pci: release that leaf bridge' resource index is not used -v6

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Submitter Yinghai Lu
Date 2009-10-29 09:52:00
Message ID <4AE965C0.30206@kernel.org>
Download mbox | patch
Permalink /patch/56437/
State Superseded
Headers show

Comments

Yinghai Lu - 2009-10-29 09:52:00
only for index < 3

v2: Jesse doesn't like it is in find_free_bus_resource...
    try to move out of pci_bus_size_bridges loop.
need to apply after:
	[PATCH] pci: pciehp update the slot bridge res to get big range for pcie devices - v4
v3: add pci_setup_bridge calling after pci_bridge_release_not_used_res.
    only clear release those res for x86.
v4: Bjorn want to release use dev instead of bus.
v5: Kenji pointed out it will have problem with several level bridge.
    so let only handle leaf bridge.
v6: address Kenji's request (new pci_bus_release...). and change applying order
    move back release to pci_assign_unassigned_resource

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 drivers/pci/setup-bus.c |   65 +++++++++++++++++++++++++++++++++++++++++++++++-
 include/linux/pci.h     |    1 
 2 files changed, 65 insertions(+), 1 deletion(-)


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Jesse Barnes - 2009-10-29 16:31:44
On Thu, 29 Oct 2009 02:52:00 -0700
Yinghai Lu <yinghai@kernel.org> wrote:

> 
> only for index < 3
> 
> v2: Jesse doesn't like it is in find_free_bus_resource...
>     try to move out of pci_bus_size_bridges loop.
> need to apply after:
> 	[PATCH] pci: pciehp update the slot bridge res to get big
> range for pcie devices - v4 v3: add pci_setup_bridge calling after
> pci_bridge_release_not_used_res. only clear release those res for x86.
> v4: Bjorn want to release use dev instead of bus.
> v5: Kenji pointed out it will have problem with several level bridge.
>     so let only handle leaf bridge.
> v6: address Kenji's request (new pci_bus_release...). and change
> applying order move back release to pci_assign_unassigned_resource
> 
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>

Starting to look better...

> 
> ---
>  drivers/pci/setup-bus.c |   65
> +++++++++++++++++++++++++++++++++++++++++++++++-
> include/linux/pci.h     |    1 2 files changed, 65 insertions(+), 1
> deletion(-)
> 
> Index: linux-2.6/drivers/pci/setup-bus.c
> ===================================================================
> --- linux-2.6.orig/drivers/pci/setup-bus.c
> +++ linux-2.6/drivers/pci/setup-bus.c
> @@ -573,13 +573,68 @@ void __ref pci_bus_assign_resources(cons
>  }
>  EXPORT_SYMBOL(pci_bus_assign_resources);
>  
> +static void pci_bridge_release_not_used_res(struct pci_bus *bus)

Can we call these functions something else?  Maybe
pci_bridge_release_unused() with a kdoc comment describing exactly what
it does and why?

> +{
> +	int idx;
> +	bool changed = false;
> +	struct pci_dev *dev;
> +	struct resource *r;
> +	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
> +				  IORESOURCE_PREFETCH;
> +
> +	/* for pci bridges res only */
> +	dev = bus->self;
> +	for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_BRIDGE_RESOURCES
> + 3;
> +	    idx++) {
> +		r = &dev->resource[idx];
> +		if (!(r->flags & type_mask))
> +			continue;
> +		if (!r->parent)
> +			continue;
> +		/* if there is no child under that, we should
> release it */
> +		if (r->child)
> +			continue;
> +		if (!release_resource(r)) {
> +			dev_info(&dev->dev, "resource %d %pRt
> released\n",
> +				 idx, r);
> +			r->flags = 0;
> +			changed = true;
> +		}
> +	}
> +
> +	if (changed)
> +		pci_setup_bridge(bus);
> +}
> +
> +void __ref pci_bus_release_bridges_not_used_res(struct pci_bus *bus)

Likewise, maybe pci_bus_release_unused_bridge_res or something, with
comments again.

> +{
> +	struct pci_bus *b;
> +
> +	/* If the bus is cardbus, do nothing */
> +	if (bus->self && (bus->self->class >> 8) ==
> PCI_CLASS_BRIDGE_CARDBUS)
> +		return;
> +
> +	/* We only release the resources under the leaf bridge */
> +	if (list_empty(&bus->children)) {
> +		if (!pci_is_root_bus(bus))
> +			pci_bridge_release_not_used_res(bus);
> +		return;
> +	}
> +
> +	/* Scan child buses if the bus is not leaf */
> +	list_for_each_entry(b, &bus->children, node)
> +		pci_bus_release_bridges_not_used_res(b);
> +}
> +EXPORT_SYMBOL(pci_bus_release_bridges_not_used_res);
> +
>  static void pci_bus_dump_res(struct pci_bus *bus)
>  {
>          int i;
>  
>          for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
>                  struct resource *res = bus->resource[i];
> -                if (!res || !res->end)
> +
> +		if (!res || !res->end || !res->flags)
>                          continue;
>  
>  		dev_printk(KERN_DEBUG, &bus->dev, "resource %d
> %pRt\n", i, res); @@ -608,6 +663,14 @@
> pci_assign_unassigned_resources(void) {
>  	struct pci_bus *bus;
>  
> +	/*
> +	 * Try to release leaf bridge's resources that there is not
> child
> +	 * under it
> +	 */
> +	list_for_each_entry(bus, &pci_root_buses, node) {
> +		pci_bus_release_bridges_not_used_res(bus);
> +	}
> +

Also I wonder if we need to make this a command line option that isn't
run by default?

Really, as Eric says, we need a real dynamic allocation system with the
ability to move devices around at some point.  Any volunteers? :)
Yinghai Lu - 2009-10-29 17:10:22
Jesse Barnes wrote:
> On Thu, 29 Oct 2009 02:52:00 -0700
> Yinghai Lu <yinghai@kernel.org> wrote:
> 
>> only for index < 3
>>
>> v2: Jesse doesn't like it is in find_free_bus_resource...
>>     try to move out of pci_bus_size_bridges loop.
>> need to apply after:
>> 	[PATCH] pci: pciehp update the slot bridge res to get big
>> range for pcie devices - v4 v3: add pci_setup_bridge calling after
>> pci_bridge_release_not_used_res. only clear release those res for x86.
>> v4: Bjorn want to release use dev instead of bus.
>> v5: Kenji pointed out it will have problem with several level bridge.
>>     so let only handle leaf bridge.
>> v6: address Kenji's request (new pci_bus_release...). and change
>> applying order move back release to pci_assign_unassigned_resource
>>
>> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> 
> Starting to look better...
> 
>> ---
>>  drivers/pci/setup-bus.c |   65
>> +++++++++++++++++++++++++++++++++++++++++++++++-
>> include/linux/pci.h     |    1 2 files changed, 65 insertions(+), 1
>> deletion(-)
>>
>> Index: linux-2.6/drivers/pci/setup-bus.c
>> ===================================================================
>> --- linux-2.6.orig/drivers/pci/setup-bus.c
>> +++ linux-2.6/drivers/pci/setup-bus.c
>> @@ -573,13 +573,68 @@ void __ref pci_bus_assign_resources(cons
>>  }
>>  EXPORT_SYMBOL(pci_bus_assign_resources);
>>  
>> +static void pci_bridge_release_not_used_res(struct pci_bus *bus)
> 
> Can we call these functions something else?  Maybe
> pci_bridge_release_unused() with a kdoc comment describing exactly what
> it does and why?

ok.

> 
>> +{
>> +	int idx;
>> +	bool changed = false;
>> +	struct pci_dev *dev;
>> +	struct resource *r;
>> +	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
>> +				  IORESOURCE_PREFETCH;
>> +
>> +	/* for pci bridges res only */
>> +	dev = bus->self;
>> +	for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_BRIDGE_RESOURCES
>> + 3;
>> +	    idx++) {
>> +		r = &dev->resource[idx];
>> +		if (!(r->flags & type_mask))
>> +			continue;
>> +		if (!r->parent)
>> +			continue;
>> +		/* if there is no child under that, we should
>> release it */
>> +		if (r->child)
>> +			continue;
>> +		if (!release_resource(r)) {
>> +			dev_info(&dev->dev, "resource %d %pRt
>> released\n",
>> +				 idx, r);
>> +			r->flags = 0;
>> +			changed = true;
>> +		}
>> +	}
>> +
>> +	if (changed)
>> +		pci_setup_bridge(bus);
>> +}
>> +
>> +void __ref pci_bus_release_bridges_not_used_res(struct pci_bus *bus)
> 
> Likewise, maybe pci_bus_release_unused_bridge_res or something, with
> comments again.

ok

> 
>> +{
>> +	struct pci_bus *b;
>> +
>> +	/* If the bus is cardbus, do nothing */
>> +	if (bus->self && (bus->self->class >> 8) ==
>> PCI_CLASS_BRIDGE_CARDBUS)
>> +		return;
>> +
>> +	/* We only release the resources under the leaf bridge */
>> +	if (list_empty(&bus->children)) {
>> +		if (!pci_is_root_bus(bus))
>> +			pci_bridge_release_not_used_res(bus);
>> +		return;
>> +	}
>> +
>> +	/* Scan child buses if the bus is not leaf */
>> +	list_for_each_entry(b, &bus->children, node)
>> +		pci_bus_release_bridges_not_used_res(b);
>> +}
>> +EXPORT_SYMBOL(pci_bus_release_bridges_not_used_res);
>> +
>>  static void pci_bus_dump_res(struct pci_bus *bus)
>>  {
>>          int i;
>>  
>>          for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
>>                  struct resource *res = bus->resource[i];
>> -                if (!res || !res->end)
>> +
>> +		if (!res || !res->end || !res->flags)
>>                          continue;
>>  
>>  		dev_printk(KERN_DEBUG, &bus->dev, "resource %d
>> %pRt\n", i, res); @@ -608,6 +663,14 @@
>> pci_assign_unassigned_resources(void) {
>>  	struct pci_bus *bus;
>>  
>> +	/*
>> +	 * Try to release leaf bridge's resources that there is not
>> child
>> +	 * under it
>> +	 */
>> +	list_for_each_entry(bus, &pci_root_buses, node) {
>> +		pci_bus_release_bridges_not_used_res(bus);
>> +	}
>> +
> 
> Also I wonder if we need to make this a command line option that isn't
> run by default?

thinking:
1. try not to touch bridge resource and do the allocation and record the fail device
2. release leaf bridge for those failed device
3. do second around bus_size and allocation.

> 
> Really, as Eric says, we need a real dynamic allocation system with the
> ability to move devices around at some point.  Any volunteers? :)

that will need suspend driver and rescan allocation and wakeup driver...

YH

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Jesse Barnes - 2009-10-29 17:51:57
On Thu, 29 Oct 2009 10:10:22 -0700
Yinghai Lu <yinghai@kernel.org> wrote:
> > Also I wonder if we need to make this a command line option that
> > isn't run by default?
> 
> thinking:
> 1. try not to touch bridge resource and do the allocation and record
> the fail device 2. release leaf bridge for those failed device
> 3. do second around bus_size and allocation.

Yeah, that would make it more automatic at least, which would be nice.

> > Really, as Eric says, we need a real dynamic allocation system with
> > the ability to move devices around at some point.  Any
> > volunteers? :)
> 
> that will need suspend driver and rescan allocation and wakeup
> driver...

Right, it's fairly invasive.  But it's the right direction to go long
term.

Patch

Index: linux-2.6/drivers/pci/setup-bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-bus.c
+++ linux-2.6/drivers/pci/setup-bus.c
@@ -573,13 +573,68 @@  void __ref pci_bus_assign_resources(cons
 }
 EXPORT_SYMBOL(pci_bus_assign_resources);
 
+static void pci_bridge_release_not_used_res(struct pci_bus *bus)
+{
+	int idx;
+	bool changed = false;
+	struct pci_dev *dev;
+	struct resource *r;
+	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+				  IORESOURCE_PREFETCH;
+
+	/* for pci bridges res only */
+	dev = bus->self;
+	for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_BRIDGE_RESOURCES + 3;
+	    idx++) {
+		r = &dev->resource[idx];
+		if (!(r->flags & type_mask))
+			continue;
+		if (!r->parent)
+			continue;
+		/* if there is no child under that, we should release it */
+		if (r->child)
+			continue;
+		if (!release_resource(r)) {
+			dev_info(&dev->dev, "resource %d %pRt released\n",
+				 idx, r);
+			r->flags = 0;
+			changed = true;
+		}
+	}
+
+	if (changed)
+		pci_setup_bridge(bus);
+}
+
+void __ref pci_bus_release_bridges_not_used_res(struct pci_bus *bus)
+{
+	struct pci_bus *b;
+
+	/* If the bus is cardbus, do nothing */
+	if (bus->self && (bus->self->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS)
+		return;
+
+	/* We only release the resources under the leaf bridge */
+	if (list_empty(&bus->children)) {
+		if (!pci_is_root_bus(bus))
+			pci_bridge_release_not_used_res(bus);
+		return;
+	}
+
+	/* Scan child buses if the bus is not leaf */
+	list_for_each_entry(b, &bus->children, node)
+		pci_bus_release_bridges_not_used_res(b);
+}
+EXPORT_SYMBOL(pci_bus_release_bridges_not_used_res);
+
 static void pci_bus_dump_res(struct pci_bus *bus)
 {
         int i;
 
         for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
                 struct resource *res = bus->resource[i];
-                if (!res || !res->end)
+
+		if (!res || !res->end || !res->flags)
                         continue;
 
 		dev_printk(KERN_DEBUG, &bus->dev, "resource %d %pRt\n", i, res);
@@ -608,6 +663,14 @@  pci_assign_unassigned_resources(void)
 {
 	struct pci_bus *bus;
 
+	/*
+	 * Try to release leaf bridge's resources that there is not child
+	 * under it
+	 */
+	list_for_each_entry(bus, &pci_root_buses, node) {
+		pci_bus_release_bridges_not_used_res(bus);
+	}
+
 	/* Depth first, calculate sizes and alignments of all
 	   subordinate buses. */
 	list_for_each_entry(bus, &pci_root_buses, node) {
Index: linux-2.6/include/linux/pci.h
===================================================================
--- linux-2.6.orig/include/linux/pci.h
+++ linux-2.6/include/linux/pci.h
@@ -758,6 +758,7 @@  int pci_vpd_truncate(struct pci_dev *dev
 /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */
 void pci_bus_assign_resources(const struct pci_bus *bus);
 void pci_bus_size_bridges(struct pci_bus *bus);
+void pci_bus_release_bridges_not_used_res(struct pci_bus *bus);
 int pci_claim_resource(struct pci_dev *, int);
 void pci_assign_unassigned_resources(void);
 void pdev_enable_device(struct pci_dev *);