Commit b07f2ebc authored by Yinghai Lu's avatar Yinghai Lu Committed by Jesse Barnes
Browse files

PCI: add a PCI resource reallocation config option 



Add a new config option, PCI_REALLOC_ENABLE_AUTO, which will
automatically try to re-allocate PCI resources if PCI_IOV support is
enabled and the SR-IOV resources are unassigned.  Behavior can still be
controlled using the pci=realloc= parameter.

-v2: According to Jesse, adding one CONFIG option for distribution to
     disable it or enable it.
-v3: update Kconfig text (jbarnes)

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent eb572e7c

drivers/pci/Kconfig

+13 −0
Original line number Original line Diff line number Diff line
@@ -31,6 +31,19 @@ config PCI_DEBUG 




	  When in doubt, say N.

	  When in doubt, say N.





config PCI_REALLOC_ENABLE_AUTO

	bool "Enable PCI resource re-allocation detection"

	depends on PCI

	help

	  Say Y here if you want the PCI core to detect if PCI resource

	  re-allocation needs to be enabled. You can always use pci=realloc=on

          or pci=realloc=off to override it.  Note this feature is a no-op

          unless PCI_IOV support is also enabled; in that case it will

          automatically re-allocate PCI resources if SR-IOV BARs have not

          been allocated by the BIOS.



	  When in doubt, say N.



config PCI_STUB

config PCI_STUB

	tristate "PCI Stub driver"

	tristate "PCI Stub driver"

	depends on PCI

	depends on PCI

drivers/pci/setup-bus.c

+28 −0
Original line number Original line Diff line number Diff line
@@ -1294,6 +1294,31 @@ static bool __init pci_realloc_enabled(void) 
	return pci_realloc_enable >= user_enabled;

	return pci_realloc_enable >= user_enabled;

}

}





static void __init pci_realloc_detect(void)

{

#if defined(CONFIG_PCI_IOV) && defined(CONFIG_PCI_REALLOC_ENABLE_AUTO)

	struct pci_dev *dev = NULL;



	if (pci_realloc_enable != undefined)

		return;



	for_each_pci_dev(dev) {

		int i;



		for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) {

			struct resource *r = &dev->resource[i];



			/* Not assigned, or rejected by kernel ? */

			if (r->flags && !r->start) {

				pci_realloc_enable = auto_enabled;



				return;

			}

		}

	}

#endif

}



/*

/*

 * first try will not touch pci bridge res

 * first try will not touch pci bridge res

 * second  and later try will clear small leaf bridge res

 * second  and later try will clear small leaf bridge res
@@ -1315,6 +1340,7 @@ pci_assign_unassigned_resources(void) 
	int pci_try_num = 1;

	int pci_try_num = 1;





	/* don't realloc if asked to do so */

	/* don't realloc if asked to do so */

	pci_realloc_detect();

	if (pci_realloc_enabled()) {

	if (pci_realloc_enabled()) {

		int max_depth = pci_get_max_depth();

		int max_depth = pci_get_max_depth();
@@ -1349,6 +1375,8 @@ again: 
	if (tried_times >= pci_try_num) {

	if (tried_times >= pci_try_num) {

		if (pci_realloc_enable == undefined)

		if (pci_realloc_enable == undefined)

			printk(KERN_INFO "Some PCI device resources are unassigned, try booting with pci=realloc\n");

			printk(KERN_INFO "Some PCI device resources are unassigned, try booting with pci=realloc\n");

		else if (pci_realloc_enable == auto_enabled)

			printk(KERN_INFO "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");





		free_list(&fail_head);

		free_list(&fail_head);

		goto enable_and_dump;

		goto enable_and_dump;

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