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Commit f483d392 authored by Ram Pai's avatar Ram Pai Committed by Jesse Barnes
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PCI: conditional resource-reallocation through kernel parameter pci=realloc 


    
Multiple attempts to dynamically reallocate pci resources have
unfortunately lead to regressions. Though we continue to fix the
regressions and fine tune the dynamic-reallocation behavior, we have not
reached a acceptable state yet.
    
This patch provides a interim solution. It disables dynamic reallocation
by default, but adds the ability to enable it through pci=realloc kernel
command line parameter.
    
Tested-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: default avatarRam Pai <linuxram@us.ibm.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent a2fa83fa

Documentation/kernel-parameters.txt

+2 −0
Original line number Original line Diff line number Diff line
@@ -2015,6 +2015,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
				the default.

				the default.

				off: Turn ECRC off

				off: Turn ECRC off

				on: Turn ECRC on.

				on: Turn ECRC on.

		realloc		reallocate PCI resources if allocations done by BIOS

				are erroneous.





	pcie_aspm=	[PCIE] Forcibly enable or disable PCIe Active State Power

	pcie_aspm=	[PCIE] Forcibly enable or disable PCIe Active State Power

			Management.

			Management.

drivers/pci/pci.c

+2 −0
Original line number Original line Diff line number Diff line
@@ -3483,6 +3483,8 @@ static int __init pci_setup(char *str) 
				pci_no_msi();

				pci_no_msi();

			} else if (!strcmp(str, "noaer")) {

			} else if (!strcmp(str, "noaer")) {

				pci_no_aer();

				pci_no_aer();

			} else if (!strncmp(str, "realloc", 7)) {

				pci_realloc();

			} else if (!strcmp(str, "nodomains")) {

			} else if (!strcmp(str, "nodomains")) {

				pci_no_domains();

				pci_no_domains();

			} else if (!strncmp(str, "cbiosize=", 9)) {

			} else if (!strncmp(str, "cbiosize=", 9)) {

drivers/pci/pci.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -146,6 +146,8 @@ static inline void pci_no_msi(void) { } 
static inline void pci_msi_init_pci_dev(struct pci_dev *dev) { }

static inline void pci_msi_init_pci_dev(struct pci_dev *dev) { }

#endif

#endif





extern void pci_realloc(void);



static inline int pci_no_d1d2(struct pci_dev *dev)

static inline int pci_no_d1d2(struct pci_dev *dev)

{

{

	unsigned int parent_dstates = 0;

	unsigned int parent_dstates = 0;

drivers/pci/setup-bus.c

+15 −0
Original line number Original line Diff line number Diff line
@@ -47,6 +47,13 @@ struct resource_list_x { 
	(head)->next = NULL;				\

	(head)->next = NULL;				\

} while (0)

} while (0)





int pci_realloc_enable = 0;

#define pci_realloc_enabled() pci_realloc_enable

void pci_realloc(void)

{

	pci_realloc_enable = 1;

}



/**

/**

 * add_to_list() - add a new resource tracker to the list

 * add_to_list() - add a new resource tracker to the list

 * @head:	Head of the list

 * @head:	Head of the list
@@ -1025,6 +1032,7 @@ static int __init pci_get_max_depth(void) 
	return depth;

	return depth;

}

}







/*

/*

 * 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
@@ -1068,6 +1076,13 @@ pci_assign_unassigned_resources(void) 
	/* any device complain? */

	/* any device complain? */

	if (!head.next)

	if (!head.next)

		goto enable_and_dump;

		goto enable_and_dump;



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

	if (!pci_realloc_enabled()) {

		free_list(resource_list_x, &head);

		goto enable_and_dump;

	}



	failed_type = 0;

	failed_type = 0;

	for (list = head.next; list;) {

	for (list = head.next; list;) {

		failed_type |= list->flags;

		failed_type |= list->flags;