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Commit 28760489 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Jesse Barnes
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PCI: pcie: Ensure hotplug ports have a minimum number of resources 



In general a BIOS may goof or we may hotplug in a hotplug controller.
In either case the kernel needs to reserve resources for plugging
in more devices in the future instead of creating a minimal resource
assignment.

We already do this for cardbus bridges I am just adding a variant
for pcie bridges.

v2: Make testing for pcie hotplug bridges based on a flag.

    So far we only set the flag for pcie but a header_quirk
    could easily be added for the non-standard pci hotplug
    bridges.

Signed-off-by: default avatarEric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 0ba379ec

drivers/pci/pci.c

+10 −0
Original line number Diff line number Diff line
@@ -41,6 +41,12 @@ int pci_domains_supported = 1; 
unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;

unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;



#define DEFAULT_HOTPLUG_IO_SIZE		(256)

#define DEFAULT_HOTPLUG_MEM_SIZE	(2*1024*1024)

/* pci=hpmemsize=nnM,hpiosize=nn can override this */

unsigned long pci_hotplug_io_size  = DEFAULT_HOTPLUG_IO_SIZE;

unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;



/**

 * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children

 * @bus: pointer to PCI bus structure to search
@@ -2732,6 +2738,10 @@ static int __init pci_setup(char *str) 
							strlen(str + 19));

			} else if (!strncmp(str, "ecrc=", 5)) {

				pcie_ecrc_get_policy(str + 5);

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

				pci_hotplug_io_size = memparse(str + 9, &str);

			} else if (!strncmp(str, "hpmemsize=", 10)) {

				pci_hotplug_mem_size = memparse(str + 10, &str);

			} else {

				printk(KERN_ERR "PCI: Unknown option `%s'\n",

						str);

drivers/pci/probe.c

+18 −0
Original line number Diff line number Diff line
@@ -697,6 +697,23 @@ static void set_pcie_port_type(struct pci_dev *pdev) 
	pdev->pcie_type = (reg16 & PCI_EXP_FLAGS_TYPE) >> 4;

}



static void set_pcie_hotplug_bridge(struct pci_dev *pdev)

{

	int pos;

	u16 reg16;

	u32 reg32;



	pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);

	if (!pos)

		return;

	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);

	if (!(reg16 & PCI_EXP_FLAGS_SLOT))

		return;

	pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &reg32);

	if (reg32 & PCI_EXP_SLTCAP_HPC)

		pdev->is_hotplug_bridge = 1;

}



#define LEGACY_IO_RESOURCE	(IORESOURCE_IO | IORESOURCE_PCI_FIXED)



/**
@@ -804,6 +821,7 @@ int pci_setup_device(struct pci_dev *dev) 
		pci_read_irq(dev);

		dev->transparent = ((dev->class & 0xff) == 1);

		pci_read_bases(dev, 2, PCI_ROM_ADDRESS1);

		set_pcie_hotplug_bridge(dev);

		break;



	case PCI_HEADER_TYPE_CARDBUS:		    /* CardBus bridge header */

drivers/pci/setup-bus.c

+17 −5
Original line number Diff line number Diff line
@@ -309,7 +309,7 @@ static struct resource *find_free_bus_resource(struct pci_bus *bus, unsigned lon 
   since these windows have 4K granularity and the IO ranges

   of non-bridge PCI devices are limited to 256 bytes.

   We must be careful with the ISA aliasing though. */

static void pbus_size_io(struct pci_bus *bus)

static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)

{

	struct pci_dev *dev;

	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
@@ -336,6 +336,8 @@ static void pbus_size_io(struct pci_bus *bus) 
				size1 += r_size;

		}

	}

	if (size < min_size)

		size = min_size;

/* To be fixed in 2.5: we should have sort of HAVE_ISA

   flag in the struct pci_bus. */

#if defined(CONFIG_ISA) || defined(CONFIG_EISA)
@@ -354,7 +356,8 @@ static void pbus_size_io(struct pci_bus *bus) 


/* Calculate the size of the bus and minimal alignment which

   guarantees that all child resources fit in this size. */

static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long type)

static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,

			 unsigned long type, resource_size_t min_size)

{

	struct pci_dev *dev;

	resource_size_t min_align, align, size;
@@ -404,6 +407,8 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long 
			mem64_mask &= r->flags & IORESOURCE_MEM_64;

		}

	}

	if (size < min_size)

		size = min_size;



	align = 0;

	min_align = 0;
@@ -483,6 +488,7 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus) 
{

	struct pci_dev *dev;

	unsigned long mask, prefmask;

	resource_size_t min_mem_size = 0, min_io_size = 0;



	list_for_each_entry(dev, &bus->devices, bus_list) {

		struct pci_bus *b = dev->subordinate;
@@ -512,8 +518,12 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus) 


	case PCI_CLASS_BRIDGE_PCI:

		pci_bridge_check_ranges(bus);

		if (bus->self->is_hotplug_bridge) {

			min_io_size  = pci_hotplug_io_size;

			min_mem_size = pci_hotplug_mem_size;

		}

	default:

		pbus_size_io(bus);

		pbus_size_io(bus, min_io_size);

		/* If the bridge supports prefetchable range, size it

		   separately. If it doesn't, or its prefetchable window

		   has already been allocated by arch code, try
@@ -521,9 +531,11 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus) 
		   resources. */

		mask = IORESOURCE_MEM;

		prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;

		if (pbus_size_mem(bus, prefmask, prefmask))

		if (pbus_size_mem(bus, prefmask, prefmask, min_mem_size))

			mask = prefmask; /* Success, size non-prefetch only. */

		pbus_size_mem(bus, mask, IORESOURCE_MEM);

		else

			min_mem_size += min_mem_size;

		pbus_size_mem(bus, mask, IORESOURCE_MEM, min_mem_size);

		break;

	}

}

include/linux/pci.h

+4 −0
Original line number Diff line number Diff line
@@ -278,6 +278,7 @@ struct pci_dev { 
	unsigned int	is_physfn:1;

	unsigned int	is_virtfn:1;

	unsigned int	reset_fn:1;

	unsigned int    is_hotplug_bridge:1;

	pci_dev_flags_t dev_flags;

	atomic_t	enable_cnt;	/* pci_enable_device has been called */
@@ -1245,6 +1246,9 @@ extern int pci_pci_problems; 
extern unsigned long pci_cardbus_io_size;

extern unsigned long pci_cardbus_mem_size;



extern unsigned long pci_hotplug_io_size;

extern unsigned long pci_hotplug_mem_size;



int pcibios_add_platform_entries(struct pci_dev *dev);

void pcibios_disable_device(struct pci_dev *dev);

int pcibios_set_pcie_reset_state(struct pci_dev *dev,