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Commit 376f70ac authored by Jiang Liu's avatar Jiang Liu Committed by Bjorn Helgaas
Browse files

x86/PCI: use RCU list to protect mmconfig list 



Use RCU list to protect mmconfig list from dynamic change
when supporting PCI host bridge hotplug.

Reviewed-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarJiang Liu <liuj97@gmail.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 846e4023

arch/x86/pci/mmconfig-shared.c

+12 −6
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ 
#include <linux/bitmap.h>

#include <linux/dmi.h>

#include <linux/slab.h>

#include <linux/mutex.h>

#include <linux/rculist.h>

#include <asm/e820.h>

#include <asm/pci_x86.h>

#include <asm/acpi.h>
@@ -25,6 +27,7 @@ 


/* Indicate if the mmcfg resources have been placed into the resource table. */

static int __initdata pci_mmcfg_resources_inserted;

static DEFINE_MUTEX(pci_mmcfg_lock);



LIST_HEAD(pci_mmcfg_list);
@@ -45,20 +48,20 @@ static __init void free_all_mmcfg(void) 
		pci_mmconfig_remove(cfg);

}



static __init void list_add_sorted(struct pci_mmcfg_region *new)

static __devinit void list_add_sorted(struct pci_mmcfg_region *new)

{

	struct pci_mmcfg_region *cfg;



	/* keep list sorted by segment and starting bus number */

	list_for_each_entry(cfg, &pci_mmcfg_list, list) {

	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) {

		if (cfg->segment > new->segment ||

		    (cfg->segment == new->segment &&

		     cfg->start_bus >= new->start_bus)) {

			list_add_tail(&new->list, &cfg->list);

			list_add_tail_rcu(&new->list, &cfg->list);

			return;

		}

	}

	list_add_tail(&new->list, &pci_mmcfg_list);

	list_add_tail_rcu(&new->list, &pci_mmcfg_list);

}



static __devinit struct pci_mmcfg_region *pci_mmconfig_alloc(int segment,
@@ -101,8 +104,11 @@ static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start, 
	struct pci_mmcfg_region *new;



	new = pci_mmconfig_alloc(segment, start, end, addr);

	if (new)

	if (new) {

		mutex_lock(&pci_mmcfg_lock);

		list_add_sorted(new);

		mutex_unlock(&pci_mmcfg_lock);

	}



	return new;

}
@@ -111,7 +117,7 @@ struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus) 
{

	struct pci_mmcfg_region *cfg;



	list_for_each_entry(cfg, &pci_mmcfg_list, list)

	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)

		if (cfg->segment == segment &&

		    cfg->start_bus <= bus && bus <= cfg->end_bus)

			return cfg;

arch/x86/pci/mmconfig_32.c

+11 −2
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 


#include <linux/pci.h>

#include <linux/init.h>

#include <linux/rcupdate.h>

#include <asm/e820.h>

#include <asm/pci_x86.h>

#include <acpi/acpi.h>
@@ -60,9 +61,12 @@ err: *value = -1; 
		return -EINVAL;

	}



	rcu_read_lock();

	base = get_base_addr(seg, bus, devfn);

	if (!base)

	if (!base) {

		rcu_read_unlock();

		goto err;

	}



	raw_spin_lock_irqsave(&pci_config_lock, flags);
@@ -80,6 +84,7 @@ err: *value = -1; 
		break;

	}

	raw_spin_unlock_irqrestore(&pci_config_lock, flags);

	rcu_read_unlock();



	return 0;

}
@@ -93,9 +98,12 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, 
	if ((bus > 255) || (devfn > 255) || (reg > 4095))

		return -EINVAL;



	rcu_read_lock();

	base = get_base_addr(seg, bus, devfn);

	if (!base)

	if (!base) {

		rcu_read_unlock();

		return -EINVAL;

	}



	raw_spin_lock_irqsave(&pci_config_lock, flags);
@@ -113,6 +121,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, 
		break;

	}

	raw_spin_unlock_irqrestore(&pci_config_lock, flags);

	rcu_read_unlock();



	return 0;

}

arch/x86/pci/mmconfig_64.c

+11 −2
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/init.h>

#include <linux/acpi.h>

#include <linux/bitmap.h>

#include <linux/rcupdate.h>

#include <asm/e820.h>

#include <asm/pci_x86.h>
@@ -34,9 +35,12 @@ err: *value = -1; 
		return -EINVAL;

	}



	rcu_read_lock();

	addr = pci_dev_base(seg, bus, devfn);

	if (!addr)

	if (!addr) {

		rcu_read_unlock();

		goto err;

	}



	switch (len) {

	case 1:
@@ -49,6 +53,7 @@ err: *value = -1; 
		*value = mmio_config_readl(addr + reg);

		break;

	}

	rcu_read_unlock();



	return 0;

}
@@ -62,9 +67,12 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, 
	if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))

		return -EINVAL;



	rcu_read_lock();

	addr = pci_dev_base(seg, bus, devfn);

	if (!addr)

	if (!addr) {

		rcu_read_unlock();

		return -EINVAL;

	}



	switch (len) {

	case 1:
@@ -77,6 +85,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, 
		mmio_config_writel(addr + reg, value);

		break;

	}

	rcu_read_unlock();



	return 0;

}