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Message-ID: <CAE9FiQWrsPagd6JH1H_k1jOQ_NQau4PK_QmHTtzwqOi1QamhrQ@mail.gmail.com>
Date: Sun, 8 Apr 2012 12:12:35 -0700
From: Yinghai Lu <yinghai@...nel.org>
To: Jiang Liu <liuj97@...il.com>
Cc: Taku Izumi <izumi.taku@...fujitsu.com>,
Kenji Kaneshige <kaneshige.kenji@...fujitsu.com>,
Bjorn Helgaas <bhelgaas@...gle.com>,
Jiang Liu <jiang.liu@...wei.com>,
Keping Chen <chenkeping@...wei.com>,
linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org
Subject: Re: [PATCH 1/2] PCI,x86: introduce new MMCFG interfaces to support
PCI host bridge hotplug
On Sun, Apr 8, 2012 at 10:12 AM, Jiang Liu <liuj97@...il.com> wrote:
> This patch introduces two new interfaces, pci_mmconfig_insert() and
> pci_mmconfig_delete(), to support PCI host bridge hotplug on x86 platforms.
>
> Signed-off-by: Jiang Liu <jiang.liu@...wei.com>
> ---
> arch/x86/include/asm/pci_x86.h | 4 +
> arch/x86/pci/mmconfig-shared.c | 186 +++++++++++++++++++++++++++++++---------
> arch/x86/pci/mmconfig_32.c | 28 ++++++-
> arch/x86/pci/mmconfig_64.c | 35 +++++++-
> 4 files changed, 206 insertions(+), 47 deletions(-)
this patch is way too big. at least could split it to five patches.
>
> diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
> index b3a5317..ba8570c 100644
> --- a/arch/x86/include/asm/pci_x86.h
> +++ b/arch/x86/include/asm/pci_x86.h
> @@ -135,6 +135,10 @@ struct pci_mmcfg_region {
>
> extern int __init pci_mmcfg_arch_init(void);
> extern void __init pci_mmcfg_arch_free(void);
> +extern int __devinit pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg);
> +extern void __devinit pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg);
> +extern int __devinit pci_mmconfig_insert(int seg, int start, int end, u64 addr);
> +extern int __devinit pci_mmconfig_delete(int seg, int start, int end, u64 addr);
> extern struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus);
>
> extern struct list_head pci_mmcfg_list;
> diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
> index 301e325..dda9470 100644
> --- a/arch/x86/pci/mmconfig-shared.c
> +++ b/arch/x86/pci/mmconfig-shared.c
> @@ -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>
> @@ -45,24 +47,25 @@ 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 __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
> - int end, u64 addr)
> +static __devinit struct pci_mmcfg_region *pci_mmconfig_alloc(int segment,
> + int start,
> + int end, u64 addr)
> {
> struct pci_mmcfg_region *new;
> struct resource *res;
> @@ -79,8 +82,6 @@ static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
> new->start_bus = start;
> new->end_bus = end;
>
> - list_add_sorted(new);
> -
> res = &new->res;
> res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
> res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
> @@ -96,11 +97,23 @@ static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
> return new;
> }
>
> +static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
> + int end, u64 addr)
> +{
> + struct pci_mmcfg_region *new;
> +
> + new = pci_mmconfig_alloc(segment, start, end, addr);
> + if (new)
> + list_add_sorted(new);
> +
> + return new;
> +}
> +
above two change could be in separated patch.
> 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;
> @@ -364,8 +377,8 @@ static void __init pci_mmcfg_insert_resources(void)
> pci_mmcfg_resources_inserted = 1;
> }
>
> -static acpi_status __init check_mcfg_resource(struct acpi_resource *res,
> - void *data)
> +static acpi_status __devinit check_mcfg_resource(struct acpi_resource *res,
> + void *data)
> {
> struct resource *mcfg_res = data;
> struct acpi_resource_address64 address;
> @@ -401,8 +414,8 @@ static acpi_status __init check_mcfg_resource(struct acpi_resource *res,
> return AE_OK;
> }
>
> -static acpi_status __init find_mboard_resource(acpi_handle handle, u32 lvl,
> - void *context, void **rv)
> +static acpi_status __devinit find_mboard_resource(acpi_handle handle, u32 lvl,
> + void *context, void **rv)
> {
> struct resource *mcfg_res = context;
>
> @@ -415,7 +428,7 @@ static acpi_status __init find_mboard_resource(acpi_handle handle, u32 lvl,
> return AE_OK;
> }
>
> -static int __init is_acpi_reserved(u64 start, u64 end, unsigned not_used)
> +static int __devinit is_acpi_reserved(u64 start, u64 end, unsigned not_used)
> {
> struct resource mcfg_res;
>
> @@ -434,8 +447,9 @@ static int __init is_acpi_reserved(u64 start, u64 end, unsigned not_used)
>
> typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type);
>
> -static int __init is_mmconf_reserved(check_reserved_t is_reserved,
> - struct pci_mmcfg_region *cfg, int with_e820)
> +static int __devinit is_mmconf_reserved(check_reserved_t is_reserved,
> + struct pci_mmcfg_region *cfg,
> + int with_e820)
> {
> u64 addr = cfg->res.start;
> u64 size = resource_size(&cfg->res);
> @@ -474,39 +488,38 @@ static int __init is_mmconf_reserved(check_reserved_t is_reserved,
> return valid;
> }
>
> +static int __devinit pci_mmcfg_check_reserved(struct pci_mmcfg_region *cfg,
> + int early)
> +{
> + if (!early && !acpi_disabled) {
> + if (is_mmconf_reserved(is_acpi_reserved, cfg, 0))
> + return 1;
> + else
> + printk(KERN_ERR FW_BUG PREFIX
> + "MMCONFIG at %pR not reserved in "
> + "ACPI motherboard resources\n",
> + &cfg->res);
> + }
> +
> + /* Don't try to do this check unless configuration
> + type 1 is available. how about type 2 ?*/
> + if (raw_pci_ops)
> + return is_mmconf_reserved(e820_all_mapped, cfg, 1);
> +
> + return 0;
> +}
> +
> static void __init pci_mmcfg_reject_broken(int early)
> {
> struct pci_mmcfg_region *cfg;
>
> list_for_each_entry(cfg, &pci_mmcfg_list, list) {
> - int valid = 0;
> -
> - if (!early && !acpi_disabled) {
> - valid = is_mmconf_reserved(is_acpi_reserved, cfg, 0);
> -
> - if (valid)
> - continue;
> - else
> - printk(KERN_ERR FW_BUG PREFIX
> - "MMCONFIG at %pR not reserved in "
> - "ACPI motherboard resources\n",
> - &cfg->res);
> + if (pci_mmcfg_check_reserved(cfg, early) == 0) {
> + printk(KERN_INFO PREFIX "not using MMCONFIG\n");
> + free_all_mmcfg();
> + return;
> }
> -
> - /* Don't try to do this check unless configuration
> - type 1 is available. how about type 2 ?*/
> - if (raw_pci_ops)
> - valid = is_mmconf_reserved(e820_all_mapped, cfg, 1);
> -
> - if (!valid)
> - goto reject;
> }
> -
> - return;
> -
> -reject:
> - printk(KERN_INFO PREFIX "not using MMCONFIG\n");
> - free_all_mmcfg();
> }
>
> static int __initdata known_bridge;
above two changes could be in separated patch.
> @@ -665,3 +678,92 @@ static int __init pci_mmcfg_late_insert_resources(void)
> * with other system resources.
> */
> late_initcall(pci_mmcfg_late_insert_resources);
> +
> +static DEFINE_MUTEX(pci_mmcfg_lock);
> +
> +/* Add MMCFG information for hot-added host bridges at runtime */
> +int __devinit pci_mmconfig_insert(int segment, int start, int end, u64 addr)
> +{
> + int rc;
> + struct pci_mmcfg_region *cfg = NULL;
> +
> + if (addr == 0 || segment < 0 || segment > USHRT_MAX ||
> + start < 0 || start > 255 || end < start || end > 255)
> + return -EINVAL;
> +
> + mutex_lock(&pci_mmcfg_lock);
> + cfg = pci_mmconfig_lookup(segment, start);
> + if (cfg) {
> + if (cfg->start_bus == start && cfg->end_bus == end &&
> + cfg->address == addr) {
> + rc = -EEXIST;
> + } else {
> + rc = -EINVAL;
> + printk(KERN_WARNING PREFIX
> + "MMCONFIG for domain %04x [bus %02x-%02x] "
> + "conflicts with domain %04x [bus %02x-%02x]\n",
> + segment, start, end,
> + cfg->segment, cfg->start_bus, cfg->end_bus);
> + }
> + goto out;
> + }
> +
> + cfg = pci_mmconfig_alloc(segment, start, end, addr);
> + if (cfg == NULL) {
> + rc = -ENOMEM;
> + } else if (!pci_mmcfg_check_reserved(cfg, 0)) {
> + rc = -EINVAL;
> + printk(KERN_WARNING PREFIX
> + "MMCONFIG for domain %04x [bus %02x-%02x] "
> + "isn't reserved\n", segment, start, end);
> + } else if (insert_resource(&iomem_resource, &cfg->res)) {
> + rc = -EBUSY;
> + printk(KERN_WARNING PREFIX
> + "failed to insert resource for domain "
> + "%04x [bus %02x-%02x]\n", segment, start, end);
> + } else if (pci_mmcfg_arch_map(cfg)) {
> + rc = -EBUSY;
> + printk(KERN_WARNING PREFIX
> + "failed to map resource for domain "
> + "%04x [bus %02x-%02x]\n", segment, start, end);
> + } else {
> + list_add_sorted(cfg);
> + cfg = NULL;
> + rc = 0;
> + }
> +
> + if (cfg) {
> + if (cfg->res.parent)
> + release_resource(&cfg->res);
> + kfree(cfg);
> + }
> +
> +out:
> + mutex_unlock(&pci_mmcfg_lock);
> +
> + return rc;
> +}
> +
> +/* Delete MMCFG information at runtime */
> +int __devinit pci_mmconfig_delete(int segment, int start, int end, u64 addr)
> +{
> + struct pci_mmcfg_region *cfg;
> +
> + mutex_lock(&pci_mmcfg_lock);
> + list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) {
> + if (cfg->segment == segment && cfg->start_bus == start &&
> + cfg->end_bus == end && cfg->address == addr) {
> + list_del_rcu(&cfg->list);
> + synchronize_rcu();
> + pci_mmcfg_arch_unmap(cfg);
> + if (cfg->res.parent)
> + release_resource(&cfg->res);
> + mutex_unlock(&pci_mmcfg_lock);
> + kfree(cfg);
> + return 0;
> + }
> + }
> + mutex_unlock(&pci_mmcfg_lock);
> +
> + return -ENOENT;
> +}
new added _insert/_remove could be in another patch.
> diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
> index 5372e86..c2756de 100644
> --- a/arch/x86/pci/mmconfig_32.c
> +++ b/arch/x86/pci/mmconfig_32.c
> @@ -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;
> }
> @@ -132,3 +141,18 @@ int __init pci_mmcfg_arch_init(void)
> void __init pci_mmcfg_arch_free(void)
> {
> }
> +
> +int __devinit pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg)
> +{
> + return 0;
> +}
> +
> +void __devinit pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg)
> +{
> + unsigned long flags;
> +
> + /* Invalidate the cached mmcfg map entry. */
> + raw_spin_lock_irqsave(&pci_config_lock, flags);
> + mmcfg_last_accessed_device = 0;
> + raw_spin_unlock_irqrestore(&pci_config_lock, flags);
> +}
> diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
> index 915a493..6822dd6 100644
> --- a/arch/x86/pci/mmconfig_64.c
> +++ b/arch/x86/pci/mmconfig_64.c
> @@ -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;
> }
> @@ -86,7 +95,7 @@ static const struct pci_raw_ops pci_mmcfg = {
> .write = pci_mmcfg_write,
> };
>
> -static void __iomem * __init mcfg_ioremap(struct pci_mmcfg_region *cfg)
> +static void __iomem * __devinit mcfg_ioremap(struct pci_mmcfg_region *cfg)
> {
> void __iomem *addr;
> u64 start, size;
> @@ -129,3 +138,23 @@ void __init pci_mmcfg_arch_free(void)
> }
> }
> }
> +
> +int __devinit pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg)
> +{
> + cfg->virt = mcfg_ioremap(cfg);
> + if (!cfg->virt) {
> + printk(KERN_ERR PREFIX "can't map MMCONFIG at %pR\n",
> + &cfg->res);
> + return -ENOMEM;
> + }
> +
> + return 0;
> +}
> +
> +void __devinit pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg)
> +{
> + if (cfg && cfg->virt) {
> + iounmap(cfg->virt + PCI_MMCFG_BUS_OFFSET(cfg->start_bus));
> + cfg->virt = NULL;
> + }
> +}
another one.
> --
> 1.7.5.4
>
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