Re: [PATCH 2/2] PCI, ACPI, x86: update MMCFG information whenhot-plugging PCI host bridges
From: Yinghai Lu
Date: Sun Apr 08 2012 - 15:19:09 EST
On Sun, Apr 8, 2012 at 10:12 AM, Jiang Liu <liuj97@xxxxxxxxx> wrote:
> This patch enhances pci_root driver to update MMCFG information when
> hot-plugging PCI root bridges on x86 platforms.
>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
> ---
> arch/x86/pci/acpi.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++
> drivers/acpi/pci_root.c | 20 ++++++++++++++++
> include/acpi/acnames.h | 1 +
> include/linux/pci-acpi.h | 3 ++
> 4 files changed, 82 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index da0149d..9184970 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -488,6 +488,64 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
> return bus;
> }
>
> +int arch_acpi_pci_root_add(struct acpi_pci_root *root)
> +{
> + int result = 0;
> + acpi_status status;
> + unsigned long long base_addr;
> + struct pci_mmcfg_region *cfg;
> +
> + /*
> + * Try to insert MMCFG information for host bridges with _CBA method
> + */
> + status = acpi_evaluate_integer(root->device->handle, METHOD_NAME__CBA,
> + NULL, &base_addr);
> + if (ACPI_SUCCESS(status)) {
> + result = pci_mmconfig_insert(root->segment,
> + root->secondary.start,
> + root->secondary.end,
> + base_addr);
> + /*
> + * MMCFG information for hot-pluggable host bridges may have
> + * already been added by __pci_mmcfg_init();
> + */
> + if (result == -EEXIST)
> + result = 0;
> + } else if (status == AE_NOT_FOUND) {
> + /*
> + * Check whether MMCFG information has been added for
> + * host bridges without _CBA method.
> + */
> + rcu_read_lock();
> + cfg = pci_mmconfig_lookup(root->segment, root->secondary.start);
> + if (!cfg || cfg->end_bus < root->secondary.end)
> + result = -ENODEV;
> + rcu_read_unlock();
> + } else
> + result = -ENODEV;
> +
> + return result;
> +}
> +
> +int arch_acpi_pci_root_remove(struct acpi_pci_root *root)
> +{
> + acpi_status status;
> + unsigned long long base_addr;
> +
> + /* Remove MMCFG information for host bridges with _CBA method */
> + status = acpi_evaluate_integer(root->device->handle, METHOD_NAME__CBA,
> + NULL, &base_addr);
add one flag in acpi_pci_root about we added mmconf for it before?
like mmconf_added?
> + if (ACPI_SUCCESS(status))
> + return pci_mmconfig_delete(root->segment,
> + root->secondary.start,
> + root->secondary.end,
> + base_addr);
> + else if (status != AE_NOT_FOUND)
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> int __init pci_acpi_init(void)
> {
> struct pci_dev *dev = NULL;
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index 4a7d575..a62bfa8 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -448,6 +448,16 @@ out:
> }
> EXPORT_SYMBOL(acpi_pci_osc_control_set);
>
> +int __weak arch_acpi_pci_root_add(struct acpi_pci_root *root)
> +{
> + return 0;
> +}
> +
> +int __weak arch_acpi_pci_root_remove(struct acpi_pci_root *root)
> +{
> + return 0;
> +}
> +
> static int __devinit acpi_pci_root_add(struct acpi_device *device)
> {
> unsigned long long segment, bus;
> @@ -504,6 +514,14 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
> strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
> device->driver_data = root;
>
> + if (arch_acpi_pci_root_add(root)) {
> + printk(KERN_ERR PREFIX
> + "can't add MMCFG information for Bus %04x:%02x\n",
> + root->segment, (unsigned int)root->secondary.start);
> + result = -ENODEV;
> + goto out_free;
> + }
> +
> /*
> * All supported architectures that use ACPI have support for
> * PCI domains, so we indicate this in _OSC support capabilities.
> @@ -629,6 +647,7 @@ out_del_root:
> list_del_rcu(&root->node);
> mutex_unlock(&acpi_pci_root_lock);
> synchronize_rcu();
> + arch_acpi_pci_root_remove(root);
> out_free:
> kfree(root);
> return result;
> @@ -679,6 +698,7 @@ out:
> list_del_rcu(&root->node);
> mutex_unlock(&acpi_pci_root_lock);
> synchronize_rcu();
> + arch_acpi_pci_root_remove(root);
> kfree(root);
>
> return 0;
> diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
> index 38f5088..99bda75 100644
> --- a/include/acpi/acnames.h
> +++ b/include/acpi/acnames.h
> @@ -62,6 +62,7 @@
> #define METHOD_NAME__AEI "_AEI"
> #define METHOD_NAME__PRW "_PRW"
> #define METHOD_NAME__SRS "_SRS"
> +#define METHOD_NAME__CBA "_CBA"
>
> /* Method names - these methods must appear at the namespace root */
>
> diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
> index ac93634..816b971 100644
> --- a/include/linux/pci-acpi.h
> +++ b/include/linux/pci-acpi.h
> @@ -38,6 +38,9 @@ static inline acpi_handle acpi_pci_get_bridge_handle(struct pci_bus *pbus)
>
> void acpi_pci_root_rescan(void);
>
> +extern int arch_acpi_pci_root_add(struct acpi_pci_root *root);
> +extern int arch_acpi_pci_root_remove(struct acpi_pci_root *root);
> +
don't need extern here.
> #else
>
> static inline void acpi_pci_root_rescan(void) { }
> --
> 1.7.5.4
>
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