On Fri, May 4, 2012 at 9:00 PM, Jiang Liu <liuj97@xxxxxxxxx> wrote:
> From: Jiang Liu <jiang.liu@xxxxxxxxxx>
>
> This patch enhances pci_root driver to update MMCFG information when
> hot-plugging PCI root bridges on x86 platforms.
>
> Signed-off-by: Jiang Liu <liuj97@xxxxxxxxx>
> ---
> arch/x86/include/asm/pci_x86.h | 1 +
> arch/x86/pci/acpi.c | 57 ++++++++++++++++++++++++++++++++++++++++
> arch/x86/pci/mmconfig_32.c | 2 +-
> arch/x86/pci/mmconfig_64.c | 2 +-
> drivers/acpi/pci_root.c | 22 ++++++++++++++++
> include/acpi/acnames.h | 1 +
> include/acpi/acpi_bus.h | 1 +
> include/linux/pci-acpi.h | 4 +++
> 8 files changed, 88 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
> index 3252c97..5e1d9a6 100644
> --- a/arch/x86/include/asm/pci_x86.h
> +++ b/arch/x86/include/asm/pci_x86.h
> @@ -100,6 +100,7 @@ struct pci_raw_ops {
> extern const struct pci_raw_ops *raw_pci_ops;
> extern const struct pci_raw_ops *raw_pci_ext_ops;
>
> +extern const struct pci_raw_ops pci_mmcfg;
> extern const struct pci_raw_ops pci_direct_conf1;
> extern bool port_cf9_safe;
>
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index da0149d..80cc3fa 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -4,6 +4,7 @@
> #include <linux/irq.h>
> #include <linux/dmi.h>
> #include <linux/slab.h>
> +#include <linux/pci-acpi.h>
> #include <asm/numa.h>
> #include <asm/pci_x86.h>
>
> @@ -488,6 +489,62 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
> return bus;
> }
>
> +int __devinit arch_acpi_pci_root_add(struct acpi_pci_root *root,
> + unsigned long long base_addr)
> +{
> + int result;
> +
> + /* return success if MMCFG is not in use */
> + if (raw_pci_ext_ops && raw_pci_ext_ops != &pci_mmcfg)
> + return 0;
> +
> + if (!(pci_probe & PCI_PROBE_MMCONF)) {
> + /* still could use raw_pci_ops for devices on segment 0 */
> + if (root->segment == 0)
> + return 0;
> +
> + printk(KERN_ERR "MMCFG is disabled, "
> + "can't access CFG space for Bus %04x:%02x\n",
> + root->segment, (unsigned int)root->secondary.start);
> + return -ENODEV;
> + }
> +
> + result = pci_mmconfig_insert(root->segment, root->secondary.start,
> + root->secondary.end, base_addr);
> + if (result == -EEXIST) {
> + /* return success if MMCFG item already exists */
> + result = 0;
> + } else if (result == 0) {
> + /* enable MMCFG if it hasn't been enabled yet */
> + if (raw_pci_ext_ops == NULL)
> + raw_pci_ext_ops = &pci_mmcfg;
> + root->mmconf_added = true;
> + } else if (root->segment == 0 && raw_pci_ext_ops == NULL &&
> + raw_pci_ops != NULL) {
> + /*
> + * system doesn't support extended configuration space,
> + * still could use raw_pci_ops with it
> + */
> + result = 0;
> + } else {
> + printk(KERN_ERR
> + "can't add MMCFG information for Bus %04x:%02x\n",
> + root->segment, (unsigned int)root->secondary.start);
> + }
> +
> + return result;
> +}
> +
> +void arch_acpi_pci_root_remove(struct acpi_pci_root *root)
> +{
> + if (root->mmconf_added) {
> + pci_mmconfig_delete(root->segment,
> + root->secondary.start,
> + root->secondary.end);
> + root->mmconf_added = false;
> + }
> +}
> +
> int __init pci_acpi_init(void)
> {
> struct pci_dev *dev = NULL;
> diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
> index a22785d..db63ac2 100644
> --- a/arch/x86/pci/mmconfig_32.c
> +++ b/arch/x86/pci/mmconfig_32.c
> @@ -126,7 +126,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
> return 0;
> }
>
> -static const struct pci_raw_ops pci_mmcfg = {
> +const struct pci_raw_ops pci_mmcfg = {
> .read = pci_mmcfg_read,
> .write = pci_mmcfg_write,
> };
> diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
> index 4e05779..34c08dd 100644
> --- a/arch/x86/pci/mmconfig_64.c
> +++ b/arch/x86/pci/mmconfig_64.c
> @@ -90,7 +90,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
> return 0;
> }
>
> -static const struct pci_raw_ops pci_mmcfg = {
> +const struct pci_raw_ops pci_mmcfg = {
> .read = pci_mmcfg_read,
> .write = pci_mmcfg_write,
> };
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index b313125..8d3f821 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,
> + unsigned long long base_addr)
> +{
> + return 0;
> +}
> +
> +void __weak arch_acpi_pci_root_remove(struct acpi_pci_root *root)
> +{
> +}
> +
> static int __devinit acpi_pci_root_add(struct acpi_device *device)
> {
> unsigned long long segment, bus;
> @@ -457,6 +467,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
> acpi_handle handle;
> struct acpi_device *child;
> u32 flags, base_flags;
> + unsigned long long base_addr;
>
> root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
> if (!root)
> @@ -504,6 +515,15 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
> strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
> device->driver_data = root;
>
> + status = acpi_evaluate_integer(root->device->handle, METHOD_NAME__CBA,
> + NULL, &base_addr);
> + if (ACPI_FAILURE(status))
> + base_addr = 0;
I think the MCFG lookup should happen here, since MCFG is a generic
ACPI table and is not arch-specific. Maybe something like
"phys_addr_t acpi_mcfg_lookup(int domain, struct resource *bus_nr, int
*last_bus_nr)" that would return the bus 0-relative base address (like
what _CBA gives you) and the end of the bus number range from MCFG.
> + if (arch_acpi_pci_root_add(root, base_addr)) {
This should be something like "pci_add_mmconfig(int domain, struct
resource *bus_nr, phys_addr_t base)". The bus_nr resource would be
the range from _CRS or a copy truncated to the end we found in MCFG.
> + result = -ENODEV;
I don't think this is a fatal error. If we don't have MMCONFIG space
for this host bridge, we can just fall back to the default pci_ops and
still use the host bridge.
> + goto out_free;
> + }
> +
> /*
> * All supported architectures that use ACPI have support for
> * PCI domains, so we indicate this in _OSC support capabilities.
> @@ -629,6 +649,7 @@ 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;
> @@ -686,6 +707,7 @@ 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/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 333d38c..4171277 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -371,6 +371,7 @@ struct acpi_pci_root {
> u32 osc_support_set; /* _OSC state of support bits */
> u32 osc_control_set; /* _OSC state of control bits */
> bool hot_added;
> + bool mmconf_added;
> };
>
> /* helper */
> diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
> index 4462350..d017dc0 100644
> --- a/include/linux/pci-acpi.h
> +++ b/include/linux/pci-acpi.h
> @@ -18,6 +18,10 @@ extern acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
> struct pci_dev *pci_dev);
> extern acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev);
>
> +int arch_acpi_pci_root_add(struct acpi_pci_root *root,
> + unsigned long long base_addr);
> +void arch_acpi_pci_root_remove(struct acpi_pci_root *root);
> +
> static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev)
> {
> struct pci_bus *pbus = pdev->bus;
> --
> 1.7.9.5
>
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