Subject: [PATCH V1 11/11] arm64, pci, acpi: Support for ACPI based PCI hostbridge init

From: [email-masked] (Sinan Kaya)
Date: Wed, 28 Oct 2015 16:36:00 -0400

On 10/28/2015 2:46 PM, Sinan Kaya wrote:
>
> On 10/27/2015 12:38 PM, Tomasz Nowicki wrote:
>> Because of two patch series:
>> 1. Jiang Liu's common interface to support PCI host bridge init
>> 2. Refactoring of MMCONFIG, part of this patch set
>> now we can think about PCI buses enumeration for ARM64 and ACPI tables.
>>
>> This patch introduce ACPI based PCI hostbridge init calls which
>> use information from MCFG table (PCI config space regions) and
>> _CRS (IO/irq resources) to initialize PCI hostbridge.
>>
>> Signed-off-by: Tomasz Nowicki <[email-masked]>
>> Signed-off-by: Hanjun Guo <[email-masked]>
>> Signed-off-by: Suravee Suthikulpanit <[email-masked]>
>> CC: Arnd Bergmann <[email-masked]>
>> CC: Catalin Marinas <[email-masked]>
>> CC: Liviu Dudau <[email-masked]>
>> CC: Lorenzo Pieralisi <[email-masked]>
>> CC: Will Deacon <[email-masked]>
>> ---
>>   arch/arm64/Kconfig      |   6 ++
>>   arch/arm64/kernel/pci.c | 208
>> +++++++++++++++++++++++++++++++++++++++++++++---
>>   2 files changed, 202 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 07d1811..bbcc6b1 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -89,6 +89,7 @@ config ARM64
>>       select SPARSE_IRQ
>>       select SYSCTL_EXCEPTION_TRACE
>>       select HAVE_CONTEXT_TRACKING
>> +    select HAVE_PCI_ECAM
>>       help
>>         ARM 64-bit (AArch64) Linux support.
>>
>> @@ -202,6 +203,11 @@ source "drivers/pci/Kconfig"
>>   source "drivers/pci/pcie/Kconfig"
>>   source "drivers/pci/hotplug/Kconfig"
>>
>> +config PCI_MMCONFIG
>> +    def_bool y
>> +    select PCI_ECAM
>> +    depends on ACPI
>> +
>>   endmenu
>>
>>   menu "Kernel Features"
>> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
>> index b3d098b..66cc1ae 100644
>> --- a/arch/arm64/kernel/pci.c
>> +++ b/arch/arm64/kernel/pci.c
>> @@ -11,12 +11,15 @@
>>    */
>>
>>   #include <linux/acpi.h>
>> +#include <linux/ecam.h>
>>   #include <linux/init.h>
>>   #include <linux/io.h>
>>   #include <linux/kernel.h>
>>   #include <linux/mm.h>
>> +#include <linux/of_address.h>
>>   #include <linux/of_pci.h>
>>   #include <linux/of_platform.h>
>> +#include <linux/pci-acpi.h>
>>   #include <linux/slab.h>
>>
>>   #include <asm/pci-bridge.h>
>> @@ -52,35 +55,216 @@ int pcibios_enable_device(struct pci_dev *dev,
>> int mask)
>>   }
>>
>>   /*
>> - * Try to assign the IRQ number from DT when adding a new device
>> + * Try to assign the IRQ number from DT/ACPI when adding a new device
>>    */
>>   int pcibios_add_device(struct pci_dev *dev)
>>   {
>> -    dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
>> +    if (acpi_disabled)
>> +        dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
>> +#ifdef CONFIG_ACPI
>> +    else
>> +        acpi_pci_irq_enable(dev);
>> +#endif
>>
>>       return 0;
>>   }
>>
>> +#ifdef CONFIG_ACPI
>> +int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
>> +{
>> +    struct acpi_pci_root *root = bridge->bus->sysdata;
>> +
>> +    ACPI_COMPANION_SET(&bridge->dev, root->device);
>> +    return 0;
>> +}
>> +
>> +void pcibios_add_bus(struct pci_bus *bus)
>> +{
>> +    acpi_pci_add_bus(bus);
>> +}
>> +
>> +void pcibios_remove_bus(struct pci_bus *bus)
>> +{
>> +    acpi_pci_remove_bus(bus);
>> +}
>> +
>> +static int __init pcibios_assign_resources(void)
>> +{
>> +    if (acpi_disabled)
>> +        return 0;
>> +
>> +    pci_assign_unassigned_resources();
>> +    return 0;
>> +}
>>   /*
>> - * raw_pci_read/write - Platform-specific PCI config space access.
>> + * rootfs_initcall comes after subsys_initcall and fs_initcall_sync,
>> + * so we know acpi scan and PCI_FIXUP_FINAL quirks have both run.
>>    */
>> -int raw_pci_read(unsigned int domain, unsigned int bus,
>> -          unsigned int devfn, int reg, int len, u32 *val)
>> +rootfs_initcall(pcibios_assign_resources);
>> +
>> +static void __iomem *
>> +pci_mcfg_dev_base(struct pci_bus *bus, unsigned int devfn, int offset)
>>   {
>> -    return -ENXIO;
>> +    struct pci_mmcfg_region *cfg;
>> +
>> +    cfg = pci_mmconfig_lookup(pci_domain_nr(bus), bus->number);
>> +    if (cfg && cfg->virt)
>> +        return cfg->virt +
>> +            (PCI_MMCFG_BUS_OFFSET(bus->number) | (devfn << 12)) +
>> +            offset;
>> +    return NULL;
>>   }
>>
>> -int raw_pci_write(unsigned int domain, unsigned int bus,
>> -        unsigned int devfn, int reg, int len, u32 val)
>> +struct pci_ops pci_root_ops = {
>> +    .map_bus = pci_mcfg_dev_base,
>> +    .read = pci_generic_config_read,
>> +    .write = pci_generic_config_write,
>
>
> Can you change these with pci_generic_config_read32 and
> pci_generic_config_write32? We have some targets that can only do 32
> bits PCI config space access.
>
>> +};
>> +
>> +#ifdef CONFIG_PCI_MMCONFIG
>> +static int pci_add_mmconfig_region(struct acpi_pci_root_info *ci)
>>   {
>> -    return -ENXIO;
>> +    struct pci_mmcfg_region *cfg;
>> +    struct acpi_pci_root *root;
>> +    int seg, start, end, err;
>> +
>> +    root = ci->root;
>> +    seg = root->segment;
>> +    start = root->secondary.start;
>> +    end = root->secondary.end;
>> +
>> +    cfg = pci_mmconfig_lookup(seg, start);
>> +    if (cfg)
>> +        return 0;
>> +
>> +    cfg = pci_mmconfig_alloc(seg, start, end, root->mcfg_addr);
>> +    if (!cfg)
>> +        return -ENOMEM;
>> +
>> +    err = pci_mmconfig_inject(cfg);
>> +    return err;
>>   }
>>
>> -#ifdef CONFIG_ACPI
>> +static void pci_remove_mmconfig_region(struct acpi_pci_root_info *ci)
>> +{
>> +    struct acpi_pci_root *root = ci->root;
>> +    struct pci_mmcfg_region *cfg;
>> +
>> +    cfg = pci_mmconfig_lookup(root->segment, root->secondary.start);
>> +    if (cfg)
>> +        return;
>> +
>> +    if (cfg->hot_added)
>> +        pci_mmconfig_delete(root->segment, root->secondary.start,
>> +                    root->secondary.end);
>> +}
>> +#else
>> +static int pci_add_mmconfig_region(struct acpi_pci_root_info *ci)
>> +{
>> +    return 0;
>> +}
>> +
>> +static void pci_remove_mmconfig_region(struct acpi_pci_root_info *ci)
>> { }
>> +#endif
>> +
>> +static int pci_acpi_root_init_info(struct acpi_pci_root_info *ci)
>> +{
>> +    return pci_add_mmconfig_region(ci);
>> +}
>> +
>> +static void pci_acpi_root_release_info(struct acpi_pci_root_info *ci)
>> +{
>> +    pci_remove_mmconfig_region(ci);
>> +    kfree(ci);
>> +}
>> +
>> +static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info
>> *ci)
>> +{
>> +    struct resource_entry *entry, *tmp;
>> +    int ret;
>> +
>> +    ret = acpi_pci_probe_root_resources(ci);
>> +    if (ret < 0)
>> +        return ret;
>> +
>> +    resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
>> +        struct resource *res = entry->res;
>> +
>> +        /*
>> +         * Special handling for ARM IO range
>> +         * TODO: need to move pci_register_io_range() function out
>> +         * of drivers/of/address.c for both used by DT and ACPI
>> +         */
>> +        if (res->flags & IORESOURCE_IO) {
>> +            unsigned long port;
>> +            int err;
>> +            resource_size_t length = res->end - res->start;
>> +
>> +            err = pci_register_io_range(res->start, length);
>> +            if (err) {
>> +                resource_list_destroy_entry(entry);
>> +                continue;
>> +            }
>> +
>> +            port = pci_address_to_pio(res->start);
>> +            if (port == (unsigned long)-1) {
>> +                resource_list_destroy_entry(entry);
>> +                continue;
>> +            }
>> +
>> +            res->start = port;
>> +            res->end = res->start + length - 1;
>> +
>> +            if (pci_remap_iospace(res, res->start) < 0)
>> +                resource_list_destroy_entry(entry);
>> +        }
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +static struct acpi_pci_root_ops acpi_pci_root_ops = {
>> +    .pci_ops = &pci_root_ops,
>> +    .init_info = pci_acpi_root_init_info,
>> +    .release_info = pci_acpi_root_release_info,
>> +    .prepare_resources = pci_acpi_root_prepare_resources,
>> +};
>> +
>>   /* Root bridge scanning */
>>   struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>>   {
>> -    /* TODO: Should be revisited when implementing PCI on ACPI */
>> -    return NULL;
>> +    int node = acpi_get_node(root->device->handle);
>> +    int domain = root->segment;
>> +    int busnum = root->secondary.start;
>> +    struct acpi_pci_root_info *info;
>> +    struct pci_bus *bus;
>> +
>> +    if (domain && !pci_domains_supported) {
>> +        pr_warn("PCI %04x:%02x: multiple domains not supported.\n",
>> +            domain, busnum);
>> +        return NULL;
>> +    }
>> +
>> +    info = kzalloc_node(sizeof(*info), GFP_KERNEL, node);
>> +    if (!info) {
>> +        dev_err(&root->device->dev,
>> +            "pci_bus %04x:%02x: ignored (out of memory)\n",
>> +            domain, busnum);
>> +        return NULL;
>> +    }
>> +
>> +    bus = acpi_pci_root_create(root, &acpi_pci_root_ops, info, root);
>> +
>> +    /* After the PCI-E bus has been walked and all devices discovered,
>> +     * configure any settings of the fabric that might be necessary.
>> +     */
>> +    if (bus) {
>> +        struct pci_bus *child;
>> +
>> +        list_for_each_entry(child, &bus->children, node)
>> +            pcie_bus_configure_settings(child);
>> +    }
>> +
>> +    return bus;
>>   }
>>   #endif
>>
>

Tomasz,
I was asked to test your new patchset on our platform. With the new 
patchset, I'm seeing two problems.

1. ACPI code is unable to discover the interrupt numbers when objects 
are ordered as follows in the ACPI file

PNP0A08 object
PNP0C0F INTA object
PNP0C0F INTB object
PNP0C0F INTC object
PNP0C0F INTD object

This gives me invalid link context error.

pci 0000:00:00.0: PCI INT A: no GSI
pci 0000:01:00.0: Derived GSI for 0000:01:00.0 INT A from 0000:00:00.0
acpi PNP0C0F:00: Invalid link context

If I order it like this in the ACPI file,

PNP0C0F INTA object
PNP0C0F INTB object
PNP0C0F INTC object
PNP0C0F INTD object
PNP0A08 object

then, the legacy interrupt numbers can be discovered properly.

2. The second problem is about the PCIe resources.

pci_0000:01:00.0:_can't_enable_device:_BAR_0_[mem_0x80100100000-0x80100101fff_64bit]_not_claimed
pci 0000:01:00.0: Can't enable PCI device, BIOS handoff failed.
pci 0000:00:00.0: BAR 14: assigned [mem 0x80100100000-0x801003fffff]
pci 0000:00:00.0: BAR 13: no space for [io  size 0x1000]
pci 0000:00:00.0: BAR 13: failed to assign [io  size 0x1000]
pci 0000:00:00.0: BAR 13: no space for [io  size 0x1000]
pci 0000:00:00.0: BAR 13: failed to assign [io  size 0x1000]
pci 0000:01:00.0: BAR 0: assigned [mem 0x80100100000-0x80100101fff 64bit]

For some reason, the kernel is unable to assign resources.

I appreciate any pointers you might give.

-- 
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
Linux Foundation Collaborative Project