Re: [PATCH 2/3] amd/pci: Support additional MMIO ranges capabilities

[Bjorn Helgaas]

On Wed, Mar 5, 2014 at 2:06 PM,  <suravee.suthikulpanit@xxxxxxx> wrote:
> From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
>
> This patch adds supports for additional MMIO ranges (16 ranges)
> Also, each MMIO base/limit can now supports upto 48-bit MMIO address.
> However, this requires initializing the ECS sooner since the new registers
> are in the ECS ranges.

Sorry I didn't look at this before; I had thought the _PXM issue was
the main point of this series.

What's the reason for this particular patch?  Does this fix a problem?

The original reason for amd_bus.c was to figure out host bridge
aperture and NUMA information before Linux knew how to deal with _CRS
methods.  But Linux does pay attention to the PNP0A08 and PNP0A03 _CRS
methods now, so the info from amd_bus.c shouldn't be necessary in most
cases.

Bjorn

> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
> Tested-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx>
> ---
>  arch/x86/pci/amd_bus.c |  116 +++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 94 insertions(+), 22 deletions(-)
>
> diff --git a/arch/x86/pci/amd_bus.c b/arch/x86/pci/amd_bus.c
> index 4041cbe..577995e 100644
> --- a/arch/x86/pci/amd_bus.c
> +++ b/arch/x86/pci/amd_bus.c
> @@ -15,15 +15,28 @@
>  #define AMD_NB_F0_UNIT_ID                       0x64
>  #define AMD_NB_F1_MMIO_BASE_REG                 0x80
>  #define AMD_NB_F1_MMIO_LIMIT_REG                0x84
> +#define AMD_NB_F1_MMIO_BASE_LIMIT_HI_REG        0x180
>  #define AMD_NB_F1_IO_BASEA_DDR_REG              0xc0
>  #define AMD_NB_F1_IO_LIMIT_ADDR_REG             0xc4
>  #define AMD_NB_F1_CONFIG_MAP_REG                0xe0
>
>  #define RANGE_NUM                               16
> -#define AMD_NB_F1_MMIO_RANGES                   8
> +#define AMD_NB_F1_MMIO_RANGES                   16
>  #define AMD_NB_F1_IOPORT_RANGES                 4
>  #define AMD_NB_F1_CONFIG_MAP_RANGES             4
>
> +#define AMD_PCIE_CF8(bus, dev, fn, reg) \
> +                       (0x80000000 | \
> +                       ((reg & 0xF00) << 16) | \
> +                       ((bus & 0xF) << 16) | \
> +                       ((dev & 0x1F) << 11) | \
> +                       ((fn & 0x7) << 8) | \
> +                       ((reg & 0xFC)))
> +
> +static bool amd_early_ecs_enabled;
> +
> +static int __init pci_io_ecs_init(u8 bus, u8 slot);
> +
>  /*
>   * This discovers the pcibus <-> node mapping on AMD K8.
>   * also get peer root bus resource for io,mmio
> @@ -44,6 +57,20 @@ static struct amd_hostbridge hb_probes[] __initdata = {
>         { 0xff, 0   , PCI_DEVICE_ID_AMD_10H_NB_HT },
>  };
>
> +/* This version of read_pci_config allows reading of registers in ECS area */
> +static inline int _amd_read_pci_config(u8 bus, u8 slot, u8 fn, u32 offset)
> +{
> +       u32 value;
> +
> +       if ((!amd_early_ecs_enabled) && (offset > 0xFF))
> +               return -1;
> +
> +       outl(AMD_PCIE_CF8(bus, slot, fn, offset), 0xcf8);
> +       value = inl(0xcfc);
> +
> +       return value;
> +}
> +
>  static struct pci_root_info __init *find_pci_root_info(int node, int link)
>  {
>         struct pci_root_info *info;
> @@ -53,6 +80,9 @@ static struct pci_root_info __init *find_pci_root_info(int node, int link)
>                 if (info->node == node && info->link == link)
>                         return info;
>
> +       pr_warn("AMD-Bus: WARNING: Failed to find root info for node %#x, link %#x\n",
> +               node, link);
> +
>         return NULL;
>  }
>
> @@ -65,6 +95,7 @@ static void __init set_mp_bus_range_to_node(int min_bus, int max_bus, int node)
>                 set_mp_bus_to_node(j, node);
>  #endif
>  }
> +
>  /**
>   * early_fill_mp_bus_to_node()
>   * called before pcibios_scan_root and pci_scan_bus
> @@ -132,6 +163,12 @@ static int __init early_fill_mp_bus_info(void)
>
>         printk(KERN_DEBUG "Found AMD hostbridge at %x:%x.0\n", bus, slot);
>
> +       /* We enabling ECS mode prior to probing MMIO since
> +        * the MMIO-related registers are in the ECS area.
> +        */
> +       pci_io_ecs_init(bus, slot);
> +
> +       found = false;
>         for (i = 0; i < AMD_NB_F1_CONFIG_MAP_RANGES; i++) {
>                 int min_bus;
>                 int max_bus;
> @@ -142,6 +179,7 @@ static int __init early_fill_mp_bus_info(void)
>                 if ((reg & 7) != 3)
>                         continue;
>
> +               found = true;
>                 min_bus = (reg >> 16) & 0xff;
>                 max_bus = (reg >> 24) & 0xff;
>                 node = (reg >> 4) & 0x07;
> @@ -151,6 +189,14 @@ static int __init early_fill_mp_bus_info(void)
>                 info = alloc_pci_root_info(min_bus, max_bus, node, link);
>         }
>
> +       if (!found) {
> +               /* In case there is no AMDNB_F1_CONFIG_MAP_REGs,
> +                * we just use default to bus 0, node 0 link 0)
> +                */
> +               set_mp_bus_range_to_node(0, 0, 0);
> +               info = alloc_pci_root_info(0, 0, 0, 0);
> +       }
> +
>         /* get the default node and link for left over res */
>         reg = read_pci_config(bus, slot, 0, AMD_NB_F0_NODE_ID);
>         def_node = (reg >> 8) & 0x07;
> @@ -159,6 +205,7 @@ static int __init early_fill_mp_bus_info(void)
>
>         memset(range, 0, sizeof(range));
>         add_range(range, RANGE_NUM, 0, 0, 0xffff + 1);
> +
>         /* io port resource */
>         for (i = 0; i < AMD_NB_F1_IOPORT_RANGES; i++) {
>                 reg = read_pci_config(bus, slot, 1,
> @@ -186,6 +233,7 @@ static int __init early_fill_mp_bus_info(void)
>                 update_res(info, start, end, IORESOURCE_IO, 1);
>                 subtract_range(range, RANGE_NUM, start, end + 1);
>         }
> +
>         /* add left over io port range to def node/link, [0, 0xffff] */
>         /* find the position */
>         info = find_pci_root_info(def_node, def_link);
> @@ -229,23 +277,45 @@ static int __init early_fill_mp_bus_info(void)
>
>         /* mmio resource */
>         for (i = 0; i < AMD_NB_F1_MMIO_RANGES; i++) {
> -               reg = read_pci_config(bus, slot, 1,
> -                               AMD_NB_F1_MMIO_BASE_REG + (i << 3));
> +               u64 tmp;
> +               u32 base = AMD_NB_F1_MMIO_BASE_REG + (i << 3);
> +               u32 limit = AMD_NB_F1_MMIO_LIMIT_REG + (i << 3);
> +               u32 base_limit_hi = AMD_NB_F1_MMIO_BASE_LIMIT_HI_REG + (i << 2);
> +
> +               if (i >= 12) {
> +                       /* Range 12 base/limit starts at 0x2A0 */
> +                       base += 0x1c0;
> +                       limit += 0x1c0;
> +                       /* Range 12 base/limit hi starts at 0x2C0 */
> +                       base_limit_hi += 0x110;
> +               } else if (i >= 8) {
> +                       /* Range 8 base/limit starts at 0x1A0 */
> +                       base += 0xe0;
> +                       limit += 0xe0;
> +                       /* Range 12 base/limit hi starts at 0x1C0 */
> +                       base_limit_hi += 0x20;
> +               }
> +
> +               /* Base lo */
> +               reg = _amd_read_pci_config(bus, slot, 1, base);
>                 if (!(reg & 3))
>                         continue;
>
> -               start = reg & 0xffffff00; /* 39:16 on 31:8*/
> -               start <<= 8;
> -               reg = read_pci_config(bus, slot, 1,
> -                               AMD_NB_F1_MMIO_LIMIT_REG + (i << 3));
> +               start = (reg & 0xffffff00UL) << 8; /* 39:16 on 31:8*/
> +
> +               /* Limit lo */
> +               reg = _amd_read_pci_config(bus, slot, 1, limit);
>                 node = reg & 0x07;
>                 link = (reg >> 4) & 0x03;
> -               end = (reg & 0xffffff00);
> -               end <<= 8;
> -               end |= 0xffff;
> +               end = (reg & 0xffffff00UL) << 8; /* 39:16 on 31:8*/
> +               end |= 0xffffUL;
>
> -               info = find_pci_root_info(node, link);
> +               /* Base/Limit hi */
> +               tmp = _amd_read_pci_config(bus, slot, 1, base_limit_hi);
> +               start |= ((tmp & 0xffUL) << 40);
> +               end |= ((tmp & (0xffUL << 16)) << 24);
>
> +               info = find_pci_root_info(node, link);
>                 if (!info)
>                         continue;
>
> @@ -373,20 +443,24 @@ static struct notifier_block amd_cpu_notifier = {
>         .notifier_call  = amd_cpu_notify,
>  };
>
> -static void __init pci_enable_pci_io_ecs(void)
> +static void __init pci_enable_pci_io_ecs(u8 bus, u8 slot)
>  {
>  #ifdef CONFIG_AMD_NB
>         unsigned int i, n;
> +       u8 limit;
>
>         for (n = i = 0; !n && amd_nb_bus_dev_ranges[i].dev_limit; ++i) {
> -               u8 bus = amd_nb_bus_dev_ranges[i].bus;
> -               u8 slot = amd_nb_bus_dev_ranges[i].dev_base;
> -               u8 limit = amd_nb_bus_dev_ranges[i].dev_limit;
> +               /* Try matching for the bus range */
> +               if ((bus != amd_nb_bus_dev_ranges[i].bus) ||
> +                   (slot != amd_nb_bus_dev_ranges[i].dev_base))
> +                       continue;
> +
> +               limit = amd_nb_bus_dev_ranges[i].dev_limit;
>
> +               /* Setup all northbridges within the range */
>                 for (; slot < limit; ++slot) {
>                         u32 val = read_pci_config(bus, slot, 3, 0);
> -
> -                       if (!early_is_amd_nb(val))
> +                       if (!val)
>                                 continue;
>
>                         val = read_pci_config(bus, slot, 3, 0x8c);
> @@ -394,13 +468,14 @@ static void __init pci_enable_pci_io_ecs(void)
>                                 val |= ENABLE_CF8_EXT_CFG >> 32;
>                                 write_pci_config(bus, slot, 3, 0x8c, val);
>                         }
> +                       amd_early_ecs_enabled = true;
>                         ++n;
>                 }
>         }
>  #endif
>  }
>
> -static int __init pci_io_ecs_init(void)
> +static int __init pci_io_ecs_init(u8 bus, u8 slot)
>  {
>         int cpu;
>
> @@ -408,9 +483,7 @@ static int __init pci_io_ecs_init(void)
>          if (boot_cpu_data.x86 < 0x10)
>                 return 0;
>
> -       /* Try the PCI method first. */
> -       if (early_pci_allowed())
> -               pci_enable_pci_io_ecs();
> +       pci_enable_pci_io_ecs(bus, slot);
>
>         register_cpu_notifier(&amd_cpu_notifier);
>         for_each_online_cpu(cpu)
> @@ -427,7 +500,6 @@ static int __init amd_postcore_init(void)
>                 return 0;
>
>         early_fill_mp_bus_info();
> -       pci_io_ecs_init();
>
>         return 0;
>  }
> --
> 1.7.10.4
>
>
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