Hi RobH, Robin,

On 5/8/2020 6:36 PM, Kishon Vijay Abraham I wrote:
> Cadence PCIe core driver (host mode) uses "cdns,no-bar-match-nbits"
> property to configure the number of bits passed through from PCIe
> address to internal address in Inbound Address Translation register.
> This only used the NO MATCH BAR.
> 
> However standard PCI dt-binding already defines "dma-ranges" to
> describe the address ranges accessible by PCIe controller. Add support
> in Cadence PCIe host driver to parse dma-ranges and configure the
> inbound regions for BAR0, BAR1 and NO MATCH BAR. Cadence IP specifies
> maximum size for BAR0 as 256GB, maximum size for BAR1 as 2 GB, so if
> the dma-ranges specifies a size larger than the maximum allowed, the
> driver will split and configure the BARs.
> 
> Legacy device tree binding compatibility is maintained by retaining
> support for "cdns,no-bar-match-nbits".

Do you have any comments for this patch?

Tom,

where you able to test this in Cadence platform?

Thanks
Kishon

> 
> Signed-off-by: Kishon Vijay Abraham I <kis...@ti.com>
> ---
>  .../controller/cadence/pcie-cadence-host.c    | 141 ++++++++++++++++--
>  drivers/pci/controller/cadence/pcie-cadence.h |  17 ++-
>  2 files changed, 141 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c 
> b/drivers/pci/controller/cadence/pcie-cadence-host.c
> index 6ecebb79057a..2485ecd8434d 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence-host.c
> +++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
> @@ -11,6 +11,12 @@
>  
>  #include "pcie-cadence.h"
>  
> +static u64 cdns_rp_bar_max_size[] = {
> +     [RP_BAR0] = _ULL(128 * SZ_2G),
> +     [RP_BAR1] = SZ_2G,
> +     [RP_NO_BAR] = SZ_64T,
> +};
> +
>  void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
>                              int where)
>  {
> @@ -106,6 +112,117 @@ static int cdns_pcie_host_init_root_port(struct 
> cdns_pcie_rc *rc)
>       return 0;
>  }
>  
> +static void cdns_pcie_host_bar_ib_config(struct cdns_pcie_rc *rc,
> +                                      enum cdns_pcie_rp_bar bar,
> +                                      u64 cpu_addr, u32 aperture)
> +{
> +     struct cdns_pcie *pcie = &rc->pcie;
> +     u32 addr0, addr1;
> +
> +     addr0 = CDNS_PCIE_AT_IB_RP_BAR_ADDR0_NBITS(aperture) |
> +             (lower_32_bits(cpu_addr) & GENMASK(31, 8));
> +     addr1 = upper_32_bits(cpu_addr);
> +     cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR0(bar), addr0);
> +     cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR1(bar), addr1);
> +}
> +
> +static int cdns_pcie_host_bar_config(struct cdns_pcie_rc *rc,
> +                                  struct resource_entry *entry,
> +                                  enum cdns_pcie_rp_bar *index)
> +{
> +     u64 cpu_addr, pci_addr, size, winsize;
> +     struct cdns_pcie *pcie = &rc->pcie;
> +     struct device *dev = pcie->dev;
> +     enum cdns_pcie_rp_bar bar;
> +     unsigned long flags;
> +     u32 aperture;
> +     u32 value;
> +
> +     cpu_addr = entry->res->start;
> +     flags = entry->res->flags;
> +     pci_addr = entry->res->start - entry->offset;
> +     size = resource_size(entry->res);
> +     bar = *index;
> +
> +     if (entry->offset) {
> +             dev_err(dev, "Cannot map PCI addr: %llx to CPU addr: %llx\n",
> +                     pci_addr, cpu_addr);
> +             return -EINVAL;
> +     }
> +
> +     value = cdns_pcie_readl(pcie, CDNS_PCIE_LM_RC_BAR_CFG);
> +     while (size > 0) {
> +             if (bar > RP_NO_BAR) {
> +                     dev_err(dev, "Failed to map inbound regions!\n");
> +                     return -EINVAL;
> +             }
> +
> +             winsize = size;
> +             if (size > cdns_rp_bar_max_size[bar])
> +                     winsize = cdns_rp_bar_max_size[bar];
> +
> +             aperture = ilog2(winsize);
> +
> +             cdns_pcie_host_bar_ib_config(rc, bar, cpu_addr, aperture);
> +
> +             if (bar == RP_NO_BAR)
> +                     break;
> +
> +             if (winsize + cpu_addr >= SZ_4G) {
> +                     if (!(flags & IORESOURCE_PREFETCH))
> +                             value |= LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar);
> +                     value |= LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar);
> +             } else {
> +                     if (!(flags & IORESOURCE_PREFETCH))
> +                             value |= LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar);
> +                     value |= LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar);
> +             }
> +
> +             value |= LM_RC_BAR_CFG_APERTURE(bar, aperture);
> +
> +             size -= winsize;
> +             cpu_addr += winsize;
> +             bar++;
> +     }
> +     cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
> +     *index = bar;
> +
> +     return 0;
> +}
> +
> +static int cdns_pcie_host_map_dma_ranges(struct cdns_pcie_rc *rc)
> +{
> +     enum cdns_pcie_rp_bar bar = RP_BAR0;
> +     struct cdns_pcie *pcie = &rc->pcie;
> +     struct device *dev = pcie->dev;
> +     struct device_node *np = dev->of_node;
> +     struct pci_host_bridge *bridge;
> +     struct resource_entry *entry;
> +     u32 no_bar_nbits = 32;
> +     int err;
> +
> +     bridge = pci_host_bridge_from_priv(rc);
> +     if (!bridge)
> +             return -ENOMEM;
> +
> +     if (list_empty(&bridge->dma_ranges)) {
> +             of_property_read_u32(np, "cdns,no-bar-match-nbits",
> +                                  &no_bar_nbits);
> +             cdns_pcie_host_bar_ib_config(rc, RP_NO_BAR, 0x0, no_bar_nbits);
> +             return 0;
> +     }
> +
> +     resource_list_for_each_entry(entry, &bridge->dma_ranges) {
> +             err = cdns_pcie_host_bar_config(rc, entry, &bar);
> +             if (err) {
> +                     dev_err(dev, "Fail to configure IB using dma-ranges\n");
> +                     return err;
> +             }
> +     }
> +
> +     return 0;
> +}
> +
>  static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
>  {
>       struct cdns_pcie *pcie = &rc->pcie;
> @@ -160,16 +277,9 @@ static int 
> cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
>               r++;
>       }
>  
> -     /*
> -      * Set Root Port no BAR match Inbound Translation registers:
> -      * needed for MSI and DMA.
> -      * Root Port BAR0 and BAR1 are disabled, hence no need to set their
> -      * inbound translation registers.
> -      */
> -     addr0 = CDNS_PCIE_AT_IB_RP_BAR_ADDR0_NBITS(rc->no_bar_nbits);
> -     addr1 = 0;
> -     cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR0(RP_NO_BAR), addr0);
> -     cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR1(RP_NO_BAR), addr1);
> +     err = cdns_pcie_host_map_dma_ranges(rc);
> +     if (err)
> +             return err;
>  
>       return 0;
>  }
> @@ -179,10 +289,16 @@ static int cdns_pcie_host_init(struct device *dev,
>                              struct cdns_pcie_rc *rc)
>  {
>       struct resource *bus_range = NULL;
> +     struct pci_host_bridge *bridge;
>       int err;
>  
> +     bridge = pci_host_bridge_from_priv(rc);
> +     if (!bridge)
> +             return -ENOMEM;
> +
>       /* Parse our PCI ranges and request their resources */
> -     err = pci_parse_request_of_pci_ranges(dev, resources, NULL, &bus_range);
> +     err = pci_parse_request_of_pci_ranges(dev, resources,
> +                                           &bridge->dma_ranges, &bus_range);
>       if (err)
>               return err;
>  
> @@ -239,9 +355,6 @@ int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
>       pcie = &rc->pcie;
>       pcie->is_rc = true;
>  
> -     rc->no_bar_nbits = 32;
> -     of_property_read_u32(np, "cdns,no-bar-match-nbits", &rc->no_bar_nbits);
> -
>       rc->vendor_id = 0xffff;
>       of_property_read_u32(np, "vendor-id", &rc->vendor_id);
>  
> diff --git a/drivers/pci/controller/cadence/pcie-cadence.h 
> b/drivers/pci/controller/cadence/pcie-cadence.h
> index f349f5828a58..336237a7025c 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence.h
> +++ b/drivers/pci/controller/cadence/pcie-cadence.h
> @@ -92,6 +92,20 @@
>  #define  CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_64BITS                0x6
>  #define  CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_64BITS       0x7
>  
> +#define LM_RC_BAR_CFG_CTRL_DISABLED(bar)             \
> +             (CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED << (((bar) * 8) + 6))
> +#define LM_RC_BAR_CFG_CTRL_IO_32BITS(bar)            \
> +             (CDNS_PCIE_LM_BAR_CFG_CTRL_IO_32BITS << (((bar) * 8) + 6))
> +#define LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar)           \
> +             (CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_32BITS << (((bar) * 8) + 6))
> +#define LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar)      \
> +     (CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_32BITS << (((bar) * 8) + 6))
> +#define LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar)           \
> +             (CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_64BITS << (((bar) * 8) + 6))
> +#define LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar)      \
> +     (CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_64BITS << (((bar) * 8) + 6))
> +#define LM_RC_BAR_CFG_APERTURE(bar, aperture)                \
> +                                     (((aperture) - 2) << ((bar) * 8))
>  
>  /*
>   * Endpoint Function Registers (PCI configuration space for endpoint 
> functions)
> @@ -266,8 +280,6 @@ struct cdns_pcie {
>   * @bus_range: first/last buses behind the PCIe host controller
>   * @cfg_base: IO mapped window to access the PCI configuration space of a
>   *            single function at a time
> - * @no_bar_nbits: Number of bits to keep for inbound (PCIe -> CPU) address
> - *                translation (nbits sets into the "no BAR match" register)
>   * @vendor_id: PCI vendor ID
>   * @device_id: PCI device ID
>   */
> @@ -276,7 +288,6 @@ struct cdns_pcie_rc {
>       struct resource         *cfg_res;
>       struct resource         *bus_range;
>       void __iomem            *cfg_base;
> -     u32                     no_bar_nbits;
>       u32                     vendor_id;
>       u32                     device_id;
>  };
> 

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