Re: [PATCH v3 4/4] PCI: cadence: Use "dma-ranges" instead of "cdns,no-bar-match-nbits" property

From: Kishon Vijay Abraham I
Date: Mon May 18 2020 - 07:12:28 EST

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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 <kishon@xxxxxx>
> ---
> .../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;
> };
>

Next message: Miklos Szeredi: "Re: kernel BUG at mm/hugetlb.c:LINE!"
Previous message: Mark Brown: "Re: [PATCH v2 02/19] spi: dw: Add Tx/Rx finish wait methods to the MID DMA"
Next in thread: Rob Herring: "Re: [PATCH v3 4/4] PCI: cadence: Use "dma-ranges" instead of "cdns,no-bar-match-nbits" property"
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