On Mon, Sep 01, 2025 at 05:20:45PM GMT, hans.zhang@xxxxxxxxxxx wrote:
> From: Manikandan K Pillai <mpillai@xxxxxxxxxxx>
>
> Add support for Cadence PCIe RP and EP configuration for High
> Performance Architecture (HPA) controllers. The Cadence High Performance
> controllers are the latest PCIe controllers that have support for DMA,
> optional IDE and updated register set.
>
> Signed-off-by: Manikandan K Pillai <mpillai@xxxxxxxxxxx>
> Co-developed-by: Hans Zhang <hans.zhang@xxxxxxxxxxx>
> Signed-off-by: Hans Zhang <hans.zhang@xxxxxxxxxxx>
> ---
> drivers/pci/controller/cadence/Makefile | 11 +-
> .../cadence/pcie-cadence-host-hpa.c | 579 ++++++++++++++++++
> .../pci/controller/cadence/pcie-cadence-hpa.c | 205 +++++++
> drivers/pci/controller/cadence/pcie-cadence.c | 11 +
> drivers/pci/controller/cadence/pcie-cadence.h | 75 ++-
> 5 files changed, 872 insertions(+), 9 deletions(-)
> create mode 100644 drivers/pci/controller/cadence/pcie-cadence-host-hpa.c
> create mode 100644 drivers/pci/controller/cadence/pcie-cadence-hpa.c
>
> diff --git a/drivers/pci/controller/cadence/Makefile b/drivers/pci/controller/cadence/Makefile
> index e45f72388bbb..ee3bd0a69b5c 100644
> --- a/drivers/pci/controller/cadence/Makefile
> +++ b/drivers/pci/controller/cadence/Makefile
> @@ -1,6 +1,11 @@
> # SPDX-License-Identifier: GPL-2.0
> -obj-$(CONFIG_PCIE_CADENCE) += pcie-cadence.o
> -obj-$(CONFIG_PCIE_CADENCE_HOST) += pcie-cadence-host-common.o pcie-cadence-host.o
> -obj-$(CONFIG_PCIE_CADENCE_EP) += pcie-cadence-ep-common.o pcie-cadence-ep.o
> +
> +pcie-cadence-mod-y := pcie-cadence-hpa.o pcie-cadence.o
> +pcie-cadence-host-mod-y := pcie-cadence-host-common.o pcie-cadence-host.o pcie-cadence-host-hpa.o
> +pcie-cadence-ep-mod-y := pcie-cadence-ep-common.o pcie-cadence-ep.o
> +
> +obj-$(CONFIG_PCIE_CADENCE) = pcie-cadence-mod.o
> +obj-$(CONFIG_PCIE_CADENCE_HOST) += pcie-cadence-host-mod.o
> +obj-$(CONFIG_PCIE_CADENCE_EP) += pcie-cadence-ep-mod.o
> obj-$(CONFIG_PCIE_CADENCE_PLAT) += pcie-cadence-plat.o
> obj-$(CONFIG_PCI_J721E) += pci-j721e.o
> diff --git a/drivers/pci/controller/cadence/pcie-cadence-host-hpa.c b/drivers/pci/controller/cadence/pcie-cadence-host-hpa.c
> new file mode 100644
> index 000000000000..9e47b1bf41d7
> --- /dev/null
> +++ b/drivers/pci/controller/cadence/pcie-cadence-host-hpa.c
> @@ -0,0 +1,579 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Cadence PCIe host controller driver.
> + *
> + * Copyright (c) 2019, Cadence Design Systems
Really? Is this driver developed in 2019? Just making sure it is not a typo.
> + * Author: Manikandan K Pillai <mpillai@xxxxxxxxxxx>
> + */
> +#include <linux/delay.h>
> +#include <linux/kernel.h>
> +#include <linux/list_sort.h>
> +#include <linux/of_address.h>
> +#include <linux/of_pci.h>
> +#include <linux/platform_device.h>
> +
> +#include "pcie-cadence.h"
> +#include "pcie-cadence-host-common.h"
> +
> +static u8 bar_aperture_mask[] = {
> + [RP_BAR0] = 0x1f,
> + [RP_BAR1] = 0x0f,
> +};
> +
> +void __iomem *cdns_pci_hpa_map_bus(struct pci_bus *bus, unsigned int devfn,
> + int where)
> +{
> + struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
> + struct cdns_pcie_rc *rc = pci_host_bridge_priv(bridge);
> + struct cdns_pcie *pcie = &rc->pcie;
> + unsigned int busn = bus->number;
> + u32 addr0, desc0, desc1, ctrl0;
> + u32 regval;
> +
> + if (pci_is_root_bus(bus)) {
> + /*
> + * Only the root port (devfn == 0) is connected to this bus.
> + * All other PCI devices are behind some bridge hence on another
> + * bus.
> + */
> + if (devfn)
> + return NULL;
> +
> + return pcie->reg_base + (where & 0xfff);
> + }
> +
> + /* Clear AXI link-down status */
> + regval = cdns_pcie_hpa_readl(pcie, REG_BANK_AXI_SLAVE, CDNS_PCIE_HPA_AT_LINKDOWN);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE, CDNS_PCIE_HPA_AT_LINKDOWN,
> + (regval & ~GENMASK(0, 0)));
> +
> + desc0 = 0;
> + desc1 = 0;
> + ctrl0 = 0;
I don't think you need to 0 initialize there variables.
> +
> + /* Update Output registers for AXI region 0 */
> + addr0 = CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0_NBITS(12) |
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0_DEVFN(devfn) |
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0_BUS(busn);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0(0), addr0);
> +
> + desc1 = cdns_pcie_hpa_readl(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC1(0));
> + desc1 &= ~CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN_MASK;
> + desc1 |= CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN(0);
> + ctrl0 = CDNS_PCIE_HPA_AT_OB_REGION_CTRL0_SUPPLY_BUS |
> + CDNS_PCIE_HPA_AT_OB_REGION_CTRL0_SUPPLY_DEV_FN;
> +
> + if (busn == bridge->busnr + 1)
> + desc0 |= CDNS_PCIE_HPA_AT_OB_REGION_DESC0_TYPE_CONF_TYPE0;
You can directly assign 'desc0' here and below.
> + else
> + desc0 |= CDNS_PCIE_HPA_AT_OB_REGION_DESC0_TYPE_CONF_TYPE1;
> +
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC0(0), desc0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC1(0), desc1);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CTRL0(0), ctrl0);
> +
> + return rc->cfg_base + (where & 0xfff);
> +}
> +
> +int cdns_pcie_hpa_host_wait_for_link(struct cdns_pcie *pcie)
> +{
> + struct device *dev = pcie->dev;
> + int retries;
> +
> + /* Check if the link is up or not */
> + for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
> + if (cdns_pcie_hpa_link_up(pcie)) {
> + dev_info(dev, "Link up\n");
> + return 0;
> + }
> + usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
> + }
> + return -ETIMEDOUT;
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_host_wait_for_link);
I don't see an user for this API in this series. So make it static.
> +
> +int cdns_pcie_hpa_host_start_link(struct cdns_pcie_rc *rc)
This function is not starting the link, but waiting for link up. So I guess you
can move the retrain part to cdns_pcie_hpa_host_wait_for_link() and drop this
function altogether.
> +{
> + struct cdns_pcie *pcie = &rc->pcie;
> + int ret;
> +
> + ret = cdns_pcie_hpa_host_wait_for_link(pcie);
> +
> + /* Retrain link for Gen2 training defect if quirk flag is set */
Drop this comment as the flag is self explanatory.
> + if (!ret && rc->quirk_retrain_flag)
> + ret = cdns_pcie_retrain(pcie);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_host_start_link);
Same here. I do see many APIs getting exported without users. Maybe these are
the remnants of the dropping EP driver in this version. Make them static.
> +
> +static struct pci_ops cdns_pcie_hpa_host_ops = {
> + .map_bus = cdns_pci_hpa_map_bus,
> + .read = pci_generic_config_read,
> + .write = pci_generic_config_write,
> +};
> +
> +static void cdns_pcie_hpa_host_enable_ptm_response(struct cdns_pcie *pcie)
> +{
> + u32 val;
> +
> + val = cdns_pcie_hpa_readl(pcie, REG_BANK_IP_REG, CDNS_PCIE_HPA_LM_PTM_CTRL);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_IP_REG, CDNS_PCIE_HPA_LM_PTM_CTRL,
> + val | CDNS_PCIE_HPA_LM_TPM_CTRL_PTMRSEN);
> +}
> +
> +static int cdns_pcie_hpa_host_bar_ib_config(struct cdns_pcie_rc *rc,
> + enum cdns_pcie_rp_bar bar,
> + u64 cpu_addr, u64 size,
> + unsigned long flags)
> +{
> + struct cdns_pcie *pcie = &rc->pcie;
> + u32 addr0, addr1, aperture, value;
> +
> + if (!rc->avail_ib_bar[bar])
> + return -EBUSY;
-ENOMEM or -ENODEV?
> +
> + rc->avail_ib_bar[bar] = false;
> +
> + aperture = ilog2(size);
> + addr0 = CDNS_PCIE_HPA_AT_IB_RP_BAR_ADDR0_NBITS(aperture) |
> + (lower_32_bits(cpu_addr) & GENMASK(31, 8));
> + addr1 = upper_32_bits(cpu_addr);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_MASTER,
> + CDNS_PCIE_HPA_AT_IB_RP_BAR_ADDR0(bar), addr0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_MASTER,
> + CDNS_PCIE_HPA_AT_IB_RP_BAR_ADDR1(bar), addr1);
> +
> + if (bar == RP_NO_BAR)
> + return 0;
Are you sure that you want to check for RP_NO_BAR in the middle and not at the
start?
> +
> + value = cdns_pcie_hpa_readl(pcie, REG_BANK_IP_CFG_CTRL_REG, CDNS_PCIE_HPA_LM_RC_BAR_CFG);
> + value &= ~(HPA_LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar) |
> + HPA_LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar) |
> + HPA_LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar) |
> + HPA_LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar) |
> + HPA_LM_RC_BAR_CFG_APERTURE(bar, bar_aperture_mask[bar] + 2));
> + if (size + cpu_addr >= SZ_4G) {
> + if (!(flags & IORESOURCE_PREFETCH))
> + value |= HPA_LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar);
> + value |= HPA_LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar);
> + } else {
> + if (!(flags & IORESOURCE_PREFETCH))
> + value |= HPA_LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar);
> + value |= HPA_LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar);
> + }
> +
> + value |= HPA_LM_RC_BAR_CFG_APERTURE(bar, aperture);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_IP_CFG_CTRL_REG, CDNS_PCIE_HPA_LM_RC_BAR_CFG, value);
> +
> + return 0;
> +}
> +
> +static int cdns_pcie_hpa_host_bar_config(struct cdns_pcie_rc *rc,
> + struct resource_entry *entry)
Since the CSKY platform is not defining any 'dma-ranges' in binding, this whole
code related to setting up the IB mapping becomes dead code. I know that this is
a generic cadence library. But still dead code is of no use to anyone.
So please drop it now and add whenever a controller implementation that makes
use of it gets added.
> +{
> + 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;
> + int ret;
> +
> + cpu_addr = entry->res->start;
> + pci_addr = entry->res->start - entry->offset;
> + flags = entry->res->flags;
> + size = resource_size(entry->res);
> +
> + if (entry->offset) {
> + dev_err(dev, "PCI addr: %llx must be equal to CPU addr: %llx\n",
> + pci_addr, cpu_addr);
> + return -EINVAL;
> + }
> +
> + while (size > 0) {
> + /*
> + * Try to find a minimum BAR whose size is greater than
> + * or equal to the remaining resource_entry size. This will
> + * fail if the size of each of the available BARs is less than
> + * the remaining resource_entry size.
> + *
> + * If a minimum BAR is found, IB ATU will be configured and
> + * exited.
> + */
> + bar = cdns_pcie_host_find_min_bar(rc, size);
> + if (bar != RP_BAR_UNDEFINED) {
> + ret = cdns_pcie_hpa_host_bar_ib_config(rc, bar, cpu_addr,
> + size, flags);
> + if (ret)
> + dev_err(dev, "IB BAR: %d config failed\n", bar);
> + return ret;
> + }
> +
> + /*
> + * If the control reaches here, it would mean the remaining
> + * resource_entry size cannot be fitted in a single BAR. So we
> + * find a maximum BAR whose size is less than or equal to the
> + * remaining resource_entry size and split the resource entry
> + * so that part of resource entry is fitted inside the maximum
> + * BAR. The remaining size would be fitted during the next
> + * iteration of the loop.
> + *
> + * If a maximum BAR is not found, there is no way we can fit
> + * this resource_entry, so we error out.
> + */
> + bar = cdns_pcie_host_find_max_bar(rc, size);
> + if (bar == RP_BAR_UNDEFINED) {
> + dev_err(dev, "No free BAR to map cpu_addr %llx\n",
> + cpu_addr);
> + return -EINVAL;
> + }
> +
> + winsize = bar_max_size[bar];
> + ret = cdns_pcie_hpa_host_bar_ib_config(rc, bar, cpu_addr, winsize, flags);
> + if (ret) {
> + dev_err(dev, "IB BAR: %d config failed\n", bar);
> + return ret;
> + }
> +
> + size -= winsize;
> + cpu_addr += winsize;
> + }
> +
> + return 0;
> +}
> +
> +static int cdns_pcie_hpa_host_map_dma_ranges(struct cdns_pcie_rc *rc)
> +{
> + 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);
> + err = cdns_pcie_hpa_host_bar_ib_config(rc, RP_NO_BAR, 0x0,
> + (u64)1 << no_bar_nbits, 0);
> + if (err)
> + dev_err(dev, "IB BAR: %d config failed\n", RP_NO_BAR);
> + return err;
> + }
> +
> + list_sort(NULL, &bridge->dma_ranges, cdns_pcie_host_dma_ranges_cmp);
> +
> + resource_list_for_each_entry(entry, &bridge->dma_ranges) {
> + err = cdns_pcie_hpa_host_bar_config(rc, entry);
> + if (err) {
> + dev_err(dev, "Fail to configure IB using dma-ranges\n");
> + return err;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int cdns_pcie_hpa_host_init_root_port(struct cdns_pcie_rc *rc)
> +{
> + struct cdns_pcie *pcie = &rc->pcie;
> + u32 value, ctrl;
> +
> + /*
> + * Set the root complex BAR configuration register:
root complex or Root Port?
> + * - disable both BAR0 and BAR1
> + * - enable Prefetchable Memory Base and Limit registers in type 1
> + * config space (64 bits)
> + * - enable IO Base and Limit registers in type 1 config
> + * space (32 bits)
> + */
> +
> + ctrl = CDNS_PCIE_HPA_LM_BAR_CFG_CTRL_DISABLED;
> + value = CDNS_PCIE_HPA_LM_RC_BAR_CFG_BAR0_CTRL(ctrl) |
> + CDNS_PCIE_HPA_LM_RC_BAR_CFG_BAR1_CTRL(ctrl) |
> + CDNS_PCIE_HPA_LM_RC_BAR_CFG_PREFETCH_MEM_ENABLE |
> + CDNS_PCIE_HPA_LM_RC_BAR_CFG_PREFETCH_MEM_64BITS |
> + CDNS_PCIE_HPA_LM_RC_BAR_CFG_IO_ENABLE |
> + CDNS_PCIE_HPA_LM_RC_BAR_CFG_IO_32BITS;
> + cdns_pcie_hpa_writel(pcie, REG_BANK_IP_CFG_CTRL_REG,
> + CDNS_PCIE_HPA_LM_RC_BAR_CFG, value);
> +
> + if (rc->vendor_id != 0xffff)
> + cdns_pcie_hpa_rp_writew(pcie, PCI_VENDOR_ID, rc->vendor_id);
> +
> + if (rc->device_id != 0xffff)
> + cdns_pcie_hpa_rp_writew(pcie, PCI_DEVICE_ID, rc->device_id);
> +
> + cdns_pcie_hpa_rp_writeb(pcie, PCI_CLASS_REVISION, 0);
> + cdns_pcie_hpa_rp_writeb(pcie, PCI_CLASS_PROG, 0);
> + cdns_pcie_hpa_rp_writew(pcie, PCI_CLASS_DEVICE, PCI_CLASS_BRIDGE_PCI);
> +
> + return 0;
> +}
> +
> +static void cdns_pcie_hpa_create_region_for_ecam(struct cdns_pcie_rc *rc)
> +{
> + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(rc);
> + struct resource *cfg_res = rc->cfg_res;
> + struct cdns_pcie *pcie = &rc->pcie;
> + u32 value, root_port_req_id_reg, pcie_bus_number_reg;
rp_bdf, rc_bus_nr
> + u32 ecam_addr_0, region_size_0, request_id_0;
So ECAM address is always 32bit? For all Cadence IP implementations?
> + int busnr = 0, secbus = 0, subbus = 0;
> + struct resource_entry *entry;
> + resource_size_t size;
> + u32 axi_address_low;
> + int nbits;
> + u64 sz;
> +
> + entry = resource_list_first_type(&bridge->windows, IORESOURCE_BUS);
> + if (entry) {
> + busnr = entry->res->start;
> + secbus = (busnr < 0xff) ? (busnr + 1) : 0xff;
> + subbus = entry->res->end;
> + }
> + size = resource_size(cfg_res);
> + sz = 1ULL << fls64(size - 1);
> + nbits = ilog2(sz);
> + if (nbits < 8)
> + nbits = 8;
> +
> + root_port_req_id_reg = ((busnr & 0xff) << 8);
> + pcie_bus_number_reg = ((subbus & 0xff) << 16) | ((secbus & 0xff) << 8) |
> + (busnr & 0xff);
> + ecam_addr_0 = cfg_res->start;
Doesn't the platform require 'cfg_res->start' to be aligned to 256 MiB? The bus
range seem to be 0xff, so the Cadence IP allocates 8 bits for 'bus'. As per the
PCIe spec r6.0, sec 7.2.2, says:
'the base address of the range is aligned to a 2(n+20)-byte memory address
boundary'
So the 'cfg_res->start' should be aligned to 2^28 byte (256 MiB) address.
> + region_size_0 = nbits - 1;
> + request_id_0 = ((busnr & 0xff) << 8);
> +
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_TAG_MANAGEMENT, 0x200000);
> +
> + /* Taking slave err as OKAY */
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE, CDNS_PCIE_HPA_SLAVE_RESP,
> + 0x0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_SLAVE_RESP + 0x4, 0x0);
> +
> + /* Program the register "i_root_port_req_id_reg" with RP's BDF */
> + cdns_pcie_hpa_writel(pcie, REG_BANK_IP_REG, I_ROOT_PORT_REQ_ID_REG,
> + root_port_req_id_reg);
> +
> + /**
> + * Program the register "i_pcie_bus_numbers" with Primary(RP's bus number),
> + * secondary and subordinate bus numbers
> + */
> + cdns_pcie_hpa_writel(pcie, REG_BANK_RP, I_PCIE_BUS_NUMBERS,
> + pcie_bus_number_reg);
> +
> + /* Program the register "lm_hal_sbsa_ctrl[0]" to enable the sbsa */
> + value = cdns_pcie_hpa_readl(pcie, REG_BANK_IP_REG, LM_HAL_SBSA_CTRL);
> + value |= BIT(0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_IP_REG, LM_HAL_SBSA_CTRL, value);
> +
> + /* Program region[0] for ECAM */
> + axi_address_low = (ecam_addr_0 & 0xfff00000) | region_size_0;
Could you explain what is getting programmed and why?
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0(0),
> + axi_address_low);
> +
> + /* rc0-high-axi-address */
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR1(0), 0x0);
> + /* Type-1 CFG */
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC0(0), 0x05000000);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC1(0),
> + (request_id_0 << 16));
> +
> + /* All AXI bits pass through PCIe */
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0(0), 0x1b);
> + /* PCIe address-high */
What is this address?
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR1(0), 0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CTRL0(0), 0x06000000);
> +}
> +
> +static void cdns_pcie_hpa_create_region_for_cfg(struct cdns_pcie_rc *rc)
> +{
> + struct cdns_pcie *pcie = &rc->pcie;
> + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(rc);
> + struct resource *cfg_res = rc->cfg_res;
> + struct resource_entry *entry;
> + u64 cpu_addr = cfg_res->start;
> + u32 addr0, addr1, desc1;
> + int busnr = 0;
> +
> + entry = resource_list_first_type(&bridge->windows, IORESOURCE_BUS);
> + if (entry)
> + busnr = entry->res->start;
> +
> + /*
> + * Reserve region 0 for PCI configure space accesses:
> + * OB_REGION_PCI_ADDR0 and OB_REGION_DESC0 are updated dynamically by
> + * cdns_pci_map_bus(), other region registers are set here once for all
> + */
> + addr1 = 0;
No need to initalize addr1 if you pass 0 to
CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR1() directly. Initializing it causes slight
confusion.
> + desc1 = CDNS_PCIE_HPA_AT_OB_REGION_DESC1_BUS(busnr);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR1(0), addr1);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC1(0), desc1);
> +
> + addr0 = CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0_NBITS(12) |
> + (lower_32_bits(cpu_addr) & GENMASK(31, 8));
> + addr1 = upper_32_bits(cpu_addr);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0(0), addr0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR1(0), addr1);
> +}
> +
> +static int cdns_pcie_hpa_host_init_address_translation(struct cdns_pcie_rc *rc)
> +{
> + struct cdns_pcie *pcie = &rc->pcie;
> + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(rc);
> + struct resource_entry *entry;
> + int r = 0, busnr = 0;
> +
> + if (rc->ecam_supported)
> + cdns_pcie_hpa_create_region_for_ecam(rc);
> + else
> + cdns_pcie_hpa_create_region_for_cfg(rc);
> +
> + entry = resource_list_first_type(&bridge->windows, IORESOURCE_BUS);
> + if (entry)
> + busnr = entry->res->start;
> +
> + r++;
> + if (pcie->msg_res)
> + cdns_pcie_hpa_set_outbound_region_for_normal_msg(pcie, busnr, 0, r,
> + pcie->msg_res->start);
What is this MSG region for?
> +
> + r++;
> + resource_list_for_each_entry(entry, &bridge->windows) {
> + struct resource *res = entry->res;
> + u64 pci_addr = res->start - entry->offset;
> +
> + if (resource_type(res) == IORESOURCE_IO)
> + cdns_pcie_hpa_set_outbound_region(pcie, busnr, 0, r,
> + true,
> + pci_pio_to_address(res->start),
> + pci_addr,
> + resource_size(res));
> + else
> + cdns_pcie_hpa_set_outbound_region(pcie, busnr, 0, r,
> + false,
> + res->start,
> + pci_addr,
> + resource_size(res));
> +
> + r++;
Why do you need to increment 'r' here?
> + }
> +
> + if (rc->no_inbound_map)
> + return 0;
> + else
> + return cdns_pcie_hpa_host_map_dma_ranges(rc);
> +}
> +
> +int cdns_pcie_hpa_host_init(struct cdns_pcie_rc *rc)
> +{
> + int err;
> +
> + err = cdns_pcie_hpa_host_init_root_port(rc);
> + if (err)
> + return err;
> +
> + return cdns_pcie_hpa_host_init_address_translation(rc);
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_host_init);
> +
> +int cdns_pcie_hpa_host_link_setup(struct cdns_pcie_rc *rc)
> +{
> + struct cdns_pcie *pcie = &rc->pcie;
> + struct device *dev = rc->pcie.dev;
> + int ret;
> +
> + if (rc->quirk_detect_quiet_flag)
> + cdns_pcie_hpa_detect_quiet_min_delay_set(&rc->pcie);
> +
> + cdns_pcie_hpa_host_enable_ptm_response(pcie);
> +
> + ret = cdns_pcie_start_link(pcie);
> + if (ret) {
> + dev_err(dev, "Failed to start link\n");
> + return ret;
> + }
> +
> + ret = cdns_pcie_hpa_host_start_link(rc);
> + if (ret)
> + dev_dbg(dev, "PCIe link never came up\n");
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_host_link_setup);
> +
> +int cdns_pcie_hpa_host_setup(struct cdns_pcie_rc *rc)
> +{
> + struct device *dev = rc->pcie.dev;
> + struct platform_device *pdev = to_platform_device(dev);
> + struct pci_host_bridge *bridge;
> + enum cdns_pcie_rp_bar bar;
> + struct cdns_pcie *pcie;
> + struct resource *res;
> + int ret;
> +
> + bridge = pci_host_bridge_from_priv(rc);
> + if (!bridge)
> + return -ENOMEM;
> +
> + pcie = &rc->pcie;
> + pcie->is_rc = true;
> +
> + if (!pcie->reg_base) {
> + pcie->reg_base = devm_platform_ioremap_resource_byname(pdev, "reg");
> + if (IS_ERR(pcie->reg_base)) {
> + dev_err(dev, "missing \"reg\"\n");
> + return PTR_ERR(pcie->reg_base);
> + }
> + }
> +
> + /* ECAM config space is remapped at glue layer */
> + if (!rc->cfg_base) {
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
> + rc->cfg_base = devm_pci_remap_cfg_resource(dev, res);
> + if (IS_ERR(rc->cfg_base))
> + return PTR_ERR(rc->cfg_base);
> + rc->cfg_res = res;
> + }
> +
> + ret = cdns_pcie_hpa_host_link_setup(rc);
You should only ignore the 'waiting for link up' error and not the actual
start_link error.
> +
> + for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++)
> + rc->avail_ib_bar[bar] = true;
> +
> + ret = cdns_pcie_hpa_host_init(rc);
> + if (ret)
> + return ret;
> +
> + if (!bridge->ops)
> + bridge->ops = &cdns_pcie_hpa_host_ops;
> +
> + return pci_host_probe(bridge);
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_host_setup);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Cadence PCIe host controller driver");
> diff --git a/drivers/pci/controller/cadence/pcie-cadence-hpa.c b/drivers/pci/controller/cadence/pcie-cadence-hpa.c
> new file mode 100644
> index 000000000000..76c1de5ea9ee
> --- /dev/null
> +++ b/drivers/pci/controller/cadence/pcie-cadence-hpa.c
> @@ -0,0 +1,205 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Cadence PCIe controller driver.
> + *
> + * Copyright (c) 2019, Cadence Design Systems
> + * Author: Manikandan K Pillai <mpillai@xxxxxxxxxxx>
> + */
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +
> +#include "pcie-cadence.h"
> +
> +bool cdns_pcie_hpa_link_up(struct cdns_pcie *pcie)
> +{
> + u32 pl_reg_val;
> +
> + pl_reg_val = cdns_pcie_hpa_readl(pcie, REG_BANK_IP_REG, CDNS_PCIE_HPA_PHY_DBG_STS_REG0);
> + if (pl_reg_val & GENMASK(0, 0))
> + return true;
> + return false;
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_link_up);
> +
> +int cdns_pcie_hpa_start_link(struct cdns_pcie *pcie)
Where is this function used?
> +{
> + u32 pl_reg_val;
> +
> + pl_reg_val = cdns_pcie_hpa_readl(pcie, REG_BANK_IP_REG, CDNS_PCIE_HPA_PHY_LAYER_CFG0);
> + pl_reg_val |= CDNS_PCIE_HPA_LINK_TRNG_EN_MASK;
> + cdns_pcie_hpa_writel(pcie, REG_BANK_IP_REG, CDNS_PCIE_HPA_PHY_LAYER_CFG0, pl_reg_val);
> + return 0;
> +}
> +
> +void cdns_pcie_hpa_stop_link(struct cdns_pcie *pcie)
Where is this function used?
> +{
> + u32 pl_reg_val;
> +
> + pl_reg_val = cdns_pcie_hpa_readl(pcie, REG_BANK_IP_REG, CDNS_PCIE_HPA_PHY_LAYER_CFG0);
> + pl_reg_val &= ~CDNS_PCIE_HPA_LINK_TRNG_EN_MASK;
> + cdns_pcie_hpa_writel(pcie, REG_BANK_IP_REG, CDNS_PCIE_HPA_PHY_LAYER_CFG0, pl_reg_val);
> +}
> +
> +void cdns_pcie_hpa_detect_quiet_min_delay_set(struct cdns_pcie *pcie)
> +{
> + u32 delay = 0x3;
> + u32 ltssm_control_cap;
> +
> + /* Set the LTSSM Detect Quiet state min. delay to 2ms */
> + ltssm_control_cap = cdns_pcie_hpa_readl(pcie, REG_BANK_IP_REG,
> + CDNS_PCIE_HPA_PHY_LAYER_CFG0);
> + ltssm_control_cap = ((ltssm_control_cap &
> + ~CDNS_PCIE_HPA_DETECT_QUIET_MIN_DELAY_MASK) |
> + CDNS_PCIE_HPA_DETECT_QUIET_MIN_DELAY(delay));
> +
> + cdns_pcie_hpa_writel(pcie, REG_BANK_IP_REG,
> + CDNS_PCIE_HPA_PHY_LAYER_CFG0, ltssm_control_cap);
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_detect_quiet_min_delay_set);
> +
> +void cdns_pcie_hpa_set_outbound_region(struct cdns_pcie *pcie, u8 busnr, u8 fn,
> + u32 r, bool is_io,
> + u64 cpu_addr, u64 pci_addr, size_t size)
> +{
> + /*
> + * roundup_pow_of_two() returns an unsigned long, which is not suited
> + * for 64bit values
> + */
> + u64 sz = 1ULL << fls64(size - 1);
> + int nbits = ilog2(sz);
> + u32 addr0, addr1, desc0, desc1, ctrl0;
> +
> + if (nbits < 8)
> + nbits = 8;
> +
> + /* Set the PCI address */
> + addr0 = CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0_NBITS(nbits) |
> + (lower_32_bits(pci_addr) & GENMASK(31, 8));
> + addr1 = upper_32_bits(pci_addr);
> +
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0(r), addr0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR1(r), addr1);
> +
> + /* Set the PCIe header descriptor */
> + if (is_io)
> + desc0 = CDNS_PCIE_HPA_AT_OB_REGION_DESC0_TYPE_IO;
> + else
> + desc0 = CDNS_PCIE_HPA_AT_OB_REGION_DESC0_TYPE_MEM;
> + desc1 = 0;
> + ctrl0 = 0;
> +
> + /*
> + * Whether Bit [26] is set or not inside DESC0 register of the outbound
> + * PCIe descriptor, the PCI function number must be set into
> + * Bits [31:24] of DESC1 anyway.
> + *
> + * In Root Complex mode, the function number is always 0 but in Endpoint
> + * mode, the PCIe controller may support more than one function. This
> + * function number needs to be set properly into the outbound PCIe
> + * descriptor.
> + *
> + * Besides, setting Bit [26] is mandatory when in Root Complex mode:
> + * then the driver must provide the bus, resp. device, number in
> + * Bits [31:24] of DESC1, resp. Bits[23:16] of DESC0. Like the function
> + * number, the device number is always 0 in Root Complex mode.
> + *
> + * However when in Endpoint mode, we can clear Bit [26] of DESC0, hence
> + * the PCIe controller will use the captured values for the bus and
> + * device numbers.
> + */
> + if (pcie->is_rc) {
> + /* The device and function numbers are always 0 */
> + desc1 = CDNS_PCIE_HPA_AT_OB_REGION_DESC1_BUS(busnr) |
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN(0);
> + ctrl0 = CDNS_PCIE_HPA_AT_OB_REGION_CTRL0_SUPPLY_BUS |
> + CDNS_PCIE_HPA_AT_OB_REGION_CTRL0_SUPPLY_DEV_FN;
> + } else {
> + /*
> + * Use captured values for bus and device numbers but still
> + * need to set the function number
> + */
> + desc1 |= CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN(fn);
> + }
> +
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC0(r), desc0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC1(r), desc1);
> +
> + addr0 = CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0_NBITS(nbits) |
> + (lower_32_bits(cpu_addr) & GENMASK(31, 8));
> + addr1 = upper_32_bits(cpu_addr);
> +
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0(r), addr0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR1(r), addr1);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CTRL0(r), ctrl0);
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_set_outbound_region);
> +
> +void cdns_pcie_hpa_set_outbound_region_for_normal_msg(struct cdns_pcie *pcie,
> + u8 busnr, u8 fn,
> + u32 r, u64 cpu_addr)
> +{
> + u32 addr0, addr1, desc0, desc1, ctrl0;
> +
> + desc0 = CDNS_PCIE_HPA_AT_OB_REGION_DESC0_TYPE_NORMAL_MSG;
> + desc1 = 0;
> + ctrl0 = 0;
> +
> + /* See cdns_pcie_set_outbound_region() comments above */
> + if (pcie->is_rc) {
> + desc1 = CDNS_PCIE_HPA_AT_OB_REGION_DESC1_BUS(busnr) |
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN(0);
> + ctrl0 = CDNS_PCIE_HPA_AT_OB_REGION_CTRL0_SUPPLY_BUS |
> + CDNS_PCIE_HPA_AT_OB_REGION_CTRL0_SUPPLY_DEV_FN;
> + } else {
> + desc1 |= CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN(fn);
> + }
> +
> + addr0 = CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0_NBITS(17) |
> + (lower_32_bits(cpu_addr) & GENMASK(31, 8));
> + addr1 = upper_32_bits(cpu_addr);
> +
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0(r), 0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR1(r), 0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC0(r), desc0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC1(r), desc1);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0(r), addr0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR1(r), addr1);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CTRL0(r), ctrl0);
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_set_outbound_region_for_normal_msg);
> +
> +void cdns_pcie_hpa_reset_outbound_region(struct cdns_pcie *pcie, u32 r)
Where is this function used?
> +{
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0(r), 0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR1(r), 0);
> +
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC0(r), 0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_DESC1(r), 0);
> +
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0(r), 0);
> + cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
> + CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR1(r), 0);
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_hpa_reset_outbound_region);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Cadence PCIe controller driver");
> diff --git a/drivers/pci/controller/cadence/pcie-cadence.c b/drivers/pci/controller/cadence/pcie-cadence.c
> index 5603f214f4c7..62252befcf47 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence.c
> +++ b/drivers/pci/controller/cadence/pcie-cadence.c
> @@ -9,6 +9,17 @@
>
> #include "pcie-cadence.h"
>
> +bool cdns_pcie_linkup(struct cdns_pcie *pcie)
Where is this function used?
> +{
> + u32 pl_reg_val;
> +
> + pl_reg_val = cdns_pcie_readl(pcie, CDNS_PCIE_LM_BASE);
> + if (pl_reg_val & GENMASK(0, 0))
> + return true;
> + return false;
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_linkup);
> +
> void cdns_pcie_detect_quiet_min_delay_set(struct cdns_pcie *pcie)
> {
> u32 delay = 0x3;
> diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
> index 1174cf597bb0..b8b44ce0a594 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence.h
> +++ b/drivers/pci/controller/cadence/pcie-cadence.h
> @@ -7,6 +7,7 @@
> #define _PCIE_CADENCE_H
>
> #include <linux/kernel.h>
> +#include <linux/module.h>
> #include <linux/pci.h>
> #include <linux/pci-epf.h>
> #include <linux/phy/phy.h>
> @@ -42,9 +43,9 @@ enum cdns_pcie_reg_bank {
> };
>
> struct cdns_pcie_ops {
> - int (*start_link)(struct cdns_pcie *pcie);
> - void (*stop_link)(struct cdns_pcie *pcie);
> - bool (*link_up)(struct cdns_pcie *pcie);
> + int (*start_link)(struct cdns_pcie *pcie);
> + void (*stop_link)(struct cdns_pcie *pcie);
> + bool (*link_up)(struct cdns_pcie *pcie);
Spurious change?
> u64 (*cpu_addr_fixup)(struct cdns_pcie *pcie, u64 cpu_addr);
> };
>
> @@ -76,6 +77,7 @@ struct cdns_plat_pcie_of_data {
> * struct cdns_pcie - private data for Cadence PCIe controller drivers
> * @reg_base: IO mapped register base
> * @mem_res: start/end offsets in the physical system memory to map PCI accesses
> + * @msg_res: Region for send message to map PCI accesses
> * @dev: PCIe controller
> * @is_rc: tell whether the PCIe controller mode is Root Complex or Endpoint.
> * @phy_count: number of supported PHY devices
> @@ -88,6 +90,7 @@ struct cdns_plat_pcie_of_data {
> struct cdns_pcie {
> void __iomem *reg_base;
> struct resource *mem_res;
> + struct resource *msg_res;
> struct device *dev;
> bool is_rc;
> int phy_count;
> @@ -110,6 +113,8 @@ struct cdns_pcie {
> * available
> * @quirk_retrain_flag: Retrain link as quirk for PCIe Gen2
> * @quirk_detect_quiet_flag: LTSSM Detect Quiet min delay set as quirk
> + * @ecam_supported: Whether the ECAM is supported
> + * @no_inbound_map: Whether inbound mapping is supported
> */
> struct cdns_pcie_rc {
> struct cdns_pcie pcie;
> @@ -120,6 +125,8 @@ struct cdns_pcie_rc {
> bool avail_ib_bar[CDNS_PCIE_RP_MAX_IB];
> unsigned int quirk_retrain_flag:1;
> unsigned int quirk_detect_quiet_flag:1;
> + unsigned int ecam_supported:1;
> + unsigned int no_inbound_map:1;
> };
>
> /**
> @@ -303,6 +310,29 @@ static inline u16 cdns_pcie_rp_readw(struct cdns_pcie *pcie, u32 reg)
> return cdns_pcie_read_sz(addr, 0x2);
> }
>
> +static inline void cdns_pcie_hpa_rp_writeb(struct cdns_pcie *pcie,
> + u32 reg, u8 value)
> +{
> + void __iomem *addr = pcie->reg_base + CDNS_PCIE_HPA_RP_BASE + reg;
> +
> + cdns_pcie_write_sz(addr, 0x1, value);
> +}
> +
> +static inline void cdns_pcie_hpa_rp_writew(struct cdns_pcie *pcie,
> + u32 reg, u16 value)
Where is this function used?
> +{
> + void __iomem *addr = pcie->reg_base + CDNS_PCIE_HPA_RP_BASE + reg;
> +
> + cdns_pcie_write_sz(addr, 0x2, value);
> +}
> +
> +static inline u16 cdns_pcie_hpa_rp_readw(struct cdns_pcie *pcie, u32 reg)
> +{
Where is this function used?
Please drop all dead code.
- Mani
--
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