On Mon, 12 Apr 2021 18:30:53 +0300
<bpeled@xxxxxxxxxxx> wrote:
> From: Ben Peled <bpeled@xxxxxxxxxxx>
>
> In PCIE ISR routine caused by RST_LINK_DOWN
> we schedule work to handle the link-down procedure.
> Link-down procedure will:
> 1. Remove PCIe bus
> 2. Reset the MAC
> 3. Reconfigure link back up
> 4. Rescan PCIe bus
>
> Signed-off-by: Ben Peled <bpeled@xxxxxxxxxxx>
Trivial comment inline.
Also, something odd with quotes around PATCH in the title you probably
want to clean up.
> ---
> drivers/pci/controller/dwc/pcie-armada8k.c | 68 ++++++++++++++++++++
> 1 file changed, 68 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-armada8k.c b/drivers/pci/controller/dwc/pcie-armada8k.c
> index b2278b1..4eb8607 100644
> --- a/drivers/pci/controller/dwc/pcie-armada8k.c
> +++ b/drivers/pci/controller/dwc/pcie-armada8k.c
> @@ -22,6 +22,8 @@
> #include <linux/resource.h>
> #include <linux/of_pci.h>
> #include <linux/of_irq.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
>
> #include "pcie-designware.h"
>
> @@ -33,6 +35,9 @@ struct armada8k_pcie {
> struct clk *clk_reg;
> struct phy *phy[ARMADA8K_PCIE_MAX_LANES];
> unsigned int phy_count;
> + struct regmap *sysctrl_base;
> + u32 mac_rest_bitmask;
> + struct work_struct recover_link_work;
> };
>
> #define PCIE_VENDOR_REGS_OFFSET 0x8000
> @@ -73,6 +78,8 @@ struct armada8k_pcie {
> #define AX_USER_DOMAIN_MASK 0x3
> #define AX_USER_DOMAIN_SHIFT 4
>
> +#define UNIT_SOFT_RESET_CONFIG_REG 0x268
> +
> #define to_armada8k_pcie(x) dev_get_drvdata((x)->dev)
>
> static void armada8k_pcie_disable_phys(struct armada8k_pcie *pcie)
> @@ -224,6 +231,49 @@ static int armada8k_pcie_host_init(struct pcie_port *pp)
>
> return 0;
> }
> +static void armada8k_pcie_recover_link(struct work_struct *ws)
> +{
> + struct armada8k_pcie *pcie = container_of(ws, struct armada8k_pcie, recover_link_work);
> + struct pcie_port *pp = &pcie->pci->pp;
> + struct pci_bus *bus = pp->bridge->bus;
> + struct pci_dev *root_port;
> + int ret;
> +
> + root_port = pci_get_slot(bus, 0);
> + if (!root_port) {
> + dev_err(pcie->pci->dev, "failed to get root port\n");
> + return;
> + }
> + pci_lock_rescan_remove();
> + pci_stop_and_remove_bus_device(root_port);
> + /*
> + * Sleep needed to make sure all pcie transactions and access
> + * are flushed before resetting the mac
> + */
> + msleep(100);
> +
> + /* Reset mac */
> + regmap_update_bits_base(pcie->sysctrl_base, UNIT_SOFT_RESET_CONFIG_REG,
> + pcie->mac_rest_bitmask, 0, NULL, false, true);
> + udelay(1);
> + regmap_update_bits_base(pcie->sysctrl_base, UNIT_SOFT_RESET_CONFIG_REG,
> + pcie->mac_rest_bitmask, pcie->mac_rest_bitmask,
> + NULL, false, true);
> + udelay(1);
> + ret = armada8k_pcie_host_init(pp);
> + if (ret) {
> + dev_err(pcie->pci->dev, "failed to initialize host: %d\n", ret);
> + pci_unlock_rescan_remove();
> + pci_dev_put(root_port);
> + return;
> + }
> +
> + bus = NULL;
> + while ((bus = pci_find_next_bus(bus)) != NULL)
> + pci_rescan_bus(bus);
> + pci_unlock_rescan_remove();
> + pci_dev_put(root_port);
> +}
>
> static irqreturn_t armada8k_pcie_irq_handler(int irq, void *arg)
> {
> @@ -262,6 +312,9 @@ static irqreturn_t armada8k_pcie_irq_handler(int irq, void *arg)
> * initiate a link retrain. If link retrains were
> * possible, that is.
> */
> + if (pcie->sysctrl_base && pcie->mac_rest_bitmask)
> + schedule_work(&pcie->recover_link_work);
> +
> dev_dbg(pci->dev, "%s: link went down\n", __func__);
> }
>
> @@ -330,6 +383,8 @@ static int armada8k_pcie_probe(struct platform_device *pdev)
>
> pcie->pci = pci;
>
> + INIT_WORK(&pcie->recover_link_work, armada8k_pcie_recover_link);
> +
> pcie->clk = devm_clk_get(dev, NULL);
> if (IS_ERR(pcie->clk))
> return PTR_ERR(pcie->clk);
> @@ -357,6 +412,19 @@ static int armada8k_pcie_probe(struct platform_device *pdev)
> goto fail_clkreg;
> }
>
> + pcie->sysctrl_base = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> + "marvell,system-controller");
> + if (IS_ERR(pcie->sysctrl_base)) {
> + dev_warn(dev, "failed to find marvell,system-controller\n");
> + pcie->sysctrl_base = 0x0;
= NULL; ?
> + }
> +
> + ret = of_property_read_u32(pdev->dev.of_node, "marvell,mac-reset-bit-mask",
> + &pcie->mac_rest_bitmask);
> + if (ret < 0) {
> + dev_warn(dev, "couldn't find mac reset bit mask: %d\n", ret);
> + pcie->mac_rest_bitmask = 0x0;
> + }
> ret = armada8k_pcie_setup_phys(pcie);
> if (ret)
> goto fail_clkreg;
