On Thu, Jun 18, 2020 at 05:38:09PM +0900, Kunihiko Hayashi wrote:
> The misc interrupts consisting of PME, AER, and Link event, is handled
> by INTx handler, however, these interrupts should be also handled by
> MSI handler.
Define what you mean please.
> This adds the function uniphier_pcie_misc_isr() that handles misc
> interrupts, which is called from both INTx and MSI handlers.
> This function detects PME and AER interrupts with the status register,
> and invoke PME and AER drivers related to MSI.
>
> And this sets the mask for misc interrupts from INTx if MSI is enabled
> and sets the mask for misc interrupts from MSI if MSI is disabled.
>
> Cc: Marc Zyngier <maz@xxxxxxxxxx>
> Cc: Jingoo Han <jingoohan1@xxxxxxxxx>
> Cc: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-uniphier.c | 57 ++++++++++++++++++++++++------
> 1 file changed, 46 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
> index a5401a0..5ce2479 100644
> --- a/drivers/pci/controller/dwc/pcie-uniphier.c
> +++ b/drivers/pci/controller/dwc/pcie-uniphier.c
> @@ -44,7 +44,9 @@
> #define PCL_SYS_AUX_PWR_DET BIT(8)
>
> #define PCL_RCV_INT 0x8108
> +#define PCL_RCV_INT_ALL_INT_MASK GENMASK(28, 25)
> #define PCL_RCV_INT_ALL_ENABLE GENMASK(20, 17)
> +#define PCL_RCV_INT_ALL_MSI_MASK GENMASK(12, 9)
> #define PCL_CFG_BW_MGT_STATUS BIT(4)
> #define PCL_CFG_LINK_AUTO_BW_STATUS BIT(3)
> #define PCL_CFG_AER_RC_ERR_MSI_STATUS BIT(2)
> @@ -167,7 +169,15 @@ static void uniphier_pcie_stop_link(struct dw_pcie *pci)
>
> static void uniphier_pcie_irq_enable(struct uniphier_pcie_priv *priv)
> {
> - writel(PCL_RCV_INT_ALL_ENABLE, priv->base + PCL_RCV_INT);
> + u32 val;
> +
> + val = PCL_RCV_INT_ALL_ENABLE;
> + if (pci_msi_enabled())
> + val |= PCL_RCV_INT_ALL_INT_MASK;
> + else
> + val |= PCL_RCV_INT_ALL_MSI_MASK;
> +
> + writel(val, priv->base + PCL_RCV_INT);
> writel(PCL_RCV_INTX_ALL_ENABLE, priv->base + PCL_RCV_INTX);
> }
>
> @@ -231,32 +241,56 @@ static const struct irq_domain_ops uniphier_intx_domain_ops = {
> .map = uniphier_pcie_intx_map,
> };
>
> -static void uniphier_pcie_irq_handler(struct irq_desc *desc)
> +static void uniphier_pcie_misc_isr(struct pcie_port *pp, bool is_msi)
> {
> - struct pcie_port *pp = irq_desc_get_handler_data(desc);
> struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
> - struct irq_chip *chip = irq_desc_get_chip(desc);
> - unsigned long reg;
> - u32 val, bit, virq;
> + u32 val, virq;
>
> - /* INT for debug */
> val = readl(priv->base + PCL_RCV_INT);
>
> if (val & PCL_CFG_BW_MGT_STATUS)
> dev_dbg(pci->dev, "Link Bandwidth Management Event\n");
> +
> if (val & PCL_CFG_LINK_AUTO_BW_STATUS)
> dev_dbg(pci->dev, "Link Autonomous Bandwidth Event\n");
> - if (val & PCL_CFG_AER_RC_ERR_MSI_STATUS)
> - dev_dbg(pci->dev, "Root Error\n");
> - if (val & PCL_CFG_PME_MSI_STATUS)
> - dev_dbg(pci->dev, "PME Interrupt\n");
> +
> + if (is_msi) {
> + if (val & PCL_CFG_AER_RC_ERR_MSI_STATUS)
> + dev_dbg(pci->dev, "Root Error Status\n");
> +
> + if (val & PCL_CFG_PME_MSI_STATUS)
> + dev_dbg(pci->dev, "PME Interrupt\n");
> +
> + if (val & (PCL_CFG_AER_RC_ERR_MSI_STATUS |
> + PCL_CFG_PME_MSI_STATUS)) {
> + virq = irq_linear_revmap(pp->irq_domain, 0);
I think this is wrong. pp->irq_domain is the DWC MSI domain, how do
you know that hwirq 0 *is* the AER/PME interrupt ?
It just *works* in this case because the port driver probes and alloc
MSIs before any PCI device has a chance to do it and actually I think
this is just wrong also because hwirq 0 *is* usable by devices but
it can't be used because current code takes it for the PME/AER interrupt
(which AFAICS is an internal signal disconnected from the DWC MSI
interrupt controller).
I think this extra glue logic should be separate MSI domain
otherwise there is no way you can reliably look-up the virq
corresponding to AER/PME.
How does it work in HW ? Is the root port really sending a memory
write to raise an IRQ or it just signal the IRQ through internal
logic ? I think the root port MSI handling is different from the
DWC logic and should be treated separately.
Lorenzo
> + generic_handle_irq(virq);
> + }
> + }
>
> writel(val, priv->base + PCL_RCV_INT);
> +}
> +
> +static void uniphier_pcie_msi_host_isr(struct pcie_port *pp)
> +{
> + uniphier_pcie_misc_isr(pp, true);
> +}
> +
> +static void uniphier_pcie_irq_handler(struct irq_desc *desc)
> +{
> + struct pcie_port *pp = irq_desc_get_handler_data(desc);
> + struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> + struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> + unsigned long reg;
> + u32 val, bit, virq;
>
> /* INTx */
> chained_irq_enter(chip, desc);
>
> + uniphier_pcie_misc_isr(pp, false);
> +
> val = readl(priv->base + PCL_RCV_INTX);
> reg = FIELD_GET(PCL_RCV_INTX_ALL_STATUS, val);
>
> @@ -330,6 +364,7 @@ static int uniphier_pcie_host_init(struct pcie_port *pp)
>
> static const struct dw_pcie_host_ops uniphier_pcie_host_ops = {
> .host_init = uniphier_pcie_host_init,
> + .msi_host_isr = uniphier_pcie_msi_host_isr,
> };
>
> static int uniphier_add_pcie_port(struct uniphier_pcie_priv *priv,
> --
> 2.7.4
>
