--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/riscv-aplic.h>
+#include <linux/irqchip/riscv-imsic.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-aplic-main.h"
+
+static void aplic_msi_irq_mask(struct irq_data *d)
+{
+ aplic_irq_mask(d);
+ irq_chip_mask_parent(d);
+}
+
+static void aplic_msi_irq_unmask(struct irq_data *d)
+{
+ irq_chip_unmask_parent(d);
+ aplic_irq_unmask(d);
+}
+
+static void aplic_msi_irq_eoi(struct irq_data *d)
+{
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+ /*
+ * EOI handling is required only for level-triggered interrupts
+ * when APLIC is in MSI mode.
+ */
+
+ switch (irqd_get_trigger_type(d)) {
+ case IRQ_TYPE_LEVEL_LOW:
+ case IRQ_TYPE_LEVEL_HIGH:
+ /*
+ * The section "4.9.2 Special consideration for level-sensitive interrupt
+ * sources" of the RISC-V AIA specification says:
+ *
+ * A second option is for the interrupt service routine to write the
+ * APLIC’s source identity number for the interrupt to the domain’s
+ * setipnum register just before exiting. This will cause the interrupt’s
+ * pending bit to be set to one again if the source is still asserting
+ * an interrupt, but not if the source is not asserting an interrupt.
+ */
+ writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE);
+ break;
+ }
+}
+
+static void aplic_msi_write_msg(struct irq_data *d, struct msi_msg *msg)
+{
+ unsigned int group_index, hart_index, guest_index, val;
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+ struct aplic_msicfg *mc = &priv->msicfg;
+ phys_addr_t tppn, tbppn, msg_addr;
+ void __iomem *target;
+
+ /* For zeroed MSI, simply write zero into the target register */
+ if (!msg->address_hi && !msg->address_lo && !msg->data) {
+ target = priv->regs + APLIC_TARGET_BASE;
+ target += (d->hwirq - 1) * sizeof(u32);
+ writel(0, target);
+ return;
+ }
+
+ /* Sanity check on message data */
+ WARN_ON(msg->data > APLIC_TARGET_EIID_MASK);
+
+ /* Compute target MSI address */
+ msg_addr = (((u64)msg->address_hi) << 32) | msg->address_lo;
+ tppn = msg_addr >> APLIC_xMSICFGADDR_PPN_SHIFT;
+
+ /* Compute target HART Base PPN */
+ tbppn = tppn;
+ tbppn &= ~APLIC_xMSICFGADDR_PPN_HART(mc->lhxs);
+ tbppn &= ~APLIC_xMSICFGADDR_PPN_LHX(mc->lhxw, mc->lhxs);
+ tbppn &= ~APLIC_xMSICFGADDR_PPN_HHX(mc->hhxw, mc->hhxs);
+ WARN_ON(tbppn != mc->base_ppn);
+
+ /* Compute target group and hart indexes */
+ group_index = (tppn >> APLIC_xMSICFGADDR_PPN_HHX_SHIFT(mc->hhxs)) &
+ APLIC_xMSICFGADDR_PPN_HHX_MASK(mc->hhxw);
+ hart_index = (tppn >> APLIC_xMSICFGADDR_PPN_LHX_SHIFT(mc->lhxs)) &
+ APLIC_xMSICFGADDR_PPN_LHX_MASK(mc->lhxw);
+ hart_index |= (group_index << mc->lhxw);
+ WARN_ON(hart_index > APLIC_TARGET_HART_IDX_MASK);
+
+ /* Compute target guest index */
+ guest_index = tppn & APLIC_xMSICFGADDR_PPN_HART(mc->lhxs);
+ WARN_ON(guest_index > APLIC_TARGET_GUEST_IDX_MASK);
+
+ /* Update IRQ TARGET register */
+ target = priv->regs + APLIC_TARGET_BASE;
+ target += (d->hwirq - 1) * sizeof(u32);
+ val = FIELD_PREP(APLIC_TARGET_HART_IDX, hart_index);
+ val |= FIELD_PREP(APLIC_TARGET_GUEST_IDX, guest_index);
+ val |= FIELD_PREP(APLIC_TARGET_EIID, msg->data);
+ writel(val, target);
+}
+
+static void aplic_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
+{
+ arg->desc = desc;
+ arg->hwirq = (u32)desc->data.icookie.value;
+}
+
+static int aplic_msi_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
+ unsigned long *hwirq, unsigned int *type)
+{
+ struct msi_domain_info *info = d->host_data;
+ struct aplic_priv *priv = info->data;
+
+ return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type);
+}
+
+static const struct msi_domain_template aplic_msi_template = {
+ .chip = {
+ .name = "APLIC-MSI",
+ .irq_mask = aplic_msi_irq_mask,
+ .irq_unmask = aplic_msi_irq_unmask,
+ .irq_set_type = aplic_irq_set_type,
+ .irq_eoi = aplic_msi_irq_eoi,
+#ifdef CONFIG_SMP
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+#endif
+ .irq_write_msi_msg = aplic_msi_write_msg,
+ .flags = IRQCHIP_SET_TYPE_MASKED |
+ IRQCHIP_SKIP_SET_WAKE |
+ IRQCHIP_MASK_ON_SUSPEND,
+ },
+
+ .ops = {
+ .set_desc = aplic_msi_set_desc,
+ .msi_translate = aplic_msi_translate,
+ },
+
+ .info = {
+ .bus_token = DOMAIN_BUS_WIRED_TO_MSI,
+ .flags = MSI_FLAG_USE_DEV_FWNODE,
+ .handler = handle_fasteoi_irq,
+ .handler_name = "fasteoi",
+ },
+};
+
+int aplic_msi_setup(struct device *dev, void __iomem *regs)
+{
+ const struct imsic_global_config *imsic_global;
+ struct aplic_priv *priv;
+ struct aplic_msicfg *mc;
+ phys_addr_t pa;
+ int rc;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ rc = aplic_setup_priv(priv, dev, regs);
+ if (rc) {
+ dev_err(dev, "failed to create APLIC context\n");
+ return rc;
+ }
+ mc = &priv->msicfg;
+
+ /*
+ * The APLIC outgoing MSI config registers assume target MSI
+ * controller to be RISC-V AIA IMSIC controller.
+ */
+ imsic_global = imsic_get_global_config();
+ if (!imsic_global) {
+ dev_err(dev, "IMSIC global config not found\n");
+ return -ENODEV;
+ }
+
+ /* Find number of guest index bits (LHXS) */
+ mc->lhxs = imsic_global->guest_index_bits;
+ if (APLIC_xMSICFGADDRH_LHXS_MASK < mc->lhxs) {
+ dev_err(dev, "IMSIC guest index bits big for APLIC LHXS\n");
+ return -EINVAL;
+ }
+
+ /* Find number of HART index bits (LHXW) */
+ mc->lhxw = imsic_global->hart_index_bits;
+ if (APLIC_xMSICFGADDRH_LHXW_MASK < mc->lhxw) {
+ dev_err(dev, "IMSIC hart index bits big for APLIC LHXW\n");
+ return -EINVAL;
+ }
+
+ /* Find number of group index bits (HHXW) */
+ mc->hhxw = imsic_global->group_index_bits;
+ if (APLIC_xMSICFGADDRH_HHXW_MASK < mc->hhxw) {
+ dev_err(dev, "IMSIC group index bits big for APLIC HHXW\n");
+ return -EINVAL;
+ }
+
+ /* Find first bit position of group index (HHXS) */
+ mc->hhxs = imsic_global->group_index_shift;
+ if (mc->hhxs < (2 * APLIC_xMSICFGADDR_PPN_SHIFT)) {
+ dev_err(dev, "IMSIC group index shift should be >= %d\n",
+ (2 * APLIC_xMSICFGADDR_PPN_SHIFT));
+ return -EINVAL;
+ }
+ mc->hhxs -= (2 * APLIC_xMSICFGADDR_PPN_SHIFT);
+ if (APLIC_xMSICFGADDRH_HHXS_MASK < mc->hhxs) {
+ dev_err(dev, "IMSIC group index shift big for APLIC HHXS\n");
+ return -EINVAL;
+ }
+
+ /* Compute PPN base */
+ mc->base_ppn = imsic_global->base_addr >> APLIC_xMSICFGADDR_PPN_SHIFT;
+ mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_HART(mc->lhxs);
+ mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_LHX(mc->lhxw, mc->lhxs);
+ mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_HHX(mc->hhxw, mc->hhxs);
+
+ /* Setup global config and interrupt delivery */
+ aplic_init_hw_global(priv, true);
+
+ /* Set the APLIC device MSI domain if not available */
+ if (!dev_get_msi_domain(dev)) {
+ /*
+ * The device MSI domain for OF devices is only set at the
+ * time of populating/creating OF device. If the device MSI
+ * domain is discovered later after the OF device is created
+ * then we need to set it explicitly before using any platform
+ * MSI functions.
+ *
+ * In case of APLIC device, the parent MSI domain is always
+ * IMSIC and the IMSIC MSI domains are created later through
+ * the platform driver probing so we set it explicitly here.
+ */
+ if (is_of_node(dev->fwnode))
+ of_msi_configure(dev, to_of_node(dev->fwnode));
+ }
+
+ if (!msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN, &aplic_msi_template,
+ priv->nr_irqs + 1, priv, priv)) {
+ dev_err(dev, "failed to create MSI irq domain\n");
+ return -ENOMEM;
+ }
+
+ /* Advertise the interrupt controller */
+ pa = priv->msicfg.base_ppn << APLIC_xMSICFGADDR_PPN_SHIFT;
+ dev_info(dev, "%d interrupts forwared to MSI base %pa\n", priv->nr_irqs, &pa);
+
+ return 0;
+}
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