On 2020-08-19 04:42, Mark-PK Tsai wrote:
Add MStar interrupt controller support using hierarchy irq
domain.

Signed-off-by: Mark-PK Tsai <mark-pk.t...@mediatek.com>
---
 drivers/irqchip/Kconfig        |   7 ++
 drivers/irqchip/Makefile       |   1 +
 drivers/irqchip/irq-mst-intc.c | 195 +++++++++++++++++++++++++++++++++
 3 files changed, 203 insertions(+)
 create mode 100644 drivers/irqchip/irq-mst-intc.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index bb70b7177f94..c3a9d880a4ea 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -571,4 +571,11 @@ config LOONGSON_PCH_MSI
        help
          Support for the Loongson PCH MSI Controller.

+config MST_IRQ
+       bool "MStar Interrupt Controller"
+       select IRQ_DOMAIN
+       select IRQ_DOMAIN_HIERARCHY
+       help
+         Support MStar Interrupt Controller.

What selects it? Can it have a default for the relevant platforms?

+
 endmenu
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 133f9c45744a..e2688a62403e 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -111,3 +111,4 @@ obj-$(CONFIG_LOONGSON_HTPIC) += irq-loongson-htpic.o
 obj-$(CONFIG_LOONGSON_HTVEC)           += irq-loongson-htvec.o
 obj-$(CONFIG_LOONGSON_PCH_PIC)         += irq-loongson-pch-pic.o
 obj-$(CONFIG_LOONGSON_PCH_MSI)         += irq-loongson-pch-msi.o
+obj-$(CONFIG_MST_IRQ)                  += irq-mst-intc.o
diff --git a/drivers/irqchip/irq-mst-intc.c b/drivers/irqchip/irq-mst-intc.c
new file mode 100644
index 000000000000..38d567741860
--- /dev/null
+++ b/drivers/irqchip/irq-mst-intc.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/*
+ * Copyright (c) 2020 MediaTek Inc.
+ * Author Mark-PK Tsai <mark-pk.t...@mediatek.com>
+ */
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#define INTC_MASK      0x0
+#define INTC_EOI       0x20
+
+struct mst_intc_chip_data {
+       raw_spinlock_t lock;
+       unsigned int irq_start, nr_irqs;
+       void __iomem *base;
+       bool no_eoi;

nit: please align the fields of the data structure on a vertical line.

+};
+
+static void mst_poke_irq(struct irq_data *d, u32 offset)

Given that this is supposed to be the opposite of "clear", this
should be mst_set_irq().

+{
+       irq_hw_number_t hwirq = irqd_to_hwirq(d);
+       struct mst_intc_chip_data *cd = irq_data_get_irq_chip_data(d);
+       u16 val, mask;
+
+       mask = 1 << (hwirq % 16);
+       offset += (hwirq / 16) * 4;
+
+       raw_spin_lock(&cd->lock);
+       val = readw_relaxed(cd->base + offset) | mask;
+       writew_relaxed(val, cd->base + offset);
+       raw_spin_unlock(&cd->lock);

Small improvement, but you still miss the fact that a masking
operation can also occur from an interrupt handler, and this
will cause a deadlock. You need to disable interrupts as well.

+}
+
+static void mst_clear_irq(struct irq_data *d, u32 offset)
+{
+       irq_hw_number_t hwirq = irqd_to_hwirq(d);
+       struct mst_intc_chip_data *cd = irq_data_get_irq_chip_data(d);
+       u16 val, mask;
+
+       mask = 1 << (hwirq % 16);
+       offset += (hwirq / 16) * 4;
+
+       raw_spin_lock(&cd->lock);
+       val = readw_relaxed(cd->base + offset) & ~mask;
+       writew_relaxed(val, cd->base + offset);
+       raw_spin_unlock(&cd->lock);
+}
+
+static void mst_intc_mask_irq(struct irq_data *d)
+{
+       mst_poke_irq(d, INTC_MASK);
+       irq_chip_mask_parent(d);
+}
+
+static void mst_intc_unmask_irq(struct irq_data *d)
+{
+       mst_clear_irq(d, INTC_MASK);
+       irq_chip_unmask_parent(d);
+}
+
+static void mst_intc_eoi_irq(struct irq_data *d)
+{
+       struct mst_intc_chip_data *cd = irq_data_get_irq_chip_data(d);
+
+       if (!cd->no_eoi)
+               mst_poke_irq(d, INTC_EOI);
+
+       irq_chip_eoi_parent(d);
+}
+
+static struct irq_chip mst_intc_chip = {
+       .name                   = "mst-intc",
+       .irq_mask               = mst_intc_mask_irq,
+       .irq_unmask             = mst_intc_unmask_irq,
+       .irq_eoi                = mst_intc_eoi_irq,
+       .irq_get_irqchip_state  = irq_chip_get_parent_state,
+       .irq_set_irqchip_state  = irq_chip_set_parent_state,
+       .irq_set_affinity       = irq_chip_set_affinity_parent,
+       .irq_set_vcpu_affinity  = irq_chip_set_vcpu_affinity_parent,
+       .irq_set_type           = irq_chip_set_type_parent,
+       .irq_retrigger          = irq_chip_retrigger_hierarchy,
+       .flags                  = IRQCHIP_SET_TYPE_MASKED |
+                                 IRQCHIP_SKIP_SET_WAKE |
+                                 IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int mst_intc_domain_translate(struct irq_domain *d,
+                                    struct irq_fwspec *fwspec,
+                                    unsigned long *hwirq,
+                                    unsigned int *type)
+{
+       if (is_of_node(fwspec->fwnode)) {
+               if (fwspec->param_count != 3)
+                       return -EINVAL;
+
+               /* No PPI should point to this domain */
+               if (fwspec->param[0] != 0)
+                       return -EINVAL;
+
+               *hwirq = fwspec->param[1];
+               *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
+               return 0;
+       }
+
+       return -EINVAL;
+}
+
+static int mst_intc_domain_alloc(struct irq_domain *domain, unsigned int virq,
+                                unsigned int nr_irqs, void *data)
+{
+       int i;
+       irq_hw_number_t hwirq;
+       struct irq_fwspec parent_fwspec, *fwspec = data;
+       struct mst_intc_chip_data *cd = (struct mst_intc_chip_data
*)domain->host_data;

No cast necessary here.

+
+       /* Not GIC compliant */
+       if (fwspec->param_count != 3)
+               return -EINVAL;
+
+       /* No PPI should point to this domain */
+       if (fwspec->param[0])
+               return -EINVAL;
+
+       if (fwspec->param[1] >= cd->nr_irqs)

This condition is bogus, as it doesn't take into account the nr_irqs
parameter.

+               return -EINVAL;
+
+       hwirq = fwspec->param[1];
+       for (i = 0; i < nr_irqs; i++)
+               irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+                                             &mst_intc_chip,
+                                             domain->host_data);
+
+       parent_fwspec = *fwspec;
+       parent_fwspec.fwnode = domain->parent->fwnode;
+       parent_fwspec.param[1] = cd->irq_start + hwirq;
+ return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &parent_fwspec);
+}
+
+static const struct irq_domain_ops mst_intc_domain_ops = {
+       .translate      = mst_intc_domain_translate,
+       .alloc          = mst_intc_domain_alloc,
+       .free           = irq_domain_free_irqs_common,
+};
+
+int __init
+mst_intc_of_init(struct device_node *dn, struct device_node *parent)
+{
+       struct irq_domain *domain, *domain_parent;
+       struct mst_intc_chip_data *cd;
+       unsigned int irq_start, irq_end;

unsigned int != u32.

+
+       domain_parent = irq_find_host(parent);
+       if (!domain_parent) {
+               pr_err("mst-intc: interrupt-parent not found\n");
+               return -EINVAL;
+       }
+
+ if (of_property_read_u32_index(dn, "mstar,irqs-map-range", 0, &irq_start) || + of_property_read_u32_index(dn, "mstar,irqs-map-range", 1, &irq_end))
+               return -EINVAL;
+
+       cd = kzalloc(sizeof(*cd), GFP_KERNEL);
+       if (!cd)
+               return -ENOMEM;
+
+       cd->base = of_iomap(dn, 0);
+       if (!cd->base) {
+               kfree(cd);
+               return -ENOMEM;
+       }
+
+       cd->no_eoi = of_property_read_bool(dn, "mstar,intc-no-eoi");
+       raw_spin_lock_init(&cd->lock);
+       cd->irq_start = irq_start;
+       cd->nr_irqs = irq_end - irq_start + 1;
+       domain = irq_domain_add_hierarchy(domain_parent, 0, cd->nr_irqs, dn,
+                                         &mst_intc_domain_ops, cd);
+       if (!domain) {
+               iounmap(cd->base);
+               kfree(cd);
+               return -ENOMEM;
+       }
+
+       return 0;
+}
+
+IRQCHIP_DECLARE(mst_intc, "mstar,mst-intc", mst_intc_of_init);

Thanks,

        M.
--
Jazz is not dead. It just smells funny...

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