[PATCH 05/11] powerpc/xics: Add a native ICS backend for microwatt
Paul Mackerras
paulus at ozlabs.org
Tue Jun 15 09:00:43 AEST 2021
From: Benjamin Herrenschmidt <benh at kernel.crashing.org>
This is a simple native ICS backend that matches the layout of
the Microwatt implementation of ICS.
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
arch/powerpc/boot/dts/microwatt.dts | 18 ++
arch/powerpc/platforms/microwatt/Kconfig | 2 +
arch/powerpc/platforms/microwatt/setup.c | 8 +
arch/powerpc/sysdev/xics/Kconfig | 3 +
arch/powerpc/sysdev/xics/Makefile | 1 +
arch/powerpc/sysdev/xics/ics-native.c | 257 +++++++++++++++++++++++
arch/powerpc/sysdev/xics/xics-common.c | 2 +
7 files changed, 291 insertions(+)
create mode 100644 arch/powerpc/sysdev/xics/ics-native.c
diff --git a/arch/powerpc/boot/dts/microwatt.dts b/arch/powerpc/boot/dts/microwatt.dts
index a72177e5041d..2e75600320e8 100644
--- a/arch/powerpc/boot/dts/microwatt.dts
+++ b/arch/powerpc/boot/dts/microwatt.dts
@@ -106,7 +106,25 @@ soc at c0000000 {
compatible = "simple-bus";
#address-cells = <1>;
#size-cells = <1>;
+ interrupt-parent = <&ICS>;
ranges = <0 0 0xc0000000 0x40000000>;
+
+ interrupt-controller at 4000 {
+ compatible = "openpower,xics-presentation", "ibm,ppc-xicp";
+ ibm,interrupt-server-ranges = <0x0 0x1>;
+ reg = <0x4000 0x100>;
+ };
+
+ ICS: interrupt-controller at 5000 {
+ compatible = "openpower,xics-sources";
+ interrupt-controller;
+ interrupt-ranges = <0x10 0x10>;
+ reg = <0x5000 0x100>;
+ #address-cells = <0>;
+ #size-cells = <0>;
+ #interrupt-cells = <2>;
+ };
+
};
};
diff --git a/arch/powerpc/platforms/microwatt/Kconfig b/arch/powerpc/platforms/microwatt/Kconfig
index 3be01e78ce57..b52c869c0eb8 100644
--- a/arch/powerpc/platforms/microwatt/Kconfig
+++ b/arch/powerpc/platforms/microwatt/Kconfig
@@ -3,6 +3,8 @@ config PPC_MICROWATT
depends on PPC_BOOK3S_64 && !SMP
bool "Microwatt SoC platform"
select PPC_XICS
+ select PPC_ICS_NATIVE
+ select PPC_ICP_NATIVE
select PPC_NATIVE
help
This option enables support for FPGA-based Microwatt implementations.
diff --git a/arch/powerpc/platforms/microwatt/setup.c b/arch/powerpc/platforms/microwatt/setup.c
index 5af4adf881bc..1c1b7791fa57 100644
--- a/arch/powerpc/platforms/microwatt/setup.c
+++ b/arch/powerpc/platforms/microwatt/setup.c
@@ -10,8 +10,15 @@
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_platform.h>
+
#include <asm/machdep.h>
#include <asm/time.h>
+#include <asm/xics.h>
+
+static void __init microwatt_init_IRQ(void)
+{
+ xics_init();
+}
static int __init microwatt_probe(void)
{
@@ -27,5 +34,6 @@ machine_arch_initcall(microwatt, microwatt_populate);
define_machine(microwatt) {
.name = "microwatt",
.probe = microwatt_probe,
+ .init_IRQ = microwatt_init_IRQ,
.calibrate_decr = generic_calibrate_decr,
};
diff --git a/arch/powerpc/sysdev/xics/Kconfig b/arch/powerpc/sysdev/xics/Kconfig
index 304614c920aa..063d9195891f 100644
--- a/arch/powerpc/sysdev/xics/Kconfig
+++ b/arch/powerpc/sysdev/xics/Kconfig
@@ -12,3 +12,6 @@ config PPC_ICP_HV
config PPC_ICS_RTAS
def_bool n
+
+config PPC_ICS_NATIVE
+ def_bool n
diff --git a/arch/powerpc/sysdev/xics/Makefile b/arch/powerpc/sysdev/xics/Makefile
index ba1e3117b1c0..747063927c6c 100644
--- a/arch/powerpc/sysdev/xics/Makefile
+++ b/arch/powerpc/sysdev/xics/Makefile
@@ -4,4 +4,5 @@ obj-y += xics-common.o
obj-$(CONFIG_PPC_ICP_NATIVE) += icp-native.o
obj-$(CONFIG_PPC_ICP_HV) += icp-hv.o
obj-$(CONFIG_PPC_ICS_RTAS) += ics-rtas.o
+obj-$(CONFIG_PPC_ICS_NATIVE) += ics-native.o
obj-$(CONFIG_PPC_POWERNV) += ics-opal.o icp-opal.o
diff --git a/arch/powerpc/sysdev/xics/ics-native.c b/arch/powerpc/sysdev/xics/ics-native.c
new file mode 100644
index 000000000000..d450502f4053
--- /dev/null
+++ b/arch/powerpc/sysdev/xics/ics-native.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ICS backend for OPAL managed interrupts.
+ *
+ * Copyright 2011 IBM Corp.
+ */
+
+//#define DEBUG
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <linux/spinlock.h>
+#include <linux/msi.h>
+#include <linux/list.h>
+
+#include <asm/prom.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/irq.h>
+#include <asm/errno.h>
+#include <asm/xics.h>
+#include <asm/opal.h>
+#include <asm/firmware.h>
+
+struct ics_native {
+ struct ics ics;
+ struct device_node *node;
+ void __iomem *base;
+ u32 ibase;
+ u32 icount;
+};
+#define to_ics_native(_ics) container_of(_ics, struct ics_native, ics)
+
+static void __iomem *ics_native_xive(struct ics_native *in, unsigned int vec)
+{
+ return in->base + 0x800 + ((vec - in->ibase) << 2);
+}
+
+static void ics_native_unmask_irq(struct irq_data *d)
+{
+ unsigned int vec = (unsigned int)irqd_to_hwirq(d);
+ struct ics *ics = irq_data_get_irq_chip_data(d);
+ struct ics_native *in = to_ics_native(ics);
+ unsigned int server;
+
+ pr_devel("ics-native: unmask virq %d [hw 0x%x]\n", d->irq, vec);
+
+ if (vec < in->ibase || vec >= (in->ibase + in->icount))
+ return;
+
+ server = xics_get_irq_server(d->irq, irq_data_get_affinity_mask(d), 0);
+ out_be32(ics_native_xive(in, vec), (server << 8) | DEFAULT_PRIORITY);
+}
+
+static unsigned int ics_native_startup(struct irq_data *d)
+{
+#ifdef CONFIG_PCI_MSI
+ /*
+ * The generic MSI code returns with the interrupt disabled on the
+ * card, using the MSI mask bits. Firmware doesn't appear to unmask
+ * at that level, so we do it here by hand.
+ */
+ if (irq_data_get_msi_desc(d))
+ pci_msi_unmask_irq(d);
+#endif
+
+ /* unmask it */
+ ics_native_unmask_irq(d);
+ return 0;
+}
+
+static void ics_native_do_mask(struct ics_native *in, unsigned int vec)
+{
+ out_be32(ics_native_xive(in, vec), 0xff);
+}
+
+static void ics_native_mask_irq(struct irq_data *d)
+{
+ unsigned int vec = (unsigned int)irqd_to_hwirq(d);
+ struct ics *ics = irq_data_get_irq_chip_data(d);
+ struct ics_native *in = to_ics_native(ics);
+
+ pr_devel("ics-native: mask virq %d [hw 0x%x]\n", d->irq, vec);
+
+ if (vec < in->ibase || vec >= (in->ibase + in->icount))
+ return;
+ ics_native_do_mask(in, vec);
+}
+
+static int ics_native_set_affinity(struct irq_data *d,
+ const struct cpumask *cpumask,
+ bool force)
+{
+ unsigned int vec = (unsigned int)irqd_to_hwirq(d);
+ struct ics *ics = irq_data_get_irq_chip_data(d);
+ struct ics_native *in = to_ics_native(ics);
+ int server;
+ u32 xive;
+
+ if (vec < in->ibase || vec >= (in->ibase + in->icount))
+ return -EINVAL;
+
+ server = xics_get_irq_server(d->irq, cpumask, 1);
+ if (server == -1) {
+ pr_warn("%s: No online cpus in the mask %*pb for irq %d\n",
+ __func__, cpumask_pr_args(cpumask), d->irq);
+ return -1;
+ }
+
+ xive = in_be32(ics_native_xive(in, vec));
+ xive = (xive & 0xff) | (server << 8);
+ out_be32(ics_native_xive(in, vec), xive);
+
+ return IRQ_SET_MASK_OK;
+}
+
+static struct irq_chip ics_native_irq_chip = {
+ .name = "ICS",
+ .irq_startup = ics_native_startup,
+ .irq_mask = ics_native_mask_irq,
+ .irq_unmask = ics_native_unmask_irq,
+ .irq_eoi = NULL, /* Patched at init time */
+ .irq_set_affinity = ics_native_set_affinity,
+ .irq_set_type = xics_set_irq_type,
+ .irq_retrigger = xics_retrigger,
+};
+
+static int ics_native_map(struct ics *ics, unsigned int virq)
+{
+ unsigned int vec = (unsigned int)virq_to_hw(virq);
+ struct ics_native *in = to_ics_native(ics);
+
+ pr_devel("%s: vec=0x%x\n", __func__, vec);
+
+ if (vec < in->ibase || vec >= (in->ibase + in->icount))
+ return -EINVAL;
+
+ irq_set_chip_and_handler(virq, &ics_native_irq_chip, handle_fasteoi_irq);
+ irq_set_chip_data(virq, ics);
+
+ return 0;
+}
+
+static void ics_native_mask_unknown(struct ics *ics, unsigned long vec)
+{
+ struct ics_native *in = to_ics_native(ics);
+
+ if (vec < in->ibase || vec >= (in->ibase + in->icount))
+ return;
+
+ ics_native_do_mask(in, vec);
+}
+
+static long ics_native_get_server(struct ics *ics, unsigned long vec)
+{
+ struct ics_native *in = to_ics_native(ics);
+ u32 xive;
+
+ if (vec < in->ibase || vec >= (in->ibase + in->icount))
+ return -EINVAL;
+
+ xive = in_be32(ics_native_xive(in, vec));
+ return (xive >> 8) & 0xfff;
+}
+
+static int ics_native_host_match(struct ics *ics, struct device_node *node)
+{
+ struct ics_native *in = to_ics_native(ics);
+
+ return in->node == node;
+}
+
+static struct ics ics_native_template = {
+ .map = ics_native_map,
+ .mask_unknown = ics_native_mask_unknown,
+ .get_server = ics_native_get_server,
+ .host_match = ics_native_host_match,
+};
+
+static int __init ics_native_add_one(struct device_node *np)
+{
+ struct ics_native *ics;
+ u32 ranges[2];
+ int rc, count;
+
+ ics = kzalloc(sizeof(struct ics_native), GFP_KERNEL);
+ if (!ics)
+ return -ENOMEM;
+ ics->node = of_node_get(np);
+ memcpy(&ics->ics, &ics_native_template, sizeof(struct ics));
+
+ ics->base = of_iomap(np, 0);
+ if (!ics->base) {
+ pr_err("Failed to map %pOFP\n", np);
+ rc = -ENOMEM;
+ goto fail;
+ }
+
+ count = of_property_count_u32_elems(np, "interrupt-ranges");
+ if (count < 2 || count & 1) {
+ pr_err("Failed to read interrupt-ranges of %pOFP\n", np);
+ rc = -EINVAL;
+ goto fail;
+ }
+ if (count > 2) {
+ pr_warn("ICS %pOFP has %d ranges, only one supported\n",
+ np, count >> 1);
+ }
+ rc = of_property_read_u32_array(np, "interrupt-ranges",
+ ranges, 2);
+ if (rc) {
+ pr_err("Failed to read interrupt-ranges of %pOFP\n", np);
+ goto fail;
+ }
+ ics->ibase = ranges[0];
+ ics->icount = ranges[1];
+
+ pr_info("ICS native initialized for sources %d..%d\n",
+ ics->ibase, ics->ibase + ics->icount - 1);
+
+ /* Register ourselves */
+ xics_register_ics(&ics->ics);
+
+ return 0;
+fail:
+ of_node_put(ics->node);
+ kfree(ics);
+ return rc;
+}
+
+int __init ics_native_init(void)
+{
+ struct device_node *ics;
+ bool found_one = false;
+
+ /* We need to patch our irq chip's EOI to point to the
+ * right ICP
+ */
+ ics_native_irq_chip.irq_eoi = icp_ops->eoi;
+
+ /* Find native ICS in the device-tree */
+ for_each_compatible_node(ics, NULL, "openpower,xics-sources") {
+ if (ics_native_add_one(ics) == 0)
+ found_one = true;
+ }
+
+ if (found_one)
+ pr_info("ICS native backend registered\n");
+
+ return found_one ? 0 : -ENODEV;
+}
diff --git a/arch/powerpc/sysdev/xics/xics-common.c b/arch/powerpc/sysdev/xics/xics-common.c
index 7e4305c01bac..de41ab91f793 100644
--- a/arch/powerpc/sysdev/xics/xics-common.c
+++ b/arch/powerpc/sysdev/xics/xics-common.c
@@ -476,6 +476,8 @@ void __init xics_init(void)
rc = ics_rtas_init();
if (rc < 0)
rc = ics_opal_init();
+ if (rc < 0)
+ rc = ics_native_init();
if (rc < 0)
pr_warn("XICS: Cannot find a Source Controller !\n");
--
2.31.1
More information about the Linuxppc-dev
mailing list