Merge patch series "Implement ACPI on aarch64"

Patrick Rudolph <patrick.rudolph@9elements.com> says:

Based on the existing work done by Simon Glass this series adds
support for booting aarch64 devices using ACPI only.
As first target QEMU SBSA support is added, which relies on ACPI
only to boot an OS. As secondary target the Raspberry Pi4 was used,
which is broadly available and allows easy testing of the proposed
solution.

The series is split into ACPI cleanups and code movements, adding
Arm specific ACPI tables and finally SoC and mainboard related
changes to boot a Linux on the QEMU SBSA and RPi4. Currently only the
mandatory ACPI tables are supported, allowing to boot into Linux
without errors.

The QEMU SBSA support is feature complete and provides the same
functionality as the EDK2 implementation.

The changes were tested on real hardware as well on QEMU v9.0:

qemu-system-aarch64 -machine sbsa-ref -nographic -cpu cortex-a57 \
                    -pflash secure-world.rom \
                    -pflash unsecure-world.rom

qemu-system-aarch64 -machine raspi4b -kernel u-boot.bin -cpu cortex-a72 \
-smp 4 -m 2G -drive file=raspbian.img,format=raw,index=0 \
-dtb bcm2711-rpi-4-b.dtb -nographic

Tested against FWTS V24.03.00.

Known issues:
- The QEMU rpi4 support is currently limited as it doesn't emulate PCI,
  USB or ethernet devices!
- The SMP bringup doesn't work on RPi4, but works in QEMU (Possibly
  cache related).
- PCI on RPI4 isn't working on real hardware since the pcie_brcmstb
  Linux kernel module doesn't support ACPI yet.

Link: https://lore.kernel.org/r/20241023132116.970117-1-patrick.rudolph@9elements.com

1 files changed, 214 insertions, 0 deletions

diff --git a/drivers/cpu/bcm283x_cpu.c b/drivers/cpu/bcm283x_cpu.c
new file mode 100644
index 00000000000..59a7b142c95
--- /dev/null
+++ b/drivers/cpu/bcm283x_cpu.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2024 9elements GmbH
+ */
+
+#include <cpu.h>
+#include <cpu_func.h>
+#include <dm.h>
+#include <fdt_support.h>
+#include <acpi/acpigen.h>
+#include <asm/armv8/cpu.h>
+#include <asm/cache.h>
+#include <asm/io.h>
+#include <asm/global_data.h>
+#include <asm/system.h>
+#include <asm-generic/sections.h>
+#include <linux/bitops.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include "armv8_cpu.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct bcm_plat {
+	u64 release_addr;
+};
+
+static int cpu_bcm_get_desc(const struct udevice *dev, char *buf, int size)
+{
+	struct cpu_plat *plat = dev_get_parent_plat(dev);
+	const char *name;
+
+	if (size < 32)
+		return -ENOSPC;
+
+	if (device_is_compatible(dev, "arm,cortex-a53"))
+		name = "A53";
+	else if (device_is_compatible(dev, "arm,cortex-a72"))
+		name = "A72";
+	else
+		name = "?";
+
+	snprintf(buf, size, "Broadcom Cortex-%s at %u MHz\n",
+		 name, plat->timebase_freq);
+
+	return 0;
+}
+
+static int cpu_bcm_get_info(const struct udevice *dev, struct cpu_info *info)
+{
+	struct cpu_plat *plat = dev_get_parent_plat(dev);
+
+	info->cpu_freq = plat->timebase_freq * 1000;
+	info->features = BIT(CPU_FEAT_L1_CACHE) | BIT(CPU_FEAT_MMU);
+
+	return 0;
+}
+
+static int cpu_bcm_get_count(const struct udevice *dev)
+{
+	return uclass_id_count(UCLASS_CPU);
+}
+
+static int cpu_bcm_get_vendor(const struct udevice *dev,  char *buf, int size)
+{
+	snprintf(buf, size, "Broadcom");
+
+	return 0;
+}
+
+static int cpu_bcm_is_current(struct udevice *dev)
+{
+	struct cpu_plat *plat = dev_get_parent_plat(dev);
+
+	if (plat->cpu_id == (read_mpidr() & 0xffff))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * bcm_cpu_on - Releases the secondary CPU from it's spintable
+ *
+ * Write the CPU's spintable mailbox and let the CPU enter U-Boot.
+ *
+ * @dev: Device to start
+ * @return: zero on success or error code on failure.
+ */
+static int bcm_cpu_on(struct udevice *dev)
+{
+	struct bcm_plat *plat = dev_get_plat(dev);
+	ulong *start_address;
+
+	if (plat->release_addr == ~0ULL)
+		return -ENODATA;
+
+	start_address = map_physmem(plat->release_addr, sizeof(uintptr_t), MAP_NOCACHE);
+
+	/* Point secondary CPU to U-Boot entry */
+	*start_address = (uintptr_t)_start;
+
+	/* Make sure the other CPUs see the written start address */
+	if (!CONFIG_IS_ENABLED(SYS_DCACHE_OFF))
+		flush_dcache_all();
+
+	/* Send an event to wake up the secondary CPU. */
+	asm("dsb	ishst\n"
+	    "sev");
+
+	unmap_physmem(start_address, MAP_NOCACHE);
+
+	return 0;
+}
+
+static const struct cpu_ops cpu_bcm_ops = {
+	.get_desc	= cpu_bcm_get_desc,
+	.get_info	= cpu_bcm_get_info,
+	.get_count	= cpu_bcm_get_count,
+	.get_vendor	= cpu_bcm_get_vendor,
+	.is_current	= cpu_bcm_is_current,
+};
+
+static const struct udevice_id cpu_bcm_ids[] = {
+	{ .compatible = "arm,cortex-a53" },	/* RPi 3 */
+	{ .compatible = "arm,cortex-a72" },	/* RPi 4 */
+	{ }
+};
+
+static int bcm_cpu_bind(struct udevice *dev)
+{
+	struct cpu_plat *plat = dev_get_parent_plat(dev);
+
+	plat->cpu_id = dev_read_addr(dev);
+
+	return 0;
+}
+
+/**
+ * bcm_cpu_of_to_plat - Gather spin-table release address
+ *
+ * Read the spin-table release address to allow all seconary CPUs to enter
+ * U-Boot when necessary.
+ *
+ * @dev: Device to start
+ */
+static int bcm_cpu_of_to_plat(struct udevice *dev)
+{
+	struct bcm_plat *plat = dev_get_plat(dev);
+	const char *prop;
+
+	if (CONFIG_IS_ENABLED(ARMV8_MULTIENTRY)) {
+		plat->release_addr = ~0ULL;
+
+		prop = dev_read_string(dev, "enable-method");
+		if (!prop || strcmp(prop, "spin-table"))
+			return -ENODEV;
+
+		plat->release_addr = dev_read_u64_default(dev, "cpu-release-addr", ~0ULL);
+
+		if (plat->release_addr == ~0ULL)
+			return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int bcm_cpu_probe(struct udevice *dev)
+{
+	struct cpu_plat *plat = dev_get_parent_plat(dev);
+	struct clk clk;
+	int ret;
+
+	/* Get a clock if it exists */
+	ret = clk_get_by_index(dev, 0, &clk);
+	if (!ret) {
+		ret = clk_enable(&clk);
+		if (ret && (ret != -ENOSYS || ret != -EOPNOTSUPP))
+			return ret;
+		ret = clk_get_rate(&clk);
+		if (IS_ERR_VALUE(ret))
+			return ret;
+		plat->timebase_freq = ret;
+	}
+
+	/*
+	 * The armstub holds the secondary CPUs in a spinloop. When
+	 * ARMV8_MULTIENTRY is enabled release the secondary CPUs and
+	 * let them enter U-Boot as well.
+	 */
+	if (CONFIG_IS_ENABLED(ARMV8_MULTIENTRY)) {
+		ret = bcm_cpu_on(dev);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+struct acpi_ops bcm283x_cpu_acpi_ops = {
+	.fill_ssdt	= armv8_cpu_fill_ssdt,
+	.fill_madt	= armv8_cpu_fill_madt,
+};
+
+U_BOOT_DRIVER(cpu_bcm_drv) = {
+	.name		= "bcm283x_cpu",
+	.id		= UCLASS_CPU,
+	.of_match	= cpu_bcm_ids,
+	.ops		= &cpu_bcm_ops,
+	.probe		= bcm_cpu_probe,
+	.bind		= bcm_cpu_bind,
+	.of_to_plat	= bcm_cpu_of_to_plat,
+	.plat_auto	= sizeof(struct bcm_plat),
+	ACPI_OPS_PTR(&bcm283x_cpu_acpi_ops)
+};