LoongArch: Add boot and setup routines

Add basic boot, setup and reset routines for LoongArch. Now, LoongArch
machines use UEFI-based firmware. The firmware passes configuration
information to the kernel via ACPI and DMI/SMBIOS.

Currently an existing interface between the kernel and the bootloader
is implemented. Kernel gets 2 values from the bootloader, passed in
registers a0 and a1; a0 is an "EFI boot flag" distinguishing UEFI and
non-UEFI firmware, while a1 is a pointer to an FDT with systable,
memmap, cmdline and initrd information.

The standard UEFI boot protocol (EFISTUB) will be added later.

Cc: linux-efi@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Co-developed-by: Yun Liu <liuyun@loongson.cn>
Signed-off-by: Yun Liu <liuyun@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

1 files changed, 169 insertions, 0 deletions

diff --git a/arch/loongarch/kernel/acpi.c b/arch/loongarch/kernel/acpi.c
new file mode 100644
index 000000000000..a644220bb426
--- /dev/null
+++ b/arch/loongarch/kernel/acpi.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * acpi.c - Architecture-Specific Low-Level ACPI Boot Support
+ *
+ * Author: Jianmin Lv <lvjianmin@loongson.cn>
+ *         Huacai Chen <chenhuacai@loongson.cn>
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/memblock.h>
+#include <linux/serial_core.h>
+#include <asm/io.h>
+#include <asm/loongson.h>
+
+int acpi_disabled;
+EXPORT_SYMBOL(acpi_disabled);
+int acpi_noirq;
+int acpi_pci_disabled;
+EXPORT_SYMBOL(acpi_pci_disabled);
+int acpi_strict = 1; /* We have no workarounds on LoongArch */
+int num_processors;
+int disabled_cpus;
+enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
+
+u64 acpi_saved_sp;
+
+#define MAX_CORE_PIC 256
+
+#define PREFIX			"ACPI: "
+
+int acpi_gsi_to_irq(u32 gsi, unsigned int *irqp)
+{
+	if (irqp != NULL)
+		*irqp = acpi_register_gsi(NULL, gsi, -1, -1);
+	return (*irqp >= 0) ? 0 : -EINVAL;
+}
+EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
+
+int acpi_isa_irq_to_gsi(unsigned int isa_irq, u32 *gsi)
+{
+	if (gsi)
+		*gsi = isa_irq;
+	return 0;
+}
+
+/*
+ * success: return IRQ number (>=0)
+ * failure: return < 0
+ */
+int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
+{
+	struct irq_fwspec fwspec;
+
+	switch (gsi) {
+	case GSI_MIN_CPU_IRQ ... GSI_MAX_CPU_IRQ:
+		fwspec.fwnode = liointc_domain->fwnode;
+		fwspec.param[0] = gsi - GSI_MIN_CPU_IRQ;
+		fwspec.param_count = 1;
+
+		return irq_create_fwspec_mapping(&fwspec);
+
+	case GSI_MIN_LPC_IRQ ... GSI_MAX_LPC_IRQ:
+		if (!pch_lpc_domain)
+			return -EINVAL;
+
+		fwspec.fwnode = pch_lpc_domain->fwnode;
+		fwspec.param[0] = gsi - GSI_MIN_LPC_IRQ;
+		fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
+		fwspec.param_count = 2;
+
+		return irq_create_fwspec_mapping(&fwspec);
+
+	case GSI_MIN_PCH_IRQ ... GSI_MAX_PCH_IRQ:
+		if (!pch_pic_domain[0])
+			return -EINVAL;
+
+		fwspec.fwnode = pch_pic_domain[0]->fwnode;
+		fwspec.param[0] = gsi - GSI_MIN_PCH_IRQ;
+		fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
+		fwspec.param_count = 2;
+
+		return irq_create_fwspec_mapping(&fwspec);
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(acpi_register_gsi);
+
+void acpi_unregister_gsi(u32 gsi)
+{
+
+}
+EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
+
+void __init __iomem * __acpi_map_table(unsigned long phys, unsigned long size)
+{
+
+	if (!phys || !size)
+		return NULL;
+
+	return early_memremap(phys, size);
+}
+void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
+{
+	if (!map || !size)
+		return;
+
+	early_memunmap(map, size);
+}
+
+void __init __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
+{
+	if (!memblock_is_memory(phys))
+		return ioremap(phys, size);
+	else
+		return ioremap_cache(phys, size);
+}
+
+void __init acpi_boot_table_init(void)
+{
+	/*
+	 * If acpi_disabled, bail out
+	 */
+	if (acpi_disabled)
+		return;
+
+	/*
+	 * Initialize the ACPI boot-time table parser.
+	 */
+	if (acpi_table_init()) {
+		disable_acpi();
+		return;
+	}
+}
+
+static void __init acpi_process_madt(void)
+{
+	loongson_sysconf.nr_cpus = num_processors;
+}
+
+int __init acpi_boot_init(void)
+{
+	/*
+	 * If acpi_disabled, bail out
+	 */
+	if (acpi_disabled)
+		return -1;
+
+	loongson_sysconf.boot_cpu_id = read_csr_cpuid();
+
+	/*
+	 * Process the Multiple APIC Description Table (MADT), if present
+	 */
+	acpi_process_madt();
+
+	/* Do not enable ACPI SPCR console by default */
+	acpi_parse_spcr(earlycon_acpi_spcr_enable, false);
+
+	return 0;
+}
+
+void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
+{
+	memblock_reserve(addr, size);
+}