x86: Generate a valid ACPI table

Implement write_acpi_table() to create a minimal working ACPI table.
This includes writing FACS, XSDT, RSDP, FADT, MCFG, MADT, DSDT & SSDT
ACPI table entries.

Use a Kconfig option GENERATE_ACPI_TABLE to tell U-Boot whether we need
actually write the APCI table just like we did for PIRQ routing, MP table
and SFI tables. With ACPI table existence, linux kernel gets control of
power management, thermal management, configuration management and
monitoring in hardware.

Signed-off-by: Saket Sinha <saket.sinha89@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tidied up whitespace and aligned some tabs:
Signed-off-by: Simon Glass <sjg@chromium.org>

3 files changed, 442 insertions, 0 deletions

diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index dcfe9ee..6ecd6db 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -30,6 +30,7 @@ obj-y += physmem.o
 obj-$(CONFIG_X86_RAMTEST) += ramtest.o
 obj-y += sfi.o
 obj-y	+= string.o
+obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi_table.o
 obj-y	+= tables.o
 obj-$(CONFIG_SYS_X86_TSC_TIMER)	+= tsc_timer.o
 obj-$(CONFIG_CMD_ZBOOT)	+= zimage.o
diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
new file mode 100644
index 0000000..ab1db7e
--- /dev/null
+++ b/arch/x86/lib/acpi_table.c
@@ -0,0 +1,436 @@
+/*
+ * Based on acpi.c from coreboot
+ *
+ * Copyright (C) 2015, Saket Sinha <saket.sinha89@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <cpu.h>
+#include <dm.h>
+#include <dm/uclass-internal.h>
+#include <dm/lists.h>
+#include <asm/acpi_table.h>
+#include <asm/cpu.h>
+#include <asm/ioapic.h>
+#include <asm/lapic.h>
+#include <asm/tables.h>
+#include <asm/pci.h>
+
+/*
+ * IASL compiles the dsdt entries and
+ * writes the hex values to AmlCode array.
+ * CamelCase cannot be handled here.
+ */
+extern const unsigned char AmlCode[];
+
+/**
+* Add an ACPI table to the RSDT (and XSDT) structure, recalculate length
+* and checksum.
+*/
+static void acpi_add_table(struct acpi_rsdp *rsdp, void *table)
+{
+	int i, entries_num;
+	struct acpi_rsdt *rsdt;
+	struct acpi_xsdt *xsdt = NULL;
+
+	/* The RSDT is mandatory while the XSDT is not */
+	rsdt = (struct acpi_rsdt *)rsdp->rsdt_address;
+
+	if (rsdp->xsdt_address)
+		xsdt = (struct acpi_xsdt *)((u32)rsdp->xsdt_address);
+
+	/* This should always be MAX_ACPI_TABLES */
+	entries_num = ARRAY_SIZE(rsdt->entry);
+
+	for (i = 0; i < entries_num; i++) {
+		if (rsdt->entry[i] == 0)
+			break;
+	}
+
+	if (i >= entries_num) {
+		debug("ACPI: Error: too many tables.\n");
+		return;
+	}
+
+	/* Add table to the RSDT */
+	rsdt->entry[i] = (u32)table;
+
+	/* Fix RSDT length or the kernel will assume invalid entries */
+	rsdt->header.length = sizeof(acpi_header_t) + (sizeof(u32) * (i + 1));
+
+	/* Re-calculate checksum */
+	rsdt->header.checksum = 0;
+	rsdt->header.checksum = table_compute_checksum((u8 *)rsdt,
+						       rsdt->header.length);
+
+	/*
+	 * And now the same thing for the XSDT. We use the same index as for
+	 * now we want the XSDT and RSDT to always be in sync in U-Boot
+	 */
+	if (xsdt) {
+		/* Add table to the XSDT */
+		xsdt->entry[i] = (u64)(u32)table;
+
+		/* Fix XSDT length */
+		xsdt->header.length = sizeof(acpi_header_t) +
+			 (sizeof(u64) * (i + 1));
+
+		/* Re-calculate checksum */
+		xsdt->header.checksum = 0;
+		xsdt->header.checksum = table_compute_checksum((u8 *)xsdt,
+				xsdt->header.length);
+	}
+}
+
+static int acpi_create_madt_lapic(struct acpi_madt_lapic *lapic,
+			 u8 cpu, u8 apic)
+{
+	lapic->type = LOCALAPIC; /* Local APIC structure */
+	lapic->length = sizeof(struct acpi_madt_lapic);
+	lapic->flags = LOCAL_APIC_FLAG_ENABLED; /* Processor/LAPIC enabled */
+	lapic->processor_id = cpu;
+	lapic->apic_id = apic;
+
+	return lapic->length;
+}
+
+unsigned long acpi_create_madt_lapics(unsigned long current)
+{
+	struct udevice *dev;
+
+	for (uclass_find_first_device(UCLASS_CPU, &dev);
+	     dev;
+	     uclass_find_next_device(&dev)) {
+		struct cpu_platdata *plat = dev_get_parent_platdata(dev);
+
+		current += acpi_create_madt_lapic(
+			(struct acpi_madt_lapic *)current,
+			plat->cpu_id, plat->cpu_id);
+		}
+		return current;
+}
+
+int acpi_create_madt_ioapic(struct acpi_madt_ioapic *ioapic, u8 id, u32 addr,
+			 u32 gsi_base)
+{
+	ioapic->type = IOAPIC;
+	ioapic->length = sizeof(struct acpi_madt_ioapic);
+	ioapic->reserved = 0x00;
+	ioapic->gsi_base = gsi_base;
+	ioapic->ioapic_id = id;
+	ioapic->ioapic_addr = addr;
+
+	return ioapic->length;
+}
+
+int acpi_create_madt_irqoverride(struct acpi_madt_irqoverride *irqoverride,
+			 u8 bus, u8 source, u32 gsirq, u16 flags)
+{
+	irqoverride->type = IRQSOURCEOVERRIDE;
+	irqoverride->length = sizeof(struct acpi_madt_irqoverride);
+	irqoverride->bus = bus;
+	irqoverride->source = source;
+	irqoverride->gsirq = gsirq;
+	irqoverride->flags = flags;
+
+	return irqoverride->length;
+}
+
+int acpi_create_madt_lapic_nmi(struct acpi_madt_lapic_nmi *lapic_nmi,
+			 u8 cpu, u16 flags, u8 lint)
+{
+	lapic_nmi->type = LOCALNMITYPE;
+	lapic_nmi->length = sizeof(struct acpi_madt_lapic_nmi);
+	lapic_nmi->flags = flags;
+	lapic_nmi->processor_id = cpu;
+	lapic_nmi->lint = lint;
+
+	return lapic_nmi->length;
+}
+
+static void fill_header(acpi_header_t *header, char *signature, int length)
+{
+	memcpy(header->signature, signature, length);
+	memcpy(header->oem_id, OEM_ID, 6);
+	memcpy(header->oem_table_id, ACPI_TABLE_CREATOR, 8);
+	memcpy(header->asl_compiler_id, ASLC, 4);
+}
+
+static void acpi_create_madt(struct acpi_madt *madt)
+{
+	acpi_header_t *header = &(madt->header);
+	unsigned long current = (unsigned long)madt + sizeof(struct acpi_madt);
+
+	memset((void *)madt, 0, sizeof(struct acpi_madt));
+
+	/* Fill out header fields */
+	fill_header(header, "APIC", 4);
+	header->length = sizeof(struct acpi_madt);
+
+	/* ACPI 1.0/2.0: 1, ACPI 3.0: 2, ACPI 4.0: 3 */
+	header->revision = ACPI_REV_ACPI_2_0;
+
+	madt->lapic_addr = LAPIC_DEFAULT_BASE;
+	madt->flags = PCAT_COMPAT;
+
+	current = acpi_fill_madt(current);
+
+	/* (Re)calculate length and checksum */
+	header->length = current - (unsigned long)madt;
+
+	header->checksum = table_compute_checksum((void *)madt, header->length);
+}
+
+static int acpi_create_mcfg_mmconfig(struct acpi_mcfg_mmconfig *mmconfig,
+			 u32 base, u16 seg_nr, u8 start, u8 end)
+{
+	memset(mmconfig, 0, sizeof(*mmconfig));
+	mmconfig->base_address = base;
+	mmconfig->base_reserved = 0;
+	mmconfig->pci_segment_group_number = seg_nr;
+	mmconfig->start_bus_number = start;
+	mmconfig->end_bus_number = end;
+
+	return sizeof(struct acpi_mcfg_mmconfig);
+}
+
+static unsigned long acpi_fill_mcfg(unsigned long current)
+{
+	current += acpi_create_mcfg_mmconfig
+		((struct acpi_mcfg_mmconfig *)current,
+		 CONFIG_PCIE_ECAM_BASE, 0x0, 0x0, 255);
+
+	return current;
+}
+
+/* MCFG is defined in the PCI Firmware Specification 3.0 */
+static void acpi_create_mcfg(struct acpi_mcfg *mcfg)
+{
+	acpi_header_t *header = &(mcfg->header);
+	unsigned long current = (unsigned long)mcfg + sizeof(struct acpi_mcfg);
+
+	memset((void *)mcfg, 0, sizeof(struct acpi_mcfg));
+
+	/* Fill out header fields */
+	fill_header(header, "MCFG", 4);
+	header->length = sizeof(struct acpi_mcfg);
+
+	/* ACPI 1.0/2.0: 1, ACPI 3.0: 2, ACPI 4.0: 3 */
+	header->revision = ACPI_REV_ACPI_2_0;
+
+	current = acpi_fill_mcfg(current);
+
+	/* (Re)calculate length and checksum */
+	header->length = current - (unsigned long)mcfg;
+	header->checksum = table_compute_checksum((void *)mcfg, header->length);
+}
+
+static void acpi_create_facs(struct acpi_facs *facs)
+{
+	memset((void *)facs, 0, sizeof(struct acpi_facs));
+
+	memcpy(facs->signature, "FACS", 4);
+	facs->length = sizeof(struct acpi_facs);
+	facs->hardware_signature = 0;
+	facs->firmware_waking_vector = 0;
+	facs->global_lock = 0;
+	facs->flags = 0;
+	facs->x_firmware_waking_vector_l = 0;
+	facs->x_firmware_waking_vector_h = 0;
+	facs->version = 1; /* ACPI 1.0: 0, ACPI 2.0/3.0: 1, ACPI 4.0: 2 */
+}
+
+static void acpi_write_rsdt(struct acpi_rsdt *rsdt)
+{
+	acpi_header_t *header = &(rsdt->header);
+
+	/* Fill out header fields */
+	fill_header(header, "RSDT", 4);
+	header->length = sizeof(struct acpi_rsdt);
+
+	/* ACPI 1.0/2.0: 1, ACPI 3.0: 2, ACPI 4.0: 3 */
+	header->revision = ACPI_REV_ACPI_2_0;
+
+	/* Entries are filled in later, we come with an empty set */
+
+	/* Fix checksum */
+	header->checksum = table_compute_checksum((void *)rsdt,
+			sizeof(struct acpi_rsdt));
+}
+
+static void acpi_write_xsdt(struct acpi_xsdt *xsdt)
+{
+	acpi_header_t *header = &(xsdt->header);
+
+	/* Fill out header fields */
+	fill_header(header, "XSDT", 4);
+	header->length = sizeof(struct acpi_xsdt);
+
+	/* ACPI 1.0/2.0: 1, ACPI 3.0: 2, ACPI 4.0: 3 */
+	header->revision = ACPI_REV_ACPI_2_0;
+
+	/* Entries are filled in later, we come with an empty set */
+
+	/* Fix checksum */
+	header->checksum = table_compute_checksum((void *)xsdt,
+			sizeof(struct acpi_xsdt));
+}
+
+static void acpi_write_rsdp(struct acpi_rsdp *rsdp, struct acpi_rsdt *rsdt,
+			 struct acpi_xsdt *xsdt)
+{
+	memset(rsdp, 0, sizeof(struct acpi_rsdp));
+
+	memcpy(rsdp->signature, RSDP_SIG, 8);
+	memcpy(rsdp->oem_id, OEM_ID, 6);
+
+	rsdp->length = sizeof(struct acpi_rsdp);
+	rsdp->rsdt_address = (u32)rsdt;
+
+	/*
+	* Revision: ACPI 1.0: 0, ACPI 2.0/3.0/4.0: 2
+	*
+	* Some OSes expect an XSDT to be present for RSD PTR revisions >= 2.
+	* If we don't have an ACPI XSDT, force ACPI 1.0 (and thus RSD PTR
+	* revision 0)
+	*/
+	if (xsdt == NULL) {
+		rsdp->revision = ACPI_RSDP_REV_ACPI_1_0;
+	} else {
+		rsdp->xsdt_address = (u64)(u32)xsdt;
+		rsdp->revision = ACPI_RSDP_REV_ACPI_2_0;
+	}
+
+	/* Calculate checksums */
+	rsdp->checksum = table_compute_checksum((void *)rsdp, 20);
+	rsdp->ext_checksum = table_compute_checksum((void *)rsdp,
+			sizeof(struct acpi_rsdp));
+}
+
+static void acpi_create_ssdt_generator(acpi_header_t *ssdt,
+			 const char *oem_table_id)
+{
+	unsigned long current = (unsigned long)ssdt + sizeof(acpi_header_t);
+
+	memset((void *)ssdt, 0, sizeof(acpi_header_t));
+
+	memcpy(&ssdt->signature, "SSDT", 4);
+	/* Access size in ACPI 2.0c/3.0/4.0/5.0 */
+	ssdt->revision = ACPI_REV_ACPI_3_0;
+	memcpy(&ssdt->oem_id, OEM_ID, 6);
+	memcpy(&ssdt->oem_table_id, oem_table_id, 8);
+	ssdt->oem_revision = OEM_REVISION;
+	memcpy(&ssdt->asl_compiler_id, ASLC, 4);
+	ssdt->asl_compiler_revision = ASL_COMPILER_REVISION;
+	ssdt->length = sizeof(acpi_header_t);
+
+	/* (Re)calculate length and checksum */
+	ssdt->length = current - (unsigned long)ssdt;
+	ssdt->checksum = table_compute_checksum((void *)ssdt, ssdt->length);
+}
+
+unsigned long write_acpi_tables(unsigned long start)
+{
+	unsigned long current;
+	struct acpi_rsdp *rsdp;
+	struct acpi_rsdt *rsdt;
+	struct acpi_xsdt *xsdt;
+	struct acpi_facs *facs;
+	acpi_header_t *dsdt;
+	struct acpi_fadt *fadt;
+	struct acpi_mcfg *mcfg;
+	struct acpi_madt *madt;
+	acpi_header_t *ssdt;
+
+	current = start;
+
+	/* Align ACPI tables to 16byte */
+	current = ALIGN(current, 16);
+
+	debug("ACPI: Writing ACPI tables at %lx.\n", start);
+
+	/* We need at least an RSDP and an RSDT Table */
+	rsdp = (struct acpi_rsdp *)current;
+	current += sizeof(struct acpi_rsdp);
+	current = ALIGN(current, 16);
+	rsdt = (struct acpi_rsdt *)current;
+	current += sizeof(struct acpi_rsdt);
+	current = ALIGN(current, 16);
+	xsdt = (struct acpi_xsdt *)current;
+	current += sizeof(struct acpi_xsdt);
+	current = ALIGN(current, 16);
+
+	/* clear all table memory */
+	memset((void *)start, 0, current - start);
+
+	acpi_write_rsdp(rsdp, rsdt, xsdt);
+	acpi_write_rsdt(rsdt);
+	acpi_write_xsdt(xsdt);
+
+	debug("ACPI:    * FACS\n");
+	facs = (struct acpi_facs *)current;
+	current += sizeof(struct acpi_facs);
+	current = ALIGN(current, 16);
+
+	acpi_create_facs(facs);
+
+	debug("ACPI:    * DSDT\n");
+	dsdt = (acpi_header_t *)current;
+	memcpy(dsdt, &AmlCode, sizeof(acpi_header_t));
+	if (dsdt->length >= sizeof(acpi_header_t)) {
+		current += sizeof(acpi_header_t);
+		memcpy((char *)current,
+				(char *)&AmlCode + sizeof(acpi_header_t),
+				dsdt->length - sizeof(acpi_header_t));
+		current += dsdt->length - sizeof(acpi_header_t);
+
+		/* (Re)calculate length and checksum */
+		dsdt->length = current - (unsigned long)dsdt;
+		dsdt->checksum = 0;
+		dsdt->checksum = table_compute_checksum((void *)dsdt,
+				dsdt->length);
+	}
+	current = ALIGN(current, 16);
+
+	debug("ACPI:    * FADT\n");
+	fadt = (struct acpi_fadt *)current;
+	current += sizeof(struct acpi_fadt);
+	current = ALIGN(current, 16);
+	acpi_create_fadt(fadt, facs, dsdt);
+	acpi_add_table(rsdp, fadt);
+
+	debug("ACPI:    * MCFG\n");
+	mcfg = (struct acpi_mcfg *)current;
+	acpi_create_mcfg(mcfg);
+	if (mcfg->header.length > sizeof(struct acpi_mcfg)) {
+		current += mcfg->header.length;
+		current = ALIGN(current, 16);
+		acpi_add_table(rsdp, mcfg);
+	}
+
+	debug("ACPI:    * MADT\n");
+	madt = (struct acpi_madt *)current;
+	acpi_create_madt(madt);
+	if (madt->header.length > sizeof(struct acpi_madt)) {
+		current += madt->header.length;
+		acpi_add_table(rsdp, madt);
+	}
+	current = ALIGN(current, 16);
+
+	debug("ACPI:    * SSDT\n");
+	ssdt = (acpi_header_t *)current;
+	acpi_create_ssdt_generator(ssdt, ACPI_TABLE_CREATOR);
+	if (ssdt->length > sizeof(acpi_header_t)) {
+		current += ssdt->length;
+		acpi_add_table(rsdp, ssdt);
+		current = ALIGN(current, 16);
+	}
+
+	debug("current = %lx\n", current);
+
+	debug("ACPI: done.\n");
+
+	return current;
+}
diff --git a/arch/x86/lib/tables.c b/arch/x86/lib/tables.c
index 75ffbc1..f15b2e2 100644
--- a/arch/x86/lib/tables.c
+++ b/arch/x86/lib/tables.c
@@ -8,6 +8,7 @@
 #include <asm/sfi.h>
 #include <asm/mpspec.h>
 #include <asm/tables.h>
+#include <asm/acpi_table.h>
 
 u8 table_compute_checksum(void *v, int len)
 {
@@ -51,4 +52,8 @@ void write_tables(void)
 	rom_table_end = write_mp_table(rom_table_end);
 	rom_table_end = ALIGN(rom_table_end, 1024);
 #endif
+#ifdef CONFIG_GENERATE_ACPI_TABLE
+	rom_table_end = write_acpi_tables(rom_table_end);
+	rom_table_end = ALIGN(rom_table_end, 1024);
+#endif
 }