dt: device discovery with devicetree initial implementation

Author: AkeKoomsin-IGEL

.clang-format

@@ -63,3 +63,5 @@ ForEachMacros:
   - LIST4_FOREACH
   - LIST4_FOREACH_DELETABLE
   - ARRAYLIST_FOREACH
+  - fdt_for_each_subnode
+  - fdt_for_each_property_offset

Kconfig

@@ -474,3 +474,11 @@ config DEBUG_SERIAL
 	bool
 	default n
 	prompt "Debug serial for Linux early console"
+
+config DEVICETREE
+	bool
+	default y
+	prompt "Enable support for discovering devices with Devicetree"
+	help
+	  If ACPI is optional or not available on the target architecture, it
+	  is recommended to set this option to 'y'.

LICENSE

@@ -27,6 +27,7 @@ subdirs-$(CONFIG_VPN) += vpn
 subdirs-$(CONFIG_IDMAN) += idman
 subdirs-y += net
 subdirs-$(CONFIG_IP) += ip
+subdirs-$(CONFIG_DEVICETREE) += devtree
 asubdirs-$(CONFIG_CRYPTO) += crypto
 psubdirs-y += process
 

Makefile

@@ -31,6 +31,7 @@
 #include <Protocol/BlockIoCrypto.h>
 #include <Protocol/LoadedImage.h>
 #include <Protocol/SimpleFileSystem.h>
+#include <efi_extra/config_table.h>
 #include <efi_extra/device_path_helper.h>
 #include <uefi_boot.h>
 
@@ -53,6 +54,8 @@ static EFI_GUID LoadedImageProtocol = EFI_LOADED_IMAGE_PROTOCOL_GUID;
 static EFI_GUID FileSystemProtocol = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID;
 static EFI_GUID BlockIoCryptoProtocol = EFI_BLOCK_IO_CRYPTO_PROTOCOL_GUID;
 
+static EFI_GUID DtbTableGUID = EFI_DTB_TABLE_GUID;
+
 static EFI_HANDLE saved_image;
 static EFI_SYSTEM_TABLE *saved_systab;
 
@@ -126,6 +129,35 @@ create_file_path (EFI_DEVICE_PATH_PROTOCOL *dp, CHAR16 *newname, CHAR16 *buf,
 #include "bsdriver_load.h"
 #include "acpi_table_mod.h"
 
+static BOOLEAN
+guid_cmp (EFI_GUID *g1, EFI_GUID *g2)
+{
+	UINT64 *p1, *p2;
+
+	/* GUID is 128 bits. So, we can treat it as an array of UINT64. */
+	p1 = (UINT64 *)g1;
+	p2 = (UINT64 *)g2;
+
+	return p1[0] == p2[0] && p1[1] == p2[1];
+}
+
+static BOOLEAN
+search_config_tab_dtb (EFI_SYSTEM_TABLE *systab, void **fdt_base)
+{
+	EFI_CONFIGURATION_TABLE *ct = systab->ConfigurationTable;
+	UINTN i, n;
+
+	n = systab->NumberOfTableEntries;
+	for (i = 0; i < n; i++) {
+		if (guid_cmp (&ct[i].VendorGuid, &DtbTableGUID)) {
+			*fdt_base = ct[i].VendorTable;
+			return TRUE;
+		}
+	}
+
+	return FALSE;
+}
+
 EFI_STATUS EFIAPI
 efi_main (EFI_HANDLE image, EFI_SYSTEM_TABLE *systab)
 {
@@ -140,6 +172,7 @@ efi_main (EFI_HANDLE image, EFI_SYSTEM_TABLE *systab)
 	EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *fileio;
 	EFI_LOADED_IMAGE_PROTOCOL *loaded_image;
 	EFI_PHYSICAL_ADDRESS paddr = UPPER_LOAD_ADDR;
+	BOOLEAN dtb_found;
 
 	saved_image = image;
 	saved_systab = systab;
@@ -201,10 +234,15 @@ efi_main (EFI_HANDLE image, EFI_SYSTEM_TABLE *systab)
 		UEFI_BITVISOR_ACPI_TABLE_MOD_UUID,
 		acpi_table_mod
 	};
+	struct bitvisor_devtree boot_ext4 = {
+		UEFI_BITVISOR_DEVTREE_UUID,
+	};
+	dtb_found = search_config_tab_dtb (systab, &boot_ext4.fdt_base);
 	void *boot_exts[] = {
 		&boot_ext,
 		&boot_ext2,
 		&boot_ext3,
+		dtb_found ? &boot_ext4 : NULL,
 		NULL
 	};
 

boot/uefi-loader/loadvmm.c

@@ -18,6 +18,7 @@ CONSTANTS-$(CONFIG_ACPI_IGNORE_ERROR) += -DACPI_IGNORE_ERROR
 
 CFLAGS += -I$(DIR)/include
 CFLAGS += -Ivpn/lib
+CFLAGS += -Idevtree/libfdt
 CFLAGS += $(CFLAGS_EDK2_INC)
 
 subdirs-y += $(ARCH)
@@ -30,6 +31,7 @@ objs-y += calluefi.o
 objs-y += config.o
 objs-y += debug.o
 objs-y += dres.o
+objs-$(CONFIG_DEVICETREE) += dt.o
 objs-y += exint_pass.o
 objs-y += iccard.o
 objs-y += initfunc.o

core/Makefile

@@ -1,6 +1,7 @@
 CONSTANTS-$(CONFIG_ENABLE_ASSERT) += -DENABLE_ASSERT
 CONSTANTS-$(CONFIG_ACPI_DSDT) += -DACPI_DSDT
 CONSTANTS-$(CONFIG_BACKTRACE) += -DBACKTRACE
+CONSTANTS-$(CONFIG_DEVICETREE) += -DDEVICETREE
 
 CFLAGS += -Icore/include
 CFLAGS += -Idevtree/libfdt

core/aarch64/Makefile

@@ -31,9 +31,11 @@
 #include <bits.h>
 #include <common.h>
 #include <constants.h>
+#include <libfdt.h>
 #include <core/aarch64/gic.h>
 #include <core/assert.h>
 #include <core/dres.h>
+#include <core/dt.h>
 #include <core/initfunc.h>
 #include <core/mm.h>
 #include <core/mmio.h>
@@ -43,6 +45,7 @@
 #include <core/spinlock.h>
 #include <core/types.h>
 #include "../acpi.h"
+#include "../dt.h"
 #include "../exint_pass.h"
 #include "asm.h"
 #include "exception.h"
@@ -1297,16 +1300,11 @@ gic_its_init (phys_t base_phys)
 }
 
 static void
-acpi_madt_handle_gicd (struct acpi_ic_header *h)
+gicd_init (phys_t base)
 {
-	struct acpi_gicd *entry;
-	phys_t base, typer;
+	phys_t typer;
 	u32 *gicd_typer, v;
 
-	entry = (struct acpi_gicd *)h;
-	base = entry->phys_addr;
-	ASSERT (base);
-
 	typer = base + GICD_TYPER;
 	gicd_typer = mapmem_hphys (typer, sizeof *gicd_typer, MAPMEM_UC);
 	ASSERT (gicd_typer);
@@ -1334,6 +1332,19 @@ acpi_madt_handle_gicd (struct acpi_ic_header *h)
 			GIC_N_INITD_WATERMARK);
 }
 
+static void
+acpi_madt_handle_gicd (struct acpi_ic_header *h)
+{
+	struct acpi_gicd *entry;
+	phys_t base;
+
+	entry = (struct acpi_gicd *)h;
+	base = entry->phys_addr;
+	ASSERT (base);
+
+	gicd_init (base);
+}
+
 static void
 acpi_madt_handle_gic_its (struct acpi_ic_header *h)
 {
@@ -1382,16 +1393,156 @@ acpi_madt_walk (struct acpi_madt *m)
 		panic ("%s(): GIC-ITS not initialized", __func__);
 }
 
-static void
-gic_init (void)
+static int
+gic_init_acpi (void)
 {
 	struct acpi_madt *m;
 
 	m = acpi_find_entry (ACPI_MADT_SIGNATURE);
-	if (!m)
-		panic ("ACPI MADT not found\n");
+	if (m)
+		acpi_madt_walk (m);
+
+	return m ? 0 : -1;
+}
+
+#ifdef DEVICETREE
+static int
+gic_init_fdt (void)
+{
+	struct dt_reg gicd_reg;
+	struct dt_reg its_reg;
+	const void *fdt;
+	const u32 *intp_p;
+	const void *reg;
+	u32 intp;
+	int error, intc_node, node, lenp, address_cells, size_cells;
+	int ret = 0;
+	enum dt_result_t dt_error;
+
+	fdt = dt_get_fdt ();
+	if (!fdt) {
+		ret = -1;
+		goto end;
+	}
+
+	/*
+	 * Many DT seems to have this. Try searching for interrupt controller
+	 * wtih this first initially.
+	 */
+	intp_p = fdt_getprop (fdt, 0, "interrupt-parent", NULL);
+	if (!intp_p) {
+		printf ("%s(): cannot find interrupt-parent property\n",
+			__func__);
+		ret = -1;
+		goto end;
+	}
+
+	intp = fdt32_ld (intp_p);
+	intc_node = fdt_node_offset_by_phandle (fdt, intp);
+	if (intc_node < 0) {
+		printf ("%s(): cannot find node from phandle? 0x%X %d\n",
+			__func__, intp, intc_node);
+		ret = -1;
+		goto end;
+	}
+
+	error = fdt_node_check_compatible (fdt, intc_node, "arm,gic-v3");
+	if (error) {
+		printf ("%s(): interrupt controller is not GICv3 compatible\n",
+			__func__);
+		ret = -1;
+		goto end;
+	}
+
+	/* Register's address-cells and size-cells are from the parent node */
+	dt_error = dt_helper_cur_node_reg_address_size_cell (fdt, intc_node,
+							     &address_cells,
+							     &size_cells);
+	if (dt_error) {
+		printf ("%s(): cannot read parent's address/size cells\n",
+			__func__);
+		ret = -1;
+		goto end;
+	}
+
+	reg = fdt_getprop (fdt, intc_node, "reg", &lenp);
+	if (!reg) {
+		printf ("%s(): cannot find reg property\n", __func__);
+		ret = -1;
+		goto end;
+	}
+
+	/* We want GICD only for now */
+	dt_error = dt_helper_reg_extract (reg, lenp, address_cells, size_cells,
+					  &gicd_reg, 1);
+	if (dt_error) {
+		printf ("%s(): extract GICD reg fails\n", __func__);
+		ret = -1;
+		goto end;
+	}
+
+	gicd_init (gicd_reg.addr);
+
+	if (!gicd)
+		panic ("%s(): GICD not initialized", __func__);
+
+	/* Read address/size cells for the subnodes */
+	address_cells = fdt_address_cells (fdt, intc_node);
+	if (address_cells < 0) {
+		printf ("%s(): #address-cells readding error %d\n", __func__,
+			address_cells);
+		ret = -1;
+		goto end;
+	}
+	size_cells = fdt_size_cells (fdt, intc_node);
+	if (size_cells < 0) {
+		printf ("%s(): #size-cells readding error %d\n", __func__,
+			size_cells);
+		ret = -1;
+		goto end;
+	}
+
+	fdt_for_each_subnode (node, fdt, intc_node) {
+		error = fdt_node_check_compatible (fdt, node,
+						   "arm,gic-v3-its");
+		if (error)
+			continue;
+
+		reg = fdt_getprop (fdt, node, "reg", &lenp);
+		if (!reg)
+			continue;
+
+		dt_error = dt_helper_reg_extract (reg, lenp, address_cells,
+						  size_cells, &its_reg, 1);
+		if (dt_error) {
+			printf ("%s(): extract ITS reg fails\n", __func__);
+			continue;
+		}
+		gic_its_init (its_reg.addr);
+	}
+
+	if (!its)
+		panic ("%s(): GIC-ITS not initialized", __func__);
+end:
+	return ret;
+}
+#endif
+
+static void
+gic_init (void)
+{
+	int error;
+
+	error = gic_init_acpi ();
+	if (!error)
+		return;
+#ifdef DEVICETREE
+	error = gic_init_fdt ();
+	if (!error)
+		return;
+#endif
 
-	acpi_madt_walk (m);
+	panic ("%s(): no GIC found", __func__);
 }
 
 static void
@@ -1416,6 +1567,6 @@ gic_intr_off (void)
 	msr (GIC_ICC_IGRPEN1_EL1, 0x0);
 }
 
-INITFUNC ("acpi0", gic_init);
+INITFUNC ("bsp0", gic_init);
 INITFUNC ("pcpu0", gic_pcpu_lr_list_init);
 INITFUNC ("panic_dump_done0", gic_intr_off);

core/aarch64/gic.c

@@ -35,6 +35,7 @@
 #include <core/printf.h>
 #include <core/spinlock.h>
 #include <core/string.h>
+#include "../dt.h"
 #include "../uefi.h"
 #include "arm_std_regs.h"
 #include "asm.h"
@@ -102,6 +103,9 @@ vm_start (void)
 	p = tpidr_get_pcpu ();
 	p->currentvcpu = new_vcpu0;
 
+#ifdef DEVICETREE
+	dt_no_more_fdt ();
+#endif
 	/*
 	 * No more interacting with UEFI at this point. We are going to set up
 	 * GIC, and jump to the guest at this point.

core/aarch64/vm.c

@@ -32,6 +32,7 @@
 #include <core/panic.h>
 #include <core/printf.h>
 #include <core/process.h>
+#include "../dt.h"
 #include "../initfunc.h"
 #include "../uefi.h"
 #include "asm.h"
@@ -83,6 +84,9 @@ vmm_main (void)
 
 	initfunc_init ();
 	call_initfunc ("global");
+#ifdef DEVICETREE
+	dt_init ();
+#endif
 	call_initfunc ("bsp");
 	call_parallel ();
 	call_initfunc ("pcpu");