[PATCH 5/8] arm64/efi: move EFI init before early FDT processing

[ard.biesheuvel@linaro.org (Ard Biesheuvel)]

The early FDT processing is responsible for enumerating the
DT memory nodes and installing them as memblocks. This should
only be done if we are not booting via EFI, but at this point,
we don't know yet if that is the case or not.

So move the EFI init to before the early FDT processing. This involves
making some changes to the way EFI discovers the locations of the
EFI system table and the memory map, since those values are retrieved
from the FDT as well. Instead the of_scan infrastructure, it now uses
libfdt directly to access the /chosen node.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 arch/arm64/include/asm/efi.h   |  4 +--
 arch/arm64/kernel/efi.c        | 14 +++-----
 arch/arm64/kernel/setup.c      |  4 ++-
 drivers/firmware/efi/Makefile  |  1 +
 drivers/firmware/efi/efi-fdt.c | 74 +++++++++++++++++-------------------------
 include/linux/efi.h            |  3 +-
 6 files changed, 41 insertions(+), 59 deletions(-)

diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index ef572206f1c3..635101f36720 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -5,9 +5,9 @@
 #include <asm/neon.h>
 
 #ifdef CONFIG_EFI
-extern void efi_init(void);
+extern void efi_init_fdt(void *fdt);
 #else
-#define efi_init()
+#define efi_init_fdt(x)
 #endif
 
 #define efi_call_virt(f, ...)						\
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index ab21e0d58278..5369b4f96dd1 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -51,14 +51,7 @@ static struct mm_struct efi_mm = {
 	INIT_MM_CONTEXT(efi_mm)
 };
 
-static int uefi_debug __initdata;
-static int __init uefi_debug_setup(char *str)
-{
-	uefi_debug = 1;
-
-	return 0;
-}
-early_param("uefi_debug", uefi_debug_setup);
+static bool uefi_debug __initdata;
 
 static int __init is_normal_ram(efi_memory_desc_t *md)
 {
@@ -204,14 +197,15 @@ static __init void reserve_regions(void)
 	set_bit(EFI_MEMMAP, &efi.flags);
 }
 
-void __init efi_init(void)
+void __init efi_init_fdt(void *fdt)
 {
 	struct efi_fdt_params params;
 
 	/* Grab UEFI information placed in FDT by stub */
-	if (!efi_get_fdt_params(&params, uefi_debug))
+	if (!efi_get_fdt_params(fdt, &params))
 		return;
 
+	uefi_debug = params.verbose;
 	efi_system_table = params.system_table;
 
 	memblock_reserve(params.mmap & PAGE_MASK,
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 770ae9dc5a75..36ffd0a21a78 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -316,6 +316,9 @@ static void __init setup_machine_fdt(phys_addr_t dt_phys)
 {
 	void *dt_virt = fixmap_remap_fdt(dt_phys);
 
+	if (dt_virt)
+		efi_init_fdt(dt_virt);
+
 	if (!dt_virt || !early_init_dt_scan(dt_virt)) {
 		pr_crit("\n"
 			"Error: invalid device tree blob at physical address %pa (virtual address 0x%p)\n"
@@ -384,7 +387,6 @@ void __init setup_arch(char **cmdline_p)
 	 */
 	local_async_enable();
 
-	efi_init();
 	arm64_memblock_init();
 
 	/* Parse the ACPI tables for possible boot-time configuration */
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 9967dde52174..7b408a4cfc8a 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_EFI_RUNTIME_MAP)		+= runtime-map.o
 obj-$(CONFIG_EFI_RUNTIME_WRAPPERS)	+= runtime-wrappers.o
 obj-$(CONFIG_EFI_STUB)			+= libstub/
 obj-$(CONFIG_EFI_PARAMS_FROM_FDT)	+= efi-fdt.o
+CFLAGS_efi-fdt.o			:= -I$(srctree)/scripts/dtc/libfdt/
diff --git a/drivers/firmware/efi/efi-fdt.c b/drivers/firmware/efi/efi-fdt.c
index f0e7ef2ae0e9..2e0e1a5a3fbb 100644
--- a/drivers/firmware/efi/efi-fdt.c
+++ b/drivers/firmware/efi/efi-fdt.c
@@ -8,8 +8,7 @@
 
 #include <linux/init.h>
 #include <linux/efi.h>
-#include <linux/of.h>
-#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
 
 #define UEFI_PARAM(name, prop, field)			   \
 	{						   \
@@ -32,62 +31,47 @@ static __initdata struct {
 	UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
 };
 
-struct param_info {
-	int verbose;
-	int found;
-	void *params;
-};
-
-static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
-				       int depth, void *data)
+bool __init efi_get_fdt_params(void *fdt, struct efi_fdt_params *params)
 {
-	struct param_info *info = data;
 	const void *prop;
-	void *dest;
-	u64 val;
-	int i, len;
+	int node, i;
+
+	pr_info("Getting EFI parameters from FDT:\n");
 
-	if (depth != 1 || strcmp(uname, "chosen") != 0)
-		return 0;
+	node = fdt_path_offset(fdt, "/chosen");
+	if (node < 0) {
+		pr_err("/chosen node not found!\n");
+		return false;
+	}
+
+	prop = fdt_getprop(fdt, node, "bootargs", NULL);
+	params->verbose = prop && strstr(prop, "uefi_debug");
 
 	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
-		prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
-		if (!prop)
-			return 0;
-		dest = info->params + dt_params[i].offset;
-		info->found++;
+		void *dest;
+		int len;
+		u64 val;
 
-		val = of_read_number(prop, len / sizeof(u32));
+		prop = fdt_getprop(fdt, node, dt_params[i].propname, &len);
+		if (!prop)
+			goto not_found;
+		dest = (void *)params + dt_params[i].offset;
 
 		if (dt_params[i].size == sizeof(u32))
-			*(u32 *)dest = val;
+			val = *(u32 *)dest = be32_to_cpup(prop);
 		else
-			*(u64 *)dest = val;
+			val = *(u64 *)dest = be64_to_cpup(prop);
 
-		if (info->verbose)
+		if (params->verbose)
 			pr_info("  %s: 0x%0*llx\n", dt_params[i].name,
 				dt_params[i].size * 2, val);
 	}
-	return 1;
-}
-
-int __init efi_get_fdt_params(struct efi_fdt_params *params, int verbose)
-{
-	struct param_info info;
-	int ret;
+	return true;
 
-	pr_info("Getting EFI parameters from FDT:\n");
-
-	info.verbose = verbose;
-	info.found = 0;
-	info.params = params;
-
-	ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
-	if (!info.found)
+not_found:
+	if (i == 0)
 		pr_info("UEFI not found.\n");
-	else if (!ret)
-		pr_err("Can't find '%s' in device tree!\n",
-		       dt_params[info.found].name);
-
-	return ret;
+	else
+		pr_err("Can't find '%s' in device tree!\n", dt_params[i].name);
+	return false;
 }
diff --git a/include/linux/efi.h b/include/linux/efi.h
index af5be0368dec..c2be93d6156c 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -684,6 +684,7 @@ struct efi_fdt_params {
 	u32 mmap_size;
 	u32 desc_size;
 	u32 desc_ver;
+	bool verbose;
 };
 
 typedef struct {
@@ -886,7 +887,7 @@ extern void efi_initialize_iomem_resources(struct resource *code_resource,
 		struct resource *data_resource, struct resource *bss_resource);
 extern void efi_get_time(struct timespec *now);
 extern void efi_reserve_boot_services(void);
-extern int efi_get_fdt_params(struct efi_fdt_params *params, int verbose);
+extern bool efi_get_fdt_params(void *fdt, struct efi_fdt_params *params);
 extern struct efi_memory_map memmap;
 
 extern int efi_reboot_quirk_mode;
-- 
1.9.1