[PATCH 0/6] arm64: Add EFI stub and runtime services support

[PATCH 0/6] arm64: Add EFI stub and runtime services support

[Mark Salter]

This patch series adds EFI support to the arm64 kernel. This support has
two main parts: an EFI stub and runtime support. The EFI stub support
has the kernel masquerade as a PE/COFF application which can be directly
booted by EFI firmware (or by secondary loaders with EFI support). The
runtime services support provides access to various EFI firmware services
such as reboot, real-time clock, boot variables, and others.

Changes since v1:

  * Added Acks (well, one anyway)

  * The first 3 patches are new for v2 and provide more generic
    support for for following EFI patches.

  * Lots of changes based on feedback from Catalin mostly. I think
    I addressed all of his comments.

These patches have dependencies on other patches which are not yet in
the kernel but have been posted and are currently under review. In
particular:

  - Generic fixmap support being discussed here:
      http://lkml.org/lkml/2013/11/25/474
    This is now in the akpm tree

  - early_ioremap support being discussed here:
      https://lkml.org/lkml/2014/1/9/708

  - shared EFI update_fdt() function in this series:
      http://news.gmane.org/gmane.linux.kernel.efi

A repo with this patch series and the prerequisite patches is at:

  git://github.com/mosalter/linux.git (arm64-efi-patches-v2 branch)

Mark Salter (6):
  efi: create memory map iteration helper
  arm64: Add function to create identity mappings
  efi: add helper function to get UEFI params from FDT
  arm64: add EFI stub
  doc: arm64: add description of EFI stub support
  arm64: add EFI runtime services

 Documentation/arm64/booting.txt |   4 +
 Documentation/efi-stub.txt      |  12 +-
 arch/arm64/Kconfig              |  26 +++
 arch/arm64/include/asm/efi.h    |  12 ++
 arch/arm64/include/asm/mmu.h    |   1 +
 arch/arm64/kernel/Makefile      |   4 +
 arch/arm64/kernel/efi-entry.S   |  93 +++++++++++
 arch/arm64/kernel/efi-stub.c    | 181 ++++++++++++++++++++
 arch/arm64/kernel/efi.c         | 353 ++++++++++++++++++++++++++++++++++++++++
 arch/arm64/kernel/head.S        | 112 +++++++++++++
 arch/arm64/kernel/setup.c       |   6 +
 arch/arm64/mm/mmu.c             |  34 ++--
 drivers/firmware/efi/Kconfig    |   7 +
 drivers/firmware/efi/efi.c      |  79 +++++++++
 include/linux/efi.h             |  17 +-
 15 files changed, 927 insertions(+), 14 deletions(-)
 create mode 100644 arch/arm64/include/asm/efi.h
 create mode 100644 arch/arm64/kernel/efi-entry.S
 create mode 100644 arch/arm64/kernel/efi-stub.c
 create mode 100644 arch/arm64/kernel/efi.c

-- 
1.8.3.1

[PATCH 1/6] efi: create memory map iteration helper

[Mark Salter]

There are a lot of places in the kernel which iterate through an
EFI memory map. Most of these places use essentially the same
for-loop code. This patch adds a for_each_efi_memory_desc()
helper to clean up all of the existing duplicate code and avoid
more in the future.

Signed-off-by: Mark Salter <msalter@redhat.com>
---
 include/linux/efi.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/efi.h b/include/linux/efi.h
index 11ce678..9dc5b05 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -618,6 +618,12 @@ extern int efi_set_rtc_mmss(const struct timespec *now);
 extern void efi_reserve_boot_services(void);
 extern struct efi_memory_map memmap;
 
+/* Iterate through an efi_memory_map */
+#define for_each_efi_memory_desc(m, md)					   \
+	for ((md) = (m)->map;						   \
+	     (md) <= (efi_memory_desc_t *)((m)->map_end - (m)->desc_size); \
+	     (md) = (void *)(md) + (m)->desc_size)
+
 /**
  * efi_range_is_wc - check the WC bit on an address range
  * @start: starting kvirt address
-- 
1.8.3.1

[PATCH 2/6] arm64: Add function to create identity mappings

[Mark Salter]

At boot time, UEFI runtime support needs to call into the UEFI firmware
to switch to a virtual address map. This call must be made with UEFI
memory regions identity mapped. The exisitng early boot code creates
an identity map of kernel text/data but this is not sufficient for UEFI.
This patch adds a create_id_mapping() function which reuses the core
code of create_mapping() used to create the kernel RAM mappings.

Signed-off-by: Mark Salter <msalter@redhat.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
CC: linux-arm-kernel@lists.infradead.org
---
 arch/arm64/include/asm/mmu.h |  1 +
 arch/arm64/mm/mmu.c          | 34 ++++++++++++++++++++++++----------
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index f600d40..9ad4dd4 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -28,5 +28,6 @@ extern void paging_init(void);
 extern void setup_mm_for_reboot(void);
 extern void __iomem *early_io_map(phys_addr_t phys, unsigned long virt);
 extern void init_mem_pgprot(void);
+extern void create_id_mapping(phys_addr_t addr, phys_addr_t size);
 
 #endif
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 7b345e3..ccfca44 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -228,22 +228,14 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
  * Create the page directory entries and any necessary page tables for the
  * mapping specified by 'md'.
  */
-static void __init create_mapping(phys_addr_t phys, unsigned long virt,
-				  phys_addr_t size)
+static void __init __create_mapping(pgd_t *pgd, phys_addr_t phys,
+				    unsigned long virt, phys_addr_t size)
 {
 	unsigned long addr, length, end, next;
-	pgd_t *pgd;
-
-	if (virt < VMALLOC_START) {
-		pr_warning("BUG: not creating mapping for 0x%016llx at 0x%016lx - outside kernel range\n",
-			   phys, virt);
-		return;
-	}
 
 	addr = virt & PAGE_MASK;
 	length = PAGE_ALIGN(size + (virt & ~PAGE_MASK));
 
-	pgd = pgd_offset_k(addr);
 	end = addr + length;
 	do {
 		next = pgd_addr_end(addr, end);
@@ -252,6 +244,28 @@ static void __init create_mapping(phys_addr_t phys, unsigned long virt,
 	} while (pgd++, addr = next, addr != end);
 }
 
+static void __init create_mapping(phys_addr_t phys, unsigned long virt,
+				  phys_addr_t size)
+{
+	if (virt < VMALLOC_START) {
+		pr_warn("BUG: not creating mapping for 0x%016llx at 0x%016lx - outside kernel range\n",
+			phys, virt);
+		return;
+	}
+	__create_mapping(pgd_offset_k(virt & PAGE_MASK), phys, virt, size);
+}
+
+void __init create_id_mapping(phys_addr_t addr, phys_addr_t size)
+{
+	pgd_t *pgd = &idmap_pg_dir[pgd_index(addr)];
+
+	if (pgd >= &idmap_pg_dir[ARRAY_SIZE(idmap_pg_dir)]) {
+		pr_warn("BUG: not creating id mapping for 0x%016llx\n", addr);
+		return;
+	}
+	__create_mapping(pgd, addr, addr, size);
+}
+
 static void __init map_mem(void)
 {
 	struct memblock_region *reg;
-- 
1.8.3.1

[PATCH 5/6] doc: arm64: add description of EFI stub support

[Mark Salter]

Add explanation of arm64 EFI stub and kernel image header changes
needed to masquerade as a PE/COFF application.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
CC: linux-doc@vger.kernel.org
CC: Rob Landley <rob@landley.net>
---
 Documentation/arm64/booting.txt |  4 ++++
 Documentation/efi-stub.txt      | 12 +++++++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt
index a9691cc..aa95d38c 100644
--- a/Documentation/arm64/booting.txt
+++ b/Documentation/arm64/booting.txt
@@ -85,6 +85,10 @@ The decompressed kernel image contains a 64-byte header as follows:
 Header notes:
 
 - code0/code1 are responsible for branching to stext.
+- when booting through EFI, code0/code1 are initially skipped.
+  res5 is an offset to the PE header and the PE header has the EFI
+  entry point (efi_stub_entry). When the stub has done its work, it
+  jumps to code0 to resume the normal boot process.
 
 The image must be placed at the specified offset (currently 0x80000)
 from the start of the system RAM and called there. The start of the
diff --git a/Documentation/efi-stub.txt b/Documentation/efi-stub.txt
index a55a0cd..d8ad0c1 100644
--- a/Documentation/efi-stub.txt
+++ b/Documentation/efi-stub.txt
@@ -12,6 +12,11 @@ arch/arm/boot/compressed/efi-header.S and
 arch/arm/boot/compressed/efi-stub.c. EFI stub code that is shared
 between architectures is in drivers/firmware/efi/efi-stub-helper.c.
 
+For arm64, there is no compressed kernel support, so the Image itself
+masquerades as a PE/COFF image and the EFI stub is linked into the
+kernel. The arm64 EFI stub lives in arch/arm64/kernel/efi-entry.S
+and arch/arm64/kernel/efi-stub.c.
+
 By using the EFI boot stub it's possible to boot a Linux kernel
 without the use of a conventional EFI boot loader, such as grub or
 elilo. Since the EFI boot stub performs the jobs of a boot loader, in
@@ -28,7 +33,8 @@ the extension the EFI firmware loader will refuse to execute it. It's
 not possible to execute bzImage.efi from the usual Linux file systems
 because EFI firmware doesn't have support for them. For ARM the
 arch/arm/boot/zImage should be copied to the system partition, and it
-may not need to be renamed.
+may not need to be renamed. Similarly for arm64, arch/arm64/boot/Image
+should be copied but not necessarily renamed.
 
 
 **** Passing kernel parameters from the EFI shell
@@ -72,7 +78,7 @@ is passed to bzImage.efi.
 
 **** The "dtb=" option
 
-For the ARM architecture, we also need to be able to provide a device
-tree to the kernel. This is done with the "dtb=" command line option,
+For the ARM and arm64 architectures, we also need to be able to provide a
+device tree to the kernel. This is done with the "dtb=" command line option,
 and is processed in the same manner as the "initrd=" option that is
 described above.
-- 
1.8.3.1

[PATCH 6/6] arm64: add EFI runtime services

[Mark Salter]

This patch adds EFI runtime support for arm64. The runtime support allows
the kernel to access various EFI runtime services provided by EFI firmware.
Things like reboot, real time clock, EFI boot variables, and others.

Signed-off-by: Mark Salter <msalter@redhat.com>
---
 arch/arm64/Kconfig           |  16 ++
 arch/arm64/include/asm/efi.h |  12 ++
 arch/arm64/kernel/Makefile   |   1 +
 arch/arm64/kernel/efi.c      | 353 +++++++++++++++++++++++++++++++++++++++++++
 arch/arm64/kernel/setup.c    |   6 +
 include/linux/efi.h          |   2 +-
 6 files changed, 389 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/include/asm/efi.h
 create mode 100644 arch/arm64/kernel/efi.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3f1c2b2..862026d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -249,6 +249,20 @@ config CMDLINE_FORCE
 	  This is useful if you cannot or don't want to change the
 	  command-line options your boot loader passes to the kernel.
 
+config EFI
+        bool "EFI runtime service support"
+	depends on !ARM64_64K_PAGES && OF
+	select UCS2_STRING
+	select LIBFDT
+	select UEFI_PARAMS_FROM_FDT
+	help
+	  This enables the kernel to use UEFI runtime services that are
+	  available (such as the UEFI variable services).
+
+	  This option is only useful on systems that have UEFI firmware.
+	  However, even with this option, the resultant kernel should
+	  continue to boot on existing non-UEFI platforms.
+
 config EFI_STUB
 	bool "EFI stub support"
 	depends on !ARM64_64K_PAGES && OF
@@ -290,6 +304,8 @@ source "net/Kconfig"
 
 source "drivers/Kconfig"
 
+source "drivers/firmware/Kconfig"
+
 source "fs/Kconfig"
 
 source "arch/arm64/kvm/Kconfig"
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
new file mode 100644
index 0000000..a835b2c
--- /dev/null
+++ b/arch/arm64/include/asm/efi.h
@@ -0,0 +1,12 @@
+#ifndef _ASM_ARM64_EFI_H
+#define _ASM_ARM64_EFI_H
+
+#include <asm/io.h>
+
+#ifdef CONFIG_EFI
+extern void efi_init(void);
+#else
+#define efi_init()
+#endif
+
+#endif /* _ASM_ARM64_EFI_H */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 1c52b84..8897cf5a5 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -21,6 +21,7 @@ arm64-obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o
 arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o
 arm64-obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 arm64-obj-$(CONFIG_EFI_STUB)		+= efi-stub.o efi-entry.o
+arm64-obj-$(CONFIG_EFI)			+= efi.o
 
 obj-y					+= $(arm64-obj-y) vdso/
 obj-m					+= $(arm64-obj-m)
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
new file mode 100644
index 0000000..a42dc38
--- /dev/null
+++ b/arch/arm64/kernel/efi.c
@@ -0,0 +1,353 @@
+/*
+ * Extensible Firmware Interface
+ *
+ * Based on Extensible Firmware Interface Specification version 2.4
+ *
+ * Copyright (C) 2013 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/efi.h>
+#include <linux/export.h>
+#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <asm/cacheflush.h>
+#include <asm/efi.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+
+struct efi_memory_map memmap;
+
+static efi_runtime_services_t *runtime;
+
+static u64 efi_system_table;
+
+static unsigned long arm_efi_facility;
+
+/*
+ * Returns 1 if 'facility' is enabled, 0 otherwise.
+ */
+int efi_enabled(int facility)
+{
+	return test_bit(facility, &arm_efi_facility) != 0;
+}
+EXPORT_SYMBOL(efi_enabled);
+
+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 void __init efi_setup_idmap(void)
+{
+	unsigned long len;
+	struct memblock_region *r;
+
+	for_each_memblock(memory, r) {
+		/* section align addr/len */
+		len = ALIGN(r->size + (r->base & ~SECTION_MASK), SECTION_SIZE);
+		create_id_mapping(r->base & SECTION_MASK, len);
+	}
+}
+
+static int __init uefi_init(void)
+{
+	efi_char16_t *c16;
+	char vendor[100] = "unknown";
+	int i, retval;
+
+	efi.systab = early_memremap(efi_system_table,
+				    sizeof(efi_system_table_t));
+	if (efi.systab == NULL) {
+		pr_warn("Unable to map EFI system table.\n");
+		return -ENOMEM;
+	}
+
+	set_bit(EFI_BOOT, &arm_efi_facility);
+	set_bit(EFI_64BIT, &arm_efi_facility);
+
+	/*
+	 * Verify the EFI Table
+	 */
+	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
+		pr_err("System table signature incorrect\n");
+		return -EINVAL;
+	}
+	if ((efi.systab->hdr.revision >> 16) < 2)
+		pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
+			efi.systab->hdr.revision >> 16,
+			efi.systab->hdr.revision & 0xffff);
+
+	/* Show what we know for posterity */
+	c16 = early_memremap(efi.systab->fw_vendor,
+			     sizeof(vendor));
+	if (c16) {
+		for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
+			vendor[i] = c16[i];
+		vendor[i] = '\0';
+	}
+
+	pr_info("EFI v%u.%.02u by %s\n",
+		efi.systab->hdr.revision >> 16,
+		efi.systab->hdr.revision & 0xffff, vendor);
+
+	retval = efi_config_init(NULL);
+	if (retval == 0)
+		set_bit(EFI_CONFIG_TABLES, &arm_efi_facility);
+
+	early_memunmap(c16, sizeof(vendor));
+	early_memunmap(efi.systab,  sizeof(efi_system_table_t));
+
+	return retval;
+}
+
+static __initdata char memory_type_name[][32] = {
+	{"Reserved"},
+	{"Loader Code"},
+	{"Loader Data"},
+	{"Boot Code"},
+	{"Boot Data"},
+	{"Runtime Code"},
+	{"Runtime Data"},
+	{"Conventional Memory"},
+	{"Unusable Memory"},
+	{"ACPI Reclaim Memory"},
+	{"ACPI Memory NVS"},
+	{"Memory Mapped I/O"},
+	{"MMIO Port Space"},
+	{"PAL Code"},
+};
+
+static __init void reserve_regions(void)
+{
+	efi_memory_desc_t *md;
+	u64 paddr, npages, size;
+
+	if (uefi_debug)
+		pr_info("Processing EFI memory map:\n");
+
+	for_each_efi_memory_desc(&memmap, md) {
+		paddr = md->phys_addr;
+		npages = md->num_pages;
+		memrange_efi_to_native(&paddr, &npages);
+		size = npages << PAGE_SHIFT;
+
+		if (uefi_debug)
+			pr_info("  0x%012llx-0x%012llx [%s]",
+				paddr, paddr + size - 1,
+				memory_type_name[md->type]);
+
+		if ((md->attribute & EFI_MEMORY_RUNTIME) ||
+		    md->type == EFI_BOOT_SERVICES_CODE ||
+		    md->type == EFI_BOOT_SERVICES_DATA ||
+		    md->type == EFI_ACPI_RECLAIM_MEMORY) {
+			if (md->type != EFI_MEMORY_MAPPED_IO) {
+				memblock_reserve(paddr, size);
+				if (uefi_debug)
+					pr_cont("*");
+			}
+		}
+
+		if (uefi_debug)
+			pr_cont("\n");
+	}
+}
+
+static void __init free_boot_services(void)
+{
+	u64 total_freed = 0;
+	efi_memory_desc_t *md;
+
+	for_each_efi_memory_desc(&memmap, md) {
+		u64 paddr, npages, size;
+
+		if (md->type != EFI_BOOT_SERVICES_CODE &&
+		    md->type != EFI_BOOT_SERVICES_DATA)
+			continue;
+
+		/* Don't free areas not reserved by reserve_regions() */
+		if (!md->num_pages)
+			continue;
+
+		paddr = md->phys_addr;
+		npages = md->num_pages;
+		memrange_efi_to_native(&paddr, &npages);
+		size = npages << PAGE_SHIFT;
+
+		if (uefi_debug)
+			pr_info("  EFI freeing: 0x%012llx-0x%012llx [%s]\n",
+				paddr, paddr + size - 1,
+				memory_type_name[md->type]);
+
+		memblock_free(paddr, size);
+		total_freed += size;
+	}
+	if (total_freed)
+		pr_info("Freed 0x%llx bytes of EFI boot services memory",
+			total_freed);
+}
+
+void __init efi_init(void)
+{
+	struct efi_fdt_params params;
+
+	/* Grab UEFI information placed in FDT by stub */
+	if (!efi_get_fdt_params(&params, uefi_debug))
+		return;
+
+	efi_system_table = params.system_table;
+
+	memblock_reserve(params.mmap, params.mmap_size);
+	memmap.phys_map = (void *)params.mmap;
+	memmap.map = early_memremap(params.mmap, params.mmap_size);
+	memmap.map_end = memmap.map + params.mmap_size;
+	memmap.desc_size = params.desc_size;
+	memmap.desc_version = params.desc_ver;
+
+	if (uefi_init() < 0)
+		return;
+
+	reserve_regions();
+}
+
+static int __init remap_region(efi_memory_desc_t *md, void **new)
+{
+	u64 paddr, npages, size;
+
+	paddr = md->phys_addr;
+	npages = md->num_pages;
+	memrange_efi_to_native(&paddr, &npages);
+	size = npages << PAGE_SHIFT;
+
+	/*
+	 * Map everything writeback-capable as coherent memory,
+	 * anything else as device.
+	 */
+	if (md->attribute & EFI_MEMORY_WB)
+		md->virt_addr = (__force u64)ioremap_cache(paddr, size);
+	else
+		md->virt_addr = (__force u64)ioremap(paddr, size);
+
+	if (!md->virt_addr) {
+		pr_err("Unable to remap 0x%llx pages @ %p\n",
+		       npages, (void *)paddr);
+		return 0;
+	}
+
+	if (uefi_debug)
+		pr_info("  EFI remap 0x%012llx => %p\n",
+			md->phys_addr, (void *)md->virt_addr);
+
+	memcpy(*new, md, memmap.desc_size);
+	*new += memmap.desc_size;
+
+	return 1;
+}
+
+/*
+ * Called from setup_arch with interrupts disabled.
+ */
+void __init efi_enter_virtual_mode(void)
+{
+	efi_memory_desc_t *md;
+	phys_addr_t virtmap_phys;
+	void *virtmap, *virt_md;
+	efi_status_t status;
+	u64 mapsize;
+	int count = 0;
+
+	if (!efi_enabled(EFI_BOOT)) {
+		pr_info("EFI services will not be available.\n");
+		return;
+	}
+
+	pr_info("Remapping and enabling EFI services.\n");
+
+	/* replace early memmap mapping with permanent mapping */
+	mapsize = memmap.map_end - memmap.map;
+	early_memunmap(memmap.map, mapsize);
+	memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
+						   mapsize);
+	memmap.map_end = memmap.map + mapsize;
+
+	efi.memmap = &memmap;
+
+	/* Map the runtime regions */
+	virtmap_phys = memblock_alloc(mapsize, PAGE_SIZE);
+	if (!virtmap_phys) {
+		pr_err("Failed to allocate EFI virtual memmap\n");
+		return;
+	}
+	virtmap = phys_to_virt(virtmap_phys);
+	virt_md = virtmap;
+
+	for_each_efi_memory_desc(&memmap, md) {
+		if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
+		    md->type != EFI_ACPI_RECLAIM_MEMORY)
+			continue;
+		if (remap_region(md, &virt_md))
+			++count;
+	}
+
+	efi.systab = (__force void *)efi_lookup_mapped_addr(efi_system_table);
+	if (efi.systab)
+		set_bit(EFI_SYSTEM_TABLES, &arm_efi_facility);
+
+	/* boot time idmap_pg_dir is incomplete, so fill in missing parts */
+	efi_setup_idmap();
+
+	cpu_switch_mm(idmap_pg_dir, &init_mm);
+	flush_tlb_all();
+	flush_cache_all();
+
+	/* Call SetVirtualAddressMap with the physical address of the map */
+	runtime = efi.systab->runtime;
+	efi.set_virtual_address_map = runtime->set_virtual_address_map;
+
+	status = efi.set_virtual_address_map(count * memmap.desc_size,
+					     memmap.desc_size,
+					     memmap.desc_version,
+					     (efi_memory_desc_t *)virtmap_phys);
+	cpu_set_reserved_ttbr0();
+	flush_tlb_all();
+	flush_cache_all();
+
+	memblock_free(virtmap_phys, mapsize);
+
+	free_boot_services();
+
+	if (status != EFI_SUCCESS) {
+		pr_err("Failed to set EFI virtual address map! [%lx]\n",
+			status);
+		return;
+	}
+
+	/* Set up runtime services function pointers */
+	runtime = efi.systab->runtime;
+	efi.get_time = runtime->get_time;
+	efi.set_time = runtime->set_time;
+	efi.get_wakeup_time = runtime->get_wakeup_time;
+	efi.set_wakeup_time = runtime->set_wakeup_time;
+	efi.get_variable = runtime->get_variable;
+	efi.get_next_variable = runtime->get_next_variable;
+	efi.set_variable = runtime->set_variable;
+	efi.query_variable_info = runtime->query_variable_info;
+	efi.update_capsule = runtime->update_capsule;
+	efi.query_capsule_caps = runtime->query_capsule_caps;
+	efi.get_next_high_mono_count = runtime->get_next_high_mono_count;
+	efi.reset_system = runtime->reset_system;
+
+	set_bit(EFI_RUNTIME_SERVICES, &arm_efi_facility);
+}
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 5516f54..7a45095 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -41,6 +41,7 @@
 #include <linux/memblock.h>
 #include <linux/of_fdt.h>
 #include <linux/of_platform.h>
+#include <linux/efi.h>
 
 #include <asm/fixmap.h>
 #include <asm/cputype.h>
@@ -55,6 +56,7 @@
 #include <asm/traps.h>
 #include <asm/memblock.h>
 #include <asm/psci.h>
+#include <asm/efi.h>
 
 unsigned int processor_id;
 EXPORT_SYMBOL(processor_id);
@@ -229,9 +231,13 @@ void __init setup_arch(char **cmdline_p)
 
 	arm64_memblock_init();
 
+	efi_init();
 	paging_init();
 	request_standard_resources();
 
+	if (efi_enabled(EFI_BOOT))
+		efi_enter_virtual_mode();
+
 	unflatten_device_tree();
 
 	psci_init();
diff --git a/include/linux/efi.h b/include/linux/efi.h
index ff8524e..4d73efe 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -670,7 +670,7 @@ extern int __init efi_setup_pcdp_console(char *);
 #define EFI_64BIT		5	/* Is the firmware 64-bit? */
 
 #ifdef CONFIG_EFI
-# ifdef CONFIG_X86
+# if defined(CONFIG_X86) || defined(CONFIG_ARM64)
 extern int efi_enabled(int facility);
 # else
 static inline int efi_enabled(int facility)
-- 
1.8.3.1

Re: [PATCH 1/6] efi: create memory map iteration helper

[Matt Fleming]

On Fri, 10 Jan, at 05:29:05PM, Mark Salter wrote:
> There are a lot of places in the kernel which iterate through an
> EFI memory map. Most of these places use essentially the same
> for-loop code. This patch adds a for_each_efi_memory_desc()
> helper to clean up all of the existing duplicate code and avoid
> more in the future.
> 
> Signed-off-by: Mark Salter <msalter@redhat.com>
> ---
>  include/linux/efi.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 11ce678..9dc5b05 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -618,6 +618,12 @@ extern int efi_set_rtc_mmss(const struct timespec *now);
>  extern void efi_reserve_boot_services(void);
>  extern struct efi_memory_map memmap;
>  
> +/* Iterate through an efi_memory_map */
> +#define for_each_efi_memory_desc(m, md)					   \
> +	for ((md) = (m)->map;						   \
> +	     (md) <= (efi_memory_desc_t *)((m)->map_end - (m)->desc_size); \
> +	     (md) = (void *)(md) + (m)->desc_size)
> +

Err, what? I just picked up your previous patch ("x86/efi: Create memory
map iteration helper") which adds this chunk, and I didn't see a follow
up email telling me not to pick it up.

What's the plan?

-- 
Matt Fleming, Intel Open Source Technology Center

Re: [PATCH 1/6] efi: create memory map iteration helper

[Mark Salter]

On Mon, 2014-01-13 at 15:17 +0000, Matt Fleming wrote:
> On Fri, 10 Jan, at 05:29:05PM, Mark Salter wrote:
> > There are a lot of places in the kernel which iterate through an
> > EFI memory map. Most of these places use essentially the same
> > for-loop code. This patch adds a for_each_efi_memory_desc()
> > helper to clean up all of the existing duplicate code and avoid
> > more in the future.
> > 
> > Signed-off-by: Mark Salter <msalter@redhat.com>
> > ---
> >  include/linux/efi.h | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/include/linux/efi.h b/include/linux/efi.h
> > index 11ce678..9dc5b05 100644
> > --- a/include/linux/efi.h
> > +++ b/include/linux/efi.h
> > @@ -618,6 +618,12 @@ extern int efi_set_rtc_mmss(const struct timespec *now);
> >  extern void efi_reserve_boot_services(void);
> >  extern struct efi_memory_map memmap;
> >  
> > +/* Iterate through an efi_memory_map */
> > +#define for_each_efi_memory_desc(m, md)					   \
> > +	for ((md) = (m)->map;						   \
> > +	     (md) <= (efi_memory_desc_t *)((m)->map_end - (m)->desc_size); \
> > +	     (md) = (void *)(md) + (m)->desc_size)
> > +
> 
> Err, what? I just picked up your previous patch ("x86/efi: Create memory
> map iteration helper") which adds this chunk, and I didn't see a follow
> up email telling me not to pick it up.
> 
> What's the plan?
> 
Sorry, I meant to drop this one from this series. The one you picked
up is the one I wanted picked up.

--Mark

Re: [PATCH 4/6] arm64: add EFI stub

[Arnd Bergmann]

On Friday 10 January 2014, Mark Salter wrote:
> This patch adds PE/COFF header fields to the start of the Image
> so that it appears as an EFI application to EFI firmware. An EFI
> stub is included to allow direct booting of the kernel Image. Due
> to EFI firmware limitations, only little endian kernels with 4K
> page sizes are supported at this time. Support in the COFF header
> for signed images was provided by Ard Biesheuvel.
> 
> Signed-off-by: Mark Salter <msalter@redhat.com>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

You got the ordering of the S-o-b lines wrong. Since you send the
patch, your name should come last.

> +config EFI_STUB
> +	bool "EFI stub support"
> +	depends on !ARM64_64K_PAGES && OF
> +	select LIBFDT
> +	default y
> +	help
> +	  This kernel feature allows an Image to be loaded directly
> +	  by EFI firmware without the use of a bootloader.
> +	  See Documentation/efi-stub.txt for more information.
> +
>  endmenu

Why not ARM64_64K_PAGES? I thought that it was going to be the
default for a lot of distros that would need to run on UEFI systems.

>  menu "Userspace binary formats"
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index 5ba2fd4..1c52b84 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -4,6 +4,8 @@
>  
>  CPPFLAGS_vmlinux.lds	:= -DTEXT_OFFSET=$(TEXT_OFFSET)
>  AFLAGS_head.o		:= -DTEXT_OFFSET=$(TEXT_OFFSET)
> +CFLAGS_efi-stub.o 	:= -DTEXT_OFFSET=$(TEXT_OFFSET) \
> +			   -I$(src)/../../../scripts/dtc/libfdt

Hmm, this is pretty ugly. I notice the same has been done on MIPS
as well, but I'd hope we can find a proper way to do it.

> diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c
> new file mode 100644
> index 0000000..10d02bf
> --- /dev/null
> +++ b/arch/arm64/kernel/efi-stub.c
> +
> +/* Include shared EFI stub code */
> +#include "../../../drivers/firmware/efi/efi-stub-helper.c"
> +#include "../../../drivers/firmware/efi/fdt.c"

It gets worse here.

	Arnd

Re: [PATCH 4/6] arm64: add EFI stub

[Mark Salter]

On Mon, 2014-01-13 at 19:49 +0100, Arnd Bergmann wrote:
> On Friday 10 January 2014, Mark Salter wrote:
> > This patch adds PE/COFF header fields to the start of the Image
> > so that it appears as an EFI application to EFI firmware. An EFI
> > stub is included to allow direct booting of the kernel Image. Due
> > to EFI firmware limitations, only little endian kernels with 4K
> > page sizes are supported at this time. Support in the COFF header
> > for signed images was provided by Ard Biesheuvel.
> > 
> > Signed-off-by: Mark Salter <msalter@redhat.com>
> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> 
> You got the ordering of the S-o-b lines wrong. Since you send the
> patch, your name should come last.

Yes.

> 
> > +config EFI_STUB
> > +     bool "EFI stub support"
> > +     depends on !ARM64_64K_PAGES && OF
> > +     select LIBFDT
> > +     default y
> > +     help
> > +       This kernel feature allows an Image to be loaded directly
> > +       by EFI firmware without the use of a bootloader.
> > +       See Documentation/efi-stub.txt for more information.
> > +
> >  endmenu
> 
> Why not ARM64_64K_PAGES? I thought that it was going to be the
> default for a lot of distros that would need to run on UEFI systems.

The UEFI spec currently mandates 4k page size. We may be able to work
around that or get the spec changed, but for now it is just 4k pages.

> 
> >  menu "Userspace binary formats"
> > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> > index 5ba2fd4..1c52b84 100644
> > --- a/arch/arm64/kernel/Makefile
> > +++ b/arch/arm64/kernel/Makefile
> > @@ -4,6 +4,8 @@
> >  
> >  CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$(TEXT_OFFSET)
> >  AFLAGS_head.o                := -DTEXT_OFFSET=$(TEXT_OFFSET)
> > +CFLAGS_efi-stub.o    := -DTEXT_OFFSET=$(TEXT_OFFSET) \
> > +                        -I$(src)/../../../scripts/dtc/libfdt
> 
> Hmm, this is pretty ugly. I notice the same has been done on MIPS
> as well, but I'd hope we can find a proper way to do it.

Yes, I just copied that from mips. I can look into some more.

> 
> > diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c
> > new file mode 100644
> > index 0000000..10d02bf
> > --- /dev/null
> > +++ b/arch/arm64/kernel/efi-stub.c
> > +
> > +/* Include shared EFI stub code */
> > +#include "../../../drivers/firmware/efi/efi-stub-helper.c"
> > +#include "../../../drivers/firmware/efi/fdt.c"
> 
> It gets worse here.

Well, I'm open to suggestions here. The shared code has to work with
stubs which are built into kernel (arm64) and which are part of the
compressed image wrapper.

Re: [PATCH 4/6] arm64: add EFI stub

[Roy Franz]

On Tue, Jan 14, 2014 at 6:44 AM, Mark Salter <msalter@redhat.com> wrote:
> On Mon, 2014-01-13 at 19:49 +0100, Arnd Bergmann wrote:
>> On Friday 10 January 2014, Mark Salter wrote:
>> > This patch adds PE/COFF header fields to the start of the Image
>> > so that it appears as an EFI application to EFI firmware. An EFI
>> > stub is included to allow direct booting of the kernel Image. Due
>> > to EFI firmware limitations, only little endian kernels with 4K
>> > page sizes are supported at this time. Support in the COFF header
>> > for signed images was provided by Ard Biesheuvel.
>> >
>> > Signed-off-by: Mark Salter <msalter@redhat.com>
>> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>>
>> You got the ordering of the S-o-b lines wrong. Since you send the
>> patch, your name should come last.
>
> Yes.
>
>>
>> > +config EFI_STUB
>> > +     bool "EFI stub support"
>> > +     depends on !ARM64_64K_PAGES && OF
>> > +     select LIBFDT
>> > +     default y
>> > +     help
>> > +       This kernel feature allows an Image to be loaded directly
>> > +       by EFI firmware without the use of a bootloader.
>> > +       See Documentation/efi-stub.txt for more information.
>> > +
>> >  endmenu
>>
>> Why not ARM64_64K_PAGES? I thought that it was going to be the
>> default for a lot of distros that would need to run on UEFI systems.
>
> The UEFI spec currently mandates 4k page size. We may be able to work
> around that or get the spec changed, but for now it is just 4k pages.
>
>>
>> >  menu "Userspace binary formats"
>> > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
>> > index 5ba2fd4..1c52b84 100644
>> > --- a/arch/arm64/kernel/Makefile
>> > +++ b/arch/arm64/kernel/Makefile
>> > @@ -4,6 +4,8 @@
>> >
>> >  CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$(TEXT_OFFSET)
>> >  AFLAGS_head.o                := -DTEXT_OFFSET=$(TEXT_OFFSET)
>> > +CFLAGS_efi-stub.o    := -DTEXT_OFFSET=$(TEXT_OFFSET) \
>> > +                        -I$(src)/../../../scripts/dtc/libfdt
>>
>> Hmm, this is pretty ugly. I notice the same has been done on MIPS
>> as well, but I'd hope we can find a proper way to do it.
>
> Yes, I just copied that from mips. I can look into some more.
>
>>
>> > diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c
>> > new file mode 100644
>> > index 0000000..10d02bf
>> > --- /dev/null
>> > +++ b/arch/arm64/kernel/efi-stub.c
>> > +
>> > +/* Include shared EFI stub code */
>> > +#include "../../../drivers/firmware/efi/efi-stub-helper.c"
>> > +#include "../../../drivers/firmware/efi/fdt.c"
>>
>> It gets worse here.
>
> Well, I'm open to suggestions here. The shared code has to work with
> stubs which are built into kernel (arm64) and which are part of the
> compressed image wrapper.
>

The decompression algorithms are shared among the compressed image
wrappers using #include of C code, so this is
following that convention.  The only other mechanism that I saw for
sharing code with the compressed image wrappers was
copying of files, as is done with the FDT files for the ARM compressed
wrapper.  I agree that neither of these is elegant, but
whatever we do needs to work for compiling into the decompression
wrapper (arm) and the kernel proper (arm64).

Roy

Re: [PATCH 2/6] arm64: Add function to create identity mappings

[Catalin Marinas]

On Fri, Jan 10, 2014 at 10:29:06PM +0000, Mark Salter wrote:
> +void __init create_id_mapping(phys_addr_t addr, phys_addr_t size)
> +{
> +	pgd_t *pgd = &idmap_pg_dir[pgd_index(addr)];
> +
> +	if (pgd >= &idmap_pg_dir[ARRAY_SIZE(idmap_pg_dir)]) {
> +		pr_warn("BUG: not creating id mapping for 0x%016llx\n", addr);
> +		return;
> +	}

The condition above is always false since pgd_index() already ands the
index with (PTRS_PER_PGD - 1). Better check addr against something like
(PTRS_PER_PGD * PGDIR_SIZE) (for clarity, you could do other shifts,
doesn't really matter).

-- 
Catalin

Re: [PATCH 4/6] arm64: add EFI stub

[Catalin Marinas]

On Fri, Jan 10, 2014 at 10:29:08PM +0000, Mark Salter wrote:
> +ENTRY(efi_stub_entry)
> +       stp     x29, x30, [sp, #-32]!
> +
> +       /*
> +        * Call efi_entry to do the real work.
> +        * x0 and x1 are already set up by firmware. Current runtime
> +        * address of image is calculated and passed via *image_addr.
> +        *
> +        * unsigned long efi_entry(void *handle,
> +        *                         efi_system_table_t *sys_table,
> +        *                         unsigned long *image_addr) ;
> +        */
> +       adrp    x8, _text
> +        add    x8, x8, #:lo12:_text

Possibly some minor whitespace corruption (or it's our email server).

-- 
Catalin

Re: [PATCH 6/6] arm64: add EFI runtime services

[Catalin Marinas]

On Fri, Jan 10, 2014 at 10:29:10PM +0000, Mark Salter wrote:
> diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
> new file mode 100644
> index 0000000..a835b2c
> --- /dev/null
> +++ b/arch/arm64/include/asm/efi.h
> @@ -0,0 +1,12 @@
> +#ifndef _ASM_ARM64_EFI_H
> +#define _ASM_ARM64_EFI_H

__ASM_EFI_H please for consistency with the other files.

> diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
> new file mode 100644
> index 0000000..a42dc38
> --- /dev/null
> +++ b/arch/arm64/kernel/efi.c
> @@ -0,0 +1,353 @@
> +/*
> + * Extensible Firmware Interface
> + *
> + * Based on Extensible Firmware Interface Specification version 2.4
> + *
> + * Copyright (C) 2013 Linaro Ltd.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/efi.h>
> +#include <linux/export.h>
> +#include <linux/memblock.h>
> +#include <linux/of.h>
> +#include <linux/of_fdt.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +
> +#include <asm/cacheflush.h>
> +#include <asm/efi.h>
> +#include <asm/tlbflush.h>
> +#include <asm/mmu_context.h>
> +
> +struct efi_memory_map memmap;

Is this variable used outside this file or from common code? It has a
too generic name, may clash with other things.

> +static unsigned long arm_efi_facility;

You could drop the "arm_" prefix here, that's just local to this file.

> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index 5516f54..7a45095 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -41,6 +41,7 @@
>  #include <linux/memblock.h>
>  #include <linux/of_fdt.h>
>  #include <linux/of_platform.h>
> +#include <linux/efi.h>
>
>  #include <asm/fixmap.h>
>  #include <asm/cputype.h>
> @@ -55,6 +56,7 @@
>  #include <asm/traps.h>
>  #include <asm/memblock.h>
>  #include <asm/psci.h>
> +#include <asm/efi.h>
>
>  unsigned int processor_id;
>  EXPORT_SYMBOL(processor_id);
> @@ -229,9 +231,13 @@ void __init setup_arch(char **cmdline_p)
>
>         arm64_memblock_init();
>
> +       efi_init();
>         paging_init();
>         request_standard_resources();
>
> +       if (efi_enabled(EFI_BOOT))
> +               efi_enter_virtual_mode();

The common start_kernel() function already has this call:

#ifdef CONFIG_X86
	if (efi_enabled(EFI_RUNTIME_SERVICES))
		efi_enter_virtual_mode();
#endif

Could we not use it for arm64 as well? Ideally with an empty
efi_enter_virtual_mode() in include/linux/efi.h if !CONFIG_EFI but I
noticed that ia64 does a separate call and they don't seem to have
efi_enabled(), so probably not feasible for them.

--
Catalin