[RFC PATCH v2 00/11] Add UEFI support for RISC-V

[RFC PATCH v2 00/11] Add UEFI support for RISC-V

[Atish Patra]

This series adds UEFI support for RISC-V.

Linux kernel: 5.8-rc4
U-Boot: master
OpenSBI: master

Patch 1-6 are preparatory patches that fixes some of the geric efi and riscv issues.

Patch 7-9 adds the efi stub support for RISC-V which was reviewed few months back.
https://www.spinics.net/lists/linux-efi/msg19144.html

Patch 10 just renames arm-init code so that it can be used across different
architectures. Patch 11 adds the runtime services for RISC-V.

The patches can also be found in following git repo.
https://github.com/atishp04/linux/tree/uefi_riscv_5.9_v2

The patches have been verified on Qemu using bootefi command in U-Boot for both
RV32 and RV64.

For RV32, maximum allocated memory should be 1G as RISC-V kernel can not map
beyond 1G of physical memory for RV32.

EDK2 can boot quite far into Linux with current series. Currently, we are seeing
some traps from drivers (spi/network). At first glance, they don't seem to be
caused by efi. I thought it is better to get some early feedback on the series
while EDK2 issue is being debugged.

That's why uefi runtime services are not actually well tested in RISC-V.
Any suggestions to test the efi run time services are appreciated. 

Changes from v1->v2:
1. Removed patch 1 as it is already taken into efi-tree.
2. Fixed compilation issues with patch 9.
3. Moved few function prototype declaration to header file to keep kbuild happy.

Changes from previous version:
1. Added full ioremap support. 
2. Added efi runtime services support. 
3. Fixes mm issues

Anup Patel (1):
RISC-V: Move DT mapping outof fixmap

Atish Patra (10):
efi/libstub: Move the function prototypes to header file
RISC-V: Setup exception vector early
RISC-V: Add early ioremap support
RISC-V: Set maximum number of mapped pages correctly
riscv: Parse all memory blocks to remove unusable memory
include: pe.h: Add RISC-V related PE definition
RISC-V: Add PE/COFF header for EFI stub
RISC-V: Add EFI stub support.
efi: Rename arm-init to efi-init common for all arch
RISC-V: Add EFI runtime services

arch/riscv/Kconfig                            |  25 ++++
arch/riscv/Makefile                           |   1 +
arch/riscv/configs/defconfig                  |   1 +
arch/riscv/include/asm/Kbuild                 |   1 +
arch/riscv/include/asm/efi.h                  |  56 +++++++
arch/riscv/include/asm/fixmap.h               |  16 +-
arch/riscv/include/asm/io.h                   |   1 +
arch/riscv/include/asm/mmu.h                  |   2 +
arch/riscv/include/asm/pgalloc.h              |  12 ++
arch/riscv/include/asm/pgtable.h              |   4 +
arch/riscv/include/asm/sections.h             |  13 ++
arch/riscv/kernel/Makefile                    |   5 +
arch/riscv/kernel/efi-header.S                | 104 +++++++++++++
arch/riscv/kernel/efi.c                       | 106 +++++++++++++
arch/riscv/kernel/head.S                      |  27 +++-
arch/riscv/kernel/head.h                      |   2 -
arch/riscv/kernel/image-vars.h                |  51 +++++++
arch/riscv/kernel/setup.c                     |  16 +-
arch/riscv/kernel/smpboot.c                   |   1 -
arch/riscv/kernel/traps.c                     |   8 +-
arch/riscv/kernel/vmlinux.lds.S               |  22 ++-
arch/riscv/mm/init.c                          | 104 ++++++++-----
drivers/firmware/efi/Kconfig                  |   3 +-
drivers/firmware/efi/Makefile                 |   4 +-
.../firmware/efi/{arm-init.c => efi-init.c}   |   0
drivers/firmware/efi/libstub/Makefile         |  10 ++
drivers/firmware/efi/libstub/efi-stub.c       |  28 ++--
drivers/firmware/efi/libstub/efistub.h        |  16 ++
drivers/firmware/efi/libstub/riscv-stub.c     | 110 ++++++++++++++
drivers/firmware/efi/riscv-runtime.c          | 141 ++++++++++++++++++
include/linux/pe.h                            |   3 +
31 files changed, 811 insertions(+), 82 deletions(-)
create mode 100644 arch/riscv/include/asm/efi.h
create mode 100644 arch/riscv/include/asm/sections.h
create mode 100644 arch/riscv/kernel/efi-header.S
create mode 100644 arch/riscv/kernel/efi.c
create mode 100644 arch/riscv/kernel/image-vars.h
rename drivers/firmware/efi/{arm-init.c => efi-init.c} (100%)
create mode 100644 drivers/firmware/efi/libstub/riscv-stub.c
create mode 100644 drivers/firmware/efi/riscv-runtime.c

--
2.24.0

[RFC PATCH v2 01/11] efi/libstub: Move the function prototypes to header file

[Atish Patra]

The prototype of the functions handle_kernel_image & efi_enter_kernel
are defined in efi-stub.c which may result in a compiler warnings if
-Wmissing-prototypes is set in gcc compiler.

Move the prototype to efistub.h to make the compiler happy.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 drivers/firmware/efi/libstub/efi-stub.c | 17 -----------------
 drivers/firmware/efi/libstub/efistub.h  | 16 ++++++++++++++++
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 3318ec3f8e5b..a5a405d8ab44 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -121,23 +121,6 @@ static unsigned long get_dram_base(void)
 	return membase;
 }
 
-/*
- * This function handles the architcture specific differences between arm and
- * arm64 regarding where the kernel image must be loaded and any memory that
- * must be reserved. On failure it is required to free all
- * all allocations it has made.
- */
-efi_status_t handle_kernel_image(unsigned long *image_addr,
-				 unsigned long *image_size,
-				 unsigned long *reserve_addr,
-				 unsigned long *reserve_size,
-				 unsigned long dram_base,
-				 efi_loaded_image_t *image);
-
-asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
-					    unsigned long fdt_addr,
-					    unsigned long fdt_size);
-
 /*
  * EFI entry point for the arm/arm64 EFI stubs.  This is the entrypoint
  * that is described in the PE/COFF header.  Most of the code is the same
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 2c9d42264c29..85050f5a1b28 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -776,6 +776,22 @@ efi_status_t efi_load_initrd(efi_loaded_image_t *image,
 			     unsigned long *load_size,
 			     unsigned long soft_limit,
 			     unsigned long hard_limit);
+/*
+ * This function handles the architcture specific differences between arm and
+ * arm64 regarding where the kernel image must be loaded and any memory that
+ * must be reserved. On failure it is required to free all
+ * all allocations it has made.
+ */
+efi_status_t handle_kernel_image(unsigned long *image_addr,
+				 unsigned long *image_size,
+				 unsigned long *reserve_addr,
+				 unsigned long *reserve_size,
+				 unsigned long dram_base,
+				 efi_loaded_image_t *image);
+
+asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
+					    unsigned long fdt_addr,
+					    unsigned long fdt_size);
 
 void efi_handle_post_ebs_state(void);
 
-- 
2.24.0

[RFC PATCH v2 02/11] RISC-V: Move DT mapping outof fixmap

[Atish Patra]

From: Anup Patel <anup.patel@wdc.com>

Currently, RISC-V reserves 1MB of fixmap memory for device tree. However,
it maps only single PMD (2MB) space for fixmap which leaves only < 1MB space
left for other kernel features such as early ioremap which requires fixmap
as well. The fixmap size can be increased by another 2MB but it brings
additional complexity and changes the virtual memory layout as well.
If we require some additional feature requiring fixmap again, it has to be
moved again.

Technically, DT doesn't need a fixmap as the memory occupied by the DT is
only used during boot. Thus, init memory section can be used for the same
purpose as well. This simplifies fixmap implementation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/include/asm/fixmap.h |  3 ---
 arch/riscv/kernel/head.S        |  1 -
 arch/riscv/kernel/head.h        |  2 --
 arch/riscv/kernel/setup.c       |  8 +++-----
 arch/riscv/mm/init.c            | 36 ++++++++++++++-------------------
 5 files changed, 18 insertions(+), 32 deletions(-)

diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h
index 1ff075a8dfc7..11613f38228a 100644
--- a/arch/riscv/include/asm/fixmap.h
+++ b/arch/riscv/include/asm/fixmap.h
@@ -22,9 +22,6 @@
  */
 enum fixed_addresses {
 	FIX_HOLE,
-#define FIX_FDT_SIZE	SZ_1M
-	FIX_FDT_END,
-	FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,
 	FIX_PTE,
 	FIX_PMD,
 	FIX_TEXT_POKE1,
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 7ed1b22950fd..c5b529234ad8 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -244,7 +244,6 @@ clear_bss_done:
 #endif
 	/* Start the kernel */
 	call soc_early_init
-	call parse_dtb
 	tail start_kernel
 
 .Lsecondary_start:
diff --git a/arch/riscv/kernel/head.h b/arch/riscv/kernel/head.h
index 105fb0496b24..b48dda3d04f6 100644
--- a/arch/riscv/kernel/head.h
+++ b/arch/riscv/kernel/head.h
@@ -16,6 +16,4 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa);
 extern void *__cpu_up_stack_pointer[];
 extern void *__cpu_up_task_pointer[];
 
-void __init parse_dtb(void);
-
 #endif /* __ASM_HEAD_H */
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index f04373be54a6..8519a6d29857 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -49,8 +49,9 @@ atomic_t hart_lottery __section(.sdata);
 unsigned long boot_cpu_hartid;
 static DEFINE_PER_CPU(struct cpu, cpu_devices);
 
-void __init parse_dtb(void)
+static void __init parse_dtb(void)
 {
+	/* Early scan of device tree from init memory */
 	if (early_init_dt_scan(dtb_early_va))
 		return;
 
@@ -63,6 +64,7 @@ void __init parse_dtb(void)
 
 void __init setup_arch(char **cmdline_p)
 {
+	parse_dtb();
 	init_mm.start_code = (unsigned long) _stext;
 	init_mm.end_code   = (unsigned long) _etext;
 	init_mm.end_data   = (unsigned long) _edata;
@@ -74,11 +76,7 @@ void __init setup_arch(char **cmdline_p)
 
 	setup_bootmem();
 	paging_init();
-#if IS_ENABLED(CONFIG_BUILTIN_DTB)
 	unflatten_and_copy_device_tree();
-#else
-	unflatten_device_tree();
-#endif
 	clint_init_boot_cpu();
 
 #ifdef CONFIG_SWIOTLB
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index f4adb3684f3d..c18c94ab3b23 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -28,7 +28,6 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
 EXPORT_SYMBOL(empty_zero_page);
 
 extern char _start[];
-void *dtb_early_va;
 
 static void __init zone_sizes_init(void)
 {
@@ -120,8 +119,6 @@ static void __init setup_initrd(void)
 }
 #endif /* CONFIG_BLK_DEV_INITRD */
 
-static phys_addr_t dtb_early_pa __initdata;
-
 void __init setup_bootmem(void)
 {
 	struct memblock_region *reg;
@@ -158,13 +155,9 @@ void __init setup_bootmem(void)
 	setup_initrd();
 #endif /* CONFIG_BLK_DEV_INITRD */
 
-	/*
-	 * Avoid using early_init_fdt_reserve_self() since __pa() does
-	 * not work for DTB pointers that are fixmap addresses
-	 */
-	memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
-
+	early_init_fdt_reserve_self();
 	early_init_fdt_scan_reserved_mem();
+
 	memblock_allow_resize();
 	memblock_dump_all();
 
@@ -184,6 +177,10 @@ EXPORT_SYMBOL(va_pa_offset);
 unsigned long pfn_base;
 EXPORT_SYMBOL(pfn_base);
 
+#define DTB_EARLY_SIZE		SZ_1M
+static char early_dtb[DTB_EARLY_SIZE] __initdata;
+void *dtb_early_va __initdata = early_dtb;
+
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
@@ -375,7 +372,8 @@ static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
 
 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 {
-	uintptr_t va, end_va;
+	int dtb_size;
+	uintptr_t va, pa, end_va;
 	uintptr_t load_pa = (uintptr_t)(&_start);
 	uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
 	uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
@@ -424,17 +422,11 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 				   load_pa + (va - PAGE_OFFSET),
 				   map_size, PAGE_KERNEL_EXEC);
 
-	/* Create fixed mapping for early FDT parsing */
-	end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
-	for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
-		create_pte_mapping(fixmap_pte, va,
-				   dtb_pa + (va - __fix_to_virt(FIX_FDT)),
-				   PAGE_SIZE, PAGE_KERNEL);
-
-	/* Save pointer to DTB for early FDT parsing */
-	dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
-	/* Save physical address for memblock reservation */
-	dtb_early_pa = dtb_pa;
+	/* Copy FDT to init memory for early scan */
+	pa = load_pa + ((unsigned long)dtb_early_va - PAGE_OFFSET);
+	dtb_size = fdt_totalsize((void *)dtb_pa);
+	dtb_size = (dtb_size > DTB_EARLY_SIZE) ? DTB_EARLY_SIZE : dtb_size;
+	memcpy((void *)pa, (void *)dtb_pa, dtb_size);
 }
 
 static void __init setup_vm_final(void)
@@ -481,6 +473,8 @@ static void __init setup_vm_final(void)
 	local_flush_tlb_all();
 }
 #else
+void *dtb_early_va __initdata;
+
 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 {
 #ifdef CONFIG_BUILTIN_DTB
-- 
2.24.0

[RFC PATCH v2 03/11] RISC-V: Setup exception vector early

[Atish Patra]

The trap vector is set only in trap_init which may be too late in some
cases. Early ioremap/efi spits many warning messages which may be useful.

Setup the trap vector early so that any warning/bug can be handled before
generic code invokes trap_init.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/kernel/head.S    | 10 ++++++++--
 arch/riscv/kernel/smpboot.c |  1 -
 arch/riscv/kernel/traps.c   |  8 +-------
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index c5b529234ad8..eb123eda3663 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -77,10 +77,16 @@ relocate:
 	csrw CSR_SATP, a0
 .align 2
 1:
-	/* Set trap vector to spin forever to help debug */
-	la a0, .Lsecondary_park
+	/* Set trap vector to exception handler */
+	la a0, handle_exception
 	csrw CSR_TVEC, a0
 
+	/*
+	 * Set sup0 scratch register to 0, indicating to exception vector that
+	 * we are presently executing in kernel.
+	 */
+	csrw CSR_SCRATCH, zero
+
 	/* Reload the global pointer */
 .option push
 .option norelax
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 4e9922790f6e..5a9c127a380e 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -154,7 +154,6 @@ asmlinkage __visible void smp_callin(void)
 	mmgrab(mm);
 	current->active_mm = mm;
 
-	trap_init();
 	notify_cpu_starting(smp_processor_id());
 	update_siblings_masks(smp_processor_id());
 	set_cpu_online(smp_processor_id(), 1);
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 7d95cce5e47c..ad14f4466d92 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -174,13 +174,7 @@ int is_valid_bugaddr(unsigned long pc)
 }
 #endif /* CONFIG_GENERIC_BUG */
 
+/* stvec & scratch is already set from head.S */
 void trap_init(void)
 {
-	/*
-	 * Set sup0 scratch register to 0, indicating to exception vector
-	 * that we are presently executing in the kernel
-	 */
-	csr_write(CSR_SCRATCH, 0);
-	/* Set the exception vector address */
-	csr_write(CSR_TVEC, &handle_exception);
 }
-- 
2.24.0

[RFC PATCH v2 04/11] RISC-V: Add early ioremap support

[Atish Patra]

UEFI uses early IO or memory mappings for runtime services before
normal ioremap() is usable. Add the necessary fixmap bindings and
pmd mappings for generic ioremap support to work.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/Kconfig              |  1 +
 arch/riscv/include/asm/Kbuild   |  1 +
 arch/riscv/include/asm/fixmap.h | 13 +++++++++++++
 arch/riscv/include/asm/io.h     |  1 +
 arch/riscv/kernel/setup.c       |  1 +
 arch/riscv/mm/init.c            | 33 +++++++++++++++++++++++++++++++++
 6 files changed, 50 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 128192e14ff2..fda90093e588 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -32,6 +32,7 @@ config RISCV
 	select GENERIC_ARCH_TOPOLOGY if SMP
 	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_CLOCKEVENTS
+	select GENERIC_EARLY_IOREMAP
 	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
 	select GENERIC_IOREMAP
 	select GENERIC_IRQ_MULTI_HANDLER
diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index 3d9410bb4de0..59dd7be55005 100644
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
+generic-y += early_ioremap.h
 generic-y += extable.h
 generic-y += flat.h
 generic-y += kvm_para.h
diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h
index 11613f38228a..54cbf07fb4e9 100644
--- a/arch/riscv/include/asm/fixmap.h
+++ b/arch/riscv/include/asm/fixmap.h
@@ -27,6 +27,19 @@ enum fixed_addresses {
 	FIX_TEXT_POKE1,
 	FIX_TEXT_POKE0,
 	FIX_EARLYCON_MEM_BASE,
+
+	__end_of_permanent_fixed_addresses,
+	/*
+	 * Temporary boot-time mappings, used by early_ioremap(),
+	 * before ioremap() is functional.
+	 */
+#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
+#define FIX_BTMAPS_SLOTS	7
+#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
+
+	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
+	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
+
 	__end_of_fixed_addresses
 };
 
diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h
index 3835c3295dc5..c025a746a148 100644
--- a/arch/riscv/include/asm/io.h
+++ b/arch/riscv/include/asm/io.h
@@ -14,6 +14,7 @@
 #include <linux/types.h>
 #include <linux/pgtable.h>
 #include <asm/mmiowb.h>
+#include <asm/early_ioremap.h>
 
 /*
  * MMIO access functions are separated out to break dependency cycles
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 8519a6d29857..1244b433fe7c 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -72,6 +72,7 @@ void __init setup_arch(char **cmdline_p)
 
 	*cmdline_p = boot_command_line;
 
+	early_ioremap_setup();
 	parse_early_param();
 
 	setup_bootmem();
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index c18c94ab3b23..bad60686d080 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -377,6 +377,9 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 	uintptr_t load_pa = (uintptr_t)(&_start);
 	uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
 	uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
+#ifndef __PAGETABLE_PMD_FOLDED
+	pmd_t fix_bmap_spmd, fix_bmap_epmd;
+#endif
 
 	va_pa_offset = PAGE_OFFSET - load_pa;
 	pfn_base = PFN_DOWN(load_pa);
@@ -427,6 +430,36 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 	dtb_size = fdt_totalsize((void *)dtb_pa);
 	dtb_size = (dtb_size > DTB_EARLY_SIZE) ? DTB_EARLY_SIZE : dtb_size;
 	memcpy((void *)pa, (void *)dtb_pa, dtb_size);
+
+	/*
+	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
+	 * range can not span multiple pmds.
+	 */
+	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
+		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
+
+#ifndef __PAGETABLE_PMD_FOLDED
+	/*
+	 * Early ioremap fixmap is already created as it lies within first 2MB
+	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
+	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
+	 * the user if not.
+	 */
+	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
+	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
+	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
+		WARN_ON(1);
+		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
+			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
+		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
+			fix_to_virt(FIX_BTMAP_BEGIN));
+		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
+			fix_to_virt(FIX_BTMAP_END));
+
+		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
+		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
+	}
+#endif
 }
 
 static void __init setup_vm_final(void)
-- 
2.24.0

[RFC PATCH v2 05/11] RISC-V: Set maximum number of mapped pages correctly

[Atish Patra]

Currently, maximum number of mapper pages are set to the pfn calculated
from the memblock size of the memblock containing kernel. This will work
until that memblock spans the entire memory. However, it will be set to
a wrong value if there are multiple memblocks defined in kernel
(e.g. with efi runtime services).

Set the the maximum value to the pfn calculated from dram size.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/mm/init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index bad60686d080..4021706aef81 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -147,9 +147,9 @@ void __init setup_bootmem(void)
 	/* Reserve from the start of the kernel to the end of the kernel */
 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
 
-	set_max_mapnr(PFN_DOWN(mem_size));
 	max_pfn = PFN_DOWN(memblock_end_of_DRAM());
 	max_low_pfn = max_pfn;
+	set_max_mapnr(max_low_pfn);
 
 #ifdef CONFIG_BLK_DEV_INITRD
 	setup_initrd();
-- 
2.24.0

[RFC PATCH v2 06/11] riscv: Parse all memory blocks to remove unusable memory

[Atish Patra]

Currently, maximum physical memory allowed is equal to -PAGE_OFFSET.
That's why we remove any memory blocks spanning beyond that size. However,
it is done only for memblock containing linux kernel which will not work
if there are multiple memblocks.

Process all memory blocks to figure out how much memory needs to be removed
and remove at the end instead of updating the memblock list in place.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/mm/init.c | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 4021706aef81..c5268fe6e6de 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -123,26 +123,29 @@ void __init setup_bootmem(void)
 {
 	struct memblock_region *reg;
 	phys_addr_t mem_size = 0;
+	phys_addr_t total_mem = 0;
+	phys_addr_t mem_start, end = 0;
 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
 	phys_addr_t vmlinux_start = __pa_symbol(&_start);
 
 	/* Find the memory region containing the kernel */
 	for_each_memblock(memory, reg) {
-		phys_addr_t end = reg->base + reg->size;
-
-		if (reg->base <= vmlinux_start && vmlinux_end <= end) {
-			mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
-
-			/*
-			 * Remove memblock from the end of usable area to the
-			 * end of region
-			 */
-			if (reg->base + mem_size < end)
-				memblock_remove(reg->base + mem_size,
-						end - reg->base - mem_size);
-		}
+		end = reg->base + reg->size;
+		if (!total_mem)
+			mem_start = reg->base;
+		if (reg->base <= vmlinux_start && vmlinux_end <= end)
+			BUG_ON(reg->size == 0);
+		total_mem = total_mem + reg->size;
 	}
-	BUG_ON(mem_size == 0);
+
+	/*
+	 * Remove memblock from the end of usable area to the
+	 * end of region
+	 */
+	mem_size = min(total_mem, (phys_addr_t)-PAGE_OFFSET);
+	if (mem_start + mem_size < end)
+		memblock_remove(mem_start + mem_size,
+				end - mem_start - mem_size);
 
 	/* Reserve from the start of the kernel to the end of the kernel */
 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
-- 
2.24.0

[RFC PATCH v2 07/11] include: pe.h: Add RISC-V related PE definition

[Atish Patra]

Define RISC-V related machine types.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Link: https://lore.kernel.org/r/20200415195422.19866-3-atish.patra@wdc.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 include/linux/pe.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/linux/pe.h b/include/linux/pe.h
index 8ad71d763a77..daf09ffffe38 100644
--- a/include/linux/pe.h
+++ b/include/linux/pe.h
@@ -55,6 +55,9 @@
 #define	IMAGE_FILE_MACHINE_POWERPC	0x01f0
 #define	IMAGE_FILE_MACHINE_POWERPCFP	0x01f1
 #define	IMAGE_FILE_MACHINE_R4000	0x0166
+#define	IMAGE_FILE_MACHINE_RISCV32	0x5032
+#define	IMAGE_FILE_MACHINE_RISCV64	0x5064
+#define	IMAGE_FILE_MACHINE_RISCV128	0x5128
 #define	IMAGE_FILE_MACHINE_SH3		0x01a2
 #define	IMAGE_FILE_MACHINE_SH3DSP	0x01a3
 #define	IMAGE_FILE_MACHINE_SH3E		0x01a4
-- 
2.24.0

[RFC PATCH v2 08/11] RISC-V: Add PE/COFF header for EFI stub

[Atish Patra]

Linux kernel Image can appear as an EFI application With appropriate
PE/COFF header fields in the beginning of the Image header. An EFI
application loader can directly load a Linux kernel Image and an EFI
stub residing in kernel can boot Linux kernel directly.

Add the necessary PE/COFF header.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20200421033336.9663-3-atish.patra@wdc.com
[ardb: - use C prefix for c.li to ensure the expected opcode is emitted
       - align all image sections according to PE/COFF section alignment ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/riscv/include/asm/sections.h |  13 ++++
 arch/riscv/kernel/Makefile        |   4 ++
 arch/riscv/kernel/efi-header.S    | 104 ++++++++++++++++++++++++++++++
 arch/riscv/kernel/head.S          |  16 +++++
 arch/riscv/kernel/image-vars.h    |  51 +++++++++++++++
 arch/riscv/kernel/vmlinux.lds.S   |  22 ++++++-
 6 files changed, 208 insertions(+), 2 deletions(-)
 create mode 100644 arch/riscv/include/asm/sections.h
 create mode 100644 arch/riscv/kernel/efi-header.S
 create mode 100644 arch/riscv/kernel/image-vars.h

diff --git a/arch/riscv/include/asm/sections.h b/arch/riscv/include/asm/sections.h
new file mode 100644
index 000000000000..3a9971b1210f
--- /dev/null
+++ b/arch/riscv/include/asm/sections.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ */
+#ifndef __ASM_SECTIONS_H
+#define __ASM_SECTIONS_H
+
+#include <asm-generic/sections.h>
+
+extern char _start[];
+extern char _start_kernel[];
+
+#endif /* __ASM_SECTIONS_H */
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index b355cf485671..6f7a3b3771fd 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -32,6 +32,10 @@ obj-y	+= patch.o
 obj-$(CONFIG_MMU) += vdso.o vdso/
 
 obj-$(CONFIG_RISCV_M_MODE)	+= clint.o traps_misaligned.o
+OBJCOPYFLAGS := --prefix-symbols=__efistub_
+$(obj)/%.stub.o: $(obj)/%.o FORCE
+	$(call if_changed,objcopy)
+
 obj-$(CONFIG_FPU)		+= fpu.o
 obj-$(CONFIG_SMP)		+= smpboot.o
 obj-$(CONFIG_SMP)		+= smp.o
diff --git a/arch/riscv/kernel/efi-header.S b/arch/riscv/kernel/efi-header.S
new file mode 100644
index 000000000000..822b4c9ff2bb
--- /dev/null
+++ b/arch/riscv/kernel/efi-header.S
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ * Adapted from arch/arm64/kernel/efi-header.S
+ */
+
+#include <linux/pe.h>
+#include <linux/sizes.h>
+
+	.macro	__EFI_PE_HEADER
+	.long	PE_MAGIC
+coff_header:
+#ifdef CONFIG_64BIT
+	.short	IMAGE_FILE_MACHINE_RISCV64		// Machine
+#else
+	.short	IMAGE_FILE_MACHINE_RISCV32		// Machine
+#endif
+	.short	section_count				// NumberOfSections
+	.long	0 					// TimeDateStamp
+	.long	0					// PointerToSymbolTable
+	.long	0					// NumberOfSymbols
+	.short	section_table - optional_header		// SizeOfOptionalHeader
+	.short	IMAGE_FILE_DEBUG_STRIPPED | \
+		IMAGE_FILE_EXECUTABLE_IMAGE | \
+		IMAGE_FILE_LINE_NUMS_STRIPPED		// Characteristics
+
+optional_header:
+	.short	PE_OPT_MAGIC_PE32PLUS			// PE32+ format
+	.byte	0x02					// MajorLinkerVersion
+	.byte	0x14					// MinorLinkerVersion
+	.long	__pecoff_text_end - efi_header_end	// SizeOfCode
+	.long	__pecoff_data_virt_size			// SizeOfInitializedData
+	.long	0					// SizeOfUninitializedData
+	.long	__efistub_efi_pe_entry - _start		// AddressOfEntryPoint
+	.long	efi_header_end - _start			// BaseOfCode
+
+extra_header_fields:
+	.quad	0					// ImageBase
+	.long	PECOFF_SECTION_ALIGNMENT		// SectionAlignment
+	.long	PECOFF_FILE_ALIGNMENT			// FileAlignment
+	.short	0					// MajorOperatingSystemVersion
+	.short	0					// MinorOperatingSystemVersion
+	.short	LINUX_EFISTUB_MAJOR_VERSION		// MajorImageVersion
+	.short	LINUX_EFISTUB_MINOR_VERSION		// MinorImageVersion
+	.short	0					// MajorSubsystemVersion
+	.short	0					// MinorSubsystemVersion
+	.long	0					// Win32VersionValue
+
+	.long	_end - _start				// SizeOfImage
+
+	// Everything before the kernel image is considered part of the header
+	.long	efi_header_end - _start			// SizeOfHeaders
+	.long	0					// CheckSum
+	.short	IMAGE_SUBSYSTEM_EFI_APPLICATION		// Subsystem
+	.short	0					// DllCharacteristics
+	.quad	0					// SizeOfStackReserve
+	.quad	0					// SizeOfStackCommit
+	.quad	0					// SizeOfHeapReserve
+	.quad	0					// SizeOfHeapCommit
+	.long	0					// LoaderFlags
+	.long	(section_table - .) / 8			// NumberOfRvaAndSizes
+
+	.quad	0					// ExportTable
+	.quad	0					// ImportTable
+	.quad	0					// ResourceTable
+	.quad	0					// ExceptionTable
+	.quad	0					// CertificationTable
+	.quad	0					// BaseRelocationTable
+
+	// Section table
+section_table:
+	.ascii	".text\0\0\0"
+	.long	__pecoff_text_end - efi_header_end	// VirtualSize
+	.long	efi_header_end - _start			// VirtualAddress
+	.long	__pecoff_text_end - efi_header_end	// SizeOfRawData
+	.long	efi_header_end - _start			// PointerToRawData
+
+	.long	0					// PointerToRelocations
+	.long	0					// PointerToLineNumbers
+	.short	0					// NumberOfRelocations
+	.short	0					// NumberOfLineNumbers
+	.long	IMAGE_SCN_CNT_CODE | \
+		IMAGE_SCN_MEM_READ | \
+		IMAGE_SCN_MEM_EXECUTE			// Characteristics
+
+	.ascii	".data\0\0\0"
+	.long	__pecoff_data_virt_size			// VirtualSize
+	.long	__pecoff_text_end - _start		// VirtualAddress
+	.long	__pecoff_data_raw_size			// SizeOfRawData
+	.long	__pecoff_text_end - _start		// PointerToRawData
+
+	.long	0					// PointerToRelocations
+	.long	0					// PointerToLineNumbers
+	.short	0					// NumberOfRelocations
+	.short	0					// NumberOfLineNumbers
+	.long	IMAGE_SCN_CNT_INITIALIZED_DATA | \
+		IMAGE_SCN_MEM_READ | \
+		IMAGE_SCN_MEM_WRITE			// Characteristics
+
+	.set	section_count, (. - section_table) / 40
+
+	.balign	0x1000
+efi_header_end:
+	.endm
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index eb123eda3663..3a05a9222b82 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -13,6 +13,7 @@
 #include <asm/csr.h>
 #include <asm/hwcap.h>
 #include <asm/image.h>
+#include "efi-header.S"
 
 __HEAD
 ENTRY(_start)
@@ -22,10 +23,18 @@ ENTRY(_start)
 	 * Do not modify it without modifying the structure and all bootloaders
 	 * that expects this header format!!
 	 */
+#ifdef CONFIG_EFI
+	/*
+	 * This instruction decodes to "MZ" ASCII required by UEFI.
+	 */
+	c.li s4,-13
+	j _start_kernel
+#else
 	/* jump to start kernel */
 	j _start_kernel
 	/* reserved */
 	.word 0
+#endif
 	.balign 8
 #if __riscv_xlen == 64
 	/* Image load offset(2MB) from start of RAM */
@@ -43,7 +52,14 @@ ENTRY(_start)
 	.ascii RISCV_IMAGE_MAGIC
 	.balign 4
 	.ascii RISCV_IMAGE_MAGIC2
+#ifdef CONFIG_EFI
+	.word pe_head_start - _start
+pe_head_start:
+
+	__EFI_PE_HEADER
+#else
 	.word 0
+#endif
 
 .align 2
 #ifdef CONFIG_MMU
diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h
new file mode 100644
index 000000000000..8c212efb37a6
--- /dev/null
+++ b/arch/riscv/kernel/image-vars.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ * Linker script variables to be set after section resolution, as
+ * ld.lld does not like variables assigned before SECTIONS is processed.
+ * Based on arch/arm64/kerne/image-vars.h
+ */
+#ifndef __RISCV_KERNEL_IMAGE_VARS_H
+#define __RISCV_KERNEL_IMAGE_VARS_H
+
+#ifndef LINKER_SCRIPT
+#error This file should only be included in vmlinux.lds.S
+#endif
+
+#ifdef CONFIG_EFI
+
+/*
+ * The EFI stub has its own symbol namespace prefixed by __efistub_, to
+ * isolate it from the kernel proper. The following symbols are legally
+ * accessed by the stub, so provide some aliases to make them accessible.
+ * Only include data symbols here, or text symbols of functions that are
+ * guaranteed to be safe when executed at another offset than they were
+ * linked at. The routines below are all implemented in assembler in a
+ * position independent manner
+ */
+__efistub_memcmp		= memcmp;
+__efistub_memchr		= memchr;
+__efistub_memcpy		= memcpy;
+__efistub_memmove		= memmove;
+__efistub_memset		= memset;
+__efistub_strlen		= strlen;
+__efistub_strnlen		= strnlen;
+__efistub_strcmp		= strcmp;
+__efistub_strncmp		= strncmp;
+__efistub_strrchr		= strrchr;
+
+#ifdef CONFIG_KASAN
+__efistub___memcpy		= memcpy;
+__efistub___memmove		= memmove;
+__efistub___memset		= memset;
+#endif
+
+__efistub__start		= _start;
+__efistub__start_kernel		= _start_kernel;
+__efistub__end			= _end;
+__efistub__edata		= _edata;
+__efistub_screen_info		= screen_info;
+
+#endif
+
+#endif /* __RISCV_KERNEL_IMAGE_VARS_H */
diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
index e6f8016b366a..2616230da1e7 100644
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -10,6 +10,7 @@
 #include <asm/cache.h>
 #include <asm/thread_info.h>
 #include <asm/set_memory.h>
+#include "image-vars.h"
 
 #include <linux/sizes.h>
 OUTPUT_ARCH(riscv)
@@ -17,6 +18,9 @@ ENTRY(_start)
 
 jiffies = jiffies_64;
 
+PECOFF_SECTION_ALIGNMENT = 0x1000;
+PECOFF_FILE_ALIGNMENT = 0x200;
+
 SECTIONS
 {
 	/* Beginning of code and text segment */
@@ -76,6 +80,10 @@ SECTIONS
 
 	EXCEPTION_TABLE(0x10)
 
+#ifdef CONFIG_EFI
+	. = ALIGN(PECOFF_SECTION_ALIGNMENT);
+	__pecoff_text_end = .;
+#endif
 	. = ALIGN(SECTION_ALIGN);
 	_data = .;
 
@@ -83,16 +91,26 @@ SECTIONS
 	.sdata : {
 		__global_pointer$ = . + 0x800;
 		*(.sdata*)
-		/* End of data section */
-		_edata = .;
 	}
 
+#ifdef CONFIG_EFI
+	.pecoff_edata_padding : { BYTE(0); . = ALIGN(PECOFF_FILE_ALIGNMENT); }
+	__pecoff_data_raw_size = ABSOLUTE(. - __pecoff_text_end);
+#endif
+
+	/* End of data section */
+	_edata = .;
+
 	BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 0)
 
 	.rel.dyn : {
 		*(.rel.dyn*)
 	}
 
+#ifdef CONFIG_EFI
+	. = ALIGN(PECOFF_SECTION_ALIGNMENT);
+	__pecoff_data_virt_size = ABSOLUTE(. - __pecoff_text_end);
+#endif
 	_end = .;
 
 	STABS_DEBUG
-- 
2.24.0

[RFC PATCH v2 09/11] RISC-V: Add EFI stub support.

[Atish Patra]

Add a RISC-V architecture specific stub code that actually copies the
actual kernel image to a valid address and jump to it after boot services
are terminated. Enable UEFI related kernel configs as well for RISC-V.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20200421033336.9663-4-atish.patra@wdc.com
[ardb: - move hartid fetch into check_platform_features()
       - use image_size not reserve_size
       - select ISA_C ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/riscv/Kconfig                        |  22 +++++
 arch/riscv/Makefile                       |   1 +
 arch/riscv/configs/defconfig              |   1 +
 arch/riscv/include/asm/efi.h              |  36 +++++++
 drivers/firmware/efi/Kconfig              |   3 +-
 drivers/firmware/efi/libstub/Makefile     |  10 ++
 drivers/firmware/efi/libstub/riscv-stub.c | 110 ++++++++++++++++++++++
 7 files changed, 182 insertions(+), 1 deletion(-)
 create mode 100644 arch/riscv/include/asm/efi.h
 create mode 100644 drivers/firmware/efi/libstub/riscv-stub.c

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index fda90093e588..a902e98048a1 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -388,6 +388,26 @@ config CMDLINE_FORCE
 
 endchoice
 
+config EFI_STUB
+	bool
+
+config EFI
+	bool "UEFI runtime support"
+	depends on OF
+	select LIBFDT
+	select UCS2_STRING
+	select EFI_PARAMS_FROM_FDT
+	select EFI_STUB
+	select EFI_GENERIC_STUB
+	select RISCV_ISA_C
+	default y
+	help
+	  This option provides support for runtime services provided
+	  by UEFI firmware (such as non-volatile variables, realtime
+	  clock, and platform reset). A UEFI stub is also provided to
+	  allow the kernel to be booted as an EFI application. This
+	  is only useful on systems that have UEFI firmware.
+
 endmenu
 
 config BUILTIN_DTB
@@ -400,3 +420,5 @@ menu "Power management options"
 source "kernel/power/Kconfig"
 
 endmenu
+
+source "drivers/firmware/Kconfig"
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index fb6e37db836d..10df59f28add 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -80,6 +80,7 @@ head-y := arch/riscv/kernel/head.o
 core-y += arch/riscv/
 
 libs-y += arch/riscv/lib/
+libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
 
 PHONY += vdso_install
 vdso_install:
diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig
index 4da4886246a4..ae69e12d306a 100644
--- a/arch/riscv/configs/defconfig
+++ b/arch/riscv/configs/defconfig
@@ -129,3 +129,4 @@ CONFIG_DEBUG_BLOCK_EXT_DEVT=y
 # CONFIG_RUNTIME_TESTING_MENU is not set
 CONFIG_MEMTEST=y
 # CONFIG_SYSFS_SYSCALL is not set
+CONFIG_EFI=y
diff --git a/arch/riscv/include/asm/efi.h b/arch/riscv/include/asm/efi.h
new file mode 100644
index 000000000000..86da231909bb
--- /dev/null
+++ b/arch/riscv/include/asm/efi.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ */
+#ifndef _ASM_EFI_H
+#define _ASM_EFI_H
+
+#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <asm/ptrace.h>
+#include <asm/tlbflush.h>
+
+/* on RISC-V, the FDT may be located anywhere in system RAM */
+static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base)
+{
+	return ULONG_MAX;
+}
+
+/* Load initrd at enough distance from DRAM start */
+static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base,
+						    unsigned long image_addr)
+{
+	return dram_base + SZ_256M;
+}
+
+#define alloc_screen_info(x...)		(&screen_info)
+
+static inline void free_screen_info(struct screen_info *si)
+{
+}
+
+static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
+{
+}
+
+#endif /* _ASM_EFI_H */
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 3939699e62fe..a29fbd6e657e 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -111,7 +111,7 @@ config EFI_GENERIC_STUB
 
 config EFI_ARMSTUB_DTB_LOADER
 	bool "Enable the DTB loader"
-	depends on EFI_GENERIC_STUB
+	depends on EFI_GENERIC_STUB && !RISCV
 	default y
 	help
 	  Select this config option to add support for the dtb= command
@@ -128,6 +128,7 @@ config EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER
 	bool "Enable the command line initrd loader" if !X86
 	depends on EFI_STUB && (EFI_GENERIC_STUB || X86)
 	default y
+	depends on !RISCV
 	help
 	  Select this config option to add support for the initrd= command
 	  line parameter, allowing an initrd that resides on the same volume
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 4cce372edaf4..659773793043 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -23,6 +23,8 @@ cflags-$(CONFIG_ARM64)		:= $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
 cflags-$(CONFIG_ARM)		:= $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
 				   -fno-builtin -fpic \
 				   $(call cc-option,-mno-single-pic-base)
+cflags-$(CONFIG_RISCV)		:= $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
+				   -fpic
 
 cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt
 
@@ -64,6 +66,7 @@ lib-$(CONFIG_EFI_GENERIC_STUB)	+= efi-stub.o fdt.o string.o \
 lib-$(CONFIG_ARM)		+= arm32-stub.o
 lib-$(CONFIG_ARM64)		+= arm64-stub.o
 lib-$(CONFIG_X86)		+= x86-stub.o
+lib-$(CONFIG_RISCV)		+= riscv-stub.o
 CFLAGS_arm32-stub.o		:= -DTEXT_OFFSET=$(TEXT_OFFSET)
 CFLAGS_arm64-stub.o		:= -DTEXT_OFFSET=$(TEXT_OFFSET)
 
@@ -107,6 +110,13 @@ STUBCOPY_FLAGS-$(CONFIG_ARM64)	+= --prefix-alloc-sections=.init \
 				   --prefix-symbols=__efistub_
 STUBCOPY_RELOC-$(CONFIG_ARM64)	:= R_AARCH64_ABS
 
+# For RISC-V, we don't need anything special other than arm64. Keep all the
+# symbols in .init section and make sure that no absolute symbols references
+# doesn't exist.
+STUBCOPY_FLAGS-$(CONFIG_RISCV)	+= --prefix-alloc-sections=.init \
+				   --prefix-symbols=__efistub_
+STUBCOPY_RELOC-$(CONFIG_RISCV)	:= R_RISCV_HI20
+
 $(obj)/%.stub.o: $(obj)/%.o FORCE
 	$(call if_changed,stubcopy)
 
diff --git a/drivers/firmware/efi/libstub/riscv-stub.c b/drivers/firmware/efi/libstub/riscv-stub.c
new file mode 100644
index 000000000000..77c3fd6f820e
--- /dev/null
+++ b/drivers/firmware/efi/libstub/riscv-stub.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ */
+
+#include <linux/efi.h>
+#include <linux/libfdt.h>
+
+#include <asm/efi.h>
+#include <asm/sections.h>
+
+#include "efistub.h"
+
+/*
+ * RISC-V requires the kernel image to placed 2 MB aligned base for 64 bit and
+ * 4MB for 32 bit.
+ */
+#ifdef CONFIG_64BIT
+#define MIN_KIMG_ALIGN		SZ_2M
+#else
+#define MIN_KIMG_ALIGN		SZ_4M
+#endif
+
+typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long);
+
+static u32 hartid;
+
+static u32 get_boot_hartid_from_fdt(void)
+{
+	const void *fdt;
+	int chosen_node, len;
+	const fdt32_t *prop;
+
+	fdt = get_efi_config_table(DEVICE_TREE_GUID);
+	if (!fdt)
+		return U32_MAX;
+
+	chosen_node = fdt_path_offset(fdt, "/chosen");
+	if (chosen_node < 0)
+		return U32_MAX;
+
+	prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len);
+	if (!prop || len != sizeof(u32))
+		return U32_MAX;
+
+	return fdt32_to_cpu(*prop);
+}
+
+efi_status_t check_platform_features(void)
+{
+	hartid = get_boot_hartid_from_fdt();
+	if (hartid == U32_MAX) {
+		efi_err("/chosen/boot-hartid missing or invalid!\n");
+		return EFI_UNSUPPORTED;
+	}
+	return EFI_SUCCESS;
+}
+
+void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt,
+				 unsigned long fdt_size)
+{
+	unsigned long stext_offset = _start_kernel - _start;
+	unsigned long kernel_entry = entrypoint + stext_offset;
+	jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry;
+
+	/*
+	 * Jump to real kernel here with following constraints.
+	 * 1. MMU should be disabled.
+	 * 2. a0 should contain hartid
+	 * 3. a1 should DT address
+	 */
+	csr_write(CSR_SATP, 0);
+	jump_kernel(hartid, fdt);
+}
+
+efi_status_t handle_kernel_image(unsigned long *image_addr,
+				 unsigned long *image_size,
+				 unsigned long *reserve_addr,
+				 unsigned long *reserve_size,
+				 unsigned long dram_base,
+				 efi_loaded_image_t *image)
+{
+	unsigned long kernel_size = 0;
+	unsigned long preferred_addr;
+	efi_status_t status;
+
+	kernel_size = _edata - _start;
+	*image_addr = (unsigned long)_start;
+	*image_size = kernel_size + (_end - _edata);
+
+	/*
+	 * RISC-V kernel maps PAGE_OFFSET virtual address to the same physical
+	 * address where kernel is booted. That's why kernel should boot from
+	 * as low as possible to avoid wastage of memory. Currently, dram_base
+	 * is occupied by the firmware. So the preferred address for kernel to
+	 * boot is next aligned address. If preferred address is not available,
+	 * relocate_kernel will fall back to efi_low_alloc_above to allocate
+	 * lowest possible memory region as long as the address and size meets
+	 * the alignment constraints.
+	 */
+	preferred_addr = round_up(dram_base, MIN_KIMG_ALIGN) + MIN_KIMG_ALIGN;
+	status = efi_relocate_kernel(image_addr, kernel_size, *image_size,
+				     preferred_addr, MIN_KIMG_ALIGN, dram_base);
+
+	if (status != EFI_SUCCESS) {
+		efi_err("Failed to relocate kernel\n");
+		*image_size = 0;
+	}
+	return status;
+}
-- 
2.24.0

[RFC PATCH v2 10/11] efi: Rename arm-init to efi-init common for all arch

[Atish Patra]

arm-init is responsible for setting up efi runtime and doesn't actually
do any ARM specific stuff. RISC-V can use the same source code as it is.

Rename it to efi-init so that RISC-V can use it.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 drivers/firmware/efi/Makefile                   | 2 +-
 drivers/firmware/efi/{arm-init.c => efi-init.c} | 0
 2 files changed, 1 insertion(+), 1 deletion(-)
 rename drivers/firmware/efi/{arm-init.c => efi-init.c} (100%)

diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 7a216984552b..61fd1e8b26fb 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -32,7 +32,7 @@ obj-$(CONFIG_EFI_EMBEDDED_FIRMWARE)	+= embedded-firmware.o
 fake_map-y				+= fake_mem.o
 fake_map-$(CONFIG_X86)			+= x86_fake_mem.o
 
-arm-obj-$(CONFIG_EFI)			:= arm-init.o arm-runtime.o
+arm-obj-$(CONFIG_EFI)			:= efi-init.o arm-runtime.o
 obj-$(CONFIG_ARM)			+= $(arm-obj-y)
 obj-$(CONFIG_ARM64)			+= $(arm-obj-y)
 obj-$(CONFIG_EFI_CAPSULE_LOADER)	+= capsule-loader.o
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/efi-init.c
similarity index 100%
rename from drivers/firmware/efi/arm-init.c
rename to drivers/firmware/efi/efi-init.c
-- 
2.24.0

[RFC PATCH v2 11/11] RISC-V: Add EFI runtime services

[Atish Patra]

This patch adds EFI runtime service support for RISC-V.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/Kconfig                      |   2 +
 arch/riscv/include/asm/efi.h            |  20 ++++
 arch/riscv/include/asm/mmu.h            |   2 +
 arch/riscv/include/asm/pgalloc.h        |  12 ++
 arch/riscv/include/asm/pgtable.h        |   4 +
 arch/riscv/kernel/Makefile              |   1 +
 arch/riscv/kernel/efi.c                 | 106 ++++++++++++++++++
 arch/riscv/kernel/setup.c               |   7 +-
 arch/riscv/mm/init.c                    |   2 +-
 drivers/firmware/efi/Makefile           |   2 +
 drivers/firmware/efi/libstub/efi-stub.c |  11 +-
 drivers/firmware/efi/riscv-runtime.c    | 141 ++++++++++++++++++++++++
 12 files changed, 306 insertions(+), 4 deletions(-)
 create mode 100644 arch/riscv/kernel/efi.c
 create mode 100644 drivers/firmware/efi/riscv-runtime.c

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a902e98048a1..601e8b873628 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -399,7 +399,9 @@ config EFI
 	select EFI_PARAMS_FROM_FDT
 	select EFI_STUB
 	select EFI_GENERIC_STUB
+	select EFI_RUNTIME_WRAPPERS
 	select RISCV_ISA_C
+	depends on MMU
 	default y
 	help
 	  This option provides support for runtime services provided
diff --git a/arch/riscv/include/asm/efi.h b/arch/riscv/include/asm/efi.h
index 86da231909bb..93c305a638f4 100644
--- a/arch/riscv/include/asm/efi.h
+++ b/arch/riscv/include/asm/efi.h
@@ -5,11 +5,28 @@
 #ifndef _ASM_EFI_H
 #define _ASM_EFI_H
 
+#include <asm/csr.h>
 #include <asm/io.h>
 #include <asm/mmu_context.h>
 #include <asm/ptrace.h>
 #include <asm/tlbflush.h>
 
+#ifdef CONFIG_EFI
+extern void efi_init(void);
+#else
+#define efi_init()
+#endif
+
+int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
+int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
+
+#define arch_efi_call_virt_setup()      efi_virtmap_load()
+#define arch_efi_call_virt_teardown()   efi_virtmap_unload()
+
+#define arch_efi_call_virt(p, f, args...) p->f(args)
+
+#define ARCH_EFI_IRQ_FLAGS_MASK (SR_IE | SR_SPIE)
+
 /* on RISC-V, the FDT may be located anywhere in system RAM */
 static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base)
 {
@@ -33,4 +50,7 @@ static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
 {
 }
 
+void efi_virtmap_load(void);
+void efi_virtmap_unload(void);
+
 #endif /* _ASM_EFI_H */
diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h
index 967eacb01ab5..dabcf2cfb3dc 100644
--- a/arch/riscv/include/asm/mmu.h
+++ b/arch/riscv/include/asm/mmu.h
@@ -20,6 +20,8 @@ typedef struct {
 #endif
 } mm_context_t;
 
+void __init create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa,
+			       phys_addr_t sz, pgprot_t prot);
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_RISCV_MMU_H */
diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
index 3f601ee8233f..ad567bf0fb84 100644
--- a/arch/riscv/include/asm/pgalloc.h
+++ b/arch/riscv/include/asm/pgalloc.h
@@ -40,6 +40,18 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 
 #define pmd_pgtable(pmd)	pmd_page(pmd)
 
+static inline pgd_t *pgd_alloc_nomap(struct mm_struct *mm)
+{
+	pgd_t *pgd;
+
+	pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
+	if (likely(pgd != NULL))
+		memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
+
+	return pgd;
+}
+
+
 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 {
 	pgd_t *pgd;
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index eaea1f717010..d53ef48768ae 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -100,6 +100,10 @@
 
 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
+#define PAGE_KERNEL_READ	__pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
+#define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
+#define PAGE_KERNEL_READ_EXEC	__pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \
+					 | _PAGE_EXEC)
 
 #define PAGE_TABLE		__pgprot(_PAGE_TABLE)
 
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 6f7a3b3771fd..239c44c451b6 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -36,6 +36,7 @@ OBJCOPYFLAGS := --prefix-symbols=__efistub_
 $(obj)/%.stub.o: $(obj)/%.o FORCE
 	$(call if_changed,objcopy)
 
+obj-$(CONFIG_EFI)		+= efi.o
 obj-$(CONFIG_FPU)		+= fpu.o
 obj-$(CONFIG_SMP)		+= smpboot.o
 obj-$(CONFIG_SMP)		+= smp.o
diff --git a/arch/riscv/kernel/efi.c b/arch/riscv/kernel/efi.c
new file mode 100644
index 000000000000..d6c0b733f3d1
--- /dev/null
+++ b/arch/riscv/kernel/efi.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ * Adapted from arch/arm64/kernel/efi.c
+ */
+
+#include <linux/efi.h>
+#include <linux/init.h>
+
+#include <asm/efi.h>
+#include <asm/pgtable.h>
+#include <asm/pgtable-bits.h>
+
+/*
+ * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
+ * executable, everything else can be mapped with the XN bits
+ * set. Also take the new (optional) RO/XP bits into account.
+ */
+static __init pgprot_t efimem_to_pgprot_map(efi_memory_desc_t *md)
+{
+	u64 attr = md->attribute;
+	u32 type = md->type;
+
+	if (type == EFI_MEMORY_MAPPED_IO)
+		return PAGE_KERNEL;
+
+	if (WARN_ONCE(!PAGE_ALIGNED(md->phys_addr),
+		      "UEFI Runtime regions are not aligned to page size -- buggy firmware?"))
+		/*
+		 * If the region is not aligned to the page size of the OS, we
+		 * can not use strict permissions, since that would also affect
+		 * the mapping attributes of the adjacent regions.
+		 */
+		return PAGE_EXEC;
+
+	/* R-- */
+	if ((attr & (EFI_MEMORY_XP | EFI_MEMORY_RO)) ==
+	    (EFI_MEMORY_XP | EFI_MEMORY_RO))
+		return PAGE_KERNEL_READ;
+
+	/* R-X */
+	if (attr & EFI_MEMORY_RO)
+		return PAGE_KERNEL_READ_EXEC;
+
+	/* RW- */
+	if (((attr & (EFI_MEMORY_RP | EFI_MEMORY_WP | EFI_MEMORY_XP)) ==
+	     EFI_MEMORY_XP) ||
+	    type != EFI_RUNTIME_SERVICES_CODE)
+		return PAGE_KERNEL;
+
+	/* RWX */
+	return PAGE_KERNEL_EXEC;
+}
+
+int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
+{
+	pgprot_t prot = __pgprot(pgprot_val(efimem_to_pgprot_map(md)) &
+				~(_PAGE_GLOBAL));
+	int i;
+
+	/* RISC-V maps one page at a time */
+	for (i = 0; i <= md->num_pages; i++)
+		create_pgd_mapping(mm->pgd, md->virt_addr + i * PAGE_SIZE,
+				   md->phys_addr + i * PAGE_SIZE,
+				   PAGE_SIZE, prot);
+	return 0;
+}
+
+static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
+{
+	efi_memory_desc_t *md = data;
+	pte_t pte = READ_ONCE(*ptep);
+	unsigned long val;
+
+	if (md->attribute & EFI_MEMORY_RO) {
+		val = pte_val(pte) & ~_PAGE_WRITE;
+		val = pte_val(pte) | _PAGE_READ;
+		pte = __pte(val);
+	}
+	if (md->attribute & EFI_MEMORY_XP) {
+		val = pte_val(pte) & ~_PAGE_EXEC;
+		pte = __pte(val);
+	}
+	set_pte(ptep, pte);
+
+	return 0;
+}
+
+int __init efi_set_mapping_permissions(struct mm_struct *mm,
+				       efi_memory_desc_t *md)
+{
+	BUG_ON(md->type != EFI_RUNTIME_SERVICES_CODE &&
+	       md->type != EFI_RUNTIME_SERVICES_DATA);
+
+	/*
+	 * Calling apply_to_page_range() is only safe on regions that are
+	 * guaranteed to be mapped down to pages. Since we are only called
+	 * for regions that have been mapped using efi_create_mapping() above
+	 * (and this is checked by the generic Memory Attributes table parsing
+	 * routines), there is no need to check that again here.
+	 */
+	return apply_to_page_range(mm, md->virt_addr,
+				   md->num_pages << EFI_PAGE_SHIFT,
+				   set_permissions, md);
+}
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 1244b433fe7c..0a725bd8d73e 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -17,6 +17,7 @@
 #include <linux/sched/task.h>
 #include <linux/swiotlb.h>
 #include <linux/smp.h>
+#include <linux/efi.h>
 
 #include <asm/clint.h>
 #include <asm/cpu_ops.h>
@@ -26,11 +27,12 @@
 #include <asm/tlbflush.h>
 #include <asm/thread_info.h>
 #include <asm/kasan.h>
+#include <asm/efi.h>
 
 #include "head.h"
 
-#ifdef CONFIG_DUMMY_CONSOLE
-struct screen_info screen_info = {
+#if defined(CONFIG_DUMMY_CONSOLE) || defined(CONFIG_EFI)
+struct screen_info screen_info __section(.data) = {
 	.orig_video_lines	= 30,
 	.orig_video_cols	= 80,
 	.orig_video_mode	= 0,
@@ -75,6 +77,7 @@ void __init setup_arch(char **cmdline_p)
 	early_ioremap_setup();
 	parse_early_param();
 
+	efi_init();
 	setup_bootmem();
 	paging_init();
 	unflatten_and_copy_device_tree();
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index c5268fe6e6de..eab96ed24065 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -319,7 +319,7 @@ static void __init create_pmd_mapping(pmd_t *pmdp,
 #define fixmap_pgd_next		fixmap_pte
 #endif
 
-static void __init create_pgd_mapping(pgd_t *pgdp,
+void __init create_pgd_mapping(pgd_t *pgdp,
 				      uintptr_t va, phys_addr_t pa,
 				      phys_addr_t sz, pgprot_t prot)
 {
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 61fd1e8b26fb..4d628081bb2f 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -35,6 +35,8 @@ fake_map-$(CONFIG_X86)			+= x86_fake_mem.o
 arm-obj-$(CONFIG_EFI)			:= efi-init.o arm-runtime.o
 obj-$(CONFIG_ARM)			+= $(arm-obj-y)
 obj-$(CONFIG_ARM64)			+= $(arm-obj-y)
+riscv-obj-$(CONFIG_EFI)			:= efi-init.o riscv-runtime.o
+obj-$(CONFIG_RISCV)			+= $(riscv-obj-y)
 obj-$(CONFIG_EFI_CAPSULE_LOADER)	+= capsule-loader.o
 obj-$(CONFIG_EFI_EARLYCON)		+= earlycon.o
 obj-$(CONFIG_UEFI_CPER_ARM)		+= cper-arm.o
diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index a5a405d8ab44..5c26725d8fd0 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -17,7 +17,10 @@
 
 /*
  * This is the base address at which to start allocating virtual memory ranges
- * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
+ * for UEFI Runtime Services.
+ *
+ * For ARM/ARM64:
+ * This is in the low TTBR0 range so that we can use
  * any allocation we choose, and eliminate the risk of a conflict after kexec.
  * The value chosen is the largest non-zero power of 2 suitable for this purpose
  * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
@@ -25,6 +28,12 @@
  * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split,
  * map everything below 1 GB. (512 MB is a reasonable upper bound for the
  * entire footprint of the UEFI runtime services memory regions)
+ *
+ * For RISC-V:
+ * There is no specific reason for which, this address (512MB) can't be used
+ * EFI runtime virtual address for RISC-V. It also helps to use EFI runtime
+ * services on both RV32/RV64. Keep the same runtime virtual address for RISC-V
+ * as well to minimize the code churn.
  */
 #define EFI_RT_VIRTUAL_BASE	SZ_512M
 #define EFI_RT_VIRTUAL_SIZE	SZ_512M
diff --git a/drivers/firmware/efi/riscv-runtime.c b/drivers/firmware/efi/riscv-runtime.c
new file mode 100644
index 000000000000..3bc48a268f66
--- /dev/null
+++ b/drivers/firmware/efi/riscv-runtime.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Extensible Firmware Interface
+ *
+ * Based on Extensible Firmware Interface Specification version 2.4
+ *
+ * Copyright (C) 2013, 2014 Linaro Ltd.
+ */
+
+#include <linux/dmi.h>
+#include <linux/efi.h>
+#include <linux/io.h>
+#include <linux/memblock.h>
+#include <linux/mm_types.h>
+#include <linux/preempt.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/pgtable.h>
+
+#include <asm/cacheflush.h>
+#include <asm/efi.h>
+#include <asm/mmu.h>
+#include <asm/pgalloc.h>
+
+static bool __init efi_virtmap_init(void)
+{
+	efi_memory_desc_t *md;
+
+	efi_mm.pgd = pgd_alloc_nomap(&efi_mm);
+	mm_init_cpumask(&efi_mm);
+	init_new_context(NULL, &efi_mm);
+
+	for_each_efi_memory_desc(md) {
+		phys_addr_t phys = md->phys_addr;
+		int ret;
+
+		if (!(md->attribute & EFI_MEMORY_RUNTIME))
+			continue;
+		if (md->virt_addr == 0)
+			return false;
+
+		ret = efi_create_mapping(&efi_mm, md);
+		if (ret) {
+			pr_warn("  EFI remap %pa: failed to create mapping (%d)\n",
+				&phys, ret);
+			return false;
+		}
+	}
+
+	if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
+		return false;
+
+	return true;
+}
+
+/*
+ * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
+ * non-early mapping of the UEFI system table and virtual mappings for all
+ * EFI_MEMORY_RUNTIME regions.
+ */
+static int __init riscv_enable_runtime_services(void)
+{
+	u64 mapsize;
+
+	if (!efi_enabled(EFI_BOOT)) {
+		pr_info("EFI services will not be available.\n");
+		return 0;
+	}
+
+	efi_memmap_unmap();
+
+	mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
+
+	if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
+		pr_err("Failed to remap EFI memory map\n");
+		return 0;
+	}
+
+	if (efi_soft_reserve_enabled()) {
+		efi_memory_desc_t *md;
+
+		for_each_efi_memory_desc(md) {
+			int md_size = md->num_pages << EFI_PAGE_SHIFT;
+			struct resource *res;
+
+			if (!(md->attribute & EFI_MEMORY_SP))
+				continue;
+
+			res = kzalloc(sizeof(*res), GFP_KERNEL);
+			if (WARN_ON(!res))
+				break;
+
+			res->start	= md->phys_addr;
+			res->end	= md->phys_addr + md_size - 1;
+			res->name	= "Soft Reserved";
+			res->flags	= IORESOURCE_MEM;
+			res->desc	= IORES_DESC_SOFT_RESERVED;
+
+			insert_resource(&iomem_resource, res);
+		}
+	}
+
+	if (efi_runtime_disabled()) {
+		pr_info("EFI runtime services will be disabled.\n");
+		return 0;
+	}
+
+	if (efi_enabled(EFI_RUNTIME_SERVICES)) {
+		pr_info("EFI runtime services access via paravirt.\n");
+		return 0;
+	}
+
+	pr_info("Remapping and enabling EFI services.\n");
+
+	if (!efi_virtmap_init()) {
+		pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
+		return -ENOMEM;
+	}
+
+	/* Set up runtime services function pointers */
+	efi_native_runtime_setup();
+	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+
+	return 0;
+}
+early_initcall(riscv_enable_runtime_services);
+
+void efi_virtmap_load(void)
+{
+	preempt_disable();
+	switch_mm(&efi_mm, current->active_mm, NULL);
+}
+
+void efi_virtmap_unload(void)
+{
+	switch_mm(current->active_mm, &efi_mm, NULL);
+	preempt_enable();
+}
-- 
2.24.0

Re: [RFC PATCH v2 00/11] Add UEFI support for RISC-V

[Ard Biesheuvel]

On Mon, 6 Jul 2020 at 20:26, Atish Patra <atish.patra@wdc.com> wrote:
>
> This series adds UEFI support for RISC-V.
>
> Linux kernel: 5.8-rc4
> U-Boot: master
> OpenSBI: master
>
> Patch 1-6 are preparatory patches that fixes some of the geric efi and riscv issues.
>
> Patch 7-9 adds the efi stub support for RISC-V which was reviewed few months back.
> https://www.spinics.net/lists/linux-efi/msg19144.html
>
> Patch 10 just renames arm-init code so that it can be used across different
> architectures. Patch 11 adds the runtime services for RISC-V.
>
> The patches can also be found in following git repo.
> https://github.com/atishp04/linux/tree/uefi_riscv_5.9_v2
>
> The patches have been verified on Qemu using bootefi command in U-Boot for both
> RV32 and RV64.
>
> For RV32, maximum allocated memory should be 1G as RISC-V kernel can not map
> beyond 1G of physical memory for RV32.
>
> EDK2 can boot quite far into Linux with current series. Currently, we are seeing
> some traps from drivers (spi/network). At first glance, they don't seem to be
> caused by efi. I thought it is better to get some early feedback on the series
> while EDK2 issue is being debugged.
>
> That's why uefi runtime services are not actually well tested in RISC-V.
> Any suggestions to test the efi run time services are appreciated.
>
> Changes from v1->v2:
> 1. Removed patch 1 as it is already taken into efi-tree.
> 2. Fixed compilation issues with patch 9.
> 3. Moved few function prototype declaration to header file to keep kbuild happy.
>
> Changes from previous version:
> 1. Added full ioremap support.
> 2. Added efi runtime services support.
> 3. Fixes mm issues
>

Hi Atish,

This all looks reasonable to me, so I think we can merge this once you
can confirm that the runtime services actually work.

Could you explain how you are dealing with the memory map? Are memory
nodes in DT ignored entirely as they should be? What about memory
reservations?

In any case, I will take the first patch as a fix, so it should turn
up in mainline in 1~2 weeks.

Thanks,
Ard.

Re: [RFC PATCH v2 00/11] Add UEFI support for RISC-V

[Atish Patra]

On Mon, Jul 6, 2020 at 11:41 PM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Mon, 6 Jul 2020 at 20:26, Atish Patra <atish.patra@wdc.com> wrote:
> >
> > This series adds UEFI support for RISC-V.
> >
> > Linux kernel: 5.8-rc4
> > U-Boot: master
> > OpenSBI: master
> >
> > Patch 1-6 are preparatory patches that fixes some of the geric efi and riscv issues.
> >
> > Patch 7-9 adds the efi stub support for RISC-V which was reviewed few months back.
> > https://www.spinics.net/lists/linux-efi/msg19144.html
> >
> > Patch 10 just renames arm-init code so that it can be used across different
> > architectures. Patch 11 adds the runtime services for RISC-V.
> >
> > The patches can also be found in following git repo.
> > https://github.com/atishp04/linux/tree/uefi_riscv_5.9_v2
> >
> > The patches have been verified on Qemu using bootefi command in U-Boot for both
> > RV32 and RV64.
> >
> > For RV32, maximum allocated memory should be 1G as RISC-V kernel can not map
> > beyond 1G of physical memory for RV32.
> >
> > EDK2 can boot quite far into Linux with current series. Currently, we are seeing
> > some traps from drivers (spi/network). At first glance, they don't seem to be
> > caused by efi. I thought it is better to get some early feedback on the series
> > while EDK2 issue is being debugged.
> >
> > That's why uefi runtime services are not actually well tested in RISC-V.
> > Any suggestions to test the efi run time services are appreciated.
> >
> > Changes from v1->v2:
> > 1. Removed patch 1 as it is already taken into efi-tree.
> > 2. Fixed compilation issues with patch 9.
> > 3. Moved few function prototype declaration to header file to keep kbuild happy.
> >
> > Changes from previous version:
> > 1. Added full ioremap support.
> > 2. Added efi runtime services support.
> > 3. Fixes mm issues
> >
>
> Hi Atish,
>
> This all looks reasonable to me, so I think we can merge this once you
> can confirm that the runtime services actually work.
>

Blibbet pointed me towards the Firmware Test Suite (FWTS). I will try
to use that to verify basic runtime services
in addition to EDK2 testing (Abner is debugging that).

> Could you explain how you are dealing with the memory map? Are memory
> nodes in DT ignored entirely as they should be?

Yes. That is handled by the generic code (patch 10 renames arm-init to
efi-init) in the following path.
setup_arch->efi_init->reserve_regions()

What about memory
> reservations?
>

I added patches in U-Boot that parses the /reserved-memory nodes from
DT and add it to the efi reserved mappings.
As a result, Linux kernel takes care of memory reservations as per the
reserved memory regions present in efi memory map.
I am expecting EDK2 already does that as well.

Here is the relevant boot log:
----------------------------------------------------------------------------------------------------------------------
[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000

[    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')

[    0.000000] printk: bootconsole [sbi0] enabled

[    0.000000] efi: Getting UEFI parameters from /chosen in DT:

[    0.000000] efi:   System Table         : 0x00000000bff61528

[    0.000000] efi:   MemMap Address       : 0x00000000bd46e020

[    0.000000] efi:   MemMap Size          : 0x00000000000002d0

[    0.000000] efi:   MemMap Desc. Size    : 0x0000000000000028

[    0.000000] efi:   MemMap Desc. Version : 0x0000000000000001

[    0.000000] efi: EFI v2.80 by Das U-Boot

[    0.000000] efi: RTPROP=0xbe73c020 SMBIOS=0xbe736000 MEMRESERVE=0xbd671020

[    0.000000] memblock_reserve:
[0x00000000bd671020-0x00000000bd67102f]
efi_config_parse_tables+0x192/0x1e6

[    0.000000] efi: Processing EFI memory map:

[    0.000000] MEMBLOCK configuration:

[    0.000000]  memory size = 0x000000003fe00000 reserved size =
0x0000000000000010

[    0.000000]  memory.cnt  = 0x1

[    0.000000]  memory[0x0] [0x0000000080200000-0x00000000bfffffff],
0x000000003fe00000 bytes flags: 0x0

[    0.000000]  reserved.cnt  = 0x1

[    0.000000]  reserved[0x0] [0x00000000bd671020-0x00000000bd67102f],
0x0000000000000010 bytes flags: 0x0

[    0.000000] memblock_remove:
[0x0000000000000000-0xfffffffffffffffe] reserve_regions+0x56/0x134

[    0.000000] efi:   0x000080000000-0x00008003ffff [Reserved
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] OF: fdt: Ignoring memory block 0x80000000 - 0x80040000

[    0.000000] efi:   0x000080040000-0x0000801fffff [Conventional
Memory|   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] OF: fdt: Ignoring memory range 0x80040000 - 0x80200000

[    0.000000] memblock_add: [0x0000000080200000-0x00000000801fffff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x000080200000-0x0000812befff [Loader Data
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x0000000080200000-0x00000000812befff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000812bf000-0x000087efffff [Conventional
Memory|   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000812bf000-0x0000000087efffff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x000087f00000-0x000087f04fff [ACPI Reclaim
Memory|   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x0000000087f00000-0x0000000087f04fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] memblock_reserve:
[0x0000000087f00000-0x0000000087f04fff] reserve_regions+0x110/0x134

[    0.000000] efi:   0x000087f05000-0x0000bd46dfff [Conventional
Memory|   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x0000000087f05000-0x00000000bd46dfff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000bd46e000-0x0000bd672fff [Loader Data
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000bd46e000-0x00000000bd672fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000bd673000-0x0000be731fff [Loader Code
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000bd673000-0x00000000be731fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000be732000-0x0000be734fff [Reserved
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000be732000-0x00000000be734fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000be735000-0x0000be735fff [Boot Data
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000be735000-0x00000000be735fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000be736000-0x0000be736fff [Runtime Data
 |RUN|  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000be736000-0x00000000be736fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000be737000-0x0000be738fff [Boot Data
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000be737000-0x00000000be738fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000be739000-0x0000be739fff [Reserved
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000be739000-0x00000000be739fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000be73a000-0x0000be73bfff [Boot Data
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000be73a000-0x00000000be73bfff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000be73c000-0x0000be73dfff [Runtime Data
 |RUN|  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000be73c000-0x00000000be73dfff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000be73e000-0x0000bff60fff [Loader Data
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000be73e000-0x00000000bff60fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000bff61000-0x0000bff61fff [Runtime Code
 |RUN|  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000bff61000-0x00000000bff61fff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] efi:   0x0000bff62000-0x0000bfffffff [Loader Data
 |   |  |  |  |  |  |  |  |   |WB|  |  |  ]

[    0.000000] memblock_add: [0x00000000bff62000-0x00000000bfffffff]
early_init_dt_add_memory_arch+0xac/0xbc

[    0.000000] memblock_reserve:
[0x00000000bd46e000-0x00000000bd46efff] efi_init+0x132/0x1e6

[    0.000000] memblock_reserve:
[0x0000000080200000-0x00000000812befff] setup_bootmem+0x98/0x1d0

[    0.000000] initrd not found or empty - disabling initrd

[    0.000000] memblock_reserve:
[0x0000000080233000-0x00000000802348f7]
early_init_dt_reserve_memory_arch+0x14/0x1c

[    0.000000] memblock_reserve:
[0x0000000080000000-0x000000008003ffff]
early_init_dt_reserve_memory_arch+0x14/0x1c

[    0.000000] MEMBLOCK configuration:

[    0.000000]  memory size = 0x000000003fe00000 reserved size =
0x0000000001105010

[    0.000000]  memory.cnt  = 0xb

[    0.000000]  memory[0x0] [0x0000000080200000-0x00000000be731fff],
0x000000003e532000 bytes flags: 0x0

[    0.000000]  memory[0x1] [0x00000000be732000-0x00000000be734fff],
0x0000000000003000 bytes flags: 0x4

[    0.000000]  memory[0x2] [0x00000000be735000-0x00000000be735fff],
0x0000000000001000 bytes flags: 0x0

[    0.000000]  memory[0x3] [0x00000000be736000-0x00000000be736fff],
0x0000000000001000 bytes flags: 0x4

[    0.000000]  memory[0x4] [0x00000000be737000-0x00000000be738fff],
0x0000000000002000 bytes flags: 0x0

[    0.000000]  memory[0x5] [0x00000000be739000-0x00000000be739fff],
0x0000000000001000 bytes flags: 0x4

[    0.000000]  memory[0x6] [0x00000000be73a000-0x00000000be73bfff],
0x0000000000002000 bytes flags: 0x0

[    0.000000]  memory[0x7] [0x00000000be73c000-0x00000000be73dfff],
0x0000000000002000 bytes flags: 0x4

[    0.000000]  memory[0x8] [0x00000000be73e000-0x00000000bff60fff],
0x0000000001823000 bytes flags: 0x0

[    0.000000]  memory[0x9] [0x00000000bff61000-0x00000000bff61fff],
0x0000000000001000 bytes flags: 0x4

[    0.000000]  memory[0xa] [0x00000000bff62000-0x00000000bfffffff],
0x000000000009e000 bytes flags: 0x0

[    0.000000]  reserved.cnt  = 0x5

[    0.000000]  reserved[0x0] [0x0000000080000000-0x000000008003ffff],
0x0000000000040000 bytes flags: 0x0

[    0.000000]  reserved[0x1] [0x0000000080200000-0x00000000812befff],
0x00000000010bf000 bytes flags: 0x0

[    0.000000]  reserved[0x2] [0x0000000087f00000-0x0000000087f04fff],
0x0000000000005000 bytes flags: 0x0

[    0.000000]  reserved[0x3] [0x00000000bd46e000-0x00000000bd46efff],
0x0000000000001000 bytes flags: 0x0

[    0.000000]  reserved[0x4] [0x00000000bd671020-0x00000000bd67102f],
0x0000000000000010 bytes flags: 0x0

----------------------------------------------------------------------------------------------------------------------

Here is the detailed boot log.

https://pastebin.com/4LE2SY4c

> In any case, I will take the first patch as a fix, so it should turn
> up in mainline in 1~2 weeks.
>
Thanks.

> Thanks,
> Ard.



-- 
Regards,
Atish

[tip: efi/urgent] efi/libstub: Move the function prototypes to header file

[tip-bot2 for Atish Patra]

The following commit has been merged into the efi/urgent branch of tip:

Commit-ID:     3230d95cea0515a6acf3f5ff360663de4c40fd07
Gitweb:        https://git.kernel.org/tip/3230d95cea0515a6acf3f5ff360663de4c40fd07
Author:        Atish Patra <atish.patra@wdc.com>
AuthorDate:    Mon, 06 Jul 2020 10:25:59 -07:00
Committer:     Ard Biesheuvel <ardb@kernel.org>
CommitterDate: Thu, 09 Jul 2020 09:45:09 +03:00

efi/libstub: Move the function prototypes to header file

The prototype of the functions handle_kernel_image & efi_enter_kernel
are defined in efi-stub.c which may result in a compiler warnings if
-Wmissing-prototypes is set in gcc compiler.

Move the prototype to efistub.h to make the compiler happy.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20200706172609.25965-2-atish.patra@wdc.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/libstub/efi-stub.c | 17 -----------------
 drivers/firmware/efi/libstub/efistub.h  | 16 ++++++++++++++++
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 3318ec3..a5a405d 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -122,23 +122,6 @@ static unsigned long get_dram_base(void)
 }
 
 /*
- * This function handles the architcture specific differences between arm and
- * arm64 regarding where the kernel image must be loaded and any memory that
- * must be reserved. On failure it is required to free all
- * all allocations it has made.
- */
-efi_status_t handle_kernel_image(unsigned long *image_addr,
-				 unsigned long *image_size,
-				 unsigned long *reserve_addr,
-				 unsigned long *reserve_size,
-				 unsigned long dram_base,
-				 efi_loaded_image_t *image);
-
-asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
-					    unsigned long fdt_addr,
-					    unsigned long fdt_size);
-
-/*
  * EFI entry point for the arm/arm64 EFI stubs.  This is the entrypoint
  * that is described in the PE/COFF header.  Most of the code is the same
  * for both archictectures, with the arch-specific code provided in the
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 2c9d422..85050f5 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -776,6 +776,22 @@ efi_status_t efi_load_initrd(efi_loaded_image_t *image,
 			     unsigned long *load_size,
 			     unsigned long soft_limit,
 			     unsigned long hard_limit);
+/*
+ * This function handles the architcture specific differences between arm and
+ * arm64 regarding where the kernel image must be loaded and any memory that
+ * must be reserved. On failure it is required to free all
+ * all allocations it has made.
+ */
+efi_status_t handle_kernel_image(unsigned long *image_addr,
+				 unsigned long *image_size,
+				 unsigned long *reserve_addr,
+				 unsigned long *reserve_size,
+				 unsigned long dram_base,
+				 efi_loaded_image_t *image);
+
+asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
+					    unsigned long fdt_addr,
+					    unsigned long fdt_size);
 
 void efi_handle_post_ebs_state(void);