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* [RFT PATCH v3 0/9] Add UEFI support for RISC-V
@ 2020-07-16 23:40 Atish Patra
  2020-07-16 23:40 ` [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap Atish Patra
                   ` (8 more replies)
  0 siblings, 9 replies; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:40 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

This series adds UEFI support for RISC-V.

Linux kernel: 5.8-rc5 + "mm & exception handing fixes" series
U-Boot: master
OpenSBI: master

This series depends on earlier mm fixes series

http://lists.infradead.org/pipermail/linux-riscv/2020-July/001208.html

Patch 1-3 are generic riscv feature addition required for UEFI support.
Patch 4-7 adds the efi stub support for RISC-V which was reviewed few months back.
https://www.spinics.net/lists/linux-efi/msg19144.html
Patch 8 just renames arm-init code so that it can be used across different
architectures. Patch 11 adds the runtime services for RISC-V.

The working set of patches can also be found in following git repo.
https://github.com/atishp04/linux/tree/uefi_riscv_5.9_v3

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.

Runtime services have been verified with fwts. Here is the snippet of the result.

***********************************************************************
This test run on 16/07/20 at 17:54:53 on host Linux fedora-riscv
5.8.0-rc5-00015-g5e61441080fd-dirty #938 SMP Thu Jul 16 14:50:11 PDT 2020
riscv64.

Command: "fwts uefirtvariable".
Running tests: uefirtvariable.

uefirtvariable: UEFI Runtime service variable interface tests.
Test 1 of 9: Test UEFI RT service get variable interface.
SKIPPED: Test 1, Skipping test, SetVariable runtime service is not supported on
this platform.

Test 2 of 9: Test UEFI RT service get next variable name interface.
The runtime service GetNextVariableName interface function test.
SKIPPED: Test 2, Skipping test, SetVariable runtime service is not supported on
this platform.

...

Test 4 of 9: Test UEFI RT service query variable info interface.
SKIPPED: Test 4, Not support the QueryVariableInfo UEFI runtime interface:
cannot test.

ADVICE: Firmware also needs to check if the revision of system table is correct
or not. Linux kernel returns EFI_UNSUPPORTED as well, if the FirmwareRevision of
system table is less than EFI_2_00_SYSTEM_TABLE_REVISION.

...
***********************************************************************

Currently, U-Boot EFI implementation returns EFI_UNSUPPORTED for set_variable
service. That's why all tests have been skipped but I manually verified the value
returned from U-Boot not kernel :).

Changes from v2->v3:
1. Fixed few bugs in run time services page table mapping.
2. Dropped patch 1 as it is already taken into efi-tree.
3. Sent few generic mmu fixes as a separate series to ease the merge conflicts.

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 (8):
RISC-V: Add early ioremap support
RISC-V: Implement late mapping page table allocation functions
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
RISC-V: Add page table dump support for uefi

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/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                       | 105 +++++++++++++
arch/riscv/kernel/head.S                      |  17 ++-
arch/riscv/kernel/head.h                      |   2 -
arch/riscv/kernel/image-vars.h                |  51 +++++++
arch/riscv/kernel/setup.c                     |  16 +-
arch/riscv/kernel/vmlinux.lds.S               |  22 ++-
arch/riscv/mm/init.c                          | 100 ++++++++----
arch/riscv/mm/ptdump.c                        |  48 +++++-
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       |  11 +-
drivers/firmware/efi/libstub/riscv-stub.c     | 110 ++++++++++++++
drivers/firmware/efi/riscv-runtime.c          | 143 ++++++++++++++++++
include/linux/pe.h                            |   3 +
28 files changed, 823 insertions(+), 51 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


_______________________________________________
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

^ permalink raw reply	[flat|nested] 17+ messages in thread

* [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap
  2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
@ 2020-07-16 23:40 ` Atish Patra
  2020-07-17  6:32   ` Arnd Bergmann
  2020-07-16 23:40 ` [RFT PATCH v3 2/9] RISC-V: Add early ioremap support Atish Patra
                   ` (7 subsequent siblings)
  8 siblings, 1 reply; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:40 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

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 d0c5c316e9bb..eb123eda3663 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -250,7 +250,6 @@ 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 79e9d55bdf1a..5e9328fa635b 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)
 {
@@ -141,8 +140,6 @@ 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;
@@ -182,13 +179,9 @@ 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();
 
@@ -208,6 +201,10 @@ 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;
@@ -399,7 +396,8 @@ 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);
@@ -448,17 +446,11 @@ 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)
@@ -505,6 +497,8 @@ 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


_______________________________________________
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

^ permalink raw reply	[flat|nested] 17+ messages in thread

* [RFT PATCH v3 2/9] RISC-V: Add early ioremap support
  2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
  2020-07-16 23:40 ` [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap Atish Patra
@ 2020-07-16 23:40 ` Atish Patra
  2020-07-16 23:40 ` [RFT PATCH v3 3/9] RISC-V: Implement late mapping page table allocation functions Atish Patra
                   ` (6 subsequent siblings)
  8 siblings, 0 replies; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:40 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

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 3230c1d48562..e6c1c98a53fb 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -34,6 +34,7 @@ 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 5e9328fa635b..62c90161765f 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -401,6 +401,9 @@ 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);
@@ -451,6 +454,36 @@ 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


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^ permalink raw reply	[flat|nested] 17+ messages in thread

* [RFT PATCH v3 3/9] RISC-V: Implement late mapping page table allocation functions
  2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
  2020-07-16 23:40 ` [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap Atish Patra
  2020-07-16 23:40 ` [RFT PATCH v3 2/9] RISC-V: Add early ioremap support Atish Patra
@ 2020-07-16 23:40 ` Atish Patra
  2020-07-16 23:40 ` [RFT PATCH v3 4/9] include: pe.h: Add RISC-V related PE definition Atish Patra
                   ` (5 subsequent siblings)
  8 siblings, 0 replies; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:40 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

Currently, page table setup is done during setup_va_final where fixmap can
be used to create the temporary mappings. The physical frame is allocated
from memblock_alloc_* functions. However, this won't work if page table
mapping needs to be created for a different mm context (i.e. efi mm) at
a later point of time.

Use generic kernel page allocation function & macros for any mapping
after setup_vm_final.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/mm/init.c | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 62c90161765f..9f3129c76985 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -209,6 +209,7 @@ 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;
 static bool mmu_enabled;
+static bool late_mapping;
 
 #define MAX_EARLY_MAPPING_SIZE	SZ_128M
 
@@ -233,7 +234,9 @@ void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
 
 static pte_t *__init get_pte_virt(phys_addr_t pa)
 {
-	if (mmu_enabled) {
+	if (late_mapping)
+		return (pte_t *) __va(pa);
+	else if (mmu_enabled) {
 		clear_fixmap(FIX_PTE);
 		return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
 	} else {
@@ -243,13 +246,19 @@ static pte_t *__init get_pte_virt(phys_addr_t pa)
 
 static phys_addr_t __init alloc_pte(uintptr_t va)
 {
+	unsigned long vaddr;
 	/*
 	 * We only create PMD or PGD early mappings so we
 	 * should never reach here with MMU disabled.
 	 */
 	BUG_ON(!mmu_enabled);
-
-	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+	if (late_mapping) {
+		vaddr = __get_free_page(GFP_KERNEL);
+		if (!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)))
+			BUG();
+		return __pa(vaddr);
+	} else
+		return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
 }
 
 static void __init create_pte_mapping(pte_t *ptep,
@@ -278,7 +287,9 @@ pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
 
 static pmd_t *__init get_pmd_virt(phys_addr_t pa)
 {
-	if (mmu_enabled) {
+	if (late_mapping)
+		return (pmd_t *) __va(pa);
+	else if (mmu_enabled) {
 		clear_fixmap(FIX_PMD);
 		return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
 	} else {
@@ -289,8 +300,13 @@ static pmd_t *__init get_pmd_virt(phys_addr_t pa)
 static phys_addr_t __init alloc_pmd(uintptr_t va)
 {
 	uintptr_t pmd_num;
+	unsigned long vaddr;
 
-	if (mmu_enabled)
+	if (late_mapping) {
+		vaddr = __get_free_page(GFP_KERNEL);
+		BUG_ON(!vaddr);
+		return __pa(vaddr);
+	} else if (mmu_enabled)
 		return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
 
 	pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
@@ -528,6 +544,9 @@ static void __init setup_vm_final(void)
 	/* Move to swapper page table */
 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
 	local_flush_tlb_all();
+
+	/* generic page allocation function must be used to setup page table */
+	late_mapping = true;
 }
 #else
 void *dtb_early_va __initdata;
-- 
2.24.0


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^ permalink raw reply	[flat|nested] 17+ messages in thread

* [RFT PATCH v3 4/9] include: pe.h: Add RISC-V related PE definition
  2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
                   ` (2 preceding siblings ...)
  2020-07-16 23:40 ` [RFT PATCH v3 3/9] RISC-V: Implement late mapping page table allocation functions Atish Patra
@ 2020-07-16 23:40 ` Atish Patra
  2020-07-16 23:41 ` [RFT PATCH v3 5/9] RISC-V: Add PE/COFF header for EFI stub Atish Patra
                   ` (4 subsequent siblings)
  8 siblings, 0 replies; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:40 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, Palmer Dabbelt, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, linux-efi, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

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


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http://lists.infradead.org/mailman/listinfo/linux-riscv

^ permalink raw reply	[flat|nested] 17+ messages in thread

* [RFT PATCH v3 5/9] RISC-V: Add PE/COFF header for EFI stub
  2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
                   ` (3 preceding siblings ...)
  2020-07-16 23:40 ` [RFT PATCH v3 4/9] include: pe.h: Add RISC-V related PE definition Atish Patra
@ 2020-07-16 23:41 ` Atish Patra
  2020-07-16 23:41 ` [RFT PATCH v3 6/9] RISC-V: Add EFI stub support Atish Patra
                   ` (3 subsequent siblings)
  8 siblings, 0 replies; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:41 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

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


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^ permalink raw reply	[flat|nested] 17+ messages in thread

* [RFT PATCH v3 6/9] RISC-V: Add EFI stub support.
  2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
                   ` (4 preceding siblings ...)
  2020-07-16 23:41 ` [RFT PATCH v3 5/9] RISC-V: Add PE/COFF header for EFI stub Atish Patra
@ 2020-07-16 23:41 ` Atish Patra
  2020-07-16 23:41 ` [RFT PATCH v3 7/9] efi: Rename arm-init to efi-init common for all arch Atish Patra
                   ` (2 subsequent siblings)
  8 siblings, 0 replies; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:41 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

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 e6c1c98a53fb..a6569c268565 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -390,6 +390,26 @@ 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
@@ -402,3 +422,5 @@ 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


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

^ permalink raw reply	[flat|nested] 17+ messages in thread

* [RFT PATCH v3 7/9] efi: Rename arm-init to efi-init common for all arch
  2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
                   ` (5 preceding siblings ...)
  2020-07-16 23:41 ` [RFT PATCH v3 6/9] RISC-V: Add EFI stub support Atish Patra
@ 2020-07-16 23:41 ` Atish Patra
  2020-07-16 23:41 ` [RFT PATCH v3 8/9] RISC-V: Add EFI runtime services Atish Patra
  2020-07-16 23:41 ` [RFT PATCH v3 9/9] RISC-V: Add page table dump support for uefi Atish Patra
  8 siblings, 0 replies; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:41 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

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


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

^ permalink raw reply	[flat|nested] 17+ messages in thread

* [RFT PATCH v3 8/9] RISC-V: Add EFI runtime services
  2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
                   ` (6 preceding siblings ...)
  2020-07-16 23:41 ` [RFT PATCH v3 7/9] efi: Rename arm-init to efi-init common for all arch Atish Patra
@ 2020-07-16 23:41 ` Atish Patra
  2020-07-16 23:41 ` [RFT PATCH v3 9/9] RISC-V: Add page table dump support for uefi Atish Patra
  8 siblings, 0 replies; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:41 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

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/pgtable.h        |   4 +
 arch/riscv/kernel/Makefile              |   1 +
 arch/riscv/kernel/efi.c                 | 105 +++++++++++++++++
 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    | 143 ++++++++++++++++++++++++
 11 files changed, 295 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 a6569c268565..4858b19fe3a4 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -401,7 +401,9 @@ 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/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..d7a723b446c3
--- /dev/null
+++ b/arch/riscv/kernel/efi.c
@@ -0,0 +1,105 @@
+// 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 9f3129c76985..2947cff5e88a 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -356,7 +356,7 @@ 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 3318ec3f8e5b..6f9559a54cb3 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..d28e715d2bcc
--- /dev/null
+++ b/drivers/firmware/efi/riscv-runtime.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Extensible Firmware Interface
+ *
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Based on Extensible Firmware Interface Specification version 2.4
+ * Adapted from drivers/firmware/efi/arm-runtime.c
+ *
+ */
+
+#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(&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(current->active_mm, &efi_mm, NULL);
+}
+
+void efi_virtmap_unload(void)
+{
+	switch_mm(&efi_mm, current->active_mm, NULL);
+	preempt_enable();
+}
-- 
2.24.0


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^ permalink raw reply	[flat|nested] 17+ messages in thread

* [RFT PATCH v3 9/9] RISC-V: Add page table dump support for uefi
  2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
                   ` (7 preceding siblings ...)
  2020-07-16 23:41 ` [RFT PATCH v3 8/9] RISC-V: Add EFI runtime services Atish Patra
@ 2020-07-16 23:41 ` Atish Patra
  8 siblings, 0 replies; 17+ messages in thread
From: Atish Patra @ 2020-07-16 23:41 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann,
	Heinrich Schuchardt, Masahiro Yamada, Anup Patel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	linux-arm-kernel

Extend the current page table dump support in RISC-V to include efi
pages as well.

Here is the output of efi runtime page table mappings.

---[ UEFI runtime start ]---
0x0000000020002000-0x0000000020003000 0x00000000be732000 4K PTE D A . . . W R V
0x0000000020018000-0x0000000020019000 0x00000000be738000 4K PTE D A . . . W R V
0x000000002002c000-0x000000002002d000 0x00000000be73c000 4K PTE D A . . . W R V
0x0000000020031000-0x0000000020032000 0x00000000bff61000 4K PTE D A . . X W R V
---[ UEFI runtime end ]---

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/mm/ptdump.c | 48 ++++++++++++++++++++++++++++++++++++------
 1 file changed, 42 insertions(+), 6 deletions(-)

diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
index 0831c2e61a8f..ace74dec7492 100644
--- a/arch/riscv/mm/ptdump.c
+++ b/arch/riscv/mm/ptdump.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2019 SiFive
  */
 
+#include <linux/efi.h>
 #include <linux/init.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
@@ -49,6 +50,14 @@ struct addr_marker {
 	const char *name;
 };
 
+/* Private information for debugfs */
+struct ptd_mm_info {
+	struct mm_struct		*mm;
+	const struct addr_marker	*markers;
+	unsigned long base_addr;
+	unsigned long end;
+};
+
 static struct addr_marker address_markers[] = {
 #ifdef CONFIG_KASAN
 	{KASAN_SHADOW_START,	"Kasan shadow start"},
@@ -68,6 +77,28 @@ static struct addr_marker address_markers[] = {
 	{-1, NULL},
 };
 
+static struct ptd_mm_info kernel_ptd_info = {
+	.mm		= &init_mm,
+	.markers	= address_markers,
+	.base_addr	= KERN_VIRT_START,
+	.end		= ULONG_MAX,
+};
+
+#ifdef CONFIG_EFI
+static struct addr_marker efi_addr_markers[] = {
+		{ 0,		"UEFI runtime start" },
+		{ SZ_1G,	"UEFI runtime end" },
+		{ -1,		NULL }
+};
+
+static struct ptd_mm_info efi_ptd_info = {
+	.mm		= &efi_mm,
+	.markers	= efi_addr_markers,
+	.base_addr	= 0,
+	.end		= SZ_2G,
+};
+#endif
+
 /* Page Table Entry */
 struct prot_bits {
 	u64 mask;
@@ -245,22 +276,22 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr,
 	}
 }
 
-static void ptdump_walk(struct seq_file *s)
+static void ptdump_walk(struct seq_file *s, struct ptd_mm_info *pinfo)
 {
 	struct pg_state st = {
 		.seq = s,
-		.marker = address_markers,
+		.marker = pinfo->markers,
 		.level = -1,
 		.ptdump = {
 			.note_page = note_page,
 			.range = (struct ptdump_range[]) {
-				{KERN_VIRT_START, ULONG_MAX},
+				{pinfo->base_addr, pinfo->end},
 				{0, 0}
 			}
 		}
 	};
 
-	ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
+	ptdump_walk_pgd(&st.ptdump, pinfo->mm, NULL);
 }
 
 void ptdump_check_wx(void)
@@ -293,7 +324,7 @@ void ptdump_check_wx(void)
 
 static int ptdump_show(struct seq_file *m, void *v)
 {
-	ptdump_walk(m);
+	ptdump_walk(m, m->private);
 
 	return 0;
 }
@@ -308,8 +339,13 @@ static int ptdump_init(void)
 		for (j = 0; j < ARRAY_SIZE(pte_bits); j++)
 			pg_level[i].mask |= pte_bits[j].mask;
 
-	debugfs_create_file("kernel_page_tables", 0400, NULL, NULL,
+	debugfs_create_file("kernel_page_tables", 0400, NULL, &kernel_ptd_info,
 			    &ptdump_fops);
+#ifdef CONFIG_EFI
+	if (efi_enabled(EFI_RUNTIME_SERVICES))
+		debugfs_create_file("efi_page_tables", 0400, NULL, &efi_ptd_info,
+				    &ptdump_fops);
+#endif
 
 	return 0;
 }
-- 
2.24.0


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^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap
  2020-07-16 23:40 ` [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap Atish Patra
@ 2020-07-17  6:32   ` Arnd Bergmann
  2020-07-18  1:05     ` Atish Patra
  0 siblings, 1 reply; 17+ messages in thread
From: Arnd Bergmann @ 2020-07-17  6:32 UTC (permalink / raw)
  To: Atish Patra
  Cc: Mark Rutland, linux-efi, Kees Cook, Heinrich Schuchardt,
	Masahiro Yamada, Anup Patel, linux-kernel, Mike Rapoport,
	Palmer Dabbelt, Zong Li, Paul Walmsley, Greentime Hu,
	linux-riscv, Will Deacon, Ard Biesheuvel, Linux ARM

On Fri, Jul 17, 2020 at 1:41 AM Atish Patra <atish.patra@wdc.com> wrote:
>
> 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>

The patch seems fine for the moment, but I have one concern for the
long run:

> +#define DTB_EARLY_SIZE         SZ_1M
> +static char early_dtb[DTB_EARLY_SIZE] __initdata;

Hardcoding the size in .bss seems slightly problematic both for
small and for big systems. On machines with very little memory,
this can lead to running out of free pages before .initdata gets freed,
and it increases the size of the uncompressed vmlinux file by quite
a bit.

On some systems, the 1MB limit may get too small. While most dtbs
would fall into the range between 10KB and 100KB, it can also be
much larger than that, e.g. when there are DT properties that include
blobs like device firmware that gets loaded into hardware by a kernel
driver.

Is there anything stopping you from parsing the FDT in its original
location without the extra copy before it gets unflattened?

       Arnd

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^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap
  2020-07-17  6:32   ` Arnd Bergmann
@ 2020-07-18  1:05     ` Atish Patra
  2020-07-18  9:24       ` Arnd Bergmann
  0 siblings, 1 reply; 17+ messages in thread
From: Atish Patra @ 2020-07-18  1:05 UTC (permalink / raw)
  To: Arnd Bergmann
  Cc: Mark Rutland, linux-efi, Kees Cook, Heinrich Schuchardt,
	Masahiro Yamada, Anup Patel, linux-kernel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	Linux ARM

On Thu, Jul 16, 2020 at 11:32 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Fri, Jul 17, 2020 at 1:41 AM Atish Patra <atish.patra@wdc.com> wrote:
> >
> > 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>
>
> The patch seems fine for the moment, but I have one concern for the
> long run:
>
> > +#define DTB_EARLY_SIZE         SZ_1M
> > +static char early_dtb[DTB_EARLY_SIZE] __initdata;
>
> Hardcoding the size in .bss seems slightly problematic both for
> small and for big systems. On machines with very little memory,
> this can lead to running out of free pages before .initdata gets freed,
> and it increases the size of the uncompressed vmlinux file by quite
> a bit.
>
> On some systems, the 1MB limit may get too small. While most dtbs
> would fall into the range between 10KB and 100KB, it can also be
> much larger than that, e.g. when there are DT properties that include
> blobs like device firmware that gets loaded into hardware by a kernel
> driver.
>
I was not aware that we can do such things. Is there a current example of that ?

> Is there anything stopping you from parsing the FDT in its original
> location without the extra copy before it gets unflattened?
>

That's what the original code was doing. A fixmap entry was added to
map the original fdt
location to a virtual so that parse_dtb can be operated on a virtual
address. But we can't map
both FDT & early ioremap within a single PMD region( 2MB ). That's why
we removed the DT
mapping from the fixmap to .bss section. The other alternate option is
to increase the fixmap space to
4MB which seems more fragile.

>        Arnd



-- 
Regards,
Atish

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^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap
  2020-07-18  1:05     ` Atish Patra
@ 2020-07-18  9:24       ` Arnd Bergmann
  2020-07-21  4:18         ` Atish Patra
  0 siblings, 1 reply; 17+ messages in thread
From: Arnd Bergmann @ 2020-07-18  9:24 UTC (permalink / raw)
  To: Atish Patra
  Cc: Mark Rutland, linux-efi, Kees Cook, Heinrich Schuchardt,
	Masahiro Yamada, Anup Patel, linux-kernel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	Linux ARM

On Sat, Jul 18, 2020 at 3:05 AM Atish Patra <atishp@atishpatra.org> wrote:
> On Thu, Jul 16, 2020 at 11:32 PM Arnd Bergmann <arnd@arndb.de> wrote:
> > On Fri, Jul 17, 2020 at 1:41 AM Atish Patra <atish.patra@wdc.com> wrote:
> > > +#define DTB_EARLY_SIZE         SZ_1M
> > > +static char early_dtb[DTB_EARLY_SIZE] __initdata;
> >
> > Hardcoding the size in .bss seems slightly problematic both for
> > small and for big systems. On machines with very little memory,
> > this can lead to running out of free pages before .initdata gets freed,
> > and it increases the size of the uncompressed vmlinux file by quite
> > a bit.
> >
> > On some systems, the 1MB limit may get too small. While most dtbs
> > would fall into the range between 10KB and 100KB, it can also be
> > much larger than that, e.g. when there are DT properties that include
> > blobs like device firmware that gets loaded into hardware by a kernel
> > driver.
> >
> I was not aware that we can do such things. Is there a current example of that ?

I worked on a product in the distant past where the host firmware
included the ethernet controller firmware as a DT property[1] to get around
restrictions on redistributing the blob in the linux-firmware package.

For the .dts files we distribute with the kernel, that would not make
sense, and I don't know of any current machines that do this in their
system firmware.

> > Is there anything stopping you from parsing the FDT in its original
> > location without the extra copy before it gets unflattened?
>
> That's what the original code was doing. A fixmap entry was added to
> map the original fdt
> location to a virtual so that parse_dtb can be operated on a virtual
> address. But we can't map
> both FDT & early ioremap within a single PMD region( 2MB ). That's why
> we removed the DT
> mapping from the fixmap to .bss section. The other alternate option is
> to increase the fixmap space to 4MB which seems more fragile.

Could the original location just be part of the regular linear mapping of all
RAM? I'm not too familiar with the early mapping code myself, so it may not
be possible, but that would be the most logical place where I'd put it.

        Arnd

[1] drivers/net/ethernet/toshiba/spider_net.c

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^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap
  2020-07-18  9:24       ` Arnd Bergmann
@ 2020-07-21  4:18         ` Atish Patra
  2020-07-21  8:57           ` Arnd Bergmann
  0 siblings, 1 reply; 17+ messages in thread
From: Atish Patra @ 2020-07-21  4:18 UTC (permalink / raw)
  To: Arnd Bergmann
  Cc: Mark Rutland, linux-efi, Kees Cook, Heinrich Schuchardt,
	Masahiro Yamada, Anup Patel, linux-kernel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	Linux ARM

On Sat, Jul 18, 2020 at 2:24 AM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Sat, Jul 18, 2020 at 3:05 AM Atish Patra <atishp@atishpatra.org> wrote:
> > On Thu, Jul 16, 2020 at 11:32 PM Arnd Bergmann <arnd@arndb.de> wrote:
> > > On Fri, Jul 17, 2020 at 1:41 AM Atish Patra <atish.patra@wdc.com> wrote:
> > > > +#define DTB_EARLY_SIZE         SZ_1M
> > > > +static char early_dtb[DTB_EARLY_SIZE] __initdata;
> > >
> > > Hardcoding the size in .bss seems slightly problematic both for
> > > small and for big systems. On machines with very little memory,
> > > this can lead to running out of free pages before .initdata gets freed,
> > > and it increases the size of the uncompressed vmlinux file by quite
> > > a bit.
> > >
> > > On some systems, the 1MB limit may get too small. While most dtbs
> > > would fall into the range between 10KB and 100KB, it can also be
> > > much larger than that, e.g. when there are DT properties that include
> > > blobs like device firmware that gets loaded into hardware by a kernel
> > > driver.
> > >
> > I was not aware that we can do such things. Is there a current example of that ?
>
> I worked on a product in the distant past where the host firmware
> included the ethernet controller firmware as a DT property[1] to get around
> restrictions on redistributing the blob in the linux-firmware package.
>
> For the .dts files we distribute with the kernel, that would not make
> sense, and I don't know of any current machines that do this in their
> system firmware.
>
> > > Is there anything stopping you from parsing the FDT in its original
> > > location without the extra copy before it gets unflattened?
> >
> > That's what the original code was doing. A fixmap entry was added to
> > map the original fdt
> > location to a virtual so that parse_dtb can be operated on a virtual
> > address. But we can't map
> > both FDT & early ioremap within a single PMD region( 2MB ). That's why
> > we removed the DT
> > mapping from the fixmap to .bss section. The other alternate option is
> > to increase the fixmap space to 4MB which seems more fragile.
>
> Could the original location just be part of the regular linear mapping of all
> RAM?

No. Because we don't map the entire RAM until setup_vm_final().
We need to parse DT before setup_vm_final() to get the memblocks and
reserved memory regions.

I'm not too familiar with the early mapping code myself, so it may not
> be possible, but that would be the most logical place where I'd put it.
>
>         Arnd
>
> [1] drivers/net/ethernet/toshiba/spider_net.c



-- 
Regards,
Atish

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^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap
  2020-07-21  4:18         ` Atish Patra
@ 2020-07-21  8:57           ` Arnd Bergmann
  2020-07-21  9:02             ` Ard Biesheuvel
  0 siblings, 1 reply; 17+ messages in thread
From: Arnd Bergmann @ 2020-07-21  8:57 UTC (permalink / raw)
  To: Atish Patra
  Cc: Mark Rutland, linux-efi, Kees Cook, Heinrich Schuchardt,
	Masahiro Yamada, Anup Patel, linux-kernel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Zong Li, Paul Walmsley,
	Greentime Hu, linux-riscv, Will Deacon, Ard Biesheuvel,
	Linux ARM

On Tue, Jul 21, 2020 at 6:18 AM Atish Patra <atishp@atishpatra.org> wrote:
> On Sat, Jul 18, 2020 at 2:24 AM Arnd Bergmann <arnd@arndb.de> wrote:
> > On Sat, Jul 18, 2020 at 3:05 AM Atish Patra <atishp@atishpatra.org> wrote:
> > > That's what the original code was doing. A fixmap entry was added to
> > > map the original fdt
> > > location to a virtual so that parse_dtb can be operated on a virtual
> > > address. But we can't map
> > > both FDT & early ioremap within a single PMD region( 2MB ). That's why
> > > we removed the DT
> > > mapping from the fixmap to .bss section. The other alternate option is
> > > to increase the fixmap space to 4MB which seems more fragile.
> >
> > Could the original location just be part of the regular linear mapping of all
> > RAM?
>
> No. Because we don't map the entire RAM until setup_vm_final().
> We need to parse DT before setup_vm_final() to get the memblocks and
> reserved memory regions.

Ok, I see how you create a direct mapping for the kernel image, plus
the fixmap for the dtb in setup_vm(), and how moving the dtb into the
kernel image simplifies that.

I'm still wondering why you can't do the same kind of PGD mapping
for the dtb that you do for the vmlinux, creating linear page table
entries exactly for the location that holds the dtb, from dtb_pa to
dtb_pa+((struct fdt_header*)dtb_pa)->totalsize.

      Arnd

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^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap
  2020-07-21  8:57           ` Arnd Bergmann
@ 2020-07-21  9:02             ` Ard Biesheuvel
  2020-07-21  9:30               ` Anup Patel
  0 siblings, 1 reply; 17+ messages in thread
From: Ard Biesheuvel @ 2020-07-21  9:02 UTC (permalink / raw)
  To: Arnd Bergmann
  Cc: Mark Rutland, linux-efi, Kees Cook, Zong Li, Heinrich Schuchardt,
	Masahiro Yamada, Anup Patel, linux-kernel, Mike Rapoport,
	Atish Patra, Palmer Dabbelt, Paul Walmsley, Atish Patra,
	Greentime Hu, linux-riscv, Will Deacon, Linux ARM

On Tue, 21 Jul 2020 at 11:57, Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Tue, Jul 21, 2020 at 6:18 AM Atish Patra <atishp@atishpatra.org> wrote:
> > On Sat, Jul 18, 2020 at 2:24 AM Arnd Bergmann <arnd@arndb.de> wrote:
> > > On Sat, Jul 18, 2020 at 3:05 AM Atish Patra <atishp@atishpatra.org> wrote:
> > > > That's what the original code was doing. A fixmap entry was added to
> > > > map the original fdt
> > > > location to a virtual so that parse_dtb can be operated on a virtual
> > > > address. But we can't map
> > > > both FDT & early ioremap within a single PMD region( 2MB ). That's why
> > > > we removed the DT
> > > > mapping from the fixmap to .bss section. The other alternate option is
> > > > to increase the fixmap space to 4MB which seems more fragile.
> > >
> > > Could the original location just be part of the regular linear mapping of all
> > > RAM?
> >
> > No. Because we don't map the entire RAM until setup_vm_final().
> > We need to parse DT before setup_vm_final() to get the memblocks and
> > reserved memory regions.
>
> Ok, I see how you create a direct mapping for the kernel image, plus
> the fixmap for the dtb in setup_vm(), and how moving the dtb into the
> kernel image simplifies that.
>
> I'm still wondering why you can't do the same kind of PGD mapping
> for the dtb that you do for the vmlinux, creating linear page table
> entries exactly for the location that holds the dtb, from dtb_pa to
> dtb_pa+((struct fdt_header*)dtb_pa)->totalsize.
>

On arm64, we limit the size of the DT to 2MB, and reserve a pair of
PMD entries adjacent to the fixmap so we can map it r/o statically
using huge pages without using fixmap/early_ioremap slots. (Using a
pair of PMD entries allows the DT to appear at any alignment in
memory, given that PMD entries cover 2 MB each on 4k pages kernels)

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^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap
  2020-07-21  9:02             ` Ard Biesheuvel
@ 2020-07-21  9:30               ` Anup Patel
  0 siblings, 0 replies; 17+ messages in thread
From: Anup Patel @ 2020-07-21  9:30 UTC (permalink / raw)
  To: Ard Biesheuvel
  Cc: Mark Rutland, linux-efi, Kees Cook, Arnd Bergmann, Zong Li,
	Masahiro Yamada, Anup Patel, linux-kernel, Heinrich Schuchardt,
	Mike Rapoport, Atish Patra, Palmer Dabbelt, Paul Walmsley,
	Atish Patra, Greentime Hu, linux-riscv, Will Deacon, Linux ARM

On Tue, Jul 21, 2020 at 2:32 PM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Tue, 21 Jul 2020 at 11:57, Arnd Bergmann <arnd@arndb.de> wrote:
> >
> > On Tue, Jul 21, 2020 at 6:18 AM Atish Patra <atishp@atishpatra.org> wrote:
> > > On Sat, Jul 18, 2020 at 2:24 AM Arnd Bergmann <arnd@arndb.de> wrote:
> > > > On Sat, Jul 18, 2020 at 3:05 AM Atish Patra <atishp@atishpatra.org> wrote:
> > > > > That's what the original code was doing. A fixmap entry was added to
> > > > > map the original fdt
> > > > > location to a virtual so that parse_dtb can be operated on a virtual
> > > > > address. But we can't map
> > > > > both FDT & early ioremap within a single PMD region( 2MB ). That's why
> > > > > we removed the DT
> > > > > mapping from the fixmap to .bss section. The other alternate option is
> > > > > to increase the fixmap space to 4MB which seems more fragile.
> > > >
> > > > Could the original location just be part of the regular linear mapping of all
> > > > RAM?
> > >
> > > No. Because we don't map the entire RAM until setup_vm_final().
> > > We need to parse DT before setup_vm_final() to get the memblocks and
> > > reserved memory regions.
> >
> > Ok, I see how you create a direct mapping for the kernel image, plus
> > the fixmap for the dtb in setup_vm(), and how moving the dtb into the
> > kernel image simplifies that.
> >
> > I'm still wondering why you can't do the same kind of PGD mapping
> > for the dtb that you do for the vmlinux, creating linear page table
> > entries exactly for the location that holds the dtb, from dtb_pa to
> > dtb_pa+((struct fdt_header*)dtb_pa)->totalsize.
> >
>
> On arm64, we limit the size of the DT to 2MB, and reserve a pair of
> PMD entries adjacent to the fixmap so we can map it r/o statically
> using huge pages without using fixmap/early_ioremap slots. (Using a
> pair of PMD entries allows the DT to appear at any alignment in
> memory, given that PMD entries cover 2 MB each on 4k pages kernels)

The arch/riscv is common for both RV32 and RV64. On RV32, we don't
have PMD due to only two-levels in the page table.

Although, I like the idea of two consecutive PMD mappings which are not
part of FIXMAP. The RISC-V early page table is totally different from the
final init_mm page table. I think we can do two consecutive PGD mappings
in the early page table at lower addresses (quite below PAGE_OFFSET). I
will play-around with this idea.

Regards,
Anup

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^ permalink raw reply	[flat|nested] 17+ messages in thread

end of thread, back to index

Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-16 23:40 [RFT PATCH v3 0/9] Add UEFI support for RISC-V Atish Patra
2020-07-16 23:40 ` [RFT PATCH v3 1/9] RISC-V: Move DT mapping outof fixmap Atish Patra
2020-07-17  6:32   ` Arnd Bergmann
2020-07-18  1:05     ` Atish Patra
2020-07-18  9:24       ` Arnd Bergmann
2020-07-21  4:18         ` Atish Patra
2020-07-21  8:57           ` Arnd Bergmann
2020-07-21  9:02             ` Ard Biesheuvel
2020-07-21  9:30               ` Anup Patel
2020-07-16 23:40 ` [RFT PATCH v3 2/9] RISC-V: Add early ioremap support Atish Patra
2020-07-16 23:40 ` [RFT PATCH v3 3/9] RISC-V: Implement late mapping page table allocation functions Atish Patra
2020-07-16 23:40 ` [RFT PATCH v3 4/9] include: pe.h: Add RISC-V related PE definition Atish Patra
2020-07-16 23:41 ` [RFT PATCH v3 5/9] RISC-V: Add PE/COFF header for EFI stub Atish Patra
2020-07-16 23:41 ` [RFT PATCH v3 6/9] RISC-V: Add EFI stub support Atish Patra
2020-07-16 23:41 ` [RFT PATCH v3 7/9] efi: Rename arm-init to efi-init common for all arch Atish Patra
2020-07-16 23:41 ` [RFT PATCH v3 8/9] RISC-V: Add EFI runtime services Atish Patra
2020-07-16 23:41 ` [RFT PATCH v3 9/9] RISC-V: Add page table dump support for uefi Atish Patra

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