[PATCH] RISC-V: simplify BUILTIN_DTB processing

Subsystems: risc-v architecture, the rest

STALE2024d

3 messages, 3 authors, 2021-01-15 · open the first message on its own page

[PATCH] RISC-V: simplify BUILTIN_DTB processing

From: Vitaly Wool <hidden>
Date: 2021-01-11 21:21:48

Provide __dtb_start as a parameter to setup_vm() in case
CONFIG_BUILTIN_DTB is true, so we don't have to duplicate
BUILTIN_DTB specific processing in MMU-enabled and MMU-disabled
versions of setup_vm().

Signed-off-by: Vitaly Wool <redacted>
---
 arch/riscv/kernel/head.S | 4 ++++
 arch/riscv/mm/init.c     | 4 ----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 16e9941900c4..f5a9bad86e58 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S

@@ -260,7 +260,11 @@ clear_bss_done:
 
 	/* Initialize page tables and relocate to virtual addresses */
 	la sp, init_thread_union + THREAD_SIZE
+#ifdef CONFIG_BUILTIN_DTB
+	la a0, __dtb_start
+#else
 	mv a0, s1
+#endif /* CONFIG_BUILTIN_DTB */
 	call setup_vm
 #ifdef CONFIG_MMU
 	la a0, early_pg_dir

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 5b17f8d22f91..45faad7c4291 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c

@@ -615,11 +615,7 @@ static void __init setup_vm_final(void)
 #else
 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 {
-#ifdef CONFIG_BUILTIN_DTB
-	dtb_early_va = (void *) __dtb_start;
-#else
 	dtb_early_va = (void *)dtb_pa;
-#endif
 	dtb_early_pa = dtb_pa;
 }

-- 
2.20.1

Re: [PATCH] RISC-V: simplify BUILTIN_DTB processing

From: Damien Le Moal <hidden>
Date: 2021-01-12 04:57:53

On 2021/01/12 6:21, Vitaly Wool wrote:

quoted hunk

Provide __dtb_start as a parameter to setup_vm() in case
CONFIG_BUILTIN_DTB is true, so we don't have to duplicate
BUILTIN_DTB specific processing in MMU-enabled and MMU-disabled
versions of setup_vm().

Signed-off-by: Vitaly Wool <redacted>
---
 arch/riscv/kernel/head.S | 4 ++++
 arch/riscv/mm/init.c     | 4 ----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 16e9941900c4..f5a9bad86e58 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S

@@ -260,7 +260,11 @@ clear_bss_done:
 
 	/* Initialize page tables and relocate to virtual addresses */
 	la sp, init_thread_union + THREAD_SIZE
+#ifdef CONFIG_BUILTIN_DTB
+	la a0, __dtb_start
+#else
 	mv a0, s1
+#endif /* CONFIG_BUILTIN_DTB */
 	call setup_vm
 #ifdef CONFIG_MMU
 	la a0, early_pg_dir

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 5b17f8d22f91..45faad7c4291 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c

@@ -615,11 +615,7 @@ static void __init setup_vm_final(void)
 #else
 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 {
-#ifdef CONFIG_BUILTIN_DTB
-	dtb_early_va = (void *) __dtb_start;
-#else
 	dtb_early_va = (void *)dtb_pa;
-#endif
 	dtb_early_pa = dtb_pa;
 }

Tested this with a nommu kernel on a MAIX bit board (K210 SoC). No problems
detected.

Tested-by: Damien Le Moal <redacted>

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH] RISC-V: simplify BUILTIN_DTB processing

From: Anup Patel <anup@brainfault.org>
Date: 2021-01-15 09:40:34

On Tue, Jan 12, 2021 at 2:51 AM Vitaly Wool [off-list ref] wrote:

quoted hunk

Provide __dtb_start as a parameter to setup_vm() in case
CONFIG_BUILTIN_DTB is true, so we don't have to duplicate
BUILTIN_DTB specific processing in MMU-enabled and MMU-disabled
versions of setup_vm().

Signed-off-by: Vitaly Wool <redacted>
---
 arch/riscv/kernel/head.S | 4 ++++
 arch/riscv/mm/init.c     | 4 ----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 16e9941900c4..f5a9bad86e58 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S

@@ -260,7 +260,11 @@ clear_bss_done:

        /* Initialize page tables and relocate to virtual addresses */
        la sp, init_thread_union + THREAD_SIZE
+#ifdef CONFIG_BUILTIN_DTB
+       la a0, __dtb_start
+#else
        mv a0, s1
+#endif /* CONFIG_BUILTIN_DTB */
        call setup_vm
 #ifdef CONFIG_MMU
        la a0, early_pg_dir

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 5b17f8d22f91..45faad7c4291 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c

@@ -615,11 +615,7 @@ static void __init setup_vm_final(void)
 #else
 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 {
-#ifdef CONFIG_BUILTIN_DTB
-       dtb_early_va = (void *) __dtb_start;
-#else
        dtb_early_va = (void *)dtb_pa;
-#endif
        dtb_early_pa = dtb_pa;
 }

--

2.20.1

We can avoid the early DTB mapping for MMU-enabled case when
BUILTIN_DTB is enabled (same as previous discussion). Otherwise
looks good to me.

Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup

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