linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Vitaly Wool <vitaly.wool@konsulko.com>
To: linux-riscv@lists.infradead.org
Cc: Alexandre Ghiti <alex@ghiti.fr>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Jisheng Zhang <jszhang@kernel.org>,
	linux-mm@kvack.org, Nicolas Pitre <nico@fluxnic.net>,
	Vitaly Wool <vitaly.wool@konsulko.com>
Subject: [PATCH] riscv: remove .text section size limitation for XIP
Date: Mon, 11 Oct 2021 11:14:14 +0200	[thread overview]
Message-ID: <20211011091414.1998846-1-vitaly.wool@konsulko.com> (raw)

Currently there's a limit of 8MB for the .text section of a RISC-V
image in the XIP case. This breaks compilation of many automatic
builds and is generally inconvenient. This patch removes that
limitation and optimizes XIP image file size at the same time.

Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
---
 arch/riscv/include/asm/pgtable.h    |  6 ++++--
 arch/riscv/kernel/head.S            | 12 ++++++++++++
 arch/riscv/kernel/vmlinux-xip.lds.S | 10 +++++++---
 arch/riscv/mm/init.c                |  7 +++----
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 39b550310ec6..bf204e7c1f74 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -75,7 +75,8 @@
 #endif
 
 #ifdef CONFIG_XIP_KERNEL
-#define XIP_OFFSET		SZ_8M
+#define XIP_OFFSET		SZ_32M
+#define XIP_OFFSET_MASK		(SZ_32M - 1)
 #else
 #define XIP_OFFSET		0
 #endif
@@ -97,7 +98,8 @@
 #ifdef CONFIG_XIP_KERNEL
 #define XIP_FIXUP(addr) ({							\
 	uintptr_t __a = (uintptr_t)(addr);					\
-	(__a >= CONFIG_XIP_PHYS_ADDR && __a < CONFIG_XIP_PHYS_ADDR + SZ_16M) ?	\
+	(__a >= CONFIG_XIP_PHYS_ADDR && \
+	 __a < CONFIG_XIP_PHYS_ADDR + XIP_OFFSET * 2) ?	\
 		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
 		__a;								\
 	})
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index fce5184b22c3..ed316d02cd7e 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -20,10 +20,20 @@
 	REG_L t0, _xip_fixup
 	add \reg, \reg, t0
 .endm
+.macro XIP_FIXUP_FLASH_OFFSET reg
+	la t1, __data_loc
+	li t0, XIP_OFFSET_MASK
+	and t1, t1, t0
+	li t1, XIP_OFFSET
+	sub t0, t0, t1
+	sub \reg, \reg, t0
+.endm
 _xip_fixup: .dword CONFIG_PHYS_RAM_BASE - CONFIG_XIP_PHYS_ADDR - XIP_OFFSET
 #else
 .macro XIP_FIXUP_OFFSET reg
 .endm
+.macro XIP_FIXUP_FLASH_OFFSET reg
+.endm
 #endif /* CONFIG_XIP_KERNEL */
 
 __HEAD
@@ -266,6 +276,7 @@ pmp_done:
 	la a3, hart_lottery
 	mv a2, a3
 	XIP_FIXUP_OFFSET a2
+	XIP_FIXUP_FLASH_OFFSET a3
 	lw t1, (a3)
 	amoswap.w t0, t1, (a2)
 	/* first time here if hart_lottery in RAM is not set */
@@ -304,6 +315,7 @@ clear_bss_done:
 	XIP_FIXUP_OFFSET sp
 #ifdef CONFIG_BUILTIN_DTB
 	la a0, __dtb_start
+	XIP_FIXUP_OFFSET a0
 #else
 	mv a0, s1
 #endif /* CONFIG_BUILTIN_DTB */
diff --git a/arch/riscv/kernel/vmlinux-xip.lds.S b/arch/riscv/kernel/vmlinux-xip.lds.S
index 9c9f35091ef0..f5ed08262139 100644
--- a/arch/riscv/kernel/vmlinux-xip.lds.S
+++ b/arch/riscv/kernel/vmlinux-xip.lds.S
@@ -64,8 +64,11 @@ SECTIONS
 /*
  * From this point, stuff is considered writable and will be copied to RAM
  */
-	__data_loc = ALIGN(16);		/* location in file */
-	. = LOAD_OFFSET + XIP_OFFSET;	/* location in memory */
+	__data_loc = ALIGN(PAGE_SIZE);		/* location in file */
+	. = KERNEL_LINK_ADDR + XIP_OFFSET;	/* location in memory */
+
+#undef LOAD_OFFSET
+#define LOAD_OFFSET (KERNEL_LINK_ADDR + XIP_OFFSET - (__data_loc & XIP_OFFSET_MASK))
 
 	_sdata = .;			/* Start of data section */
 	_data = .;
@@ -96,7 +99,6 @@ SECTIONS
 		KEEP(*(__soc_builtin_dtb_table))
 		__soc_builtin_dtb_table_end = .;
 	}
-	PERCPU_SECTION(L1_CACHE_BYTES)
 
 	. = ALIGN(8);
 	.alternative : {
@@ -122,6 +124,8 @@ SECTIONS
 
 	BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 0)
 
+	PERCPU_SECTION(L1_CACHE_BYTES)
+
 	.rel.dyn : AT(ADDR(.rel.dyn) - LOAD_OFFSET) {
 		*(.rel.dyn*)
 	}
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index c0cddf0fc22d..24b2b8044602 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -41,7 +41,7 @@ phys_addr_t phys_ram_base __ro_after_init;
 EXPORT_SYMBOL(phys_ram_base);
 
 #ifdef CONFIG_XIP_KERNEL
-extern char _xiprom[], _exiprom[];
+extern char _xiprom[], _exiprom[], __data_loc;
 #endif
 
 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
@@ -454,10 +454,9 @@ static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
 /* called from head.S with MMU off */
 asmlinkage void __init __copy_data(void)
 {
-	void *from = (void *)(&_sdata);
-	void *end = (void *)(&_end);
+	void *from = (void *)(&__data_loc);
 	void *to = (void *)CONFIG_PHYS_RAM_BASE;
-	size_t sz = (size_t)(end - from + 1);
+	size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata));
 
 	memcpy(to, from, sz);
 }
-- 
2.30.2



             reply	other threads:[~2021-10-11  9:14 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-11  9:14 Vitaly Wool [this message]
2021-10-26 22:46 ` [PATCH] riscv: remove .text section size limitation for XIP Palmer Dabbelt

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211011091414.1998846-1-vitaly.wool@konsulko.com \
    --to=vitaly.wool@konsulko.com \
    --cc=alex@ghiti.fr \
    --cc=jszhang@kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=nico@fluxnic.net \
    --cc=palmer@dabbelt.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).