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riscv: remove .text section size limitation for XIP

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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>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Vitaly Wool 2021-10-11 11:14:14 +02:00 committed by Palmer Dabbelt
parent 241527bb84
commit f9ace4ede4
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
4 changed files with 26 additions and 9 deletions
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6
arch/riscv/include/asm/pgtable.h
View File

@ -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; \
})

12
arch/riscv/kernel/head.S
View File

@ -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 */

10
arch/riscv/kernel/vmlinux-xip.lds.S
View File

@ -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*)
}

7
arch/riscv/mm/init.c
View File

@ -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);
}