From bf9921a9c15bad089c08b94c300a6cafa035a612 Mon Sep 17 00:00:00 2001 From: Gerald Schaefer Date: Mon, 1 Apr 2019 19:10:45 +0200 Subject: [PATCH] s390: introduce .boot.preserved.data section Introduce .boot.preserve.data section which is similar to .boot.data and "shared" between the decompressor code and the decompressed kernel. The decompressor will store values in it, and copy over to the decompressed image before starting it. This method allows to avoid using pre-defined addresses and other hacks to pass values between those boot phases. Unlike .boot.data section .boot.preserved.data is NOT a part of init data, and hence will be preserved for the kernel life time. Signed-off-by: Gerald Schaefer Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky --- arch/s390/boot/compressed/decompressor.h | 2 ++ arch/s390/boot/compressed/vmlinux.lds.S | 1 + arch/s390/boot/startup.c | 4 ++++ arch/s390/include/asm/sections.h | 7 +++++++ arch/s390/include/asm/vmlinux.lds.h | 13 +++++++++++++ arch/s390/kernel/vmlinux.lds.S | 4 ++++ 6 files changed, 31 insertions(+) diff --git a/arch/s390/boot/compressed/decompressor.h b/arch/s390/boot/compressed/decompressor.h index e1c1f2e..424cf52 100644 --- a/arch/s390/boot/compressed/decompressor.h +++ b/arch/s390/boot/compressed/decompressor.h @@ -17,6 +17,8 @@ struct vmlinux_info { unsigned long bss_size; /* uncompressed image .bss size */ unsigned long bootdata_off; unsigned long bootdata_size; + unsigned long bootdata_preserved_off; + unsigned long bootdata_preserved_size; }; extern char _vmlinux_info[]; diff --git a/arch/s390/boot/compressed/vmlinux.lds.S b/arch/s390/boot/compressed/vmlinux.lds.S index 7efc393..1c8ef39 100644 --- a/arch/s390/boot/compressed/vmlinux.lds.S +++ b/arch/s390/boot/compressed/vmlinux.lds.S @@ -34,6 +34,7 @@ SECTIONS _edata = . ; } BOOT_DATA + BOOT_DATA_PRESERVED /* * uncompressed image info used by the decompressor it should match diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index bdfc554..57d7f94 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -6,6 +6,7 @@ #include "boot.h" extern char __boot_data_start[], __boot_data_end[]; +extern char __boot_data_preserved_start[], __boot_data_preserved_end[]; void error(char *x) { @@ -43,6 +44,9 @@ static void copy_bootdata(void) if (__boot_data_end - __boot_data_start != vmlinux.bootdata_size) error(".boot.data section size mismatch"); memcpy((void *)vmlinux.bootdata_off, __boot_data_start, vmlinux.bootdata_size); + if (__boot_data_preserved_end - __boot_data_preserved_start != vmlinux.bootdata_preserved_size) + error(".boot.preserved.data section size mismatch"); + memcpy((void *)vmlinux.bootdata_preserved_off, __boot_data_preserved_start, vmlinux.bootdata_preserved_size); } void startup_kernel(void) diff --git a/arch/s390/include/asm/sections.h b/arch/s390/include/asm/sections.h index 7afe462..29e5573 100644 --- a/arch/s390/include/asm/sections.h +++ b/arch/s390/include/asm/sections.h @@ -16,4 +16,11 @@ */ #define __bootdata(var) __section(.boot.data.var) var +/* + * .boot.preserved.data is similar to .boot.data, but it is not part of the + * .init section and thus will be preserved for later use in the decompressed + * kernel. + */ +#define __bootdata_preserved(var) __section(.boot.preserved.data.var) var + #endif diff --git a/arch/s390/include/asm/vmlinux.lds.h b/arch/s390/include/asm/vmlinux.lds.h index 2d127f9..cbe670a 100644 --- a/arch/s390/include/asm/vmlinux.lds.h +++ b/arch/s390/include/asm/vmlinux.lds.h @@ -18,3 +18,16 @@ *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.boot.data*))) \ __boot_data_end = .; \ } + +/* + * .boot.preserved.data is similar to .boot.data, but it is not part of the + * .init section and thus will be preserved for later use in the decompressed + * kernel. + */ +#define BOOT_DATA_PRESERVED \ + . = ALIGN(PAGE_SIZE); \ + .boot.preserved.data : { \ + __boot_data_preserved_start = .; \ + *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.boot.preserved.data*))) \ + __boot_data_preserved_end = .; \ + } diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S index 8429ab0..6ef9c62b 100644 --- a/arch/s390/kernel/vmlinux.lds.S +++ b/arch/s390/kernel/vmlinux.lds.S @@ -72,6 +72,7 @@ SECTIONS __end_ro_after_init = .; RW_DATA_SECTION(0x100, PAGE_SIZE, THREAD_SIZE) + BOOT_DATA_PRESERVED _edata = .; /* End of data section */ @@ -161,6 +162,9 @@ SECTIONS QUAD(__bss_stop - __bss_start) /* bss_size */ QUAD(__boot_data_start) /* bootdata_off */ QUAD(__boot_data_end - __boot_data_start) /* bootdata_size */ + QUAD(__boot_data_preserved_start) /* bootdata_preserved_off */ + QUAD(__boot_data_preserved_end - + __boot_data_preserved_start) /* bootdata_preserved_size */ } :NONE /* Debugging sections. */ -- 2.7.4