From 0029b4d19491cd83cfb85de0fa9ac1e175409377 Mon Sep 17 00:00:00 2001 From: Alexander Egorenkov Date: Sat, 10 Oct 2020 03:34:25 +0200 Subject: [PATCH] s390/sclp: use only one sclp early buffer to send commands A buffer that can be used for communication with SCLP is required to lie below 2GB memory address. Therefore, both sclp_info_sccb and sclp_early_sccb must fulfill this requirement if passed directly to the sclp_early_cmd() function. Instead, use only sclp_early_sccb for communication with SCLP. This allows the buffer sclp_info_sccb to be placed anywhere in the memory address space and, therefore, simplifies the process of making the decompressor relocatable later on, one thing less to relocate. And make sure that the length of the new unified early SCLP buffer is no less than the length of the removed sclp_info_sccb buffer which might be larger than the length of the sclp_early_sccb buffer. Signed-off-by: Alexander Egorenkov Acked-by: Heiko Carstens Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens --- arch/s390/boot/head.S | 3 ++- arch/s390/include/asm/sclp.h | 7 +++++-- arch/s390/include/asm/setup.h | 3 ++- drivers/s390/char/sclp_early_core.c | 12 +++++++++++- 4 files changed, 20 insertions(+), 5 deletions(-) diff --git a/arch/s390/boot/head.S b/arch/s390/boot/head.S index cafe454703b8..0cfa76fe6dfd 100644 --- a/arch/s390/boot/head.S +++ b/arch/s390/boot/head.S @@ -27,6 +27,7 @@ #include #include #include +#include #define ARCH_OFFSET 4 @@ -410,6 +411,6 @@ SYM_DATA_START(parmarea) SYM_DATA_END(parmarea) .org EARLY_SCCB_OFFSET - .fill 4096 + .fill EXT_SCCB_READ_SCP .org HEAD_END diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h index 5763769a39b6..3adbb417f740 100644 --- a/arch/s390/include/asm/sclp.h +++ b/arch/s390/include/asm/sclp.h @@ -8,8 +8,6 @@ #define _ASM_S390_SCLP_H #include -#include -#include #define SCLP_CHP_INFO_MASK_SIZE 32 #define EARLY_SCCB_SIZE PAGE_SIZE @@ -19,6 +17,10 @@ /* 24 + 16 * SCLP_MAX_CORES */ #define EXT_SCCB_READ_CPU (3 * PAGE_SIZE) +#ifndef __ASSEMBLY__ +#include +#include + struct sclp_chp_info { u8 recognized[SCLP_CHP_INFO_MASK_SIZE]; u8 standby[SCLP_CHP_INFO_MASK_SIZE]; @@ -147,4 +149,5 @@ static inline int sclp_get_core_info(struct sclp_core_info *info, int early) return _sclp_get_core_info(info); } +#endif /* __ASSEMBLY__ */ #endif /* _ASM_S390_SCLP_H */ diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h index 3a77aa96d092..cf285f57579f 100644 --- a/arch/s390/include/asm/setup.h +++ b/arch/s390/include/asm/setup.h @@ -7,6 +7,7 @@ #define _ASM_S390_SETUP_H #include +#include #include #include @@ -14,7 +15,7 @@ #define EP_STRING "S390EP" #define PARMAREA 0x10400 #define EARLY_SCCB_OFFSET 0x11000 -#define HEAD_END 0x12000 +#define HEAD_END (EARLY_SCCB_OFFSET + EXT_SCCB_READ_SCP) /* * Machine features detected in early.c diff --git a/drivers/s390/char/sclp_early_core.c b/drivers/s390/char/sclp_early_core.c index b7329af076a0..80ba6523e76e 100644 --- a/drivers/s390/char/sclp_early_core.c +++ b/drivers/s390/char/sclp_early_core.c @@ -235,11 +235,20 @@ void sclp_early_printk(const char *str) __sclp_early_printk(str, strlen(str)); } +/* + * We can't pass sclp_info_sccb to sclp_early_cmd() here directly, + * because it might not fulfil the requiremets for a SCLP communication buffer: + * - lie below 2G in memory + * - be page-aligned + * Therefore, we use the buffer sclp_early_sccb (which fulfils all those + * requirements) temporarily for communication and copy a received response + * back into the buffer sclp_info_sccb upon successful completion. + */ int __init sclp_early_read_info(void) { int i; int length = test_facility(140) ? EXT_SCCB_READ_SCP : PAGE_SIZE; - struct read_info_sccb *sccb = &sclp_info_sccb; + struct read_info_sccb *sccb = (struct read_info_sccb *)sclp_early_sccb; sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED, SCLP_CMDW_READ_SCP_INFO}; @@ -251,6 +260,7 @@ int __init sclp_early_read_info(void) if (sclp_early_cmd(commands[i], sccb)) break; if (sccb->header.response_code == 0x10) { + memcpy(&sclp_info_sccb, sccb, length); sclp_info_sccb_valid = 1; return 0; } -- 2.20.1