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[PATCH v3 3/5] pc-bios: s390x: Use reset PSW if avaliable
From: |
Janosch Frank |
Subject: |
[PATCH v3 3/5] pc-bios: s390x: Use reset PSW if avaliable |
Date: |
Mon, 31 Aug 2020 11:09:08 -0400 |
If a blob provides a reset PSW then we should use it instead of
branching to the PSW address and using our own mask.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
pc-bios/s390-ccw/bootmap.c | 3 ++-
pc-bios/s390-ccw/jump2ipl.c | 22 +++++++++++++++++-----
pc-bios/s390-ccw/s390-ccw.h | 1 +
3 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
index 8747c4ea26..5a03b1eb8b 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -515,7 +515,8 @@ static void zipl_run(ScsiBlockPtr *pte)
IPL_assert(entry->component_type == ZIPL_COMP_ENTRY_EXEC, "No EXEC entry");
/* should not return */
- jump_to_IPL_code(entry->compdat.load_psw & PSW_MASK_SHORT_ADDR);
+ write_reset_psw(entry->compdat.load_psw);
+ jump_to_IPL_code(0);
}
static void ipl_scsi(void)
diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c
index b6aad32def..5b8352d257 100644
--- a/pc-bios/s390-ccw/jump2ipl.c
+++ b/pc-bios/s390-ccw/jump2ipl.c
@@ -12,15 +12,21 @@
#define KERN_IMAGE_START 0x010000UL
#define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_64)
+#define RESET_PSW ((uint64_t)&jump_to_IPL_addr | RESET_PSW_MASK)
static uint64_t *reset_psw = 0, save_psw, ipl_continue;
+void write_reset_psw(uint64_t psw)
+{
+ *reset_psw = psw;
+}
+
static void jump_to_IPL_addr(void)
{
__attribute__((noreturn)) void (*ipl)(void) = (void *)ipl_continue;
/* Restore reset PSW */
- *reset_psw = save_psw;
+ write_reset_psw(save_psw);
ipl();
/* should not return */
@@ -43,9 +49,10 @@ void jump_to_IPL_code(uint64_t address)
* content of non-BIOS memory after we loaded the guest, so we
* save the original content and restore it in jump_to_IPL_2.
*/
- save_psw = *reset_psw;
- *reset_psw = (uint64_t) &jump_to_IPL_addr;
- *reset_psw |= RESET_PSW_MASK;
+ if (address) {
+ save_psw = *reset_psw;
+ write_reset_psw(RESET_PSW);
+ }
ipl_continue = address;
debug_print_int("set IPL addr to", ipl_continue);
@@ -77,7 +84,12 @@ void jump_to_low_kernel(void)
/* Trying to get PSW at zero address */
if (*((uint64_t *)0) & RESET_PSW_MASK) {
- jump_to_IPL_code((*((uint64_t *)0)) & PSW_MASK_SHORT_ADDR);
+ /*
+ * Surely nobody will try running directly from lowcore, so
+ * let's use 0 as an indication that we want to load the reset
+ * psw at 0x0 and not jump to the entry.
+ */
+ jump_to_IPL_code(0);
}
/* No other option left, so use the Linux kernel start address */
diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h
index 36b884cced..7090720422 100644
--- a/pc-bios/s390-ccw/s390-ccw.h
+++ b/pc-bios/s390-ccw/s390-ccw.h
@@ -78,6 +78,7 @@ int virtio_read(ulong sector, void *load_addr);
void zipl_load(void);
/* jump2ipl.c */
+void write_reset_psw(uint64_t psw);
void jump_to_IPL_code(uint64_t address);
void jump_to_low_kernel(void);
--
2.25.1
- [PATCH v3 0/5] pc-bios: s390x: Cleanup part 2, Janosch Frank, 2020/08/31
- [PATCH v3 3/5] pc-bios: s390x: Use reset PSW if avaliable,
Janosch Frank <=
- [PATCH v3 2/5] pc-bios: s390x: Save PSW rework, Janosch Frank, 2020/08/31
- [PATCH v3 4/5] pc-bios: s390x: Save io and external new PSWs before overwriting them, Janosch Frank, 2020/08/31
- [PATCH v3 5/5] pc-bios: s390x: Go into disabled wait when encountering a PGM exception, Janosch Frank, 2020/08/31
- [PATCH v3 1/5] pc-bios: s390x: Fix bootmap.c zipl component entry data handling, Janosch Frank, 2020/08/31
- Re: [PATCH v3 0/5] pc-bios: s390x: Cleanup part 2, no-reply, 2020/08/31