From: Janosch Frank <frankja@linux.ibm.com>
To: kvm@vger.kernel.org
Cc: linux-s390@vger.kernel.org, david@redhat.com, thuth@redhat.com,
pmorel@linux.ibm.com, imbrenda@linux.ibm.com
Subject: [kvm-unit-tests PATCH 2/8] s390x: Fully commit to stack save area for exceptions
Date: Tue, 9 Feb 2021 08:49:19 -0500 [thread overview]
Message-ID: <20210209134925.22248-3-frankja@linux.ibm.com> (raw)
In-Reply-To: <20210209134925.22248-1-frankja@linux.ibm.com>
Having two sets of macros for saving registers on exceptions makes
maintaining harder. Also we have limited space in the lowcore to save
stuff and by using the stack as a save area, we can stack exceptions.
So let's use the SAVE/RESTORE_REGS_STACK as the default. When we also
move the diag308 macro over we can remove the old SAVE/RESTORE_REGS
macros.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
lib/s390x/asm-offsets.c | 14 ++++++++----
lib/s390x/asm/arch_def.h | 29 ++++++++++++++++++-----
lib/s390x/asm/interrupt.h | 4 ++--
lib/s390x/interrupt.c | 14 ++++++------
s390x/cstart64.S | 19 +++++++++-------
s390x/macros.S | 48 +++++++++++++++++++++++----------------
6 files changed, 82 insertions(+), 46 deletions(-)
diff --git a/lib/s390x/asm-offsets.c b/lib/s390x/asm-offsets.c
index a19f14b9..a8942395 100644
--- a/lib/s390x/asm-offsets.c
+++ b/lib/s390x/asm-offsets.c
@@ -70,16 +70,22 @@ int main(void)
OFFSET(GEN_LC_ARS_SA, lowcore, ars_sa);
OFFSET(GEN_LC_CRS_SA, lowcore, crs_sa);
OFFSET(GEN_LC_PGM_INT_TDB, lowcore, pgm_int_tdb);
- OFFSET(__SF_SIE_CONTROL, stack_frame, empty1[0]);
- OFFSET(__SF_SIE_SAVEAREA, stack_frame, empty1[1]);
- OFFSET(__SF_SIE_REASON, stack_frame, empty1[2]);
- OFFSET(__SF_SIE_FLAGS, stack_frame, empty1[3]);
+ OFFSET(__SF_SIE_CONTROL, stack_frame, argument_area[0]);
+ OFFSET(__SF_SIE_SAVEAREA, stack_frame, argument_area[1]);
+ OFFSET(__SF_SIE_REASON, stack_frame, argument_area[2]);
+ OFFSET(__SF_SIE_FLAGS, stack_frame, argument_area[3]);
OFFSET(SIE_SAVEAREA_HOST_GRS, vm_save_area, host.grs[0]);
OFFSET(SIE_SAVEAREA_HOST_FPRS, vm_save_area, host.fprs[0]);
OFFSET(SIE_SAVEAREA_HOST_FPC, vm_save_area, host.fpc);
OFFSET(SIE_SAVEAREA_GUEST_GRS, vm_save_area, guest.grs[0]);
OFFSET(SIE_SAVEAREA_GUEST_FPRS, vm_save_area, guest.fprs[0]);
OFFSET(SIE_SAVEAREA_GUEST_FPC, vm_save_area, guest.fpc);
+ OFFSET(STACK_FRAME_INT_BACKCHAIN, stack_frame_int, back_chain);
+ OFFSET(STACK_FRAME_INT_FPC, stack_frame_int, fpc);
+ OFFSET(STACK_FRAME_INT_FPRS, stack_frame_int, fprs);
+ OFFSET(STACK_FRAME_INT_CR0, stack_frame_int, cr0);
+ OFFSET(STACK_FRAME_INT_GRS0, stack_frame_int, grs0);
+ OFFSET(STACK_FRAME_INT_GRS1, stack_frame_int, grs1);
return 0;
}
diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index 9c4e330a..eb6a961f 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -8,13 +8,30 @@
#ifndef _ASM_S390X_ARCH_DEF_H_
#define _ASM_S390X_ARCH_DEF_H_
-/*
- * We currently only specify the stack frame members needed for the
- * SIE library code.
- */
struct stack_frame {
- unsigned long back_chain;
- unsigned long empty1[5];
+ struct stack_frame *back_chain;
+ u64 reserved;
+ /* GRs 2 - 5 */
+ unsigned long argument_area[4];
+ /* GRs 6 - 15 */
+ unsigned long grs[10];
+ /* FPRs 0, 2, 4, 6 */
+ s64 fprs[4];
+};
+
+struct stack_frame_int {
+ struct stack_frame *back_chain;
+ u64 reserved;
+ /*
+ * The GRs are offset compatible with struct stack_frame so we
+ * can easily fetch GR14 for backtraces.
+ */
+ u64 grs0[14];
+ u64 grs1[2];
+ u32 res;
+ u32 fpc;
+ u64 fprs[16];
+ u64 cr0;
};
struct psw {
diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
index 1a2e2cd8..31e4766d 100644
--- a/lib/s390x/asm/interrupt.h
+++ b/lib/s390x/asm/interrupt.h
@@ -14,8 +14,8 @@
#define EXT_IRQ_SERVICE_SIG 0x2401
void register_pgm_cleanup_func(void (*f)(void));
-void handle_pgm_int(void);
-void handle_ext_int(void);
+void handle_pgm_int(struct stack_frame_int *stack);
+void handle_ext_int(struct stack_frame_int *stack);
void handle_mcck_int(void);
void handle_io_int(void);
void handle_svc_int(void);
diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
index 1ce36073..94a2cf9c 100644
--- a/lib/s390x/interrupt.c
+++ b/lib/s390x/interrupt.c
@@ -56,7 +56,7 @@ void register_pgm_cleanup_func(void (*f)(void))
pgm_cleanup_func = f;
}
-static void fixup_pgm_int(void)
+static void fixup_pgm_int(struct stack_frame_int *stack)
{
/* If we have an error on SIE we directly move to sie_exit */
if (lc->pgm_old_psw.addr >= (uint64_t)&sie_entry &&
@@ -76,7 +76,7 @@ static void fixup_pgm_int(void)
/* Handling for iep.c test case. */
if (lc->trans_exc_id & 0x80UL && lc->trans_exc_id & 0x04UL &&
!(lc->trans_exc_id & 0x08UL))
- lc->pgm_old_psw.addr = lc->sw_int_grs[14];
+ lc->pgm_old_psw.addr = stack->grs0[12];
break;
case PGM_INT_CODE_SEGMENT_TRANSLATION:
case PGM_INT_CODE_PAGE_TRANSLATION:
@@ -115,7 +115,7 @@ static void fixup_pgm_int(void)
/* suppressed/terminated/completed point already at the next address */
}
-void handle_pgm_int(void)
+void handle_pgm_int(struct stack_frame_int *stack)
{
if (!pgm_int_expected) {
/* Force sclp_busy to false, otherwise we will loop forever */
@@ -130,10 +130,10 @@ void handle_pgm_int(void)
if (pgm_cleanup_func)
(*pgm_cleanup_func)();
else
- fixup_pgm_int();
+ fixup_pgm_int(stack);
}
-void handle_ext_int(void)
+void handle_ext_int(struct stack_frame_int *stack)
{
if (!ext_int_expected &&
lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
@@ -143,13 +143,13 @@ void handle_ext_int(void)
}
if (lc->ext_int_code == EXT_IRQ_SERVICE_SIG) {
- lc->sw_int_crs[0] &= ~(1UL << 9);
+ stack->cr0 &= ~(1UL << 9);
sclp_handle_ext();
} else {
ext_int_expected = false;
}
- if (!(lc->sw_int_crs[0] & CR0_EXTM_MASK))
+ if (!(stack->cr0 & CR0_EXTM_MASK))
lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
}
diff --git a/s390x/cstart64.S b/s390x/cstart64.S
index ace0c0d9..35d20293 100644
--- a/s390x/cstart64.S
+++ b/s390x/cstart64.S
@@ -92,33 +92,36 @@ memsetxc:
.section .text
pgm_int:
- SAVE_REGS
+ SAVE_REGS_STACK
+ lgr %r2, %r15
brasl %r14, handle_pgm_int
- RESTORE_REGS
+ RESTORE_REGS_STACK
lpswe GEN_LC_PGM_OLD_PSW
ext_int:
- SAVE_REGS
+ SAVE_REGS_STACK
+ lgr %r2, %r15
brasl %r14, handle_ext_int
- RESTORE_REGS
+ RESTORE_REGS_STACK
lpswe GEN_LC_EXT_OLD_PSW
mcck_int:
- SAVE_REGS
+ SAVE_REGS_STACK
brasl %r14, handle_mcck_int
- RESTORE_REGS
+ RESTORE_REGS_STACK
lpswe GEN_LC_MCCK_OLD_PSW
io_int:
SAVE_REGS_STACK
+ lgr %r2, %r15
brasl %r14, handle_io_int
RESTORE_REGS_STACK
lpswe GEN_LC_IO_OLD_PSW
svc_int:
- SAVE_REGS
+ SAVE_REGS_STACK
brasl %r14, handle_svc_int
- RESTORE_REGS
+ RESTORE_REGS_STACK
lpswe GEN_LC_SVC_OLD_PSW
.align 8
diff --git a/s390x/macros.S b/s390x/macros.S
index e51a557a..1c8a0f7c 100644
--- a/s390x/macros.S
+++ b/s390x/macros.S
@@ -3,9 +3,10 @@
* s390x assembly macros
*
* Copyright (c) 2017 Red Hat Inc
- * Copyright (c) 2020 IBM Corp.
+ * Copyright (c) 2020, 2021 IBM Corp.
*
* Authors:
+ * Janosch Frank <frankja@linux.ibm.com>
* Pierre Morel <pmorel@linux.ibm.com>
* David Hildenbrand <david@redhat.com>
*/
@@ -41,36 +42,45 @@
/* Save registers on the stack (r15), so we can have stacked interrupts. */
.macro SAVE_REGS_STACK
- /* Allocate a stack frame for 15 general registers */
- slgfi %r15, 15 * 8
+ /* Allocate a full stack frame */
+ slgfi %r15, 32 * 8 + 4 * 8
/* Store registers r0 to r14 on the stack */
- stmg %r0, %r14, 0(%r15)
- /* Allocate a stack frame for 16 floating point registers */
- /* The size of a FP register is the size of an double word */
- slgfi %r15, 16 * 8
+ stmg %r2, %r15, STACK_FRAME_INT_GRS0(%r15)
+ stg %r0, STACK_FRAME_INT_GRS1(%r15)
+ stg %r1, STACK_FRAME_INT_GRS1 + 8(%r15)
+ /* Store the gr15 value before we allocated the new stack */
+ lgr %r0, %r15
+ algfi %r0, 32 * 8 + 4 * 8
+ stg %r0, 13 * 8 + STACK_FRAME_INT_GRS0(%r15)
+ stg %r0, STACK_FRAME_INT_BACKCHAIN(%r15)
+ /*
+ * Store CR0 and load initial CR0 so AFP is active and we can
+ * access all fprs to save them.
+ */
+ stctg %c0,%c0,STACK_FRAME_INT_CR0(%r15)
+ larl %r1, initial_cr0
+ lctlg %c0, %c0, 0(%r1)
/* Save fp register on stack: offset to SP is multiple of reg number */
.irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
- std \i, \i * 8(%r15)
+ std \i, \i * 8 + STACK_FRAME_INT_FPRS(%r15)
.endr
- /* Save fpc, but keep stack aligned on 64bits */
- slgfi %r15, 8
- stfpc 0(%r15)
+ /* Save fpc */
+ stfpc STACK_FRAME_INT_FPC(%r15)
.endm
/* Restore the register in reverse order */
.macro RESTORE_REGS_STACK
/* Restore fpc */
- lfpc 0(%r15)
- algfi %r15, 8
+ lfpc STACK_FRAME_INT_FPC(%r15)
/* Restore fp register from stack: SP still where it was left */
/* and offset to SP is a multiple of reg number */
.irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
- ld \i, \i * 8(%r15)
+ ld \i, \i * 8 + STACK_FRAME_INT_FPRS(%r15)
.endr
- /* Now that we're done, rewind the stack pointer by 16 double word */
- algfi %r15, 16 * 8
+ /* Load CR0 back */
+ lctlg %c0, %c0, STACK_FRAME_INT_CR0(%r15)
/* Load the registers from stack */
- lmg %r0, %r14, 0(%r15)
- /* Rewind the stack by 15 double word */
- algfi %r15, 15 * 8
+ lg %r0, STACK_FRAME_INT_GRS1(%r15)
+ lg %r1, STACK_FRAME_INT_GRS1 + 8(%r15)
+ lmg %r2, %r15, STACK_FRAME_INT_GRS0(%r15)
.endm
--
2.25.1
next prev parent reply other threads:[~2021-02-09 13:51 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 13:49 [kvm-unit-tests PATCH 0/8] s390x: Cleanup exception register save/restore and implement backtrace Janosch Frank
2021-02-09 13:49 ` [kvm-unit-tests PATCH 1/8] s390x: Fix fpc store address in RESTORE_REGS_STACK Janosch Frank
2021-02-09 15:14 ` Thomas Huth
2021-02-09 13:49 ` Janosch Frank [this message]
2021-02-11 14:47 ` [kvm-unit-tests PATCH 2/8] s390x: Fully commit to stack save area for exceptions Janosch Frank
2021-02-09 13:49 ` [kvm-unit-tests PATCH 3/8] RFC: s390x: Define STACK_FRAME_INT_SIZE macro Janosch Frank
2021-02-09 13:49 ` [kvm-unit-tests PATCH 4/8] s390x: Introduce and use CALL_INT_HANDLER macro Janosch Frank
2021-02-09 13:49 ` [kvm-unit-tests PATCH 5/8] s390x: Provide preliminary backtrace support Janosch Frank
2021-02-09 13:49 ` [kvm-unit-tests PATCH 6/8] s390x: Print more information on program exceptions Janosch Frank
2021-02-09 13:49 ` [kvm-unit-tests PATCH 7/8] s390x: Move diag308_load_reset to stack saving Janosch Frank
2021-02-09 13:49 ` [kvm-unit-tests PATCH 8/8] s390x: Remove SAVE/RESTORE_stack Janosch Frank
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