On Tue, 7 Mar 2023 10:10:50 +0100
Marc Hartmayer <mhartmay@xxxxxxxxxxxxx> wrote:
> Define and use a macro for the stack frame size. While at it, fix
> whitespace in the `gs_handler_asm` block.
>
> Signed-off-by: Marc Hartmayer <mhartmay@xxxxxxxxxxxxx>
> Co-developed-by: Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx>
Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
> ---
> lib/s390x/asm-offsets.c | 1 +
> s390x/Makefile | 2 +-
> s390x/cstart64.S | 2 +-
> s390x/flat.lds.S | 4 +++-
> s390x/gs.c | 38 +++++++++++++++++++++----------------
> s390x/macros.S | 4 ++--
> s390x/snippets/c/flat.lds.S | 6 ++++--
> 7 files changed, 34 insertions(+), 23 deletions(-)
>
> diff --git a/lib/s390x/asm-offsets.c b/lib/s390x/asm-offsets.c
> index f612f3277a95..188dd2e51181 100644
> --- a/lib/s390x/asm-offsets.c
> +++ b/lib/s390x/asm-offsets.c
> @@ -87,6 +87,7 @@ int main(void)
> OFFSET(STACK_FRAME_INT_GRS0, stack_frame_int, grs0);
> OFFSET(STACK_FRAME_INT_GRS1, stack_frame_int, grs1);
> DEFINE(STACK_FRAME_INT_SIZE, sizeof(struct stack_frame_int));
> + DEFINE(STACK_FRAME_SIZE, sizeof(struct stack_frame));
>
> return 0;
> }
> diff --git a/s390x/Makefile b/s390x/Makefile
> index e13a04eecb3e..fc8201f7762b 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -160,7 +160,7 @@ $(SNIPPET_DIR)/c/%.gbin: $(SNIPPET_DIR)/c/%.o $(snippet_lib) $(FLATLIBS) $(SNIPP
> $(OBJCOPY) -I binary -O elf64-s390 -B "s390:64-bit" $< $@
>
> lds-autodepend-flags = -MMD -MF $(dir $*).$(notdir $*).d -MT $@
> -%.lds: %.lds.S
> +%.lds: %.lds.S $(asm-offsets)
> $(CPP) $(lds-autodepend-flags) $(CPPFLAGS) -P -C -o $@ $<
>
> .SECONDEXPANSION:
> diff --git a/s390x/cstart64.S b/s390x/cstart64.S
> index 6f83da2a6c0a..468ace3ea4df 100644
> --- a/s390x/cstart64.S
> +++ b/s390x/cstart64.S
> @@ -38,7 +38,7 @@ start:
> /* setup stack */
> larl %r15, stackptr
> /* Clear first stack frame */
> - xc 0(160,%r15), 0(%r15)
> + xc 0(STACK_FRAME_SIZE,%r15), 0(%r15)
> /* setup initial PSW mask + control registers*/
> larl %r1, initial_psw
> lpswe 0(%r1)
> diff --git a/s390x/flat.lds.S b/s390x/flat.lds.S
> index 952f6cd457ed..0cb7e383cc76 100644
> --- a/s390x/flat.lds.S
> +++ b/s390x/flat.lds.S
> @@ -1,3 +1,5 @@
> +#include <asm/asm-offsets.h>
> +
> SECTIONS
> {
> .lowcore : {
> @@ -44,6 +46,6 @@ SECTIONS
> /*
> * stackptr set with initial stack frame preallocated
> */
> - stackptr = . - 160;
> + stackptr = . - STACK_FRAME_SIZE;
> stacktop = .;
> }
> diff --git a/s390x/gs.c b/s390x/gs.c
> index 4993eb8f43a9..9ae893eaf89a 100644
> --- a/s390x/gs.c
> +++ b/s390x/gs.c
> @@ -9,6 +9,7 @@
> * Janosch Frank <frankja@xxxxxxxxxxxxx>
> */
> #include <libcflat.h>
> +#include <asm/asm-offsets.h>
> #include <asm/page.h>
> #include <asm/facility.h>
> #include <asm/interrupt.h>
> @@ -35,22 +36,27 @@ static inline unsigned long load_guarded(unsigned long *p)
>
> /* guarded-storage event handler and finally it calls gs_handler */
> extern void gs_handler_asm(void);
> - asm(".globl gs_handler_asm\n"
> - "gs_handler_asm:\n"
> - " lgr %r14,%r15\n" /* Save current stack address in r14 */
> - " aghi %r15,-320\n" /* Allocate stack frame */
> - " stmg %r0,%r13,192(%r15)\n" /* Store regs to save area */
> - " stg %r14,312(%r15)\n"
> - " la %r2,160(%r15)\n" /* Store gscb address in this_cb */
> - " .insn rxy,0xe30000000049,0,160(%r15)\n" /* stgsc */
> - " lg %r14,24(%r2)\n" /* Get GSEPLA from GSCB*/
> - " lg %r14,40(%r14)\n" /* Get GSERA from GSEPL*/
> - " stg %r14,304(%r15)\n" /* Store GSERA in r14 of reg save area */
> - " brasl %r14,gs_handler\n" /* Jump to gs_handler */
> - " lmg %r0,%r15,192(%r15)\n" /* Restore regs */
> - " aghi %r14, 6\n" /* Add lgg instr len to GSERA */
> - " br %r14\n" /* Jump to next instruction after lgg */
> - " .size gs_handler_asm,.-gs_handler_asm\n");
> + asm ( ".macro STGSC args:vararg\n"
> + " .insn rxy,0xe30000000049,\\args\n"
> + " .endm\n"
> + " .globl gs_handler_asm\n"
> + "gs_handler_asm:\n"
> + " lgr %r14,%r15\n" /* Save current stack address in r14 */
> + ".Lgs_handler_frame = 16*8+32+" xstr(STACK_FRAME_SIZE) "\n"
> + " aghi %r15,-(.Lgs_handler_frame)\n" /* Allocate stack frame */
> + " stmg %r0,%r13,192(%r15)\n" /* Store regs to save area */
> + " stg %r14,312(%r15)\n"
> + " la %r2," xstr(STACK_FRAME_SIZE) "(%r15)\n" /* Store gscb address in this_cb */
> + " STGSC %r0," xstr(STACK_FRAME_SIZE) "(%r15)\n"
> + " lg %r14,24(%r2)\n" /* Get GSEPLA from GSCB*/
> + " lg %r14,40(%r14)\n" /* Get GSERA from GSEPL*/
> + " stg %r14,304(%r15)\n" /* Store GSERA in r14 of reg save area */
> + " brasl %r14,gs_handler\n" /* Jump to gs_handler */
> + " lmg %r0,%r15,192(%r15)\n" /* Restore regs */
> + " aghi %r14, 6\n" /* Add lgg instr len to GSERA */
> + " br %r14\n" /* Jump to next instruction after lgg */
> + ".size gs_handler_asm,.-gs_handler_asm\n"
> + );
>
> void gs_handler(struct gs_cb *this_cb)
> {
> diff --git a/s390x/macros.S b/s390x/macros.S
> index 13cff299488f..e2a56a366c70 100644
> --- a/s390x/macros.S
> +++ b/s390x/macros.S
> @@ -21,14 +21,14 @@
> /* Save the stack address in GR2 which is the first function argument */
> lgr %r2, %r15
> /* Allocate stack space for called C function, as specified in s390 ELF ABI */
> - slgfi %r15, 160
> + slgfi %r15, STACK_FRAME_SIZE
> /*
> * Save the address of the interrupt stack into the back chain
> * of the called function.
> */
> stg %r2, STACK_FRAME_INT_BACKCHAIN(%r15)
> brasl %r14, \c_func
> - algfi %r15, 160
> + algfi %r15, STACK_FRAME_SIZE
> RESTORE_REGS_STACK
> lpswe \old_psw
> .endm
> diff --git a/s390x/snippets/c/flat.lds.S b/s390x/snippets/c/flat.lds.S
> index 9e5eb66bec23..468b5f1eebe8 100644
> --- a/s390x/snippets/c/flat.lds.S
> +++ b/s390x/snippets/c/flat.lds.S
> @@ -1,3 +1,5 @@
> +#include <asm/asm-offsets.h>
> +
> SECTIONS
> {
> .lowcore : {
> @@ -18,9 +20,9 @@ SECTIONS
> . = 0x4000;
> /*
> * The stack grows down from 0x4000 to 0x2000, we pre-allocoate
> - * a frame via the -160.
> + * a frame via the -STACK_FRAME_SIZE.
> */
> - stackptr = . - 160;
> + stackptr = . - STACK_FRAME_SIZE;
> stacktop = .;
> /* Start text 0x4000 */
> .text : {
