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-rw-r--r--arch/arc/Kconfig8
-rw-r--r--arch/arc/include/asm/entry-arcv2.h10
-rw-r--r--arch/arc/include/asm/ptrace.h4
-rw-r--r--arch/arc/kernel/setup.c30
4 files changed, 43 insertions, 9 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index c9f30f4763ab..5d7fb3e7cb97 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -406,6 +406,14 @@ config ARC_HAS_DIV_REM
bool "Insn: div, divu, rem, remu"
default y
+config ARC_HAS_ACCL_REGS
+ bool "Reg Pair ACCL:ACCH (FPU and/or MPY > 6)"
+ default n
+ help
+ Depending on the configuration, CPU can contain accumulator reg-pair
+ (also referred to as r58:r59). These can also be used by gcc as GPR so
+ kernel needs to save/restore per process
+
endif # ISA_ARCV2
endmenu # "ARC CPU Configuration"
diff --git a/arch/arc/include/asm/entry-arcv2.h b/arch/arc/include/asm/entry-arcv2.h
index aee1a77934cf..ac85380d14a4 100644
--- a/arch/arc/include/asm/entry-arcv2.h
+++ b/arch/arc/include/asm/entry-arcv2.h
@@ -16,6 +16,11 @@
;
; Now manually save: r12, sp, fp, gp, r25
+#ifdef CONFIG_ARC_HAS_ACCL_REGS
+ PUSH r59
+ PUSH r58
+#endif
+
PUSH r30
PUSH r12
@@ -75,6 +80,11 @@
POP r12
POP r30
+#ifdef CONFIG_ARC_HAS_ACCL_REGS
+ POP r58
+ POP r59
+#endif
+
.endm
/*------------------------------------------------------------------------*/
diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h
index 47111d565a95..5297faa8a378 100644
--- a/arch/arc/include/asm/ptrace.h
+++ b/arch/arc/include/asm/ptrace.h
@@ -86,6 +86,10 @@ struct pt_regs {
unsigned long r12, r30;
+#ifdef CONFIG_ARC_HAS_ACCL_REGS
+ unsigned long r58, r59; /* ACCL/ACCH used by FPU / DSP MPY */
+#endif
+
/*------- Below list auto saved by h/w -----------*/
unsigned long r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11;
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index fa62404ba58f..fc8211f338ad 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -319,7 +319,8 @@ static char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
static void arc_chk_core_config(void)
{
struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
- int fpu_enabled;
+ int saved = 0, present = 0;
+ char *opt_nm = NULL;;
if (!cpu->extn.timer0)
panic("Timer0 is not present!\n");
@@ -346,17 +347,28 @@ static void arc_chk_core_config(void)
/*
* FP hardware/software config sanity
- * -If hardware contains DPFP, kernel needs to save/restore FPU state
+ * -If hardware present, kernel needs to save/restore FPU state
* -If not, it will crash trying to save/restore the non-existant regs
- *
- * (only DPDP checked since SP has no arch visible regs)
*/
- fpu_enabled = IS_ENABLED(CONFIG_ARC_FPU_SAVE_RESTORE);
- if (cpu->extn.fpu_dp && !fpu_enabled)
- pr_warn("CONFIG_ARC_FPU_SAVE_RESTORE needed for working apps\n");
- else if (!cpu->extn.fpu_dp && fpu_enabled)
- panic("FPU non-existent, disable CONFIG_ARC_FPU_SAVE_RESTORE\n");
+ if (is_isa_arcompact()) {
+ opt_nm = "CONFIG_ARC_FPU_SAVE_RESTORE";
+ saved = IS_ENABLED(CONFIG_ARC_FPU_SAVE_RESTORE);
+
+ /* only DPDP checked since SP has no arch visible regs */
+ present = cpu->extn.fpu_dp;
+ } else {
+ opt_nm = "CONFIG_ARC_HAS_ACCL_REGS";
+ saved = IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS);
+
+ /* Accumulator Low:High pair (r58:59) present if DSP MPY or FPU */
+ present = cpu->extn_mpy.dsp | cpu->extn.fpu_sp | cpu->extn.fpu_dp;
+ }
+
+ if (present && !saved)
+ pr_warn("Enable %s for working apps\n", opt_nm);
+ else if (!present && saved)
+ panic("Disable %s, hardware NOT present\n", opt_nm);
}
/*