[PATCH v1 3/4] powerpc/process: Remove useless #ifdef CONFIG_SPE

From: Christophe Leroy
Date: Mon Aug 17 2020 - 01:48:14 EST


cpu_has_feature(CPU_FTR_SPE) returns false when CONFIG_SPE is
not set.

There is no need to enclose the test in an #ifdef CONFIG_SPE.
Remove it.

CPU_FTR_SPE only exists on 32 bits. Define it as 0 on 64 bits.

We have a couple of places like:

#ifdef CONFIG_SPE
if (cpu_has_feature(CPU_FTR_SPE)) {
do_something_that_requires_CONFIG_SPE
} else {
return -EINVAL;
}
#else
return -EINVAL;
#endif

Replace them by a cleaner version:

if (cpu_has_feature(CPU_FTR_SPE)) {
#ifdef CONFIG_SPE
do_something_that_requires_CONFIG_SPE
#endif
} else {
return -EINVAL;
}

When CONFIG_SPE is not set, this resolves to an unconditional
return of -EINVAL

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/cputable.h | 1 +
arch/powerpc/kernel/process.c | 21 +++++++--------------
2 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index fdddb822d564..cc21dbcc6794 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -165,6 +165,7 @@ static inline void cpu_feature_keys_init(void) { }
#else /* CONFIG_PPC32 */
/* Define these to 0 for the sake of tests in common code */
#define CPU_FTR_PPC_LE (0)
+#define CPU_FTR_SPE (0)
#endif

/*
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 360415689f8a..7090c99a60d9 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -413,10 +413,8 @@ static int __init init_msr_all_available(void)
msr_all_available |= MSR_VEC;
if (cpu_has_feature(CPU_FTR_VSX))
msr_all_available |= MSR_VSX;
-#ifdef CONFIG_SPE
if (cpu_has_feature(CPU_FTR_SPE))
msr_all_available |= MSR_SPE;
-#endif

return 0;
}
@@ -446,10 +444,8 @@ void giveup_all(struct task_struct *tsk)
#endif
if (usermsr & MSR_VEC)
__giveup_altivec(tsk);
-#ifdef CONFIG_SPE
if (usermsr & MSR_SPE)
__giveup_spe(tsk);
-#endif

msr_check_and_clear(msr_all_available);
}
@@ -1843,7 +1839,6 @@ int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
* fpexc_mode. fpexc_mode is also used for setting FP exception
* mode (asyn, precise, disabled) for 'Classic' FP. */
if (val & PR_FP_EXC_SW_ENABLE) {
-#ifdef CONFIG_SPE
if (cpu_has_feature(CPU_FTR_SPE)) {
/*
* When the sticky exception bits are set
@@ -1857,16 +1852,15 @@ int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
* anyway to restore the prctl settings from
* the saved environment.
*/
+#ifdef CONFIG_SPE
tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
tsk->thread.fpexc_mode = val &
(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
+#endif
return 0;
} else {
return -EINVAL;
}
-#else
- return -EINVAL;
-#endif
}

/* on a CONFIG_SPE this does not hurt us. The bits that
@@ -1887,8 +1881,7 @@ int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
{
unsigned int val;

- if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
-#ifdef CONFIG_SPE
+ if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) {
if (cpu_has_feature(CPU_FTR_SPE)) {
/*
* When the sticky exception bits are set
@@ -1902,15 +1895,15 @@ int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
* anyway to restore the prctl settings from
* the saved environment.
*/
+#ifdef CONFIG_SPE
tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
val = tsk->thread.fpexc_mode;
+#endif
} else
return -EINVAL;
-#else
- return -EINVAL;
-#endif
- else
+ } else {
val = __unpack_fe01(tsk->thread.fpexc_mode);
+ }
return put_user(val, (unsigned int __user *) adr);
}

--
2.25.0