Module: xenomai-3
Branch: next
Commit: 42d137fca23021da0aef8222cc0146d11913464d
URL:
http://git.xenomai.org/?p=xenomai-3.git;a=commit;h=42d137fca23021da0aef8222cc0146d11913464d
Author: Gilles Chanteperdrix <gilles.chanteperd...@xenomai.org>
Date: Fri Oct 30 17:14:00 2015 +0100
cobalt/arm64: attempt at fixing fpu switch
Return to eager switching, since user-space applications use FPU
registers even when not using the FPU, but use an auxiliary backup area
when the "TIF_FOREIGN_FPSTATE" bit is set, in order to avoid clobbering
the saved FPU state.
---
.../cobalt/arch/arm64/include/asm/xenomai/thread.h | 14 +++--
kernel/cobalt/arch/arm64/thread.c | 54 +++++---------------
2 files changed, 25 insertions(+), 43 deletions(-)
diff --git a/kernel/cobalt/arch/arm64/include/asm/xenomai/thread.h
b/kernel/cobalt/arch/arm64/include/asm/xenomai/thread.h
index 9055e58..4b247ac 100644
--- a/kernel/cobalt/arch/arm64/include/asm/xenomai/thread.h
+++ b/kernel/cobalt/arch/arm64/include/asm/xenomai/thread.h
@@ -24,6 +24,7 @@
struct xnarchtcb {
struct xntcb core;
#ifdef CONFIG_XENO_ARCH_FPU
+ struct fpsimd_state xnfpsimd_state;
struct fpsimd_state *fpup;
#define xnarch_fpu_ptr(tcb) ((tcb)->fpup)
#endif
@@ -67,7 +68,10 @@ static inline void xnarch_init_root_tcb(struct xnthread
*thread)
void xnarch_init_shadow_tcb(struct xnthread *thread);
-int xnarch_fault_fpu_p(struct ipipe_trap_data *d);
+static inline int xnarch_fault_fpu_p(struct ipipe_trap_data *d)
+{
+ return xnarch_fault_trap(d) == IPIPE_TRAP_FPU_ACC;
+}
void xnarch_leave_root(struct xnthread *root);
@@ -75,8 +79,12 @@ void xnarch_save_fpu(struct xnthread *thread);
void xnarch_switch_fpu(struct xnthread *from, struct xnthread *thread);
-int xnarch_handle_fpu_fault(struct xnthread *from,
- struct xnthread *to, struct ipipe_trap_data *d);
+static inline int
+xnarch_handle_fpu_fault(struct xnthread *from,
+ struct xnthread *to, struct ipipe_trap_data *d)
+{
+ return 0;
+}
#else /* !CONFIG_XENO_ARCH_FPU */
diff --git a/kernel/cobalt/arch/arm64/thread.c
b/kernel/cobalt/arch/arm64/thread.c
index 2238751..b987e09 100644
--- a/kernel/cobalt/arch/arm64/thread.c
+++ b/kernel/cobalt/arch/arm64/thread.c
@@ -6,6 +6,7 @@
*
* ARM64 port
* Copyright (C) 2015 Dmitriy Cherkasov <dmit...@mperpetuo.com>
+ * Copyright (C) 2015 Gilles Chanteperdrix <g...@xenomai.org>
*
* Xenomai is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
@@ -41,7 +42,7 @@
static inline unsigned long get_cpacr(void)
{
unsigned long result;
- __asm__ __volatile__("mrs %0, cpacr_el1": "=r"(result));
+ __asm__ ("mrs %0, cpacr_el1": "=r"(result));
return result;
}
@@ -53,21 +54,20 @@ static inline void set_cpacr(long val)
: /* */ : "r"(val));
}
-static void enable_fpsimd(void)
+static inline void enable_fpsimd(void)
{
- unsigned long cpacr = get_cpacr();
- cpacr |= FPSIMD_EN;
- set_cpacr(cpacr);
+ set_cpacr(get_cpacr() | FPSIMD_EN);
}
-int xnarch_fault_fpu_p(struct ipipe_trap_data *d)
+static inline struct fpsimd_state *get_fpu_owner(struct xnarchtcb *rootcb)
{
- return (d->exception == IPIPE_TRAP_FPU_ACC);
-}
+ struct task_struct *curr = rootcb->core.host_task;
-static inline struct fpsimd_state *get_fpu_owner(struct xnarchtcb *tcb)
-{
- return &(tcb->core.tsp->fpsimd_state);
+ if (test_ti_thread_flag(task_thread_info(curr), TIF_FOREIGN_FPSTATE))
+ /* Foreign fpu state, use auxiliary backup area */
+ return &rootcb->xnfpsimd_state;
+
+ return &curr->thread.fpsimd_state;
}
void xnarch_leave_root(struct xnthread *root)
@@ -76,13 +76,6 @@ void xnarch_leave_root(struct xnthread *root)
rootcb->fpup = get_fpu_owner(rootcb);
}
-void xnarch_save_fpu(struct xnthread *thread)
-{
- struct xnarchtcb *tcb = &(thread->tcb);
- if (xnarch_fpu_ptr(tcb))
- fpsimd_save_state(tcb->fpup);
-}
-
void xnarch_switch_fpu(struct xnthread *from, struct xnthread *to)
{
struct fpsimd_state *const from_fpup = from ? from->tcb.fpup : NULL;
@@ -93,35 +86,16 @@ void xnarch_switch_fpu(struct xnthread *from, struct
xnthread *to)
if (from_fpup == to_fpup)
return;
- if (from_fpup)
- fpsimd_save_state(from_fpup);
+ fpsimd_save_state(from_fpup);
fpsimd_load_state(to_fpup);
-}
-
-int xnarch_handle_fpu_fault(struct xnthread *from,
- struct xnthread *to, struct ipipe_trap_data *d)
-{
- spl_t s;
-
- /* FPU should already be enabled for XNFPU tasks. */
- if (xnthread_test_state(to, XNFPU))
- BUG();
-
- xnlock_get_irqsave(&nklock, s);
- xnthread_set_state(to, XNFPU);
- xnlock_put_irqrestore(&nklock, s);
-
- xnarch_switch_fpu(from, to);
-
- return 1;
+ to_fpup->cpu = ipipe_processor_id();
}
void xnarch_init_shadow_tcb(struct xnthread *thread)
{
struct xnarchtcb *tcb = xnthread_archtcb(thread);
- tcb->fpup = &(tcb->core.host_task->thread.fpsimd_state);
- xnthread_clear_state(thread, XNFPU);
+ tcb->fpup = &tcb->core.host_task->thread.fpsimd_state;
}
#endif /* CONFIG_XENO_ARCH_FPU */
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