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authorCatalin Marinas <catalin.marinas@arm.com>2009-02-11 13:12:56 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-02-12 10:59:43 +0000
commit3d1228ead618b88e8606015cbabc49019981805d (patch)
tree5d44c936c12ff2e99732f535dd393af201e7fe67 /arch/arm/vfp
parentf373e8c0639f1720d2d0fe414990f504e113c2ba (diff)
[ARM] 5387/1: Add ptrace VFP support on ARM
This patch adds ptrace support for setting and getting the VFP registers using PTRACE_SETVFPREGS and PTRACE_GETVFPREGS. The user_vfp structure defined in asm/user.h contains 32 double registers (to cover VFPv3 and Neon hardware) and the FPSCR register. Cc: Paul Brook <paul@codesourcery.com> Cc: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/vfp')
-rw-r--r--arch/arm/vfp/vfp.h2
-rw-r--r--arch/arm/vfp/vfphw.S2
-rw-r--r--arch/arm/vfp/vfpmodule.c49
3 files changed, 49 insertions, 4 deletions
diff --git a/arch/arm/vfp/vfp.h b/arch/arm/vfp/vfp.h
index 8de86e4fead..c8c98dd44ad 100644
--- a/arch/arm/vfp/vfp.h
+++ b/arch/arm/vfp/vfp.h
@@ -377,6 +377,4 @@ struct op {
u32 flags;
};
-#if defined(CONFIG_SMP) || defined(CONFIG_PM)
extern void vfp_save_state(void *location, u32 fpexc);
-#endif
diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
index c92a08bd6a8..a5a4e57763c 100644
--- a/arch/arm/vfp/vfphw.S
+++ b/arch/arm/vfp/vfphw.S
@@ -172,7 +172,6 @@ process_exception:
@ retry the faulted instruction
ENDPROC(vfp_support_entry)
-#if defined(CONFIG_SMP) || defined(CONFIG_PM)
ENTRY(vfp_save_state)
@ Save the current VFP state
@ r0 - save location
@@ -190,7 +189,6 @@ ENTRY(vfp_save_state)
stmia r0, {r1, r2, r3, r12} @ save FPEXC, FPSCR, FPINST, FPINST2
mov pc, lr
ENDPROC(vfp_save_state)
-#endif
last_VFP_context_address:
.word last_VFP_context
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 9f476a1be2c..7e1239041b3 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -377,6 +377,55 @@ static void vfp_pm_init(void)
static inline void vfp_pm_init(void) { }
#endif /* CONFIG_PM */
+/*
+ * Synchronise the hardware VFP state of a thread other than current with the
+ * saved one. This function is used by the ptrace mechanism.
+ */
+#ifdef CONFIG_SMP
+void vfp_sync_state(struct thread_info *thread)
+{
+ /*
+ * On SMP systems, the VFP state is automatically saved at every
+ * context switch. We mark the thread VFP state as belonging to a
+ * non-existent CPU so that the saved one will be reloaded when
+ * needed.
+ */
+ thread->vfpstate.hard.cpu = NR_CPUS;
+}
+#else
+void vfp_sync_state(struct thread_info *thread)
+{
+ unsigned int cpu = get_cpu();
+ u32 fpexc = fmrx(FPEXC);
+
+ /*
+ * If VFP is enabled, the previous state was already saved and
+ * last_VFP_context updated.
+ */
+ if (fpexc & FPEXC_EN)
+ goto out;
+
+ if (!last_VFP_context[cpu])
+ goto out;
+
+ /*
+ * Save the last VFP state on this CPU.
+ */
+ fmxr(FPEXC, fpexc | FPEXC_EN);
+ vfp_save_state(last_VFP_context[cpu], fpexc);
+ fmxr(FPEXC, fpexc);
+
+ /*
+ * Set the context to NULL to force a reload the next time the thread
+ * uses the VFP.
+ */
+ last_VFP_context[cpu] = NULL;
+
+out:
+ put_cpu();
+}
+#endif
+
#include <linux/smp.h>
/*