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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/vfpmodule.c
parentf373e8c0639f1720d2d0fe414990f504e113c2ba (diff)
downloadop-kernel-dev-3d1228ead618b88e8606015cbabc49019981805d.zip
op-kernel-dev-3d1228ead618b88e8606015cbabc49019981805d.tar.gz
[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/vfpmodule.c')
-rw-r--r--arch/arm/vfp/vfpmodule.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 9f476a1..7e12390 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>
/*
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