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-rw-r--r--arch/powerpc/kernel/ptrace/ptrace-altivec.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/ptrace/ptrace-altivec.c b/arch/powerpc/kernel/ptrace/ptrace-altivec.c
new file mode 100644
index 000000000000..dd8b75dfbd06
--- /dev/null
+++ b/arch/powerpc/kernel/ptrace/ptrace-altivec.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/regset.h>
+#include <linux/elf.h>
+
+#include <asm/switch_to.h>
+
+#include "ptrace-decl.h"
+
+/*
+ * Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
+ * The transfer totals 34 quadword. Quadwords 0-31 contain the
+ * corresponding vector registers. Quadword 32 contains the vscr as the
+ * last word (offset 12) within that quadword. Quadword 33 contains the
+ * vrsave as the first word (offset 0) within the quadword.
+ *
+ * This definition of the VMX state is compatible with the current PPC32
+ * ptrace interface. This allows signal handling and ptrace to use the
+ * same structures. This also simplifies the implementation of a bi-arch
+ * (combined (32- and 64-bit) gdb.
+ */
+
+int vr_active(struct task_struct *target, const struct user_regset *regset)
+{
+ flush_altivec_to_thread(target);
+ return target->thread.used_vr ? regset->n : 0;
+}
+
+/*
+ * Regardless of transactions, 'vr_state' holds the current running
+ * value of all the VMX registers and 'ckvr_state' holds the last
+ * checkpointed value of all the VMX registers for the current
+ * transaction to fall back on in case it aborts.
+ *
+ * Userspace interface buffer layout:
+ *
+ * struct data {
+ * vector128 vr[32];
+ * vector128 vscr;
+ * vector128 vrsave;
+ * };
+ */
+int vr_get(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf)
+{
+ int ret;
+
+ flush_altivec_to_thread(target);
+
+ BUILD_BUG_ON(offsetof(struct thread_vr_state, vscr) !=
+ offsetof(struct thread_vr_state, vr[32]));
+
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.vr_state, 0,
+ 33 * sizeof(vector128));
+ if (!ret) {
+ /*
+ * Copy out only the low-order word of vrsave.
+ */
+ int start, end;
+ union {
+ elf_vrreg_t reg;
+ u32 word;
+ } vrsave;
+ memset(&vrsave, 0, sizeof(vrsave));
+
+ vrsave.word = target->thread.vrsave;
+
+ start = 33 * sizeof(vector128);
+ end = start + sizeof(vrsave);
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &vrsave,
+ start, end);
+ }
+
+ return ret;
+}
+
+/*
+ * Regardless of transactions, 'vr_state' holds the current running
+ * value of all the VMX registers and 'ckvr_state' holds the last
+ * checkpointed value of all the VMX registers for the current
+ * transaction to fall back on in case it aborts.
+ *
+ * Userspace interface buffer layout:
+ *
+ * struct data {
+ * vector128 vr[32];
+ * vector128 vscr;
+ * vector128 vrsave;
+ * };
+ */
+int vr_set(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ int ret;
+
+ flush_altivec_to_thread(target);
+
+ BUILD_BUG_ON(offsetof(struct thread_vr_state, vscr) !=
+ offsetof(struct thread_vr_state, vr[32]));
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.vr_state, 0,
+ 33 * sizeof(vector128));
+ if (!ret && count > 0) {
+ /*
+ * We use only the first word of vrsave.
+ */
+ int start, end;
+ union {
+ elf_vrreg_t reg;
+ u32 word;
+ } vrsave;
+ memset(&vrsave, 0, sizeof(vrsave));
+
+ vrsave.word = target->thread.vrsave;
+
+ start = 33 * sizeof(vector128);
+ end = start + sizeof(vrsave);
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &vrsave,
+ start, end);
+ if (!ret)
+ target->thread.vrsave = vrsave.word;
+ }
+
+ return ret;
+}