1 files changed, 119 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
new file mode 100644
index 000000000..47a92232d
--- /dev/null
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_X86_XSAVE_H
+#define __ASM_X86_XSAVE_H
+
+#include <linux/uaccess.h>
+#include <linux/types.h>
+
+#include <asm/processor.h>
+#include <asm/user.h>
+
+/* Bit 63 of XCR0 is reserved for future expansion */
+#define XFEATURE_MASK_EXTEND	(~(XFEATURE_MASK_FPSSE | (1ULL << 63)))
+
+#define XSTATE_CPUID		0x0000000d
+
+#define FXSAVE_SIZE	512
+
+#define XSAVE_HDR_SIZE	    64
+#define XSAVE_HDR_OFFSET    FXSAVE_SIZE
+
+#define XSAVE_YMM_SIZE	    256
+#define XSAVE_YMM_OFFSET    (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
+
+#define XSAVE_ALIGNMENT     64
+
+/* All currently supported user features */
+#define XFEATURE_MASK_USER_SUPPORTED (XFEATURE_MASK_FP | \
+				      XFEATURE_MASK_SSE | \
+				      XFEATURE_MASK_YMM | \
+				      XFEATURE_MASK_OPMASK | \
+				      XFEATURE_MASK_ZMM_Hi256 | \
+				      XFEATURE_MASK_Hi16_ZMM	 | \
+				      XFEATURE_MASK_PKRU | \
+				      XFEATURE_MASK_BNDREGS | \
+				      XFEATURE_MASK_BNDCSR)
+
+/* All currently supported supervisor features */
+#define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID)
+
+/*
+ * A supervisor state component may not always contain valuable information,
+ * and its size may be huge. Saving/restoring such supervisor state components
+ * at each context switch can cause high CPU and space overhead, which should
+ * be avoided. Such supervisor state components should only be saved/restored
+ * on demand. The on-demand dynamic supervisor features are set in this mask.
+ *
+ * Unlike the existing supported supervisor features, a dynamic supervisor
+ * feature does not allocate a buffer in task->fpu, and the corresponding
+ * supervisor state component cannot be saved/restored at each context switch.
+ *
+ * To support a dynamic supervisor feature, a developer should follow the
+ * dos and don'ts as below:
+ * - Do dynamically allocate a buffer for the supervisor state component.
+ * - Do manually invoke the XSAVES/XRSTORS instruction to save/restore the
+ *   state component to/from the buffer.
+ * - Don't set the bit corresponding to the dynamic supervisor feature in
+ *   IA32_XSS at run time, since it has been set at boot time.
+ */
+#define XFEATURE_MASK_DYNAMIC (XFEATURE_MASK_LBR)
+
+/*
+ * Unsupported supervisor features. When a supervisor feature in this mask is
+ * supported in the future, move it to the supported supervisor feature mask.
+ */
+#define XFEATURE_MASK_SUPERVISOR_UNSUPPORTED (XFEATURE_MASK_PT)
+
+/* All supervisor states including supported and unsupported states. */
+#define XFEATURE_MASK_SUPERVISOR_ALL (XFEATURE_MASK_SUPERVISOR_SUPPORTED | \
+				      XFEATURE_MASK_DYNAMIC | \
+				      XFEATURE_MASK_SUPERVISOR_UNSUPPORTED)
+
+#ifdef CONFIG_X86_64
+#define REX_PREFIX	"0x48, "
+#else
+#define REX_PREFIX
+#endif
+
+extern u64 xfeatures_mask_all;
+
+static inline u64 xfeatures_mask_supervisor(void)
+{
+	return xfeatures_mask_all & XFEATURE_MASK_SUPERVISOR_SUPPORTED;
+}
+
+static inline u64 xfeatures_mask_user(void)
+{
+	return xfeatures_mask_all & XFEATURE_MASK_USER_SUPPORTED;
+}
+
+static inline u64 xfeatures_mask_dynamic(void)
+{
+	if (!boot_cpu_has(X86_FEATURE_ARCH_LBR))
+		return XFEATURE_MASK_DYNAMIC & ~XFEATURE_MASK_LBR;
+
+	return XFEATURE_MASK_DYNAMIC;
+}
+
+extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
+
+extern void __init update_regset_xstate_info(unsigned int size,
+					     u64 xstate_mask);
+
+void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr);
+const void *get_xsave_field_ptr(int xfeature_nr);
+int using_compacted_format(void);
+int xfeature_size(int xfeature_nr);
+struct membuf;
+void copy_xstate_to_kernel(struct membuf to, struct xregs_state *xsave);
+int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf);
+int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf);
+void copy_supervisor_to_kernel(struct xregs_state *xsave);
+void copy_dynamic_supervisor_to_kernel(struct xregs_state *xstate, u64 mask);
+void copy_kernel_to_dynamic_supervisor(struct xregs_state *xstate, u64 mask);
+
+
+/* Validate an xstate header supplied by userspace (ptrace or sigreturn) */
+int validate_user_xstate_header(const struct xstate_header *hdr);
+
+#endif