--- /dev/null
+/*
+ * Save/restore CPU state macros
+ *
+ * Copyright (C) 2015 Mark Cave-Ayland (mark.cave-ayland@ilande.co.uk>)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2
+ *
+ */
+
+/* State size for context (see below) */
+#define CONTEXT_STATE_SIZE 0x510
+
+/* Stack size for context (allocated inline of the context stack) */
+#define CONTEXT_STACK_SIZE 0x2000
+
+/*
+ * SAVE_CPU_STATE and RESTORE_CPU_STATE are macros used to enable a context switch
+ * to C to occur within the MMU I/D TLB miss handlers.
+ *
+ * Because these handlers are called on a TLB miss, we cannot use flushw to store
+ * processor window state on the stack, as the memory areas used by each window's
+ * stack pointer may not be in the TLB, causing recursive TLB miss traps.
+ *
+ * For this reason, we save window state by manually rotating the window registers
+ * and saving their contents (along with other vital registers) into a special
+ * tlb_handler_stack defined above which is guaranteed to be locked in the TLB, and
+ * so won't cause issues with trap recursion.
+ *
+ * Once this process is complete, we remain in a TL=0, CWP=0 state (with IE=1 to allow
+ * window fill/spill traps if required), switch to our safe tlb_handler_stack and
+ * invoke the miss handler.
+ */
+
+#define SAVE_CPU_WINDOW_STATE(type) \
+ /* Save window state into context at %g1 */ \
+ rdpr %cwp, %g7; \
+ stx %g7, [%g1]; \
+ rdpr %cansave, %g7; \
+ stx %g7, [%g1 + 0x8]; \
+ rdpr %canrestore, %g7; \
+ stx %g7, [%g1 + 0x10]; \
+ rdpr %otherwin, %g7; \
+ stx %g7, [%g1 + 0x18]; \
+ rdpr %wstate, %g7; \
+ stx %g7, [%g1 + 0x20]; \
+ rdpr %cleanwin, %g7; \
+ stx %g7, [%g1 + 0x28]; \
+ \
+ stx %o0, [%g1 + 0x30]; \
+ stx %o1, [%g1 + 0x38]; \
+ stx %o2, [%g1 + 0x40]; \
+ stx %o3, [%g1 + 0x48]; \
+ stx %o4, [%g1 + 0x50]; \
+ stx %o5, [%g1 + 0x58]; \
+ stx %o6, [%g1 + 0x60]; \
+ stx %o7, [%g1 + 0x68]; \
+ \
+ rdpr %pstate, %g7; \
+ stx %g7, [%g1 + 0x70]; \
+ rd %y, %g7; \
+ stx %g7, [%g1 + 0x78]; \
+ rd %fprs, %g7; \
+ stx %g7, [%g1 + 0x80]; \
+ rdpr %tl, %g7; \
+ stx %g7, [%g1 + 0x88]; \
+ \
+ /* Now iterate through all of the windows saving all l and i registers */ \
+ add %g1, 0x90, %g5; \
+ \
+ /* Get the number of windows in %g6 */ \
+ rdpr %ver, %g6; \
+ and %g6, 0xf, %g6; \
+ \
+ mov %g6, %g4; \
+ inc %g4; \
+ \
+ /* Starting cwp in g7 */ \
+ rdpr %cwp, %g7; \
+ \
+save_cpu_window_##type: \
+ wrpr %g7, %cwp; \
+ stx %l0, [%g5]; \
+ stx %l1, [%g5 + 0x8]; \
+ stx %l2, [%g5 + 0x10]; \
+ stx %l3, [%g5 + 0x18]; \
+ stx %l4, [%g5 + 0x20]; \
+ stx %l5, [%g5 + 0x28]; \
+ stx %l6, [%g5 + 0x30]; \
+ stx %l7, [%g5 + 0x38]; \
+ stx %i0, [%g5 + 0x40]; \
+ stx %i1, [%g5 + 0x48]; \
+ stx %i2, [%g5 + 0x50]; \
+ stx %i3, [%g5 + 0x58]; \
+ stx %i4, [%g5 + 0x60]; \
+ stx %i5, [%g5 + 0x68]; \
+ stx %i6, [%g5 + 0x70]; \
+ stx %i7, [%g5 + 0x78]; \
+ dec %g7; \
+ and %g7, %g6, %g7; \
+ subcc %g4, 1, %g4; \
+ bne save_cpu_window_##type; \
+ add %g5, 0x80, %g5; \
+ \
+ /* For 8 windows with 16 registers to save in the window, memory required \
+ is 16*8*8 = 0x400 bytes */ \
+ \
+ /* Now we should be in window 0 so update the other window registers */ \
+ rdpr %ver, %g6; \
+ and %g6, 0xf, %g6; \
+ dec %g6; \
+ wrpr %g6, %cansave; \
+ \
+ wrpr %g0, %cleanwin; \
+ wrpr %g0, %canrestore; \
+ wrpr %g0, %otherwin; \
+
+
+#define SAVE_CPU_TRAP_STATE(type) \
+ /* Save trap state into context at %g1 */ \
+ add %g1, 0x490, %g5; \
+ mov 4, %g6; \
+ \
+save_trap_state_##type: \
+ deccc %g6; \
+ wrpr %g6, %tl; \
+ rdpr %tpc, %g7; \
+ stx %g7, [%g5]; \
+ rdpr %tnpc, %g7; \
+ stx %g7, [%g5 + 0x8]; \
+ rdpr %tstate, %g7; \
+ stx %g7, [%g5 + 0x10]; \
+ rdpr %tt, %g7; \
+ stx %g7, [%g5 + 0x18]; \
+ bne save_trap_state_##type; \
+ add %g5, 0x20, %g5; \
+ \
+ /* For 4 trap levels with 4 registers, memory required is \
+ 4*8*4 = 0x80 bytes */
+
+/* Save all state into context at %g1 */
+#define SAVE_CPU_STATE(type) \
+ SAVE_CPU_WINDOW_STATE(type); \
+ SAVE_CPU_TRAP_STATE(type);
+
+
+#define RESTORE_CPU_WINDOW_STATE(type) \
+ /* Restore window state from context at %g1 */ \
+ \
+ /* Get the number of windows in %g6 */ \
+ rdpr %ver, %g6; \
+ and %g6, 0xf, %g6; \
+ \
+ mov %g6, %g4; \
+ inc %g4; \
+ \
+ /* Set starting window */ \
+ ldx [%g1], %g7; \
+ \
+ /* Now iterate through all of the windows restoring all l and i registers */ \
+ add %g1, 0x90, %g5; \
+ \
+restore_cpu_window_##type: \
+ wrpr %g7, %cwp; \
+ ldx [%g5], %l0; \
+ ldx [%g5 + 0x8], %l1; \
+ ldx [%g5 + 0x10], %l2; \
+ ldx [%g5 + 0x18], %l3; \
+ ldx [%g5 + 0x20], %l4; \
+ ldx [%g5 + 0x28], %l5; \
+ ldx [%g5 + 0x30], %l6; \
+ ldx [%g5 + 0x38], %l7; \
+ ldx [%g5 + 0x40], %i0; \
+ ldx [%g5 + 0x48], %i1; \
+ ldx [%g5 + 0x50], %i2; \
+ ldx [%g5 + 0x58], %i3; \
+ ldx [%g5 + 0x60], %i4; \
+ ldx [%g5 + 0x68], %i5; \
+ ldx [%g5 + 0x70], %i6; \
+ ldx [%g5 + 0x78], %i7; \
+ dec %g7; \
+ and %g7, %g6, %g7; \
+ subcc %g4, 1, %g4; \
+ bne restore_cpu_window_##type; \
+ add %g5, 0x80, %g5; \
+ \
+ /* Restore the window registers to their original value */ \
+ ldx [%g1], %g7; \
+ wrpr %g7, %cwp; \
+ ldx [%g1 + 0x8], %g7; \
+ wrpr %g7, %cansave; \
+ ldx [%g1 + 0x10], %g7; \
+ wrpr %g7, %canrestore; \
+ ldx [%g1 + 0x18], %g7; \
+ wrpr %g7, %otherwin; \
+ ldx [%g1 + 0x20], %g7; \
+ wrpr %g7, %wstate; \
+ ldx [%g1 + 0x28], %g7; \
+ wrpr %g7, %cleanwin; \
+ \
+ ldx [%g1 + 0x30], %o0; \
+ ldx [%g1 + 0x38], %o1; \
+ ldx [%g1 + 0x40], %o2; \
+ ldx [%g1 + 0x48], %o3; \
+ ldx [%g1 + 0x50], %o4; \
+ ldx [%g1 + 0x58], %o5; \
+ ldx [%g1 + 0x60], %o6; \
+ ldx [%g1 + 0x68], %o7; \
+ \
+ ldx [%g1 + 0x70], %g7; \
+ wrpr %g7, %pstate; \
+ ldx [%g1 + 0x78], %g7; \
+ wr %g7, 0, %y; \
+ ldx [%g1 + 0x80], %g7; \
+ wr %g7, 0, %fprs; \
+
+
+#define RESTORE_CPU_TRAP_STATE(type) \
+ /* Restore trap state from context at %g1 */ \
+ add %g1, 0x490, %g5; \
+ mov 4, %g6; \
+ \
+restore_trap_state_##type: \
+ deccc %g6; \
+ wrpr %g6, %tl; \
+ ldx [%g5], %g7; \
+ wrpr %g7, %tpc; \
+ ldx [%g5 + 0x8], %g7; \
+ wrpr %g7, %tnpc; \
+ ldx [%g5 + 0x10], %g7; \
+ wrpr %g7, %tstate; \
+ ldx [%g5 + 0x18], %g7; \
+ wrpr %g7, %tt; \
+ bne restore_trap_state_##type; \
+ add %g5, 0x20, %g5; \
+ \
+ ldx [%g1 + 0x88], %g7; \
+ wrpr %g7, %tl
+
+/* Restore all state from context at %g1 */
+#define RESTORE_CPU_STATE(type) \
+ RESTORE_CPU_WINDOW_STATE(type); \
+ RESTORE_CPU_TRAP_STATE(type);
Code Review / kvmfornfv.git / blobdiff