/* * arch/xtensa/kernel/coprocessor.S * * Xtensa processor configuration-specific table of coprocessor and * other custom register layout information. * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2003 - 2007 Tensilica Inc. */ #include <linux/linkage.h> #include <asm/asm-offsets.h> #include <asm/processor.h> #include <asm/coprocessor.h> #include <asm/thread_info.h> #include <asm/uaccess.h> #include <asm/unistd.h> #include <asm/ptrace.h> #include <asm/current.h> #include <asm/pgtable.h> #include <asm/page.h> #include <asm/signal.h> #include <asm/tlbflush.h> /* * Entry condition: * * a0: trashed, original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original in DEPC * a3: a3 * depc: a2, original value saved on stack (PT_DEPC) * excsave_1: dispatch table * * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception */ /* IO protection is currently unsupported. */ ENTRY(fast_io_protect) wsr a0, excsave1 movi a0, unrecoverable_exception callx0 a0 ENDPROC(fast_io_protect) #if XTENSA_HAVE_COPROCESSORS /* * Macros for lazy context switch. */ #define SAVE_CP_REGS(x) \ .align 4; \ .Lsave_cp_regs_cp##x: \ .if XTENSA_HAVE_COPROCESSOR(x); \ xchal_cp##x##_store a2 a4 a5 a6 a7; \ .endif; \ jx a0 #define SAVE_CP_REGS_TAB(x) \ .if XTENSA_HAVE_COPROCESSOR(x); \ .long .Lsave_cp_regs_cp##x - .Lsave_cp_regs_jump_table; \ .else; \ .long 0; \ .endif; \ .long THREAD_XTREGS_CP##x #define LOAD_CP_REGS(x) \ .align 4; \ .Lload_cp_regs_cp##x: \ .if XTENSA_HAVE_COPROCESSOR(x); \ xchal_cp##x##_load a2 a4 a5 a6 a7; \ .endif; \ jx a0 #define LOAD_CP_REGS_TAB(x) \ .if XTENSA_HAVE_COPROCESSOR(x); \ .long .Lload_cp_regs_cp##x - .Lload_cp_regs_jump_table; \ .else; \ .long 0; \ .endif; \ .long THREAD_XTREGS_CP##x SAVE_CP_REGS(0) SAVE_CP_REGS(1) SAVE_CP_REGS(2) SAVE_CP_REGS(3) SAVE_CP_REGS(4) SAVE_CP_REGS(5) SAVE_CP_REGS(6) SAVE_CP_REGS(7) LOAD_CP_REGS(0) LOAD_CP_REGS(1) LOAD_CP_REGS(2) LOAD_CP_REGS(3) LOAD_CP_REGS(4) LOAD_CP_REGS(5) LOAD_CP_REGS(6) LOAD_CP_REGS(7) .align 4 .Lsave_cp_regs_jump_table: SAVE_CP_REGS_TAB(0) SAVE_CP_REGS_TAB(1) SAVE_CP_REGS_TAB(2) SAVE_CP_REGS_TAB(3) SAVE_CP_REGS_TAB(4) SAVE_CP_REGS_TAB(5) SAVE_CP_REGS_TAB(6) SAVE_CP_REGS_TAB(7) .Lload_cp_regs_jump_table: LOAD_CP_REGS_TAB(0) LOAD_CP_REGS_TAB(1) LOAD_CP_REGS_TAB(2) LOAD_CP_REGS_TAB(3) LOAD_CP_REGS_TAB(4) LOAD_CP_REGS_TAB(5) LOAD_CP_REGS_TAB(6) LOAD_CP_REGS_TAB(7) /* * coprocessor_save(buffer, index) * a2 a3 * coprocessor_load(buffer, index) * a2 a3 * * Save or load coprocessor registers for coprocessor 'index'. * The register values are saved to or loaded from them 'buffer' address. * * Note that these functions don't update the coprocessor_owner information! * */ ENTRY(coprocessor_save) entry a1, 32 s32i a0, a1, 0 movi a0, .Lsave_cp_regs_jump_table addx8 a3, a3, a0 l32i a3, a3, 0 beqz a3, 1f add a0, a0, a3 callx0 a0 1: l32i a0, a1, 0 retw ENDPROC(coprocessor_save) ENTRY(coprocessor_load) entry a1, 32 s32i a0, a1, 0 movi a0, .Lload_cp_regs_jump_table addx4 a3, a3, a0 l32i a3, a3, 0 beqz a3, 1f add a0, a0, a3 callx0 a0 1: l32i a0, a1, 0 retw ENDPROC(coprocessor_load) /* * coprocessor_flush(struct task_info*, index) * a2 a3 * coprocessor_restore(struct task_info*, index) * a2 a3 * * Save or load coprocessor registers for coprocessor 'index'. * The register values are saved to or loaded from the coprocessor area * inside the task_info structure. * * Note that these functions don't update the coprocessor_owner information! * */ ENTRY(coprocessor_flush) entry a1, 32 s32i a0, a1, 0 movi a0, .Lsave_cp_regs_jump_table addx8 a3, a3, a0 l32i a4, a3, 4 l32i a3, a3, 0 add a2, a2, a4 beqz a3, 1f add a0, a0, a3 callx0 a0 1: l32i a0, a1, 0 retw ENDPROC(coprocessor_flush) ENTRY(coprocessor_restore) entry a1, 32 s32i a0, a1, 0 movi a0, .Lload_cp_regs_jump_table addx4 a3, a3, a0 l32i a4, a3, 4 l32i a3, a3, 0 add a2, a2, a4 beqz a3, 1f add a0, a0, a3 callx0 a0 1: l32i a0, a1, 0 retw ENDPROC(coprocessor_restore) /* * Entry condition: * * a0: trashed, original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original in DEPC * a3: a3 * depc: a2, original value saved on stack (PT_DEPC) * excsave_1: dispatch table * * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception */ ENTRY(fast_coprocessor_double) wsr a0, excsave1 movi a0, unrecoverable_exception callx0 a0 ENDPROC(fast_coprocessor_double) ENTRY(fast_coprocessor) /* Save remaining registers a1-a3 and SAR */ s32i a3, a2, PT_AREG3 rsr a3, sar s32i a1, a2, PT_AREG1 s32i a3, a2, PT_SAR mov a1, a2 rsr a2, depc s32i a2, a1, PT_AREG2 /* * The hal macros require up to 4 temporary registers. We use a3..a6. */ s32i a4, a1, PT_AREG4 s32i a5, a1, PT_AREG5 s32i a6, a1, PT_AREG6 /* Find coprocessor number. Subtract first CP EXCCAUSE from EXCCAUSE */ rsr a3, exccause addi a3, a3, -EXCCAUSE_COPROCESSOR0_DISABLED /* Set corresponding CPENABLE bit -> (sar:cp-index, a3: 1<<cp-index)*/ ssl a3 # SAR: 32 - coprocessor_number movi a2, 1 rsr a0, cpenable sll a2, a2 or a0, a0, a2 wsr a0, cpenable rsync /* Retrieve previous owner. (a3 still holds CP number) */ movi a0, coprocessor_owner # list of owners addx4 a0, a3, a0 # entry for CP l32i a4, a0, 0 beqz a4, 1f # skip 'save' if no previous owner /* Disable coprocessor for previous owner. (a2 = 1 << CP number) */ l32i a5, a4, THREAD_CPENABLE xor a5, a5, a2 # (1 << cp-id) still in a2 s32i a5, a4, THREAD_CPENABLE /* * Get context save area and 'call' save routine. * (a4 still holds previous owner (thread_info), a3 CP number) */ movi a5, .Lsave_cp_regs_jump_table movi a0, 2f # a0: 'return' address addx8 a3, a3, a5 # a3: coprocessor number l32i a2, a3, 4 # a2: xtregs offset l32i a3, a3, 0 # a3: jump offset add a2, a2, a4 add a4, a3, a5 # a4: address of save routine jx a4 /* Note that only a0 and a1 were preserved. */ 2: rsr a3, exccause addi a3, a3, -EXCCAUSE_COPROCESSOR0_DISABLED movi a0, coprocessor_owner addx4 a0, a3, a0 /* Set new 'owner' (a0 points to the CP owner, a3 contains the CP nr) */ 1: GET_THREAD_INFO (a4, a1) s32i a4, a0, 0 /* Get context save area and 'call' load routine. */ movi a5, .Lload_cp_regs_jump_table movi a0, 1f addx8 a3, a3, a5 l32i a2, a3, 4 # a2: xtregs offset l32i a3, a3, 0 # a3: jump offset add a2, a2, a4 add a4, a3, a5 jx a4 /* Restore all registers and return from exception handler. */ 1: l32i a6, a1, PT_AREG6 l32i a5, a1, PT_AREG5 l32i a4, a1, PT_AREG4 l32i a0, a1, PT_SAR l32i a3, a1, PT_AREG3 l32i a2, a1, PT_AREG2 wsr a0, sar l32i a0, a1, PT_AREG0 l32i a1, a1, PT_AREG1 rfe ENDPROC(fast_coprocessor) .data ENTRY(coprocessor_owner) .fill XCHAL_CP_MAX, 4, 0 END(coprocessor_owner) #endif /* XTENSA_HAVE_COPROCESSORS */