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-rw-r--r--arch/xtensa/kernel/coprocessor.S443
1 files changed, 289 insertions, 154 deletions
diff --git a/arch/xtensa/kernel/coprocessor.S b/arch/xtensa/kernel/coprocessor.S
index 01bcb9fcfcbd..2bc1e145c0a4 100644
--- a/arch/xtensa/kernel/coprocessor.S
+++ b/arch/xtensa/kernel/coprocessor.S
@@ -8,193 +8,328 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Copyright (C) 2003 - 2005 Tensilica Inc.
- *
- * Marc Gauthier <marc@tensilica.com> <marc@alumni.uwaterloo.ca>
+ * Copyright (C) 2003 - 2007 Tensilica Inc.
*/
-/*
- * This module contains a table that describes the layout of the various
- * custom registers and states associated with each coprocessor, as well
- * as those not associated with any coprocessor ("extra state").
- * This table is included with core dumps and is available via the ptrace
- * interface, allowing the layout of such register/state information to
- * be modified in the kernel without affecting the debugger. Each
- * register or state is identified using a 32-bit "libdb target number"
- * assigned when the Xtensa processor is generated.
- */
#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>
-#if XCHAL_HAVE_CP
+/*
+ * Entry condition:
+ *
+ * a0: trashed, original value saved on stack (PT_AREG0)
+ * a1: a1
+ * a2: new stack pointer, original in DEPC
+ * a3: dispatch table
+ * depc: a2, original value saved on stack (PT_DEPC)
+ * excsave_1: a3
+ *
+ * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC
+ * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception
+ */
-#define CP_LAST ((XCHAL_CP_MAX - 1) * COPROCESSOR_INFO_SIZE)
+/* IO protection is currently unsupported. */
-ENTRY(release_coprocessors)
+ENTRY(fast_io_protect)
+ wsr a0, EXCSAVE_1
+ movi a0, unrecoverable_exception
+ callx0 a0
- entry a1, 16
- # a2: task
- movi a3, 1 << XCHAL_CP_MAX # a3: coprocessor-bit
- movi a4, coprocessor_info+CP_LAST # a4: owner-table
- # a5: tmp
- movi a6, 0 # a6: 0
- rsil a7, LOCKLEVEL # a7: PS
+#if XTENSA_HAVE_COPROCESSORS
-1: /* Check if task is coprocessor owner of coprocessor[i]. */
+/*
+ * Macros for lazy context switch.
+ */
- l32i a5, a4, COPROCESSOR_INFO_OWNER
- srli a3, a3, 1
- beqz a3, 1f
- addi a4, a4, -8
- beq a2, a5, 1b
+#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
- /* Found an entry: Clear entry CPENABLE bit to disable CP. */
+#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
- rsr a5, CPENABLE
- s32i a6, a4, COPROCESSOR_INFO_OWNER
- xor a5, a3, a5
- wsr a5, CPENABLE
- bnez a3, 1b
+#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
-1: wsr a7, PS
- rsync
- retw
+#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)
-ENTRY(disable_coprocessor)
- entry sp, 16
- rsil a7, LOCKLEVEL
- rsr a3, CPENABLE
- movi a4, 1
- ssl a2
- sll a4, a4
- and a4, a3, a4
- xor a3, a3, a4
- wsr a3, CPENABLE
- wsr a7, PS
- rsync
- retw
+ 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)
-ENTRY(enable_coprocessor)
- entry sp, 16
- rsil a7, LOCKLEVEL
- rsr a3, CPENABLE
- movi a4, 1
- ssl a2
- sll a4, a4
- or a3, a3, a4
- wsr a3, CPENABLE
- wsr a7, PS
- rsync
- retw
+ .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)
-ENTRY(save_coprocessor_extra)
- entry sp, 16
- xchal_extra_store_funcbody
- retw
+/*
+ * 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(restore_coprocessor_extra)
- entry sp, 16
- xchal_extra_load_funcbody
+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
-ENTRY(save_coprocessor_registers)
- entry sp, 16
- xchal_cpi_store_funcbody
+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
-ENTRY(restore_coprocessor_registers)
- entry sp, 16
- xchal_cpi_load_funcbody
+/*
+ * 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
+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
/*
- * The Xtensa compile-time HAL (core.h) XCHAL_*_SA_CONTENTS_LIBDB macros
- * describe the contents of coprocessor & extra save areas in terms of
- * undefined CONTENTS_LIBDB_{SREG,UREG,REGF} macros. We define these
- * latter macros here; they expand into a table of the format we want.
- * The general format is:
+ * Entry condition:
*
- * CONTENTS_LIBDB_SREG(libdbnum, offset, size, align, rsv1, name, sregnum,
- * bitmask, rsv2, rsv3)
- * CONTENTS_LIBDB_UREG(libdbnum, offset, size, align, rsv1, name, uregnum,
- * bitmask, rsv2, rsv3)
- * CONTENTS_LIBDB_REGF(libdbnum, offset, size, align, rsv1, name, index,
- * numentries, contentsize, regname_base,
- * regfile_name, rsv2, rsv3)
+ * a0: trashed, original value saved on stack (PT_AREG0)
+ * a1: a1
+ * a2: new stack pointer, original in DEPC
+ * a3: dispatch table
+ * depc: a2, original value saved on stack (PT_DEPC)
+ * excsave_1: a3
*
- * For this table, we only care about the <libdbnum>, <offset> and <size>
- * fields.
+ * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC
+ * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception
*/
-/* Map all XCHAL CONTENTS macros to the reg_entry asm macro defined below: */
-
-#define CONTENTS_LIBDB_SREG(libdbnum,offset,size,align,rsv1,name,sregnum, \
- bitmask, rsv2, rsv3) \
- reg_entry libdbnum, offset, size ;
-#define CONTENTS_LIBDB_UREG(libdbnum,offset,size,align,rsv1,name,uregnum, \
- bitmask, rsv2, rsv3) \
- reg_entry libdbnum, offset, size ;
-#define CONTENTS_LIBDB_REGF(libdbnum, offset, size, align, rsv1, name, index, \
- numentries, contentsize, regname_base, \
- regfile_name, rsv2, rsv3) \
- reg_entry libdbnum, offset, size ;
-
-/* A single table entry: */
- .macro reg_entry libdbnum, offset, size
- .ifne (__last_offset-(__last_group_offset+\offset))
- /* padding entry */
- .word (0xFC000000+__last_offset-(__last_group_offset+\offset))
- .endif
- .word \libdbnum /* actual entry */
- .set __last_offset, __last_group_offset+\offset+\size
- .endm /* reg_entry */
-
-
-/* Table entry that marks the beginning of a group (coprocessor or "extra"): */
- .macro reg_group cpnum, num_entries, align
- .set __last_group_offset, (__last_offset + \align- 1) & -\align
- .ifne \num_entries
- .word 0xFD000000+(\cpnum<<16)+\num_entries
- .endif
- .endm /* reg_group */
+ENTRY(fast_coprocessor_double)
+ wsr a0, EXCSAVE_1
+ movi a0, unrecoverable_exception
+ callx0 a0
-/*
- * Register info tables.
- */
- .section .rodata, "a"
- .globl _xtensa_reginfo_tables
- .globl _xtensa_reginfo_table_size
- .align 4
-_xtensa_reginfo_table_size:
- .word _xtensa_reginfo_table_end - _xtensa_reginfo_tables
-
-_xtensa_reginfo_tables:
- .set __last_offset, 0
- reg_group 0xFF, XCHAL_EXTRA_SA_CONTENTS_LIBDB_NUM, XCHAL_EXTRA_SA_ALIGN
- XCHAL_EXTRA_SA_CONTENTS_LIBDB
- reg_group 0, XCHAL_CP0_SA_CONTENTS_LIBDB_NUM, XCHAL_CP0_SA_ALIGN
- XCHAL_CP0_SA_CONTENTS_LIBDB
- reg_group 1, XCHAL_CP1_SA_CONTENTS_LIBDB_NUM, XCHAL_CP1_SA_ALIGN
- XCHAL_CP1_SA_CONTENTS_LIBDB
- reg_group 2, XCHAL_CP2_SA_CONTENTS_LIBDB_NUM, XCHAL_CP2_SA_ALIGN
- XCHAL_CP2_SA_CONTENTS_LIBDB
- reg_group 3, XCHAL_CP3_SA_CONTENTS_LIBDB_NUM, XCHAL_CP3_SA_ALIGN
- XCHAL_CP3_SA_CONTENTS_LIBDB
- reg_group 4, XCHAL_CP4_SA_CONTENTS_LIBDB_NUM, XCHAL_CP4_SA_ALIGN
- XCHAL_CP4_SA_CONTENTS_LIBDB
- reg_group 5, XCHAL_CP5_SA_CONTENTS_LIBDB_NUM, XCHAL_CP5_SA_ALIGN
- XCHAL_CP5_SA_CONTENTS_LIBDB
- reg_group 6, XCHAL_CP6_SA_CONTENTS_LIBDB_NUM, XCHAL_CP6_SA_ALIGN
- XCHAL_CP6_SA_CONTENTS_LIBDB
- reg_group 7, XCHAL_CP7_SA_CONTENTS_LIBDB_NUM, XCHAL_CP7_SA_ALIGN
- XCHAL_CP7_SA_CONTENTS_LIBDB
- .word 0xFC000000 /* invalid register number,marks end of table*/
-_xtensa_reginfo_table_end:
-#endif
+ENTRY(fast_coprocessor)
+
+ /* Save remaining registers a1-a3 and SAR */
+
+ xsr a3, EXCSAVE_1
+ 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
+
+ .data
+ENTRY(coprocessor_owner)
+ .fill XCHAL_CP_MAX, 4, 0
+
+#endif /* XTENSA_HAVE_COPROCESSORS */
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