[XTENSA] Add support for configurable registers and coprocessors
The Xtensa architecture allows to define custom instructions and
registers. Registers that are bound to a coprocessor are only
accessible if the corresponding enable bit is set, which allows
to implement a 'lazy' context switch mechanism. Other registers
needs to be saved and restore at the time of the context switch
or during interrupt handling.
This patch adds support for these additional states:
- save and restore registers that are used by the compiler upon
interrupt entry and exit.
- context switch additional registers unbound to any coprocessor
- 'lazy' context switch of registers bound to a coprocessor
- ptrace interface to provide access to additional registers
- update configuration files in include/asm-xtensa/variant-fsf
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/include/asm-xtensa/coprocessor.h b/include/asm-xtensa/coprocessor.h
index aa21210..e5849bb 100644
--- a/include/asm-xtensa/coprocessor.h
+++ b/include/asm-xtensa/coprocessor.h
@@ -5,81 +5,168 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Copyright (C) 2003 - 2005 Tensilica Inc.
+ * Copyright (C) 2003 - 2007 Tensilica Inc.
*/
+
#ifndef _XTENSA_COPROCESSOR_H
#define _XTENSA_COPROCESSOR_H
-#include <asm/variant/core.h>
+#include <linux/stringify.h>
#include <asm/variant/tie.h>
+#include <asm/types.h>
-#if !XCHAL_HAVE_CP
+#ifdef __ASSEMBLY__
+# include <asm/variant/tie-asm.h>
-#define XTENSA_CP_EXTRA_OFFSET 0
-#define XTENSA_CP_EXTRA_ALIGN 1 /* must be a power of 2 */
-#define XTENSA_CP_EXTRA_SIZE 0
+.macro xchal_sa_start a b
+ .set .Lxchal_pofs_, 0
+ .set .Lxchal_ofs_, 0
+.endm
-#else
+.macro xchal_sa_align ptr minofs maxofs ofsalign totalign
+ .set .Lxchal_ofs_, .Lxchal_ofs_ + .Lxchal_pofs_ + \totalign - 1
+ .set .Lxchal_ofs_, (.Lxchal_ofs_ & -\totalign) - .Lxchal_pofs_
+.endm
-#define XTOFS(last_start,last_size,align) \
- ((last_start+last_size+align-1) & -align)
+#define _SELECT ( XTHAL_SAS_TIE | XTHAL_SAS_OPT \
+ | XTHAL_SAS_CC \
+ | XTHAL_SAS_CALR | XTHAL_SAS_CALE | XTHAL_SAS_GLOB )
-#define XTENSA_CP_EXTRA_OFFSET 0
-#define XTENSA_CP_EXTRA_ALIGN XCHAL_EXTRA_SA_ALIGN
+.macro save_xtregs_opt ptr clb at1 at2 at3 at4 offset
+ .if XTREGS_OPT_SIZE > 0
+ addi \clb, \ptr, \offset
+ xchal_ncp_store \clb \at1 \at2 \at3 \at4 select=_SELECT
+ .endif
+.endm
-#define XTENSA_CPE_CP0_OFFSET \
- XTOFS(XTENSA_CP_EXTRA_OFFSET, XCHAL_EXTRA_SA_SIZE, XCHAL_CP0_SA_ALIGN)
-#define XTENSA_CPE_CP1_OFFSET \
- XTOFS(XTENSA_CPE_CP0_OFFSET, XCHAL_CP0_SA_SIZE, XCHAL_CP1_SA_ALIGN)
-#define XTENSA_CPE_CP2_OFFSET \
- XTOFS(XTENSA_CPE_CP1_OFFSET, XCHAL_CP1_SA_SIZE, XCHAL_CP2_SA_ALIGN)
-#define XTENSA_CPE_CP3_OFFSET \
- XTOFS(XTENSA_CPE_CP2_OFFSET, XCHAL_CP2_SA_SIZE, XCHAL_CP3_SA_ALIGN)
-#define XTENSA_CPE_CP4_OFFSET \
- XTOFS(XTENSA_CPE_CP3_OFFSET, XCHAL_CP3_SA_SIZE, XCHAL_CP4_SA_ALIGN)
-#define XTENSA_CPE_CP5_OFFSET \
- XTOFS(XTENSA_CPE_CP4_OFFSET, XCHAL_CP4_SA_SIZE, XCHAL_CP5_SA_ALIGN)
-#define XTENSA_CPE_CP6_OFFSET \
- XTOFS(XTENSA_CPE_CP5_OFFSET, XCHAL_CP5_SA_SIZE, XCHAL_CP6_SA_ALIGN)
-#define XTENSA_CPE_CP7_OFFSET \
- XTOFS(XTENSA_CPE_CP6_OFFSET, XCHAL_CP6_SA_SIZE, XCHAL_CP7_SA_ALIGN)
-#define XTENSA_CP_EXTRA_SIZE \
- XTOFS(XTENSA_CPE_CP7_OFFSET, XCHAL_CP7_SA_SIZE, 16)
+.macro load_xtregs_opt ptr clb at1 at2 at3 at4 offset
+ .if XTREGS_OPT_SIZE > 0
+ addi \clb, \ptr, \offset
+ xchal_ncp_load \clb \at1 \at2 \at3 \at4 select=_SELECT
+ .endif
+.endm
+#undef _SELECT
-#if XCHAL_CP_NUM > 0
-# ifndef __ASSEMBLY__
+#define _SELECT ( XTHAL_SAS_TIE | XTHAL_SAS_OPT \
+ | XTHAL_SAS_NOCC \
+ | XTHAL_SAS_CALR | XTHAL_SAS_CALE | XTHAL_SAS_GLOB )
+
+.macro save_xtregs_user ptr clb at1 at2 at3 at4 offset
+ .if XTREGS_USER_SIZE > 0
+ addi \clb, \ptr, \offset
+ xchal_ncp_store \clb \at1 \at2 \at3 \at4 select=_SELECT
+ .endif
+.endm
+
+.macro load_xtregs_user ptr clb at1 at2 at3 at4 offset
+ .if XTREGS_USER_SIZE > 0
+ addi \clb, \ptr, \offset
+ xchal_ncp_load \clb \at1 \at2 \at3 \at4 select=_SELECT
+ .endif
+.endm
+#undef _SELECT
+
+
+
+#endif /* __ASSEMBLY__ */
+
/*
- * Tasks that own contents of (last user) each coprocessor.
- * Entries are 0 for not-owned or non-existent coprocessors.
- * Note: The size of this structure is fixed to 8 bytes in entry.S
+ * XTENSA_HAVE_COPROCESSOR(x) returns 1 if coprocessor x is configured.
+ *
+ * XTENSA_HAVE_IO_PORT(x) returns 1 if io-port x is configured.
+ *
*/
-typedef struct {
- struct task_struct *owner; /* owner */
- int offset; /* offset in cpextra space. */
-} coprocessor_info_t;
-# else
-# define COPROCESSOR_INFO_OWNER 0
-# define COPROCESSOR_INFO_OFFSET 4
-# define COPROCESSOR_INFO_SIZE 8
-# endif
-#endif
-#endif /* XCHAL_HAVE_CP */
+#define XTENSA_HAVE_COPROCESSOR(x) \
+ ((XCHAL_CP_MASK ^ XCHAL_CP_PORT_MASK) & (1 << (x)))
+#define XTENSA_HAVE_COPROCESSORS \
+ (XCHAL_CP_MASK ^ XCHAL_CP_PORT_MASK)
+#define XTENSA_HAVE_IO_PORT(x) \
+ (XCHAL_CP_PORT_MASK & (1 << (x)))
+#define XTENSA_HAVE_IO_PORTS \
+ XCHAL_CP_PORT_MASK
#ifndef __ASSEMBLY__
-# if XCHAL_CP_NUM > 0
-struct task_struct;
-extern void release_coprocessors (struct task_struct*);
-extern void save_coprocessor_registers(void*, int);
-# else
-# define release_coprocessors(task)
-# endif
-typedef unsigned char cp_state_t[XTENSA_CP_EXTRA_SIZE]
- __attribute__ ((aligned (XTENSA_CP_EXTRA_ALIGN)));
+
+#if XCHAL_HAVE_CP
+
+#define RSR_CPENABLE(x) do { \
+ __asm__ __volatile__("rsr %0," __stringify(CPENABLE) : "=a" (x)); \
+ } while(0);
+#define WSR_CPENABLE(x) do { \
+ __asm__ __volatile__("wsr %0," __stringify(CPENABLE) "; rsync" \
+ :: "a" (x)); \
+ } while(0);
+
+#endif /* XCHAL_HAVE_CP */
+
+
+/*
+ * Additional registers.
+ * We define three types of additional registers:
+ * ext: extra registers that are used by the compiler
+ * cpn: optional registers that can be used by a user application
+ * cpX: coprocessor registers that can only be used if the corresponding
+ * CPENABLE bit is set.
+ */
+
+#define XCHAL_SA_REG(list,compiler,x,type,y,name,z,align,size,...) \
+ __REG ## list (compiler, type, name, size, align)
+
+#define __REG0(compiler,t,name,s,a) __REG0_ ## compiler (name)
+#define __REG1(compiler,t,name,s,a) __REG1_ ## compiler (name)
+#define __REG2(c,type,...) __REG2_ ## type (__VA_ARGS__)
+
+#define __REG0_0(name)
+#define __REG0_1(name) __u32 name;
+#define __REG1_0(name) __u32 name;
+#define __REG1_1(name)
+#define __REG2_0(n,s,a) __u32 name;
+#define __REG2_1(n,s,a) unsigned char n[s] __attribute__ ((aligned(a)));
+#define __REG2_2(n,s,a) unsigned char n[s] __attribute__ ((aligned(a)));
+
+typedef struct { XCHAL_NCP_SA_LIST(0) } xtregs_opt_t
+ __attribute__ ((aligned (XCHAL_NCP_SA_ALIGN)));
+typedef struct { XCHAL_NCP_SA_LIST(1) } xtregs_user_t
+ __attribute__ ((aligned (XCHAL_NCP_SA_ALIGN)));
+
+#if XTENSA_HAVE_COPROCESSORS
+
+typedef struct { XCHAL_CP0_SA_LIST(2) } xtregs_cp0_t
+ __attribute__ ((aligned (XCHAL_CP0_SA_ALIGN)));
+typedef struct { XCHAL_CP1_SA_LIST(2) } xtregs_cp1_t
+ __attribute__ ((aligned (XCHAL_CP1_SA_ALIGN)));
+typedef struct { XCHAL_CP2_SA_LIST(2) } xtregs_cp2_t
+ __attribute__ ((aligned (XCHAL_CP2_SA_ALIGN)));
+typedef struct { XCHAL_CP3_SA_LIST(2) } xtregs_cp3_t
+ __attribute__ ((aligned (XCHAL_CP3_SA_ALIGN)));
+typedef struct { XCHAL_CP4_SA_LIST(2) } xtregs_cp4_t
+ __attribute__ ((aligned (XCHAL_CP4_SA_ALIGN)));
+typedef struct { XCHAL_CP5_SA_LIST(2) } xtregs_cp5_t
+ __attribute__ ((aligned (XCHAL_CP5_SA_ALIGN)));
+typedef struct { XCHAL_CP6_SA_LIST(2) } xtregs_cp6_t
+ __attribute__ ((aligned (XCHAL_CP6_SA_ALIGN)));
+typedef struct { XCHAL_CP7_SA_LIST(2) } xtregs_cp7_t
+ __attribute__ ((aligned (XCHAL_CP7_SA_ALIGN)));
+
+extern struct thread_info* coprocessor_owner[XCHAL_CP_MAX];
+extern void coprocessor_save(void*, int);
+extern void coprocessor_load(void*, int);
+extern void coprocessor_flush(struct thread_info*, int);
+extern void coprocessor_restore(struct thread_info*, int);
+
+extern void coprocessor_release_all(struct thread_info*);
+extern void coprocessor_flush_all(struct thread_info*);
+
+static inline void coprocessor_clear_cpenable(void)
+{
+ unsigned long i = 0;
+ WSR_CPENABLE(i);
+}
+
+#endif /* XTENSA_HAVE_COPROCESSORS */
#endif /* !__ASSEMBLY__ */
-
-
#endif /* _XTENSA_COPROCESSOR_H */