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-rw-r--r--libffi/src/arm/ffi.c504
1 files changed, 504 insertions, 0 deletions
diff --git a/libffi/src/arm/ffi.c b/libffi/src/arm/ffi.c
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+/* -----------------------------------------------------------------------
+ ffi.c - Copyright (c) 1998, 2008 Red Hat, Inc.
+
+ ARM Foreign Function Interface
+
+ Permission is hereby granted, free of charge, to any person obtaining
+ a copy of this software and associated documentation files (the
+ ``Software''), to deal in the Software without restriction, including
+ without limitation the rights to use, copy, modify, merge, publish,
+ distribute, sublicense, and/or sell copies of the Software, and to
+ permit persons to whom the Software is furnished to do so, subject to
+ the following conditions:
+
+ The above copyright notice and this permission notice shall be included
+ in all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ DEALINGS IN THE SOFTWARE.
+ ----------------------------------------------------------------------- */
+
+#include <ffi.h>
+#include <ffi_common.h>
+
+#include <stdlib.h>
+
+/* Forward declares. */
+static int vfp_type_p (ffi_type *);
+static void layout_vfp_args (ffi_cif *);
+
+/* ffi_prep_args is called by the assembly routine once stack space
+ has been allocated for the function's arguments
+
+ The vfp_space parameter is the load area for VFP regs, the return
+ value is cif->vfp_used (word bitset of VFP regs used for passing
+ arguments). These are only used for the VFP hard-float ABI.
+*/
+int ffi_prep_args(char *stack, extended_cif *ecif, float *vfp_space)
+{
+ register unsigned int i, vi = 0;
+ register void **p_argv;
+ register char *argp;
+ register ffi_type **p_arg;
+
+ argp = stack;
+
+ if ( ecif->cif->flags == FFI_TYPE_STRUCT ) {
+ *(void **) argp = ecif->rvalue;
+ argp += 4;
+ }
+
+ p_argv = ecif->avalue;
+
+ for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types;
+ (i != 0);
+ i--, p_arg++)
+ {
+ size_t z;
+
+ /* Allocated in VFP registers. */
+ if (ecif->cif->abi == FFI_VFP
+ && vi < ecif->cif->vfp_nargs && vfp_type_p (*p_arg))
+ {
+ float* vfp_slot = vfp_space + ecif->cif->vfp_args[vi++];
+ if ((*p_arg)->type == FFI_TYPE_FLOAT)
+ *((float*)vfp_slot) = *((float*)*p_argv);
+ else if ((*p_arg)->type == FFI_TYPE_DOUBLE)
+ *((double*)vfp_slot) = *((double*)*p_argv);
+ else
+ memcpy(vfp_slot, *p_argv, (*p_arg)->size);
+ p_argv++;
+ continue;
+ }
+
+ /* Align if necessary */
+ if (((*p_arg)->alignment - 1) & (unsigned) argp) {
+ argp = (char *) ALIGN(argp, (*p_arg)->alignment);
+ }
+
+ if ((*p_arg)->type == FFI_TYPE_STRUCT)
+ argp = (char *) ALIGN(argp, 4);
+
+ z = (*p_arg)->size;
+ if (z < sizeof(int))
+ {
+ z = sizeof(int);
+ switch ((*p_arg)->type)
+ {
+ case FFI_TYPE_SINT8:
+ *(signed int *) argp = (signed int)*(SINT8 *)(* p_argv);
+ break;
+
+ case FFI_TYPE_UINT8:
+ *(unsigned int *) argp = (unsigned int)*(UINT8 *)(* p_argv);
+ break;
+
+ case FFI_TYPE_SINT16:
+ *(signed int *) argp = (signed int)*(SINT16 *)(* p_argv);
+ break;
+
+ case FFI_TYPE_UINT16:
+ *(unsigned int *) argp = (unsigned int)*(UINT16 *)(* p_argv);
+ break;
+
+ case FFI_TYPE_STRUCT:
+ memcpy(argp, *p_argv, (*p_arg)->size);
+ break;
+
+ default:
+ FFI_ASSERT(0);
+ }
+ }
+ else if (z == sizeof(int))
+ {
+ *(unsigned int *) argp = (unsigned int)*(UINT32 *)(* p_argv);
+ }
+ else
+ {
+ memcpy(argp, *p_argv, z);
+ }
+ p_argv++;
+ argp += z;
+ }
+
+ /* Indicate the VFP registers used. */
+ return ecif->cif->vfp_used;
+}
+
+/* Perform machine dependent cif processing */
+ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
+{
+ int type_code;
+ /* Round the stack up to a multiple of 8 bytes. This isn't needed
+ everywhere, but it is on some platforms, and it doesn't harm anything
+ when it isn't needed. */
+ cif->bytes = (cif->bytes + 7) & ~7;
+
+ /* Set the return type flag */
+ switch (cif->rtype->type)
+ {
+ case FFI_TYPE_VOID:
+ case FFI_TYPE_FLOAT:
+ case FFI_TYPE_DOUBLE:
+ cif->flags = (unsigned) cif->rtype->type;
+ break;
+
+ case FFI_TYPE_SINT64:
+ case FFI_TYPE_UINT64:
+ cif->flags = (unsigned) FFI_TYPE_SINT64;
+ break;
+
+ case FFI_TYPE_STRUCT:
+ if (cif->abi == FFI_VFP
+ && (type_code = vfp_type_p (cif->rtype)) != 0)
+ {
+ /* A Composite Type passed in VFP registers, either
+ FFI_TYPE_STRUCT_VFP_FLOAT or FFI_TYPE_STRUCT_VFP_DOUBLE. */
+ cif->flags = (unsigned) type_code;
+ }
+ else if (cif->rtype->size <= 4)
+ /* A Composite Type not larger than 4 bytes is returned in r0. */
+ cif->flags = (unsigned)FFI_TYPE_INT;
+ else
+ /* A Composite Type larger than 4 bytes, or whose size cannot
+ be determined statically ... is stored in memory at an
+ address passed [in r0]. */
+ cif->flags = (unsigned)FFI_TYPE_STRUCT;
+ break;
+
+ default:
+ cif->flags = FFI_TYPE_INT;
+ break;
+ }
+
+ /* Map out the register placements of VFP register args.
+ The VFP hard-float calling conventions are slightly more sophisticated than
+ the base calling conventions, so we do it here instead of in ffi_prep_args(). */
+ if (cif->abi == FFI_VFP)
+ layout_vfp_args (cif);
+
+ return FFI_OK;
+}
+
+/* Prototypes for assembly functions, in sysv.S */
+extern void ffi_call_SYSV (void (*fn)(void), extended_cif *, unsigned, unsigned, unsigned *);
+extern void ffi_call_VFP (void (*fn)(void), extended_cif *, unsigned, unsigned, unsigned *);
+
+void ffi_call(ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
+{
+ extended_cif ecif;
+
+ int small_struct = (cif->flags == FFI_TYPE_INT
+ && cif->rtype->type == FFI_TYPE_STRUCT);
+ int vfp_struct = (cif->flags == FFI_TYPE_STRUCT_VFP_FLOAT
+ || cif->flags == FFI_TYPE_STRUCT_VFP_DOUBLE);
+
+ ecif.cif = cif;
+ ecif.avalue = avalue;
+
+ unsigned int temp;
+
+ /* If the return value is a struct and we don't have a return */
+ /* value address then we need to make one */
+
+ if ((rvalue == NULL) &&
+ (cif->flags == FFI_TYPE_STRUCT))
+ {
+ ecif.rvalue = alloca(cif->rtype->size);
+ }
+ else if (small_struct)
+ ecif.rvalue = &temp;
+ else if (vfp_struct)
+ {
+ /* Largest case is double x 4. */
+ ecif.rvalue = alloca(32);
+ }
+ else
+ ecif.rvalue = rvalue;
+
+ switch (cif->abi)
+ {
+ case FFI_SYSV:
+ ffi_call_SYSV (fn, &ecif, cif->bytes, cif->flags, ecif.rvalue);
+ break;
+
+ case FFI_VFP:
+ ffi_call_VFP (fn, &ecif, cif->bytes, cif->flags, ecif.rvalue);
+ break;
+
+ default:
+ FFI_ASSERT(0);
+ break;
+ }
+ if (small_struct)
+ memcpy (rvalue, &temp, cif->rtype->size);
+ else if (vfp_struct)
+ memcpy (rvalue, ecif.rvalue, cif->rtype->size);
+}
+
+/** private members **/
+
+static void ffi_prep_incoming_args_SYSV (char *stack, void **ret,
+ void** args, ffi_cif* cif, float *vfp_stack);
+
+void ffi_closure_SYSV (ffi_closure *);
+
+void ffi_closure_VFP (ffi_closure *);
+
+/* This function is jumped to by the trampoline */
+
+unsigned int
+ffi_closure_SYSV_inner (closure, respp, args, vfp_args)
+ ffi_closure *closure;
+ void **respp;
+ void *args;
+ void *vfp_args;
+{
+ // our various things...
+ ffi_cif *cif;
+ void **arg_area;
+
+ cif = closure->cif;
+ arg_area = (void**) alloca (cif->nargs * sizeof (void*));
+
+ /* this call will initialize ARG_AREA, such that each
+ * element in that array points to the corresponding
+ * value on the stack; and if the function returns
+ * a structure, it will re-set RESP to point to the
+ * structure return address. */
+
+ ffi_prep_incoming_args_SYSV(args, respp, arg_area, cif, vfp_args);
+
+ (closure->fun) (cif, *respp, arg_area, closure->user_data);
+
+ return cif->flags;
+}
+
+/*@-exportheader@*/
+static void
+ffi_prep_incoming_args_SYSV(char *stack, void **rvalue,
+ void **avalue, ffi_cif *cif,
+ /* Used only under VFP hard-float ABI. */
+ float *vfp_stack)
+/*@=exportheader@*/
+{
+ register unsigned int i, vi = 0;
+ register void **p_argv;
+ register char *argp;
+ register ffi_type **p_arg;
+
+ argp = stack;
+
+ if ( cif->flags == FFI_TYPE_STRUCT ) {
+ *rvalue = *(void **) argp;
+ argp += 4;
+ }
+
+ p_argv = avalue;
+
+ for (i = cif->nargs, p_arg = cif->arg_types; (i != 0); i--, p_arg++)
+ {
+ size_t z;
+ size_t alignment;
+
+ if (cif->abi == FFI_VFP
+ && vi < cif->vfp_nargs && vfp_type_p (*p_arg))
+ {
+ *p_argv++ = (void*)(vfp_stack + cif->vfp_args[vi++]);
+ continue;
+ }
+
+ alignment = (*p_arg)->alignment;
+ if (alignment < 4)
+ alignment = 4;
+ /* Align if necessary */
+ if ((alignment - 1) & (unsigned) argp) {
+ argp = (char *) ALIGN(argp, alignment);
+ }
+
+ z = (*p_arg)->size;
+
+ /* because we're little endian, this is what it turns into. */
+
+ *p_argv = (void*) argp;
+
+ p_argv++;
+ argp += z;
+ }
+
+ return;
+}
+
+/* How to make a trampoline. */
+
+#define FFI_INIT_TRAMPOLINE(TRAMP,FUN,CTX) \
+({ unsigned char *__tramp = (unsigned char*)(TRAMP); \
+ unsigned int __fun = (unsigned int)(FUN); \
+ unsigned int __ctx = (unsigned int)(CTX); \
+ unsigned char *insns = (unsigned char *)(CTX); \
+ *(unsigned int*) &__tramp[0] = 0xe92d000f; /* stmfd sp!, {r0-r3} */ \
+ *(unsigned int*) &__tramp[4] = 0xe59f0000; /* ldr r0, [pc] */ \
+ *(unsigned int*) &__tramp[8] = 0xe59ff000; /* ldr pc, [pc] */ \
+ *(unsigned int*) &__tramp[12] = __ctx; \
+ *(unsigned int*) &__tramp[16] = __fun; \
+ __clear_cache((&__tramp[0]), (&__tramp[19])); /* Clear data mapping. */ \
+ __clear_cache(insns, insns + 3 * sizeof (unsigned int)); \
+ /* Clear instruction \
+ mapping. */ \
+ })
+
+
+/* the cif must already be prep'ed */
+
+ffi_status
+ffi_prep_closure_loc (ffi_closure* closure,
+ ffi_cif* cif,
+ void (*fun)(ffi_cif*,void*,void**,void*),
+ void *user_data,
+ void *codeloc)
+{
+ void (*closure_func)(ffi_closure*) = NULL;
+
+ if (cif->abi == FFI_SYSV)
+ closure_func = &ffi_closure_SYSV;
+ else if (cif->abi == FFI_VFP)
+ closure_func = &ffi_closure_VFP;
+ else
+ FFI_ASSERT (0);
+
+ FFI_INIT_TRAMPOLINE (&closure->tramp[0], \
+ closure_func, \
+ codeloc);
+
+ closure->cif = cif;
+ closure->user_data = user_data;
+ closure->fun = fun;
+
+ return FFI_OK;
+}
+
+/* Below are routines for VFP hard-float support. */
+
+static int rec_vfp_type_p (ffi_type *t, int *elt, int *elnum)
+{
+ switch (t->type)
+ {
+ case FFI_TYPE_FLOAT:
+ case FFI_TYPE_DOUBLE:
+ *elt = (int) t->type;
+ *elnum = 1;
+ return 1;
+
+ case FFI_TYPE_STRUCT_VFP_FLOAT:
+ *elt = FFI_TYPE_FLOAT;
+ *elnum = t->size / sizeof (float);
+ return 1;
+
+ case FFI_TYPE_STRUCT_VFP_DOUBLE:
+ *elt = FFI_TYPE_DOUBLE;
+ *elnum = t->size / sizeof (double);
+ return 1;
+
+ case FFI_TYPE_STRUCT:;
+ {
+ int base_elt = 0, total_elnum = 0;
+ ffi_type **el = t->elements;
+ while (*el)
+ {
+ int el_elt = 0, el_elnum = 0;
+ if (! rec_vfp_type_p (*el, &el_elt, &el_elnum)
+ || (base_elt && base_elt != el_elt)
+ || total_elnum + el_elnum > 4)
+ return 0;
+ base_elt = el_elt;
+ total_elnum += el_elnum;
+ el++;
+ }
+ *elnum = total_elnum;
+ *elt = base_elt;
+ return 1;
+ }
+ default: ;
+ }
+ return 0;
+}
+
+static int vfp_type_p (ffi_type *t)
+{
+ int elt, elnum;
+ if (rec_vfp_type_p (t, &elt, &elnum))
+ {
+ if (t->type == FFI_TYPE_STRUCT)
+ {
+ if (elnum == 1)
+ t->type = elt;
+ else
+ t->type = (elt == FFI_TYPE_FLOAT
+ ? FFI_TYPE_STRUCT_VFP_FLOAT
+ : FFI_TYPE_STRUCT_VFP_DOUBLE);
+ }
+ return (int) t->type;
+ }
+ return 0;
+}
+
+static void place_vfp_arg (ffi_cif *cif, ffi_type *t)
+{
+ int reg = cif->vfp_reg_free;
+ int nregs = t->size / sizeof (float);
+ int align = ((t->type == FFI_TYPE_STRUCT_VFP_FLOAT
+ || t->type == FFI_TYPE_FLOAT) ? 1 : 2);
+ /* Align register number. */
+ if ((reg & 1) && align == 2)
+ reg++;
+ while (reg + nregs <= 16)
+ {
+ int s, new_used = 0;
+ for (s = reg; s < reg + nregs; s++)
+ {
+ new_used |= (1 << s);
+ if (cif->vfp_used & (1 << s))
+ {
+ reg += align;
+ goto next_reg;
+ }
+ }
+ /* Found regs to allocate. */
+ cif->vfp_used |= new_used;
+ cif->vfp_args[cif->vfp_nargs++] = reg;
+
+ /* Update vfp_reg_free. */
+ if (cif->vfp_used & (1 << cif->vfp_reg_free))
+ {
+ reg += nregs;
+ while (cif->vfp_used & (1 << reg))
+ reg += 1;
+ cif->vfp_reg_free = reg;
+ }
+ return;
+ next_reg: ;
+ }
+}
+
+static void layout_vfp_args (ffi_cif *cif)
+{
+ int i;
+ /* Init VFP fields */
+ cif->vfp_used = 0;
+ cif->vfp_nargs = 0;
+ cif->vfp_reg_free = 0;
+ memset (cif->vfp_args, -1, 16); /* Init to -1. */
+
+ for (i = 0; i < cif->nargs; i++)
+ {
+ ffi_type *t = cif->arg_types[i];
+ if (vfp_type_p (t))
+ place_vfp_arg (cif, t);
+ }
+}
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