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Diffstat (limited to 'ext/ffi_c/libffi/src/nios2/ffi.c')
| -rw-r--r-- | ext/ffi_c/libffi/src/nios2/ffi.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/ext/ffi_c/libffi/src/nios2/ffi.c b/ext/ffi_c/libffi/src/nios2/ffi.c new file mode 100644 index 0000000..2efa033 --- /dev/null +++ b/ext/ffi_c/libffi/src/nios2/ffi.c @@ -0,0 +1,304 @@ +/* libffi support for Altera Nios II. + + Copyright (c) 2013 Mentor Graphics. + + 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> + +/* The Nios II Processor Reference Handbook defines the procedure call + ABI as follows. + + Arguments are passed as if a structure containing the types of + the arguments were constructed. The first 16 bytes are passed in r4 + through r7, the remainder on the stack. The first 16 bytes of a function + taking variable arguments are passed in r4-r7 in the same way. + + Return values of types up to 8 bytes are returned in r2 and r3. For + return values greater than 8 bytes, the caller must allocate memory for + the result and pass the address as if it were argument 0. + + While this isn't specified explicitly in the ABI documentation, GCC + promotes integral arguments smaller than int size to 32 bits. + + Also of note, the ABI specifies that all structure objects are + aligned to 32 bits even if all their fields have a smaller natural + alignment. See FFI_AGGREGATE_ALIGNMENT. */ + + +/* Declare the assembly language hooks. */ + +extern UINT64 ffi_call_sysv (void (*) (char *, extended_cif *), + extended_cif *, + unsigned, + void (*fn) (void)); +extern void ffi_closure_sysv (void); + +/* Perform machine-dependent cif processing. */ + +ffi_status ffi_prep_cif_machdep (ffi_cif *cif) +{ + /* We always want at least 16 bytes in the parameter block since it + simplifies the low-level call function. Also round the parameter + block size up to a multiple of 4 bytes to preserve + 32-bit alignment of the stack pointer. */ + if (cif->bytes < 16) + cif->bytes = 16; + else + cif->bytes = (cif->bytes + 3) & ~3; + + return FFI_OK; +} + + +/* ffi_prep_args is called by the assembly routine to transfer arguments + to the stack using the pointers in the ecif array. + Note that the stack buffer is big enough to fit all the arguments, + but the first 16 bytes will be copied to registers for the actual + call. */ + +void ffi_prep_args (char *stack, extended_cif *ecif) +{ + char *argp = stack; + unsigned int i; + + /* The implicit return value pointer is passed as if it were a hidden + first argument. */ + if (ecif->cif->rtype->type == FFI_TYPE_STRUCT + && ecif->cif->rtype->size > 8) + { + (*(void **) argp) = ecif->rvalue; + argp += 4; + } + + for (i = 0; i < ecif->cif->nargs; i++) + { + void *avalue = ecif->avalue[i]; + ffi_type *atype = ecif->cif->arg_types[i]; + size_t size = atype->size; + size_t alignment = atype->alignment; + + /* Align argp as appropriate for the argument type. */ + if ((alignment - 1) & (unsigned) argp) + argp = (char *) ALIGN (argp, alignment); + + /* Copy the argument, promoting integral types smaller than a + word to word size. */ + if (size < sizeof (int)) + { + size = sizeof (int); + switch (atype->type) + { + case FFI_TYPE_SINT8: + *(signed int *) argp = (signed int) *(SINT8 *) avalue; + break; + + case FFI_TYPE_UINT8: + *(unsigned int *) argp = (unsigned int) *(UINT8 *) avalue; + break; + + case FFI_TYPE_SINT16: + *(signed int *) argp = (signed int) *(SINT16 *) avalue; + break; + + case FFI_TYPE_UINT16: + *(unsigned int *) argp = (unsigned int) *(UINT16 *) avalue; + break; + + case FFI_TYPE_STRUCT: + memcpy (argp, avalue, atype->size); + break; + + default: + FFI_ASSERT(0); + } + } + else if (size == sizeof (int)) + *(unsigned int *) argp = (unsigned int) *(UINT32 *) avalue; + else + memcpy (argp, avalue, size); + argp += size; + } +} + + +/* Call FN using the prepared CIF. RVALUE points to space allocated by + the caller for the return value, and AVALUE is an array of argument + pointers. */ + +void ffi_call (ffi_cif *cif, void (*fn) (void), void *rvalue, void **avalue) +{ + + extended_cif ecif; + UINT64 result; + + /* If bigret is true, this is the case where a return value of larger + than 8 bytes is handled by being passed by reference as an implicit + argument. */ + int bigret = (cif->rtype->type == FFI_TYPE_STRUCT + && cif->rtype->size > 8); + + ecif.cif = cif; + ecif.avalue = avalue; + + /* Allocate space for return value if this is the pass-by-reference case + and the caller did not provide a buffer. */ + if (rvalue == NULL && bigret) + ecif.rvalue = alloca (cif->rtype->size); + else + ecif.rvalue = rvalue; + + result = ffi_call_sysv (ffi_prep_args, &ecif, cif->bytes, fn); + + /* Now result contains the 64 bit contents returned from fn in + r2 and r3. Copy the value of the appropriate size to the user-provided + rvalue buffer. */ + if (rvalue && !bigret) + switch (cif->rtype->size) + { + case 1: + *(UINT8 *)rvalue = (UINT8) result; + break; + case 2: + *(UINT16 *)rvalue = (UINT16) result; + break; + case 4: + *(UINT32 *)rvalue = (UINT32) result; + break; + case 8: + *(UINT64 *)rvalue = (UINT64) result; + break; + default: + memcpy (rvalue, (void *)&result, cif->rtype->size); + break; + } +} + +/* This function is invoked from the closure trampoline to invoke + CLOSURE with argument block ARGS. Parse ARGS according to + CLOSURE->cfi and invoke CLOSURE->fun. */ + +static UINT64 +ffi_closure_helper (unsigned char *args, + ffi_closure *closure) +{ + ffi_cif *cif = closure->cif; + unsigned char *argp = args; + void **parsed_args = alloca (cif->nargs * sizeof (void *)); + UINT64 result; + void *retptr; + unsigned int i; + + /* First figure out what to do about the return type. If this is the + big-structure-return case, the first arg is the hidden return buffer + allocated by the caller. */ + if (cif->rtype->type == FFI_TYPE_STRUCT + && cif->rtype->size > 8) + { + retptr = *((void **) argp); + argp += 4; + } + else + retptr = (void *) &result; + + /* Fill in the array of argument pointers. */ + for (i = 0; i < cif->nargs; i++) + { + size_t size = cif->arg_types[i]->size; + size_t alignment = cif->arg_types[i]->alignment; + + /* Align argp as appropriate for the argument type. */ + if ((alignment - 1) & (unsigned) argp) + argp = (char *) ALIGN (argp, alignment); + + /* Arguments smaller than an int are promoted to int. */ + if (size < sizeof (int)) + size = sizeof (int); + + /* Store the pointer. */ + parsed_args[i] = argp; + argp += size; + } + + /* Call the user-supplied function. */ + (closure->fun) (cif, retptr, parsed_args, closure->user_data); + return result; +} + + +/* Initialize CLOSURE with a trampoline to call FUN with + CIF and USER_DATA. */ +ffi_status +ffi_prep_closure_loc (ffi_closure* closure, + ffi_cif* cif, + void (*fun) (ffi_cif*, void*, void**, void*), + void *user_data, + void *codeloc) +{ + unsigned int *tramp = (unsigned int *) &closure->tramp[0]; + int i; + + if (cif->abi != FFI_SYSV) + return FFI_BAD_ABI; + + /* The trampoline looks like: + movhi r8, %hi(ffi_closure_sysv) + ori r8, r8, %lo(ffi_closure_sysv) + movhi r9, %hi(ffi_closure_helper) + ori r0, r9, %lo(ffi_closure_helper) + movhi r10, %hi(closure) + ori r10, r10, %lo(closure) + jmp r8 + and then ffi_closure_sysv retrieves the closure pointer out of r10 + in addition to the arguments passed in the normal way for the call, + and invokes ffi_closure_helper. We encode the pointer to + ffi_closure_helper in the trampoline because making a PIC call + to it in ffi_closure_sysv would be messy (it would have to indirect + through the GOT). */ + +#define HI(x) ((((unsigned int) (x)) >> 16) & 0xffff) +#define LO(x) (((unsigned int) (x)) & 0xffff) + tramp[0] = (0 << 27) | (8 << 22) | (HI (ffi_closure_sysv) << 6) | 0x34; + tramp[1] = (8 << 27) | (8 << 22) | (LO (ffi_closure_sysv) << 6) | 0x14; + tramp[2] = (0 << 27) | (9 << 22) | (HI (ffi_closure_helper) << 6) | 0x34; + tramp[3] = (9 << 27) | (9 << 22) | (LO (ffi_closure_helper) << 6) | 0x14; + tramp[4] = (0 << 27) | (10 << 22) | (HI (closure) << 6) | 0x34; + tramp[5] = (10 << 27) | (10 << 22) | (LO (closure) << 6) | 0x14; + tramp[6] = (8 << 27) | (0x0d << 11) | 0x3a; +#undef HI +#undef LO + + /* Flush the caches. + See Example 9-4 in the Nios II Software Developer's Handbook. */ + for (i = 0; i < 7; i++) + asm volatile ("flushd 0(%0); flushi %0" :: "r"(tramp + i) : "memory"); + asm volatile ("flushp" ::: "memory"); + + closure->cif = cif; + closure->fun = fun; + closure->user_data = user_data; + + return FFI_OK; +} + |