diff options
Diffstat (limited to 'bsps/powerpc/shared/exceptions/ppc_exc_prologue.c')
| -rw-r--r-- | bsps/powerpc/shared/exceptions/ppc_exc_prologue.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/bsps/powerpc/shared/exceptions/ppc_exc_prologue.c b/bsps/powerpc/shared/exceptions/ppc_exc_prologue.c new file mode 100644 index 0000000000..09307cd944 --- /dev/null +++ b/bsps/powerpc/shared/exceptions/ppc_exc_prologue.c @@ -0,0 +1,181 @@ +/** + * @file + * + * @ingroup ppc_exc + * + * @brief PowerPC Exceptions implementation. + */ + +/* + * Copyright (C) 2007 Till Straumann <strauman@slac.stanford.edu> + * + * Copyright (C) 2009-2012 embedded brains GmbH. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#include <string.h> + +#include <bsp/vectors.h> + +/* Offset into minimal prolog where vector number is hardcoded */ +#define PPC_EXC_PROLOG_VEC_OFFSET 2 + +/* Symbols are defined by the linker */ +extern const char ppc_exc_min_prolog_size []; +extern const char ppc_exc_tgpr_clr_prolog_size []; + +/* Special prologue for handling register shadowing on 603-style CPUs */ +extern const uint32_t ppc_exc_tgpr_clr_prolog []; + +/* + * Classic prologue which determines the vector dynamically from the offset + * address. This must only be used for classic, synchronous exceptions with a + * vector offset aligned on a 256-byte boundary. + */ +extern const uint32_t ppc_exc_min_prolog_auto []; + +/* Minimal prologue templates */ +extern const uint32_t ppc_exc_min_prolog_async_tmpl_std []; +extern const uint32_t ppc_exc_min_prolog_sync_tmpl_std []; +extern const uint32_t ppc_exc_min_prolog_async_tmpl_p405_crit []; +extern const uint32_t ppc_exc_min_prolog_sync_tmpl_p405_crit []; +extern const uint32_t ppc_exc_min_prolog_async_tmpl_bookE_crit []; +extern const uint32_t ppc_exc_min_prolog_sync_tmpl_bookE_crit []; +extern const uint32_t ppc_exc_min_prolog_sync_tmpl_e500_mchk []; +extern const uint32_t ppc_exc_min_prolog_async_tmpl_e500_mchk []; +extern const uint32_t ppc_exc_min_prolog_tmpl_naked []; +extern const uint32_t ppc_exc_min_prolog_async_tmpl_normal []; + +static const uint32_t *const ppc_exc_prologue_templates [] = { + [PPC_EXC_CLASSIC] = ppc_exc_min_prolog_sync_tmpl_std, + [PPC_EXC_CLASSIC_ASYNC] = ppc_exc_min_prolog_async_tmpl_std, + [PPC_EXC_405_CRITICAL] = ppc_exc_min_prolog_sync_tmpl_p405_crit, + [PPC_EXC_405_CRITICAL_ASYNC] = ppc_exc_min_prolog_async_tmpl_p405_crit, + [PPC_EXC_BOOKE_CRITICAL] = ppc_exc_min_prolog_sync_tmpl_bookE_crit, + [PPC_EXC_BOOKE_CRITICAL_ASYNC] = ppc_exc_min_prolog_async_tmpl_bookE_crit, + [PPC_EXC_E500_MACHCHK] = ppc_exc_min_prolog_sync_tmpl_e500_mchk, + [PPC_EXC_E500_MACHCHK_ASYNC] = ppc_exc_min_prolog_async_tmpl_e500_mchk, + [PPC_EXC_NAKED] = ppc_exc_min_prolog_tmpl_naked +}; + +static bool ppc_exc_create_branch_op( + unsigned vector, + void *vector_base, + uint32_t *prologue, + size_t prologue_size +) +{ + static const uintptr_t BRANCH_OP_CODE = 18 << 26; +/* static const uintptr_t BRANCH_OP_LINK = 0x1; */ + static const uintptr_t BRANCH_OP_ABS = 0x2; + static const uintptr_t BRANCH_OP_MSK = 0x3ffffff; + size_t branch_op_index = prologue_size / 4 - 1; + uintptr_t vector_address = + (uintptr_t) ppc_exc_vector_address(vector, vector_base); + uintptr_t branch_op_address = vector_address + 4 * branch_op_index; + + /* This value may have BRANCH_OP_LINK set */ + uintptr_t target_address = prologue [branch_op_index]; + + uintptr_t branch_target_address = target_address - branch_op_address; + + /* + * We prefer to use a relative branch. This has the benefit that custom + * minimal prologues in a read-only area are relocatable. + */ + if ((branch_target_address & ~BRANCH_OP_MSK) != 0) { + /* Target to far for relative branch (PC ± 32M) */ + if (target_address >= 0xfe000001 || target_address < 0x01fffffd) { + /* Can use an absolute branch */ + branch_target_address = (target_address | BRANCH_OP_ABS) & BRANCH_OP_MSK; + } else { + return false; + } + } + + prologue [branch_op_index] = BRANCH_OP_CODE | branch_target_address; + + return true; +} + +rtems_status_code ppc_exc_make_prologue( + unsigned vector, + void *vector_base, + ppc_exc_category category, + uint32_t *prologue, + size_t *prologue_size +) +{ + const uint32_t *prologue_template = NULL; + size_t prologue_template_size = 0; + bool fixup_vector = false; + + if (!ppc_exc_is_valid_category(category)) { + return RTEMS_INVALID_NUMBER; + } + + if ( + ppc_cpu_has_shadowed_gprs() + && (vector == ASM_60X_IMISS_VECTOR + || vector == ASM_60X_DLMISS_VECTOR + || vector == ASM_60X_DSMISS_VECTOR) + ) { + prologue_template = ppc_exc_tgpr_clr_prolog; + prologue_template_size = (size_t) ppc_exc_tgpr_clr_prolog_size; + } else if ( + category == PPC_EXC_CLASSIC + && ppc_cpu_is_bookE() != PPC_BOOKE_STD + && ppc_cpu_is_bookE() != PPC_BOOKE_E500 + ) { + prologue_template = ppc_exc_min_prolog_auto; + prologue_template_size = (size_t) ppc_exc_min_prolog_size; +#ifdef PPC_EXC_CONFIG_USE_FIXED_HANDLER + } else if ( + category == PPC_EXC_CLASSIC_ASYNC + && ppc_cpu_is_bookE() == PPC_BOOKE_E500 + && (ppc_interrupt_get_disable_mask() & MSR_CE) == 0 + ) { + prologue_template = ppc_exc_min_prolog_async_tmpl_normal; + prologue_template_size = 16; + fixup_vector = true; +#endif /* PPC_EXC_CONFIG_USE_FIXED_HANDLER */ + } else { + prologue_template = ppc_exc_prologue_templates [category]; + prologue_template_size = (size_t) ppc_exc_min_prolog_size; + fixup_vector = true; + } + + if (prologue_template_size <= *prologue_size) { + *prologue_size = prologue_template_size; + + memcpy(prologue, prologue_template, prologue_template_size); + + if ( + !ppc_exc_create_branch_op( + vector, + vector_base, + prologue, + prologue_template_size + ) + ) { + return RTEMS_INVALID_ADDRESS; + } + + if (fixup_vector) { + if (vector <= 0x7fffU) { + prologue [PPC_EXC_PROLOG_VEC_OFFSET] = + (prologue [PPC_EXC_PROLOG_VEC_OFFSET] & 0xffff8000U) + | (vector & 0x7fffU); + } else { + return RTEMS_INVALID_ID; + } + } + } else { + return RTEMS_INVALID_SIZE; + } + + return RTEMS_SUCCESSFUL; +} |