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/**
* @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.com/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;
} 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;
#ifndef PPC_EXC_CONFIG_USE_FIXED_HANDLER
prologue_template_size = (size_t) ppc_exc_min_prolog_size;
fixup_vector = true;
#else /* PPC_EXC_CONFIG_USE_FIXED_HANDLER */
prologue_template_size = 8;
#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;
}
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