static bool ppc_exc_create_branch_op(
unsigned vector,
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);
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;
}
void ppc_exc_initialize_with_vector_base(
uintptr_t interrupt_stack_begin,
uintptr_t interrupt_stack_size,
void *vector_base
)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
const ppc_exc_categories *const categories = ppc_exc_current_categories();
unsigned vector = 0;
uint32_t sda_base = 0;
uint32_t r13 = 0;
if (categories == NULL) {
ppc_exc_fatal_error();
}
/* Assembly code needs SDA_BASE in r13 (SVR4 or EABI). Make sure
* early init code put it there.
*/
__asm__ volatile (
"lis %0, _SDA_BASE_@h\n"
"ori %0, %0, _SDA_BASE_@l\n"
"mr %1, 13\n"
: "=r" (sda_base), "=r"(r13)
);
if (sda_base != r13) {
ppc_exc_fatal_error();
}
ppc_exc_initialize_interrupt_stack(interrupt_stack_begin, interrupt_stack_size);
#ifndef PPC_EXC_CONFIG_BOOKE_ONLY
/* Use current MMU / RI settings when running C exception handlers */
ppc_exc_msr_bits = ppc_machine_state_register() & (MSR_DR | MSR_IR | MSR_RI);
#ifdef __ALTIVEC__
/* Need vector unit enabled to save/restore altivec context */
ppc_exc_msr_bits |= MSR_VE;
#endif
#endif /* PPC_EXC_CONFIG_BOOKE_ONLY */
if (ppc_cpu_is_bookE() == PPC_BOOKE_STD || ppc_cpu_is_bookE() == PPC_BOOKE_E500) {
ppc_exc_initialize_booke(vector_base);
}
for (vector = 0; vector <= LAST_VALID_EXC; ++vector) {
ppc_exc_category category = ppc_exc_category_for_vector(categories, vector);
if (category != PPC_EXC_INVALID) {
void *const vector_address = ppc_exc_vector_address(vector, vector_base);
uint32_t prologue [16];
size_t prologue_size = sizeof(prologue);
sc = ppc_exc_make_prologue(
vector,
vector_base,
category,
prologue,
&prologue_size
);
if (sc != RTEMS_SUCCESSFUL) {
ppc_exc_fatal_error();
}
ppc_code_copy(vector_address, prologue, prologue_size);
}
}
#ifndef PPC_EXC_CONFIG_BOOKE_ONLY
/* If we are on a classic PPC with MSR_DR enabled then
* assert that the mapping for at least this task's
* stack is write-back-caching enabled (see README/CAVEATS)
* Do this only if the cache is physically enabled.
* Since it is not easy to figure that out in a
* generic way we need help from the BSP: BSPs
* which run entirely w/o the cache may set
* ppc_exc_cache_wb_check to zero prior to calling
* this routine.
*
* We run this check only after exception handling is
* initialized so that we have some chance to get
* information printed if it fails.
*
* Note that it is unsafe to ignore this issue; if
* the check fails, do NOT disable it unless caches
* are always physically disabled.
*/
if (ppc_exc_cache_wb_check && (MSR_DR & ppc_exc_msr_bits)) {
/* The size of 63 assumes cache lines are at most 32 bytes */
uint8_t dummy[63];
uintptr_t p = (uintptr_t) dummy;
/* If the dcbz instruction raises an alignment exception
* then the stack is mapped as write-thru or caching-disabled.
* The low-level code is not capable of dealing with this
* ATM.
*/
p = (p + 31U) & ~31U;
__asm__ volatile ("dcbz 0, %0"::"b" (p));
/* If we make it thru here then things seem to be OK */
}
static void ppc_exc_initialize_booke(void *vector_base)
{
/* Interupt vector prefix register */
MTIVPR((uint32_t) vector_base);
if (
ppc_cpu_is_specific_e200(PPC_e200z0)
|| ppc_cpu_is_specific_e200(PPC_e200z1)
) {
/*
* These cores have hard wired IVOR registers. An access will case a
* program exception.
*/
return;
}
/* Interupt vector offset registers */
MTIVOR(0, ppc_exc_vector_address(ASM_BOOKE_CRIT_VECTOR, vector_base));
MTIVOR(1, ppc_exc_vector_address(ASM_MACH_VECTOR, vector_base));
MTIVOR(2, ppc_exc_vector_address(ASM_PROT_VECTOR, vector_base));
MTIVOR(3, ppc_exc_vector_address(ASM_ISI_VECTOR, vector_base));
MTIVOR(4, ppc_exc_vector_address(ASM_EXT_VECTOR, vector_base));
MTIVOR(5, ppc_exc_vector_address(ASM_ALIGN_VECTOR, vector_base));
MTIVOR(6, ppc_exc_vector_address(ASM_PROG_VECTOR, vector_base));
MTIVOR(7, ppc_exc_vector_address(ASM_FLOAT_VECTOR, vector_base));
MTIVOR(8, ppc_exc_vector_address(ASM_SYS_VECTOR, vector_base));
MTIVOR(9, ppc_exc_vector_address(ASM_BOOKE_APU_VECTOR, vector_base));
MTIVOR(10, ppc_exc_vector_address(ASM_BOOKE_DEC_VECTOR, vector_base));
MTIVOR(11, ppc_exc_vector_address(ASM_BOOKE_FIT_VECTOR, vector_base));
MTIVOR(12, ppc_exc_vector_address(ASM_BOOKE_WDOG_VECTOR, vector_base));
MTIVOR(13, ppc_exc_vector_address(ASM_BOOKE_DTLBMISS_VECTOR, vector_base));
MTIVOR(14, ppc_exc_vector_address(ASM_BOOKE_ITLBMISS_VECTOR, vector_base));
MTIVOR(15, ppc_exc_vector_address(ASM_BOOKE_DEBUG_VECTOR, vector_base));
if (ppc_cpu_is_e200() || ppc_cpu_is_e500()) {
MTIVOR(32, ppc_exc_vector_address(ASM_E500_SPE_UNAVAILABLE_VECTOR, vector_base));
MTIVOR(33, ppc_exc_vector_address(ASM_E500_EMB_FP_DATA_VECTOR, vector_base));
MTIVOR(34, ppc_exc_vector_address(ASM_E500_EMB_FP_ROUND_VECTOR, vector_base));
}
if (ppc_cpu_is_specific_e200(PPC_e200z7) || ppc_cpu_is_e500()) {
MTIVOR(35, ppc_exc_vector_address(ASM_E500_PERFMON_VECTOR, vector_base));
}
}
