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Diffstat (limited to '')
| -rw-r--r-- | c/src/lib/libbsp/powerpc/shared/irq/irq_asm.S | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/powerpc/shared/irq/irq_asm.S b/c/src/lib/libbsp/powerpc/shared/irq/irq_asm.S new file mode 100644 index 0000000000..043108155f --- /dev/null +++ b/c/src/lib/libbsp/powerpc/shared/irq/irq_asm.S @@ -0,0 +1,322 @@ +/* + * This file contains the assembly code for the PowerPC + * IRQ veneers for RTEMS. + * + * The license and distribution terms for this file may be + * found in found in the file LICENSE in this distribution or at + * http://www.OARcorp.com/rtems/license.html. + * + * Modified to support the MCP750. + * Modifications Copyright (C) 1999 Eric Valette. valette@crf.canon.fr + * + * + * $Id$ + */ + +#include <bsp/vectors.h> +#include <libcpu/cpu.h> +#include <libcpu/raw_exception.h> +#include <rtems/score/targopts.h> +#include "asm.h" + + +#define SYNC \ + sync; \ + isync + + .text + .p2align 5 + + PUBLIC_VAR(decrementer_exception_vector_prolog_code) + +SYM (decrementer_exception_vector_prolog_code): + /* + * let room for exception frame + */ + stwu r1, - (EXCEPTION_FRAME_END)(r1) + stw r4, GPR4_OFFSET(r1) + li r4, ASM_DEC_VECTOR + ba shared_raw_irq_code_entry + + PUBLIC_VAR (decrementer_exception_vector_prolog_code_size) + + decrementer_exception_vector_prolog_code_size = . - decrementer_exception_vector_prolog_code + + PUBLIC_VAR(external_exception_vector_prolog_code) + +SYM (external_exception_vector_prolog_code): + /* + * let room for exception frame + */ + stwu r1, - (EXCEPTION_FRAME_END)(r1) + stw r4, GPR4_OFFSET(r1) + li r4, ASM_EXT_VECTOR + ba shared_raw_irq_code_entry + + PUBLIC_VAR (external_exception_vector_prolog_code_size) + + external_exception_vector_prolog_code_size = . - external_exception_vector_prolog_code + + PUBLIC_VAR(shared_raw_irq_code_entry) + PUBLIC_VAR(C_dispatch_irq_handler) + + .p2align 5 +SYM (shared_raw_irq_code_entry): + /* + * Entry conditions : + * Registers already saved : R1, R4 + * R1 : points to a location with enough room for the + * interrupt frame + * R4 : vector number + */ + /* + * Save SRR0/SRR1 As soon As possible as it is the minimal needed + * to reenable exception processing + */ + stw r0, GPR0_OFFSET(r1) + stw r2, GPR2_OFFSET(r1) + stw r3, GPR3_OFFSET(r1) + + mfsrr0 r0 + mfsrr1 r2 + mfmsr r3 + + stw r0, SRR0_FRAME_OFFSET(r1) + stw r2, SRR1_FRAME_OFFSET(r1) + /* + * Enable data and instruction address translation, exception recovery + */ + ori r3, r3, MSR_RI | MSR_IR | MSR_DR + mtmsr r3 + SYNC + /* + * Push C scratch registers on the current stack. It may + * actually be the thread stack or the interrupt stack. + * Anyway we have to make it in order to be able to call C/C++ + * functions. Depending on the nesting interrupt level, we will + * switch to the right stack later. + */ + stw r5, GPR5_OFFSET(r1) + stw r6, GPR6_OFFSET(r1) + stw r7, GPR7_OFFSET(r1) + stw r8, GPR8_OFFSET(r1) + stw r9, GPR9_OFFSET(r1) + stw r10, GPR10_OFFSET(r1) + stw r11, GPR11_OFFSET(r1) + stw r12, GPR12_OFFSET(r1) + stw r13, GPR13_OFFSET(r1) + + mfcr r5 + mfctr r6 + mfxer r7 + mflr r8 + + stw r5, EXC_CR_OFFSET(r1) + stw r6, EXC_CTR_OFFSET(r1) + stw r7, EXC_XER_OFFSET(r1) + stw r8, EXC_LR_OFFSET(r1) + + /* + * Add some non volatile registers to store information + * that will be used when returning from C handler + */ + stw r14, GPR14_OFFSET(r1) + stw r15, GPR15_OFFSET(r1) + /* + * save current stack pointer location in R14 + */ + addi r14, r1, 0 + /* + * store part of _Thread_Dispatch_disable_level address in R15 + */ + addis r15,0, _Thread_Dispatch_disable_level@ha + /* + * Get current nesting level in R2 + */ + mfspr r2, SPRG0 + /* + * Check if stack switch is necessary + */ + cmpwi r2,0 + bne nested + mfspr r1, SPRG1 + +nested: + /* + * Start Incrementing nesting level in R2 + */ + addi r2,r2,1 + /* + * Start Incrementing _Thread_Dispatch_disable_level R4 = _Thread_Dispatch_disable_level + */ + lwz r6,_Thread_Dispatch_disable_level@l(r15) + /* + * store new nesting level in SPRG0 + */ + mtspr SPRG0, r2 + + addi r6, r6, 1 + mfmsr r5 + /* + * store new _Thread_Dispatch_disable_level value + */ + stw r6, _Thread_Dispatch_disable_level@l(r15) + /* + * We are now running on the interrupt stack. External and decrementer + * exceptions are still disabled. I see no purpose trying to optimize + * further assembler code. + */ + /* + * Call C exception handler for decrementer Interrupt frame is passed just + * in case... + */ + addi r3, r14, 0x8 + bl C_dispatch_irq_handler /* C_dispatch_irq_handler(cpu_interrupt_frame* r3, vector r4) */ + /* + * start decrementing nesting level. Note : do not test result against 0 + * value as an easy exit condition because if interrupt nesting level > 1 + * then _Thread_Dispatch_disable_level > 1 + */ + mfspr r2, SPRG0 + /* + * start decrementing _Thread_Dispatch_disable_level + */ + lwz r3,_Thread_Dispatch_disable_level@l(r15) + addi r2, r2, -1 /* Continue decrementing nesting level */ + addi r3, r3, -1 /* Continue decrementing _Thread_Dispatch_disable_level */ + mtspr SPRG0, r2 /* End decrementing nesting level */ + stw r3,_Thread_Dispatch_disable_level@l(r15) /* End decrementing _Thread_Dispatch_disable_level */ + cmpwi r3, 0 + /* + * switch back to original stack (done here just optimize registers + * contention. Could have been done before...) + */ + addi r1, r14, 0 + bne easy_exit /* if (_Thread_Dispatch_disable_level != 0) goto easy_exit */ + /* + * Here we are running again on the thread system stack. + * We have interrupt nesting level = _Thread_Dispatch_disable_level = 0. + * Interrupt are still disabled. Time to check if scheduler request to + * do something with the current thread... + */ + addis r4, 0, _Context_Switch_necessary@ha + lwz r5, _Context_Switch_necessary@l(r4) + cmpwi r5, 0 + bne switch + + addis r6, 0, _ISR_Signals_to_thread_executing@ha + lwz r7, _ISR_Signals_to_thread_executing@l(r6) + cmpwi r7, 0 + li r8, 0 + beq easy_exit + stw r8, _ISR_Signals_to_thread_executing@l(r6) + /* + * going to call _ThreadProcessSignalsFromIrq + * Push a complete exception like frame... + */ + stmw r16, GPR16_OFFSET(r1) + addi r3, r1, 0x8 + /* + * compute SP at exception entry + */ + addi r2, r1, EXCEPTION_FRAME_END + /* + * store it at the right place + */ + stw r2, GPR1_OFFSET(r1) + /* + * Call High Level signal handling code + */ + bl _ISR_Signals_to_thread_executing + /* + * start restoring exception like frame + */ + lwz r31, EXC_CTR_OFFSET(r1) + lwz r30, EXC_XER_OFFSET(r1) + lwz r29, EXC_CR_OFFSET(r1) + lwz r28, EXC_LR_OFFSET(r1) + + mtctr r31 + mtxer r30 + mtcr r29 + mtlr r28 + + lmw r4, GPR4_OFFSET(r1) + lwz r2, GPR2_OFFSET(r1) + lwz r0, GPR0_OFFSET(r1) + + /* + * Disable data and instruction translation. Make path non recoverable... + */ + mfmsr r3 + xori r3, r3, MSR_RI | MSR_IR | MSR_DR + mtmsr r3 + SYNC + /* + * Restore rfi related settings + */ + + lwz r3, SRR1_FRAME_OFFSET(r1) + mtsrr1 r3 + lwz r3, SRR0_FRAME_OFFSET(r1) + mtsrr0 r3 + + lwz r3, GPR3_OFFSET(r1) + addi r1,r1, EXCEPTION_FRAME_END + SYNC + rfi + +switch: + bl SYM (_Thread_Dispatch) + +easy_exit: + /* + * start restoring interrupt frame + */ + lwz r3, EXC_CTR_OFFSET(r1) + lwz r4, EXC_XER_OFFSET(r1) + lwz r5, EXC_CR_OFFSET(r1) + lwz r6, EXC_LR_OFFSET(r1) + + mtctr r3 + mtxer r4 + mtcr r5 + mtlr r6 + + lwz r15, GPR15_OFFSET(r1) + lwz r14, GPR14_OFFSET(r1) + lwz r13, GPR13_OFFSET(r1) + lwz r12, GPR12_OFFSET(r1) + lwz r11, GPR11_OFFSET(r1) + lwz r10, GPR10_OFFSET(r1) + lwz r9, GPR9_OFFSET(r1) + lwz r8, GPR8_OFFSET(r1) + lwz r7, GPR7_OFFSET(r1) + lwz r6, GPR6_OFFSET(r1) + lwz r5, GPR5_OFFSET(r1) + + /* + * Disable nested exception processing, data and instruction + * translation. + */ + mfmsr r3 + xori r3, r3, MSR_RI | MSR_IR | MSR_DR + mtmsr r3 + SYNC + /* + * Restore rfi related settings + */ + + lwz r4, SRR1_FRAME_OFFSET(r1) + lwz r2, SRR0_FRAME_OFFSET(r1) + lwz r3, GPR3_OFFSET(r1) + lwz r0, GPR0_OFFSET(r1) + + mtsrr1 r4 + mtsrr0 r2 + lwz r4, GPR4_OFFSET(r1) + lwz r2, GPR2_OFFSET(r1) + addi r1,r1, EXCEPTION_FRAME_END + SYNC + rfi + |