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d2aa9a552b
Tasks boot fine up to doing ipc using their utcbs. UTCB PLAN: - Push ipc registers into private environment instead of a shared utcb, but map-in a shared utcb to pass on long data to server tasks. - Shared utcb has unique virtual address for every thread. - Forked child does inherit parent's utcb, but cannot use it to communicate to any server. It must explicitly obtain its own utcb for that. - Clone could have a flag to explicitly not inherit parent utcb, which is the right thing to do. - MM0 serves a syscall to obtain self utcb. - By this method, upon forks tasks don't need to map-in a utcb unless they want to pass long data.
71 lines
1.8 KiB
C
71 lines
1.8 KiB
C
/*
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* Copyright (C) 2007 Bahadir Balban
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*/
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#include <arch/mm.h>
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#include <task.h>
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#include <vm_area.h>
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/* Extracts generic protection flags from architecture-specific pte */
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unsigned int vm_prot_flags(pte_t pte)
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{
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unsigned int vm_prot_flags = 0;
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unsigned int rw_flags = __MAP_USR_RW_FLAGS & PTE_PROT_MASK;
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unsigned int ro_flags = __MAP_USR_RO_FLAGS & PTE_PROT_MASK;
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/* Clear non-protection flags */
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pte &= PTE_PROT_MASK;;
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if (pte == ro_flags)
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vm_prot_flags = VM_READ | VM_EXEC;
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else if (pte == rw_flags)
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vm_prot_flags = VM_READ | VM_WRITE | VM_EXEC;
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else
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vm_prot_flags = VM_NONE;
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return vm_prot_flags;
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}
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#if defined(DEBUG_FAULT_HANDLING)
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void print_fault_params(struct fault_data *fault)
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{
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printf("%s: Handling %s fault (%s abort) from %d. fault @ 0x%x\n",
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__TASKNAME__, (fault->reason & VM_READ) ? "read" : "write",
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is_prefetch_abort(fault->kdata->fsr) ? "prefetch" : "data",
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fault->task->tid, fault->address);
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}
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#else
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void print_fault_params(struct fault_data *fault) { }
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#endif
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/*
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* PTE STATES:
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* PTE type field: 00 (Translation fault)
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* PTE type field correct, AP bits: None (Read or Write access fault)
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* PTE type field correct, AP bits: RO (Write access fault)
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*/
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/* Extracts arch-specific fault parameters and puts them into generic format */
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void set_generic_fault_params(struct fault_data *fault)
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{
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unsigned int prot_flags = vm_prot_flags(fault->kdata->pte);
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fault->reason = 0;
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if (is_prefetch_abort(fault->kdata->fsr)) {
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fault->reason |= VM_READ;
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fault->address = fault->kdata->faulty_pc;
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} else {
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fault->address = fault->kdata->far;
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/* Always assume read fault first */
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if (prot_flags & VM_NONE)
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fault->reason |= VM_READ;
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else if (prot_flags & VM_READ)
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fault->reason |= VM_WRITE;
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else
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BUG();
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}
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print_fault_params(fault);
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}
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