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minix/kernel/proto.h
Ben Gras cd8b915ed9 Primary goal for these changes is: 
- no longer have kernel have its own page table that is loaded
    on every kernel entry (trap, interrupt, exception). the primary
    purpose is to reduce the number of required reloads.
Result:
  - kernel can only access memory of process that was running when
    kernel was entered
  - kernel must be mapped into every process page table, so traps to
    kernel keep working
Problem:
  - kernel must often access memory of arbitrary processes (e.g. send
    arbitrary processes messages); this can't happen directly any more;
    usually because that process' page table isn't loaded at all, sometimes
    because that memory isn't mapped in at all, sometimes because it isn't
    mapped in read-write.
So:
  - kernel must be able to map in memory of any process, in its own
    address space.
Implementation:
  - VM and kernel share a range of memory in which addresses of
    all page tables of all processes are available. This has two purposes:
      . Kernel has to know what data to copy in order to map in a range
      . Kernel has to know where to write the data in order to map it in
    That last point is because kernel has to write in the currently loaded
    page table.
  - Processes and kernel are separated through segments; kernel segments
    haven't changed.
  - The kernel keeps the process whose page table is currently loaded
    in 'ptproc.'
  - If it wants to map in a range of memory, it writes the value of the
    page directory entry for that range into the page directory entry
    in the currently loaded map. There is a slot reserved for such
    purposes. The kernel can then access this memory directly.
  - In order to do this, its segment has been increased (and the
    segments of processes start where it ends).
  - In the pagefault handler, detect if the kernel is doing
    'trappable' memory access (i.e. a pagefault isn't a fatal
     error) and if so,
       - set the saved instruction pointer to phys_copy_fault,
	 breaking out of phys_copy
       - set the saved eax register to the address of the page
	 fault, both for sanity checking and for checking in
	 which of the two ranges that phys_copy was called
	 with the fault occured
  - Some boot-time processes do not have their own page table,
    and are mapped in with the kernel, and separated with
    segments. The kernel detects this using HASPT. If such a
    process has to be scheduled, any page table will work and
    no page table switch is done.

Major changes in kernel are
  - When accessing user processes memory, kernel no longer
    explicitly checks before it does so if that memory is OK.
    It simply makes the mapping (if necessary), tries to do the
    operation, and traps the pagefault if that memory isn't present;
    if that happens, the copy function returns EFAULT.
    So all of the CHECKRANGE_OR_SUSPEND macros are gone.
  - Kernel no longer has to copy/read and parse page tables.
  - A message copying optimisation: when messages are copied, and
    the recipient isn't mapped in, they are copied into a buffer
    in the kernel. This is done in QueueMess. The next time
    the recipient is scheduled, this message is copied into
    its memory. This happens in schedcheck().
    This eliminates the mapping/copying step for messages, and makes
    it easier to deliver messages. This eliminates soft_notify.
  - Kernel no longer creates a page table at all, so the vm_setbuf
    and pagetable writing in memory.c is gone.

Minor changes in kernel are
  - ipc_stats thrown out, wasn't used
  - misc flags all renamed to MF_*
  - NOREC_* macros to enter and leave functions that should not
    be called recursively; just sanity checks really
  - code to fully decode segment selectors and descriptors
    to print on exceptions
  - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 14:31:52 +00:00

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/* Function prototypes. */
#ifndef PROTO_H
#define PROTO_H
#include <minix/safecopies.h>
#include <archtypes.h>
#include <a.out.h>
/* Struct declarations. */
struct proc;
struct timer;
/* clock.c */
_PROTOTYPE( void clock_task, (void) );
_PROTOTYPE( clock_t get_uptime, (void) );
_PROTOTYPE( void set_timer, (struct timer *tp, clock_t t, tmr_func_t f) );
_PROTOTYPE( void reset_timer, (struct timer *tp) );
_PROTOTYPE( void ser_dump_proc, (void) );
/* main.c */
_PROTOTYPE( void main, (void) );
_PROTOTYPE( void prepare_shutdown, (int how) );
_PROTOTYPE( void minix_shutdown, (struct timer *tp) );
_PROTOTYPE( void idle_task, (void) );
/* utility.c */
_PROTOTYPE( int kprintf, (const char *fmt, ...) );
_PROTOTYPE( void minix_panic, (char *s, int n) );
/* proc.c */
_PROTOTYPE( int sys_call, (int call_nr, int src_dst,
message *m_ptr, long bit_map) );
_PROTOTYPE( void sys_call_restart, (struct proc *caller) );
_PROTOTYPE( int lock_notify, (int src, int dst) );
_PROTOTYPE( int mini_notify, (struct proc *src, endpoint_t dst) );
_PROTOTYPE( int lock_send, (int dst, message *m_ptr) );
_PROTOTYPE( void enqueue, (struct proc *rp) );
_PROTOTYPE( void dequeue, (struct proc *rp) );
_PROTOTYPE( void balance_queues, (struct timer *tp) );
_PROTOTYPE( void schedcheck, (void) );
_PROTOTYPE( struct proc *endpoint_lookup, (endpoint_t ep) );
#if DEBUG_ENABLE_IPC_WARNINGS
_PROTOTYPE( int isokendpt_f, (char *file, int line, endpoint_t e, int *p, int f));
#define isokendpt_d(e, p, f) isokendpt_f(__FILE__, __LINE__, (e), (p), (f))
#else
_PROTOTYPE( int isokendpt_f, (endpoint_t e, int *p, int f) );
#define isokendpt_d(e, p, f) isokendpt_f((e), (p), (f))
#endif
/* start.c */
_PROTOTYPE( void cstart, (U16_t cs, U16_t ds, U16_t mds,
U16_t parmoff, U16_t parmsize) );
/* system.c */
_PROTOTYPE( int get_priv, (register struct proc *rc, int proc_type) );
_PROTOTYPE( void set_sendto_bit, (struct proc *rc, int id) );
_PROTOTYPE( void unset_sendto_bit, (struct proc *rc, int id) );
_PROTOTYPE( void send_sig, (int proc_nr, int sig_nr) );
_PROTOTYPE( void cause_sig, (int proc_nr, int sig_nr) );
_PROTOTYPE( void sys_task, (void) );
#define numap_local(proc_nr, vir_addr, bytes) \
umap_local(proc_addr(proc_nr), D, (vir_addr), (bytes))
_PROTOTYPE( phys_bytes umap_grant, (struct proc *, cp_grant_id_t,
vir_bytes));
_PROTOTYPE( vir_bytes vir_verify_grant, (struct proc *, endpoint_t,
cp_grant_id_t, vir_bytes, vir_bytes, int, endpoint_t *));
_PROTOTYPE( void clear_endpoint, (struct proc *rc) );
_PROTOTYPE( phys_bytes umap_bios, (vir_bytes vir_addr, vir_bytes bytes));
_PROTOTYPE( phys_bytes umap_verify_grant, (struct proc *rp, endpoint_t grantee, cp_grant_id_t grant, vir_bytes offset, vir_bytes bytes, int access));
/* system/do_newmap.c */
_PROTOTYPE( int newmap, (struct proc *rp, struct mem_map *map_ptr) );
/* system/do_vtimer.c */
_PROTOTYPE( void vtimer_check, (struct proc *rp) );
/* interrupt.c */
_PROTOTYPE( void intr_handle, (irq_hook_t *hook) );
_PROTOTYPE( void put_irq_handler, (irq_hook_t *hook, int irq,
irq_handler_t handler) );
_PROTOTYPE( void rm_irq_handler, (irq_hook_t *hook) );
_PROTOTYPE( void enable_irq, (irq_hook_t *hook) );
_PROTOTYPE( int disable_irq, (irq_hook_t *hook) );
_PROTOTYPE( void cons_setc, (int pos, int c) );
_PROTOTYPE( void cons_seth, (int pos, int n) );
/* debug.c */
#if DEBUG_SCHED_CHECK
#define CHECK_RUNQUEUES check_runqueues_f(__FILE__, __LINE__)
_PROTOTYPE( void check_runqueues_f, (char *file, int line) );
#endif
_PROTOTYPE( char *rtsflagstr, (int flags) );
_PROTOTYPE( char *miscflagstr, (int flags) );
/* system/do_safecopy.c */
_PROTOTYPE( int verify_grant, (endpoint_t, endpoint_t, cp_grant_id_t, vir_bytes,
int, vir_bytes, vir_bytes *, endpoint_t *));
/* system/do_sysctl.c */
_PROTOTYPE( int do_sysctl, (message *m));
#if SPROFILE
/* profile.c */
_PROTOTYPE( void init_profile_clock, (u32_t) );
_PROTOTYPE( void stop_profile_clock, (void) );
#endif
/* functions defined in architecture-dependent files. */
_PROTOTYPE( phys_bytes phys_copy, (phys_bytes source, phys_bytes dest,
phys_bytes count) );
_PROTOTYPE( void phys_copy_fault, (void));
#define virtual_copy(src, dst, bytes) virtual_copy_f(src, dst, bytes, 0)
#define virtual_copy_vmcheck(src, dst, bytes) virtual_copy_f(src, dst, bytes, 1)
_PROTOTYPE( int virtual_copy_f, (struct vir_addr *src, struct vir_addr *dst,
vir_bytes bytes, int vmcheck) );
_PROTOTYPE( int data_copy, (endpoint_t from, vir_bytes from_addr,
endpoint_t to, vir_bytes to_addr, size_t bytes));
_PROTOTYPE( int data_copy_vmcheck, (endpoint_t from, vir_bytes from_addr,
endpoint_t to, vir_bytes to_addr, size_t bytes));
#define data_copy_to(d, p, v, n) data_copy(SYSTEM, (d), (p), (v), (n));
#define data_copy_from(d, p, v, n) data_copy((p), (v), SYSTEM, (d), (n));
_PROTOTYPE( void alloc_segments, (struct proc *rp) );
_PROTOTYPE( void vm_init, (struct proc *first) );
_PROTOTYPE( void vm_map_range, (u32_t base, u32_t size, u32_t offset) );
_PROTOTYPE( int vm_copy, (vir_bytes src, struct proc *srcproc,
vir_bytes dst, struct proc *dstproc, phys_bytes bytes));
_PROTOTYPE( phys_bytes umap_local, (register struct proc *rp, int seg,
vir_bytes vir_addr, vir_bytes bytes));
_PROTOTYPE( void cp_mess, (int src,phys_clicks src_clicks,
vir_bytes src_offset, phys_clicks dst_clicks, vir_bytes dst_offset));
_PROTOTYPE( phys_bytes umap_remote, (struct proc* rp, int seg,
vir_bytes vir_addr, vir_bytes bytes) );
_PROTOTYPE( phys_bytes umap_virtual, (struct proc* rp, int seg,
vir_bytes vir_addr, vir_bytes bytes) );
_PROTOTYPE( phys_bytes seg2phys, (U16_t) );
_PROTOTYPE( int vm_phys_memset, (phys_bytes source, u8_t pattern,
phys_bytes count) );
_PROTOTYPE( vir_bytes alloc_remote_segment, (u32_t *, segframe_t *,
int, phys_bytes, vir_bytes, int));
_PROTOTYPE( int arch_init_clock, (void) );
_PROTOTYPE( clock_t read_clock, (void) );
_PROTOTYPE( void clock_stop, (void) );
_PROTOTYPE( int intr_init, (int) );
_PROTOTYPE( int intr_disabled, (void) );
_PROTOTYPE( int intr_unmask, (irq_hook_t* hook) );
_PROTOTYPE( int intr_mask, (irq_hook_t* hook) );
_PROTOTYPE( void idle_task, (void) );
_PROTOTYPE( void arch_init, (void) );
_PROTOTYPE( void ser_putc, (char) );
_PROTOTYPE( void arch_shutdown, (int) );
_PROTOTYPE( void arch_get_aout_headers, (int i, struct exec *h) );
_PROTOTYPE( void restart, (void) );
_PROTOTYPE( void idle_task, (void) );
_PROTOTYPE( void read_tsc, (unsigned long *high, unsigned long *low) );
_PROTOTYPE( int arch_init_profile_clock, (u32_t freq) );
_PROTOTYPE( void arch_stop_profile_clock, (void) );
_PROTOTYPE( void arch_ack_profile_clock, (void) );
_PROTOTYPE( void do_ser_debug, (void) );
_PROTOTYPE( int arch_get_params, (char *parm, int max));
_PROTOTYPE( int arch_set_params, (char *parm, int max));
_PROTOTYPE( int arch_pre_exec, (struct proc *pr, u32_t, u32_t));
_PROTOTYPE( int arch_umap, (struct proc *pr, vir_bytes, vir_bytes,
int, phys_bytes *));
_PROTOTYPE( int arch_do_vmctl, (message *m_ptr, struct proc *p));
_PROTOTYPE( int vm_contiguous, (struct proc *targetproc, u32_t vir_buf, size_t count));
_PROTOTYPE( int vm_checkrange, (struct proc *caller, struct proc *target,
vir_bytes start, vir_bytes length, int writeflag, int checkonly));
_PROTOTYPE( void proc_stacktrace, (struct proc *proc) );
_PROTOTYPE( int vm_lookup, (struct proc *proc, vir_bytes virtual, vir_bytes *result, u32_t *ptent));
_PROTOTYPE( int vm_suspend, (struct proc *caller, struct proc *target,
phys_bytes lin, phys_bytes size, int wrflag, int type));
_PROTOTYPE( int delivermsg, (struct proc *target));
_PROTOTYPE( phys_bytes arch_switch_copymsg, (struct proc *rp, message *m,
phys_bytes lin));
#endif /* PROTO_H */
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