1335d5d700
instance numbers, encoded and decoded using macros in <minix/endpoint.h>.
proc number -> endpoint migration
. proc_nr in the interrupt hook is now an endpoint, proc_nr_e.
. m_source for messages and notifies is now an endpoint, instead of
proc number.
. isokendpt() converts an endpoint to a process number, returns
success (but fails if the process number is out of range, the
process slot is not a living process, or the given endpoint
number does not match the endpoint number in the process slot,
indicating an old process).
. okendpt() is the same as isokendpt(), but panic()s if the conversion
fails. This is mainly used for decoding message.m_source endpoints,
and other endpoint numbers in kernel data structures, which should
always be correct.
. if DEBUG_ENABLE_IPC_WARNINGS is enabled, isokendpt() and okendpt()
get passed the __FILE__ and __LINE__ of the calling lines, and
print messages about what is wrong with the endpoint number
(out of range proc, empty proc, or inconsistent endpoint number),
with the caller, making finding where the conversion failed easy
without having to include code for every call to print where things
went wrong. Sometimes this is harmless (wrong arg to a kernel call),
sometimes it's a fatal internal inconsistency (bogus m_source).
. some process table fields have been appended an _e to indicate it's
become and endpoint.
. process endpoint is stored in p_endpoint, without generation number.
it turns out the kernel never needs the generation number, except
when fork()ing, so it's decoded then.
. kernel calls all take endpoints as arguments, not proc numbers.
the one exception is sys_fork(), which needs to know in which slot
to put the child.
80 lines
2.6 KiB
C
80 lines
2.6 KiB
C
/* The kernel call implemented in this file:
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* m_type: SYS_SEGCTL
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*
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* The parameters for this kernel call are:
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* m4_l3: SEG_PHYS (physical base address)
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* m4_l4: SEG_SIZE (size of segment)
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* m4_l1: SEG_SELECT (return segment selector here)
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* m4_l2: SEG_OFFSET (return offset within segment here)
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* m4_l5: SEG_INDEX (return index into remote memory map here)
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*/
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#include "../system.h"
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#include "../protect.h"
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#if USE_SEGCTL
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/*===========================================================================*
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* do_segctl *
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*===========================================================================*/
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PUBLIC int do_segctl(m_ptr)
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register message *m_ptr; /* pointer to request message */
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{
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/* Return a segment selector and offset that can be used to reach a physical
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* address, for use by a driver doing memory I/O in the A0000 - DFFFF range.
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*/
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u16_t selector;
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vir_bytes offset;
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int i, index;
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register struct proc *rp;
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phys_bytes phys = (phys_bytes) m_ptr->SEG_PHYS;
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vir_bytes size = (vir_bytes) m_ptr->SEG_SIZE;
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int result;
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/* First check if there is a slot available for this segment. */
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rp = proc_addr(who_p);
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index = -1;
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for (i=0; i < NR_REMOTE_SEGS; i++) {
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if (! rp->p_priv->s_farmem[i].in_use) {
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index = i;
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rp->p_priv->s_farmem[i].in_use = TRUE;
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rp->p_priv->s_farmem[i].mem_phys = phys;
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rp->p_priv->s_farmem[i].mem_len = size;
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break;
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}
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}
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if (index < 0) return(ENOSPC);
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if (! machine.protected) {
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selector = phys / HCLICK_SIZE;
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offset = phys % HCLICK_SIZE;
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result = OK;
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} else {
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/* Check if the segment size can be recorded in bytes, that is, check
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* if descriptor's limit field can delimited the allowed memory region
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* precisely. This works up to 1MB. If the size is larger, 4K pages
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* instead of bytes are used.
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*/
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if (size < BYTE_GRAN_MAX) {
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init_dataseg(&rp->p_ldt[EXTRA_LDT_INDEX+i], phys, size,
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USER_PRIVILEGE);
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selector = ((EXTRA_LDT_INDEX+i)*0x08) | (1*0x04) | USER_PRIVILEGE;
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offset = 0;
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result = OK;
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} else {
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init_dataseg(&rp->p_ldt[EXTRA_LDT_INDEX+i], phys & ~0xFFFF, 0,
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USER_PRIVILEGE);
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selector = ((EXTRA_LDT_INDEX+i)*0x08) | (1*0x04) | USER_PRIVILEGE;
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offset = phys & 0xFFFF;
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result = OK;
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}
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}
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/* Request successfully done. Now return the result. */
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m_ptr->SEG_INDEX = index | REMOTE_SEG;
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m_ptr->SEG_SELECT = selector;
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m_ptr->SEG_OFFSET = offset;
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return(result);
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}
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#endif /* USE_SEGCTL */
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