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Simplified/Cleaned up pager initialization in the kernel

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This commit is contained in:
Bahadir Balban
2009-10-20 22:20:37 +03:00
parent 224b531de5
commit d2fee25924
3 changed files with 75 additions and 299 deletions
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184
src/generic/container.c
View File

@@ -47,70 +47,6 @@ void kres_insert_container(struct container *c,
kres->containers.ncont++;
}
/*
* FIXME: Remove completely. Need to be done in userspace.
* This searches pager capabilities and if it has a virtual memory area
* defined as a UTCB, uses the first entry as its utcb. If not, it is
* not an error, perhaps another pager will map its utcb.
*/
void pager_init_utcb(struct ktcb *task, struct pager *pager)
{
struct capability *cap;
/* Find a virtual memory capability with UTCB map permissions */
list_foreach_struct(cap, &pager->cap_list.caps, list) {
if (cap_rtype(cap) == CAP_RTYPE_VIRTMEM &&
cap->access & CAP_MAP_UTCB) {
/* Use first address slot as pager's utcb */
task->utcb_address = __pfn_to_addr(cap->start);
break;
}
}
}
#if 0
/*
* NOTE: This is not useful because FP stores references to
* old stack so even if stacks are copied, unwinding is not
* possible, which makes copying pointless. If there was no
* FP, it may make sense, but this is not tested.
*
* Copy current stack contents to new one,
* and jump to that stack by modifying sp and frame pointer.
*/
int switch_stacks(struct ktcb *task)
{
volatile register unsigned int stack asm("sp");
volatile register unsigned int frameptr asm("fp");
volatile register unsigned int newstack;
unsigned int stack_size = (unsigned int)_bootstack - stack;
newstack = align((unsigned long)task + PAGE_SIZE - 1,
STACK_ALIGNMENT);
/* Copy stack contents to new stack */
memcpy((void *)(newstack - stack_size),
(void *)stack, stack_size);
/*
* Switch to new stack, as new stack
* minus currently used stack size
*/
stack = newstack - stack_size;
/*
* Frame ptr is new stack minus the original
* difference from start of boot stack to current fptr
*/
frameptr = newstack -
((unsigned int)_bootstack - frameptr);
/* We should be able to return safely */
return 0;
}
#endif
/*
* TODO:
*
@@ -120,48 +56,57 @@ int switch_stacks(struct ktcb *task)
*/
/*
* Inspects pager parameters defined in the container,
* and sets up an execution environment for the pager.
*
* This involves setting up pager's ktcb, space, utcb,
* all ids, registers, and mapping its (perhaps) first
* few pages in order to make it runnable.
*
* The first pager initialization is a special-case
* since it uses the current kernel pgd.
*/
int init_first_pager(struct pager *pager,
int init_pager(struct pager *pager,
struct container *cont,
pgd_table_t *current_pgd)
{
struct ktcb *task;
struct address_space *space;
int first = !!current_pgd;
/*
* Initialize dummy current capability list pointer
* so that capability accounting can be done as normal
*
* FYI: We're still on bootstack instead of current's
* real stack. Hence this is a dummy.
*/
current->cap_list_ptr = &pager->cap_list;
/*
* Find capability from pager's list, since
* there is no ktcb, no standard path to check
* per-task capability list yet.
*/
/* Use it to allocate ktcb */
/* New ktcb allocation is needed */
task = tcb_alloc_init();
/* If first, manually allocate/initalize space */
if (first) {
if (!(space = alloc_space())) {
return -ENOMEM;
}
/* Set up space id */
space->spid = id_new(&kernel_resources.space_ids);
/* Initialize space structure */
link_init(&space->list);
mutex_init(&space->lock);
space->pgd = current_pgd;
address_space_attach(task, space);
} else {
/* Otherwise allocate conventionally */
task->space = address_space_create(0);
}
/* Initialize ktcb */
task_init_registers(task, pager->start_vma);
pager_init_utcb(task, pager);
/* Allocate space structure */
if (!(space = alloc_space()))
return -ENOMEM;
/* Set up space id */
space->spid = id_new(&kernel_resources.space_ids);
/* Initialize space structure */
link_init(&space->list);
mutex_init(&space->lock);
space->pgd = current_pgd;
address_space_attach(task, space);
/* Initialize container/pager relationships */
pager->tcb = task;
task->pager = pager;
@@ -192,64 +137,6 @@ int init_first_pager(struct pager *pager,
return 0;
}
/*
* Inspects pager parameters defined in the container,
* and sets up an execution environment for the pager.
*
* This involves setting up pager's ktcb, space, utcb,
* all ids, registers, and mapping its (perhaps) first
* few pages in order to make it runnable.
*/
int init_pager(struct pager *pager, struct container *cont)
{
struct ktcb *task;
/*
* Initialize dummy current capability list pointer
* so that capability accounting can be done as normal
* FYI: We're still on bootstack instead of current's
* real stack. Hence this is a dummy.
*/
current->cap_list_ptr = &pager->cap_list;
/* Use it to allocate ktcb */
task = tcb_alloc_init();
task_init_registers(task, pager->start_vma);
pager_init_utcb(task, pager);
task->space = address_space_create(0);
/* Initialize container/pager relationships */
pager->tcb = task;
task->pager = pager;
task->container = cont;
task->pagerid = task->tid;
task->cap_list_ptr = &pager->cap_list;
printk("%s: Mapping %lu pages from 0x%lx to 0x%lx for %s\n",
__KERNELNAME__, __pfn(page_align_up(pager->memsize)),
pager->start_lma, pager->start_vma, cont->name);
add_mapping_pgd(pager->start_lma, pager->start_vma,
page_align_up(pager->memsize),
MAP_USR_DEFAULT_FLAGS, TASK_PGD(task));
/* Initialize task scheduler parameters */
sched_init_task(task, TASK_PRIO_PAGER);
/* Give it a kick-start tick and make runnable */
task->ticks_left = 1;
sched_resume_async(task);
/* Container list that keeps all tasks */
tcb_add(task);
return 0;
}
/*
* Initialize all containers with their initial set of tasks,
* spaces, scheduler parameters such that they can be started.
@@ -259,19 +146,16 @@ int container_init_pagers(struct kernel_resources *kres,
{
struct container *cont;
struct pager *pager;
int pgidx = 0;
list_foreach_struct(cont, &kres->containers.list, list) {
for (int i = 0; i < cont->npagers; i++) {
pager = &cont->pager[i];
/* First pager initializes specially */
if (pgidx == 0)
init_first_pager(pager, cont,
current_pgd);
if (i == 0)
init_pager(pager, cont, current_pgd);
else
init_pager(pager, cont);
pgidx++;
init_pager(pager, cont, 0);
}
}

11
src/generic/resource.c
View File

@@ -477,17 +477,6 @@ int copy_container_info(struct container *c, struct container_info *cinfo)
return 0;
}
/*
* TODO:
*
* Rearrange as follows:
* 1.) Move realloc_page_tables to before container_init_pagers()
* 2.) Set up dummy current cap_list_ptr right after real capability list
* has been created. -> Think! since there are many containers!!!!!!!
* 3.) At this point, no need to do alloc_boot_pmd(), and current->cap_list_ptr
* is valid, so no custom alloc functions.
*/
/*
* Create real containers from compile-time created cinfo structures
*/