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An address environment is the property of a task group, not of a thread

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This commit is contained in:
Gregory Nutt 2014-08-22 12:32:34 -06:00
parent b01d3e396e
commit d40553b538
3 changed files with 85 additions and 133 deletions
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3
arch/z80/include/z180/arch.h
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@ -1,6 +1,5 @@
/****************************************************************************
* arch/z80/arch.h
* arch/chip/arch.h
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
@ -73,7 +72,7 @@ typedef uint8_t hw_addrenv_t;
*/
struct z180_cbr_s;
typedef FAR struct z180_cbr_s *task_addrenv_t;
typedef FAR struct z180_cbr_s *group_addrenv_t;
#endif
/****************************************************************************

6
arch/z80/include/z180/irq.h
View File

@ -173,7 +173,7 @@ typedef uint16_t chipreg_t;
struct z180_cbr_s
{
uint8_t cbr; /* The CBR value used by the thread */
uint8_t crefs; /* The number of threads sharing this CBR value */
uint8_t crefs; /* The number of task groups using this CBR value (0 or 1) */
uint8_t pages; /* The number of 4KB pages of physical memory in the allocation */
};
@ -183,10 +183,6 @@ struct z180_cbr_s
struct xcptcontext
{
/* CBR allocation */
FAR struct z180_cbr_s *cbr;
/* Register save area */
chipreg_t regs[XCPTCONTEXT_REGS];

209
arch/z80/src/z180/z180_mmu.c
View File

@ -1,7 +1,7 @@
/****************************************************************************
* arch/z80/src/z180/z180_mmu.c
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Copyright (C) 2012, 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -180,36 +180,37 @@ return g_physhandle ? OK : -ENOMEM;
* Address Environment Interfaces
*
* Low-level interfaces used in binfmt/ to instantiate tasks with address
* environments. These interfaces all operate on task_addrenv_t which is an
* abstract representation of the address environment and must be provided
* by arch/arch.h is CONFIG_ADDRENV is defined.
* environments. These interfaces all operate on type group_addrenv_t which
* is an abstract representation of a task group's address environment and
* must be defined in arch/arch.h if CONFIG_ADDRENV is defined.
*
* up_addrenv_create - Create an address environment
* up_addrenv_destroy - Destroy an address environment.
* up_addrenv_vaddr - Returns the virtual base address of the address
* environment
* up_addrenv_select - Instantiate an address environment
* up_addrenv_destroy - Destroy an address environment.
* up_addrenv_assign - Assign an address environment to a TCB
* up_addrenv_restore - Restore an address environment
* up_addrenv_assign - Assign an address environment to a group
*
* Higher-level interfaces used by the tasking logic. These interfaces are
* used by the functions in sched/ and all operate on the TCB which as been
* assigned an address environment by up_addrenv_assign().
* used by the functions in sched/ and all operate on the thread which whose
* group been assigned an address environment by up_addrenv_assign().
*
* up_addrenv_share - Clone the address environment assigned to one TCB
* up_addrenv_attach - Clone the address environment assigned to one TCB
* to another. This operation is done when a pthread
* is created that share's the same address
* environment.
* up_addrenv_release - Release the TCBs reference to an address
* environment when a task/thread exists.
* up_addrenv_detach - Release the threads reference to an address
* environment when a task/thread exits.
*
****************************************************************************/
/****************************************************************************
* Name: up_addrenv_create
*
* Description:
* This function is called from the binary loader logic when a new
* task is created in order to instantiate an address environment for the
* task. up_addrenv_create is essentially the allocator of the physical
* This function is called when a new task is created in order to
* instantiate an address environment for the new task group.
* up_addrenv_create() is essentially the allocator of the physical
* memory for the new task.
*
* Input Parameters:
@ -223,7 +224,7 @@ return g_physhandle ? OK : -ENOMEM;
*
****************************************************************************/
int up_addrenv_create(size_t envsize, FAR task_addrenv_t *addrenv)
int up_addrenv_create(size_t envsize, FAR group_addrenv_t *addrenv)
{
FAR struct z180_cbr_s *cbr;
irqstate_t flags;
@ -280,7 +281,7 @@ int up_addrenv_create(size_t envsize, FAR task_addrenv_t *addrenv)
cbr->cbr = (uint8_t)alloc;
cbr->pages = (uint8_t)npages;
*addrenv = (task_addrenv_t)cbr;
*addrenv = (group_addrenv_t)cbr;
irqrestore(flags);
return OK;
@ -293,6 +294,42 @@ errout_with_irq:
return ret;
}
/****************************************************************************
* Name: up_addrenv_destroy
*
* Description:
* This function is called when a final thread leaves the task group and
* the task group is destroyed. This function then destroys the defunct
* address environment, releasing the underlying physical memory.
*
* Input Parameters:
* addrenv - The address environment to be destroyed.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int up_addrenv_destroy(group_addrenv_t addrenv)
{
FAR struct z180_cbr_s *cbr = (FAR struct z180_cbr_s *)addrenv;
DEBUGASSERT(cbr);
/* Free the physical address space backing up the mapping */
#ifdef CONFIG_GRAN_SINGLE
gran_free((FAR void *)cbr->cbr, cbr->pages);
#else
gran_free(g_physhandle, (FAR void *)cbr->cbr, cbr->pages);
#endif
/* And make the CBR structure available for re-use */
z180_mmu_freecbr(cbr);
return OK;
}
/****************************************************************************
* Name: up_addrenv_vaddr
*
@ -311,7 +348,7 @@ errout_with_irq:
*
****************************************************************************/
int up_addrenv_vaddr(FAR task_addrenv_t addrenv, FAR void **vaddr)
int up_addrenv_vaddr(FAR group_addrenv_t addrenv, FAR void **vaddr)
{
return CONFIG_Z180_COMMON1AREA_VIRTBASE;
}
@ -334,14 +371,14 @@ int up_addrenv_vaddr(FAR task_addrenv_t addrenv, FAR void **vaddr)
* This may be used with up_addrenv_restore() to restore the original
* address environment that was in place before up_addrenv_select() was
* called. Note that this may be a task agnostic, hardware
* representation that is different from task_addrenv_t.
* representation that is different from group_addrenv_t.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int up_addrenv_select(task_addrenv_t addrenv, hw_addrenv_t *oldenv)
int up_addrenv_select(group_addrenv_t addrenv, hw_addrenv_t *oldenv)
{
FAR struct z180_cbr_s *cbr = (FAR struct z180_cbr_s *)addrenv;
irqstate_t flags;
@ -383,127 +420,76 @@ int up_addrenv_restore(hw_addrenv_t oldenv)
return OK;
}
/****************************************************************************
* Name: up_addrenv_destroy
*
* Description:
* Called from the binary loader loader during error handling to destroy
* the address environment previously created by up_addrenv_create().
*
* Input Parameters:
* addrenv - The representation of the task address environment previously
* returned by up_addrenv_create.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int up_addrenv_destroy(task_addrenv_t addrenv)
{
FAR struct z180_cbr_s *cbr = (FAR struct z180_cbr_s *)addrenv;
DEBUGASSERT(cbr);
/* Free the physical address space backing up the mapping */
#ifdef CONFIG_GRAN_SINGLE
gran_free((FAR void *)cbr->cbr, cbr->pages);
#else
gran_free(g_physhandle, (FAR void *)cbr->cbr, cbr->pages);
#endif
/* And make the CBR structure available for re-use */
z180_mmu_freecbr(cbr);
return OK;
}
/****************************************************************************
* Name: up_addrenv_assign
*
* Description:
* Assign an address environment to a TCB.
* Assign an address environment to a task group.
*
* Input Parameters:
* addrenv - The representation of the task address environment previously
* returned by up_addrenv_create.
* tcb - The TCB of the task to receive the address environment.
* returned by up_addrenv_create().
* group - The task group to receive the address environment.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int up_addrenv_assign(task_addrenv_t addrenv, FAR struct tcb_s *tcb)
int up_addrenv_assign(group_addrenv_t addrenv, FAR struct task_group_s *group)
{
FAR struct z180_cbr_s *cbr = (FAR struct z180_cbr_s *)addrenv;
/* Make sure that there is no address environment in place on this TCB */
DEBUGASSERT(cbr && tcb->xcp.cbr == NULL);
DEBUGASSERT(addrenv && group->addrenv == NULL);
/* Save the CBR strucure in the TCB. This is an atomic operation so no
/* Save the CBR structure in the group. This is an atomic operation so no
* special precautions should be needed.
*/
tcb->xcp.cbr = cbr;
group->addrenv = addrenv;
return OK;
}
/****************************************************************************
* Name: up_addrenv_share
* Name: up_addrenv_attach
*
* Description:
* This function is called from the core scheduler logic when a thread
* is created that needs to share the address ennvironment of its parent
* task. In this case, the parent's address environment needs to be
* "cloned" for the child.
* is created that needs to share the address environment of its task
* group.
*
* Input Parameters:
* ptcb - The TCB of the parent task that has the address environment.
* ctcb - The TCB of the child thread needing the address environment.
* group - The task group to which the new thread belongs.
* tcb - The tcb of the thread needing the address environment.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int up_addrenv_share(FAR const struct tcb_s *ptcb, FAR struct tcb_s *ctcb)
int up_addrenv_attach(FAR struct task_group_s *group, FAR struct tcb_s *tcb)
{
irqstate_t flags;
/* There is nothing that needs to be done */
/* Make sure that the child has no address environment. It is okay if
* if the parent does not have one.
*/
DEBUGASSERT(ctcb->xcp.cbr == NULL);
flags = irqsave();
if (ptcb->xcp.cbr)
{
/* Clone the CBR by incrementing the reference counting and saving a
* copy in the child thread's TCB.
*/
ptcb->xcp.cbr->crefs++;
ctcb->xcp.cbr = ptcb->xcp.cbr;
}
irqrestore(flags);
return OK;
}
/****************************************************************************
* Name: up_addrenv_release
* Name: up_addrenv_detach
*
* Description:
* This function is called when a task or thread exits in order to release
* its reference to an address environment. When there are no further
* references to an address environment, that address environment should
* be destroyed.
* its reference to an address environment. The address environment,
* however, should persist until up_addrenv_destroy() is called when the
* task group is itself destroyed. Any resources unique to this thread
* may be destroyed now.
*
* NOTE: In some platforms, nothing will need to be done in this case.
* Simply being a member of the group that has the address environment
* may be sufficient.
*
* Input Parameters:
* group - The group to which the thread belonged.
* tcb - The TCB of the task or thread whose the address environment will
* be released.
*
@ -512,39 +498,10 @@ int up_addrenv_share(FAR const struct tcb_s *ptcb, FAR struct tcb_s *ctcb)
*
****************************************************************************/
int up_addrenv_release(FAR struct tcb_s *tcb)
int up_addrenv_detach(FAR struct task_group_s *group,
FAR struct task_group_s *tcb);
{
FAR struct z180_cbr_s *cbr;
irqstate_t flags;
/* There is nothing that needs to be done */
/* Check if the task has an address environment. */
flags = irqsave();
cbr = tcb->xcp.cbr;
if (cbr)
{
/* Nullify the reference to the CBR structure and decrement the number
* of references on the CBR.
*/
tcb->xcp.cbr = NULL;
/* If the reference count would decrement to zero, then free the CBR
* structure.
*/
if (cbr->crefs <= 1)
{
up_addrenv_destroy(cbr);
}
else
{
/* Otherwise, just decrement the reference count */
cbr->crefs--;
}
}
irqrestore(flags);
return OK;
}