summaryrefslogtreecommitdiff
path: root/nuttx/arch/z80
diff options
context:
space:
mode:
authorGregory Nutt <gnutt@nuttx.org>2014-08-22 12:32:34 -0600
committerGregory Nutt <gnutt@nuttx.org>2014-08-22 12:32:34 -0600
commit440d27c51fed1c66e883a6d0584599e2d0569a94 (patch)
tree8d392b85ac509e0c0e26d1c4c1a8338417771381 /nuttx/arch/z80
parent3ee26908593dc30b07686f8cb3f8e23fa8ad12d5 (diff)
downloadnuttx-440d27c51fed1c66e883a6d0584599e2d0569a94.tar.gz
nuttx-440d27c51fed1c66e883a6d0584599e2d0569a94.tar.bz2
nuttx-440d27c51fed1c66e883a6d0584599e2d0569a94.zip
An address environment is the property of a task group, not of a thread
Diffstat (limited to 'nuttx/arch/z80')
-rw-r--r--nuttx/arch/z80/include/z180/arch.h3
-rw-r--r--nuttx/arch/z80/include/z180/irq.h6
-rw-r--r--nuttx/arch/z80/src/z180/z180_mmu.c209
3 files changed, 85 insertions, 133 deletions
diff --git a/nuttx/arch/z80/include/z180/arch.h b/nuttx/arch/z80/include/z180/arch.h
index d7cf82a26..72306b930 100644
--- a/nuttx/arch/z80/include/z180/arch.h
+++ b/nuttx/arch/z80/include/z180/arch.h
@@ -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
/****************************************************************************
diff --git a/nuttx/arch/z80/include/z180/irq.h b/nuttx/arch/z80/include/z180/irq.h
index 1d0c27cb4..ba809bad8 100644
--- a/nuttx/arch/z80/include/z180/irq.h
+++ b/nuttx/arch/z80/include/z180/irq.h
@@ -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];
diff --git a/nuttx/arch/z80/src/z180/z180_mmu.c b/nuttx/arch/z80/src/z180/z180_mmu.c
index 4306eaf5f..c54fda148 100644
--- a/nuttx/arch/z80/src/z180/z180_mmu.c
+++ b/nuttx/arch/z80/src/z180/z180_mmu.c
@@ -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;
@@ -294,6 +295,42 @@ errout_with_irq:
}
/****************************************************************************
+ * 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
*
* Description:
@@ -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;
@@ -384,126 +421,75 @@ int up_addrenv_restore(hw_addrenv_t oldenv)
}
/****************************************************************************
- * 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;
-
- /* Make sure that the child has no address environment. It is okay if
- * if the parent does not have one.
- */
+ /* There is nothing that needs to be done */
- 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;
-
- /* 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--;
- }
- }
+ /* There is nothing that needs to be done */
- irqrestore(flags);
return OK;
}