/****************************************************************************
* arch/arm/src/armv7/arm_addrenv_ustack.c
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Address Environment Interfaces
*
* Low-level interfaces used in binfmt/ to instantiate tasks with address
* 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_ARCH_ADDRENV is defined.
*
* up_addrenv_create - Create an address environment
* up_addrenv_destroy - Destroy an address environment.
* up_addrenv_vtext - Returns the virtual base address of the .text
* address environment
* up_addrenv_vdata - Returns the virtual base address of the .bss/.data
* address environment
* up_addrenv_heapsize - Returns the size of the initial heap allocation.
* up_addrenv_select - Instantiate an address environment
* up_addrenv_restore - Restore an address environment
* up_addrenv_clone - Copy an address environment from one location to
* another.
*
* Higher-level interfaces used by the tasking logic. These interfaces are
* used by the functions in sched/ and all operate on the thread which whose
* group been assigned an address environment by up_addrenv_clone().
*
* 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_detach - Release the threads reference to an address
* environment when a task/thread exits.
*
* CONFIG_ARCH_STACK_DYNAMIC=y indicates that the user process stack resides
* in its own address space. This options is also *required* if
* CONFIG_BUILD_KERNEL and CONFIG_LIBC_EXECFUNCS are selected. Why?
* Because the caller's stack must be preserved in its own address space
* when we instantiate the environment of the new process in order to
* initialize it.
*
* NOTE: The naming of the CONFIG_ARCH_STACK_DYNAMIC selection implies that
* dynamic stack allocation is supported. Certainly this option must be set
* if dynamic stack allocation is supported by a platform. But the more
* general meaning of this configuration environment is simply that the
* stack has its own address space.
*
* If CONFIG_ARCH_KERNEL_STACK=y is selected then the platform specific
* code must export these additional interfaces:
*
* up_addrenv_ustackalloc - Create a stack address environment
* up_addrenv_ustackfree - Destroy a stack address environment.
* up_addrenv_vustack - Returns the virtual base address of the stack
* up_addrenv_ustackselect - Instantiate a stack address environment
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/sched.h>
#include <nuttx/addrenv.h>
#include <arch/irq.h>
#include "mmu.h"
#include "addrenv.h"
#if defined(CONFIG_ARCH_ADDRENV) && defined(CONFIG_ARCH_STACK_DYNAMIC)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration */
#if (CONFIG_ARCH_STACK_VBASE & SECTION_MASK) != 0
# error CONFIG_ARCH_STACK_VBASE not aligned to section boundary
#endif
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_addrenv_ustackalloc
*
* Description:
* This function is called when a new thread is created in order to
* instantiate an address environment for the new thread's stack.
* up_addrenv_ustackalloc() is essentially the allocator of the physical
* memory for the new task's stack.
*
* Input Parameters:
* tcb - The TCB of the thread that requires the stack address environment.
* stacksize - The size (in bytes) of the initial stack address
* environment needed by the task. This region may be read/write only.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int up_addrenv_ustackalloc(FAR struct tcb_s *tcb, size_t stacksize)
{
int ret;
bvdbg("tcb=%p stacksize=%lu\n", tcb, (unsigned long)stacksize);
DEBUGASSERT(tcb);
/* Initialize the address environment list to all zeroes */
memset(tcb->xcp.ustack, 0, ARCH_STACK_NSECTS * sizeof(uintptr_t *));
/* Back the allocation up with physical pages and set up the level 2 mapping
* (which of course does nothing until the L2 page table is hooked into
* the L1 page table).
*/
/* Allocate .text space pages */
ret = arm_addrenv_create_region(tcb->xcp.ustack, ARCH_STACK_NSECTS,
CONFIG_ARCH_STACK_VBASE, stacksize,
MMU_L2_UDATAFLAGS);
if (ret < 0)
{
bdbg("ERROR: Failed to create stack region: %d\n", ret);
up_addrenv_ustackfree(tcb);
return ret;
}
return OK;
}
/****************************************************************************
* Name: up_addrenv_ustackfree
*
* Description:
* This function is called when any thread exits. This function then
* destroys the defunct address environment for the thread's stack,
* releasing the underlying physical memory.
*
* Input Parameters:
* tcb - The TCB of the thread that no longer requires the stack address
* environment.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int up_addrenv_ustackfree(FAR struct tcb_s *tcb)
{
bvdbg("tcb=%p\n", tcb);
DEBUGASSERT(tcb);
/* Destroy the stack region */
arm_addrenv_destroy_region(tcb->xcp.ustack, ARCH_STACK_NSECTS,
CONFIG_ARCH_STACK_VBASE, false);
memset(tcb->xcp.ustack, 0, ARCH_STACK_NSECTS * sizeof(uintptr_t *));
return OK;
}
/****************************************************************************
* Name: up_addrenv_vustack
*
* Description:
* Return the virtual address associated with the newly created stack
* address environment.
*
* Input Parameters:
* tcb - The TCB of the thread with the stack address environment of
* interest.
* vstack - The location to return the stack virtual base address.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int up_addrenv_vustack(FAR const struct tcb_s *tcb, FAR void **vstack)
{
bvdbg("Return=%p\n", (FAR void *)CONFIG_ARCH_STACK_VBASE);
/* Not much to do in this case */
DEBUGASSERT(tcb);
*vstack = (FAR void *)CONFIG_ARCH_STACK_VBASE;
return OK;
}
/****************************************************************************
* Name: up_addrenv_ustackselect
*
* Description:
* After an address environment has been established for a task's stack
* (via up_addrenv_ustackalloc(). This function may be called to instantiate
* that address environment in the virtual address space. This is a
* necessary step before each context switch to the newly created thread
* (including the initial thread startup).
*
* Input Parameters:
* tcb - The TCB of the thread with the stack address environment to be
* instantiated.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int up_addrenv_ustackselect(FAR const struct tcb_s *tcb)
{
uintptr_t vaddr;
uintptr_t paddr;
int i;
DEBUGASSERT(tcb);
for (vaddr = CONFIG_ARCH_STACK_VBASE, i = 0;
i < ARCH_TEXT_NSECTS;
vaddr += ARCH_STACK_NSECTS, i++)
{
/* Set (or clear) the new page table entry */
paddr = (uintptr_t)tcb->xcp.ustack[i];
if (paddr)
{
mmu_l1_setentry(paddr, vaddr, MMU_L1_PGTABFLAGS);
}
else
{
mmu_l1_clrentry(vaddr);
}
}
return OK;
}
#endif /* CONFIG_ARCH_ADDRENV && CONFIG_ARCH_STACK_DYNAMIC */
