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/* SPDX-License-Identifier: copyleft-next-0.3.1 */
/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
/**
* @file mem.c
* Memory handling syscall implementations.
* \todo Should we return more error information?
*/
#include <kmi/uapi.h>
#include <kmi/utils.h>
#include <kmi/vmem.h>
#include <kmi/dmem.h>
/**
* Memory request syscall handler.
*
* @param t Current tcb.
* @param size Minimum size of allocation.
* @param flags Flags of allocation.
* @return \ref OK and start of allocation when succesful,
* \ref ERR_OOMEM and \c NULL otherwise.
*/
SYSCALL_DEFINE2(req_mem)(struct tcb *t, sys_arg_t size, sys_arg_t flags)
{
struct tcb *r = get_cproc(t);
flags = sanitize_uvflags(flags);
vm_t start = alloc_uvmem(r, size, flags);
if (ERR_CODE(start))
return_args1(t, start);
return_args2(t, OK, start);
}
/**
* Fixed memory request syscall handler.
*
* @param t Current tcb.
* @param fixed Address which should be included in allocation.
* @param size Minimum size of allocation after \c start.
* @param flags Flags of allocation.
* @return \ref OK and start of allocation when succesful,
* \ref ERR_OOMEM and \c NULL otherwise.
*/
SYSCALL_DEFINE3(req_fixmem)(struct tcb *t, sys_arg_t fixed, sys_arg_t size,
sys_arg_t flags)
{
struct tcb *r = get_cproc(t);
flags = sanitize_uvflags(flags);
vm_t start = alloc_fixed_uvmem(r, fixed, size, flags);
if (ERR_CODE(start))
return_args1(t, start);
return_args2(t, OK, start);
}
/**
* Free memory syscall handler.
*
* @param t Current tcb.
* @param start Start of allocation to free.
* @return \ref OK and \c 0 when succesful, \ref ERR_NF and \c 0 otherwise.
*/
SYSCALL_DEFINE1(free_mem)(struct tcb *t, sys_arg_t start)
{
struct tcb *r = get_cproc(t);
stat_t status = OK;
/* try freeing normal user memory first, if that fails, try device
* memory, otherwise just assume the address is borked. */
if (!(status = free_uvmem(r, start)))
return_args1(t, OK);
if (!(status = free_devmem(r, start)))
return_args1(t, OK);
return_args1(t, status);
}
/**
* Request physical memory syscall handler.
*
* @param t Current tcb.
* @param paddr Physical address to map.
* @param size Minimum size of allocation.
* @param flags Flags of allocation.
* @return \ref OK and start of allocation when succesful,
* \ref ERR_OOMEM and \c NULL otherwise.
*/
SYSCALL_DEFINE3(req_pmem)(struct tcb *t, sys_arg_t paddr, sys_arg_t size,
sys_arg_t flags)
{
/* this will require some pondering, but essentially this syscall should
* only be used for device access, so any addresses requested should be
* outside the RAM area, and I'll probably have to implement some method
* that keeps track of used regions outside of RAM. We'll see.
*/
struct tcb *r = get_cproc(t);
flags = sanitize_uvflags(flags);
vm_t start = alloc_devmem(r, paddr, size, flags);
if (ERR_CODE(start))
return_args1(t, start);
return_args2(t, OK, start);
}
/**
* Allocate some contiguous region in memory.
* Due to page allocation constraints, this is generally just one page that's
* larger than the \p size parameter. Should work fine for 4K - 2M allocations,
* which I assume is generally what is used, but we'll see if I have to
* implement an actually good page allocator at some point.
*
* @param t Current tcb.
* @param size Minimum size of mapping.
* @param flags Flags of mapping. Unsure why you'd want anything besides VM_W |
* VM_R, but eh.
*
* @return \see sys_req_page().
*/
SYSCALL_DEFINE2(req_page)(struct tcb *t, sys_arg_t size, sys_arg_t flags)
{
struct tcb *r = get_cproc(t);
pm_t addr = 0;
vm_t start = 0;
size_t asize = 0;
flags = sanitize_uvflags(flags);
start = alloc_uvpage(r, size, flags, &addr, &asize);
if (ERR_CODE(start))
return_args1(t, start);
return_args4(t, OK, start, addr, asize);
}
/**
* Request shared memory syscall handler.
*
* @param t Current tcb.
* @param size Minimum size of allocation.
* @param flags Flags of allocation.
* @return \ref OK, start
* in that order, \ref ERR_OOMEM otherwise.
*/
SYSCALL_DEFINE2(req_sharedmem)(struct tcb *t, sys_arg_t size, sys_arg_t flags)
{
struct tcb *c = get_cproc(t);
if (!has_cap(c->caps, CAP_SHARED))
return_args1(t, ERR_PERM);
flags = sanitize_uvflags(flags);
vm_t start = alloc_shared_uvmem(c, size, flags);
if (ERR_CODE(start))
return_args1(t, start);
return_args2(t, OK, start);
}
/**
* Reference shared memory.
*
* @param t Current tcb.
* @param tid In which thread's address space to create mapping.
* @param addr Address of shared region in \p t.
* @param flags Flags of allocation.
* @return \ref ERR_OOMEM if unsucessful, otherwise \ref OK, virtual address,
* actual size, in that order. Generally the actual size should match with the
* original shared region, but I wouldn't count on it.
*/
SYSCALL_DEFINE3(ref_sharedmem)(struct tcb *t, sys_arg_t tid, sys_arg_t addr,
sys_arg_t flags)
{
struct tcb *c = get_cproc(t);
if (!has_cap(c->caps, CAP_SHARED))
return_args1(t, ERR_PERM);
struct tcb *r = get_tcb(tid);
if (!r || zombie(r))
return_args1(t, ERR_INVAL);
size_t size = 0;
flags = sanitize_uvflags(flags);
vm_t start = ref_shared_uvmem(r, c, addr, flags);
if (ERR_CODE(start))
return_args1(t, start);
return_args2(t, OK, start);
}
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