matos/core/uaddrspace.c

#include "uaddrspace.h"
#include "alloc.h"
#include "kernel.h"
#include "klibc.h"
#include "list.h"
#include "mem.h"
#include "mmuContext.h"
#include "paging.h"
#include "process.h"
#include "stdarg.h"
#include "thread.h"
#include "types.h"
#include <assert.h>
#include <stddef.h>
#include <stdint.h>

struct uAddrVirtualReg {
    uaddr_t addr;
    size_t size;
    int right;       // PAGING_MEM_*
    uint32_t offset; // in the mappedRessource
    uint flags;

    struct mappedRessource *res;
    struct uAddrVirtualReg *nextInAddrSpace, *prevInAddrSpace;
    struct uAddrVirtualReg *nextInMappedRes, *prevInMappedRes;
};

struct uAddrSpace {
    struct process *process; // The process that is represented by this AS
    struct mmu_context *ctx; // The corresponding MMU configuration

    struct uAddrVirtualReg *listVirtualReg; // List of Virtual Region used by this process

    uaddr_t heapStart; // Start of the Head
    size_t heapSize;   // Hep size -> modified by brk()
};

struct mappedRessourceOps {
    int (*open)(struct uAddrVirtualReg *vreg);
    int (*close)(struct uAddrVirtualReg *vreg);
    int (*unmap)(struct uAddrVirtualReg *vregi, uaddr_t addr, size_t size);
    int (*nopage)(struct uAddrVirtualReg *vregi, uaddr_t addr,
                  int right); // Called by the pageflt handler when the page is missing
};

struct mappedRessource {
    int right; // PAGING_MEM_*
    struct mappedRessourceOps *ops;
    struct uAddrVirtualReg *listVirtualReg;
};

struct uAddrSpace *uAddrSpaceCreate(struct process *proc)
{
    struct uAddrSpace *addr = (struct uAddrSpace *)zalloc(sizeof(struct uAddrSpace));

    if (addr == NULL)
        return NULL;

    addr->ctx = mmuContextCreate();

    if (addr->ctx == NULL) {
        free(addr);

        return NULL;
    }

    addr->process = proc;
    list_init(addr->listVirtualReg);

    return addr;
}

int uAddrSpaceDelete(struct uAddrSpace *addr)
{
    struct uAddrVirtualReg *reg;

    list_collapse_named(addr->listVirtualReg, reg, nextInAddrSpace, prevInAddrSpace) {
        // TODO Implement me with real ressources
        assertmsg(reg->res == NULL, "Unsupported mapper ressource");
        // This is memory allocated for the heap just unmap it to free it
        pr_devel("Freeing heap 0x%lx for process %s\n", reg->addr, processGetName(addr->process));
        pageUnmap(reg->addr);
        free(reg);
    }
    return mmuContextUnref(addr->ctx);
}

struct mmu_context *uAddrSpaceGetMMUContext(struct uAddrSpace *addr)
{
    return addr->ctx;
}

int uAddrSpaceSetHeap(struct uAddrSpace *as, uaddr_t addr, size_t size)
{
    as->heapStart = addr;
    as->heapSize  = size;

    return 0;
}

uaddr_t sysBrk(struct uAddrSpace *as, uaddr_t newHeapTop)
{
    int incSize;
    assert(as->heapStart);
    if (!newHeapTop || newHeapTop < as->heapStart)
        return as->heapStart + as->heapSize;

    newHeapTop = ALIGN(newHeapTop, PAGE_SIZE);

    if (newHeapTop == as->heapStart + as->heapSize)
        return newHeapTop;

    incSize = ALIGN(newHeapTop - (as->heapStart + as->heapSize), PAGE_SIZE);

    if (incSize < 0){
        //TODO how to free allocated page by uAddrSpaceCheckNAlloc
        return as->heapStart + as->heapSize;
    }

    as->heapSize += incSize;

    return as->heapStart + as->heapSize;
}

int uAddrSpaceCheckNAlloc(struct uAddrSpace *as, vaddr_t addr)
{
    struct uAddrVirtualReg *newReg;
    int right = PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ;

    pr_devel("Checking 0x%lx inside 0x%lx and 0x%lx\n", addr, as->heapStart,
             as->heapStart + as->heapSize);

    if (addr < as->heapStart || addr >= as->heapStart + as->heapSize) {
        return -1;
    }

    pr_devel("Alloc heap for process %s\n", processGetName(as->process));

    vaddr_t addrAlign = ALIGN_DOWN(addr, PAGE_SIZE);
    paddr_t ppage     = allocPhyPage(1);

    if (0 != pageMap(addrAlign, ppage, right))
        goto free_ppage;

    newReg = zalloc(sizeof(struct uAddrVirtualReg));

    if (newReg == NULL)
        goto free_ppage;

    newReg->addr = addrAlign;
    newReg->size = PAGE_SIZE;
    newReg->right = right;

    list_add_tail_named(as->listVirtualReg, newReg, nextInAddrSpace, prevInAddrSpace);

    unrefPhyPage(ppage);

    return 0;
free_ppage:
    unrefPhyPage(ppage);
    return -1;
}