xmem.c

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#include <stdbool.h>
#include <stdint.h>
 
#include <sys/kconfig.h>
#include <sys/kassert.h>
#include <sys/kdebug.h>
#include <sys/kmem.h>
 
#include <machine/amd64.h>
#include <machine/amd64op.h>
#include <machine/pmap.h>
#include <machine/mp.h>
 
#define MAX_XMEM_REGIONS 1024
 
typedef struct XMem
{
    bool        inUse;
    uintptr_t   base;
    uintptr_t   maxLength;
    uintptr_t   length;
} XMem;
 
XMem regions[MAX_XMEM_REGIONS];
 
void
XMem_Init()
{
    int r;
    uintptr_t regionSize = MEM_XMAP_LEN / MAX_XMEM_REGIONS;
 
    kprintf("Initializing XMEM ... ");
 
    for (r = 0; r < MAX_XMEM_REGIONS; r++)
    {
        regions[r].inUse = false;
        regions[r].base = MEM_XMAP_BASE + r * regionSize;
        regions[r].maxLength = regionSize;
        regions[r].length = 0;
    }
 
    kprintf("Done!\n");
}
 
XMem *
XMem_New()
{
    int r;
 
    for (r = 0; r < MAX_XMEM_REGIONS; r++)
    {
        if (!regions[r].inUse) {
            regions[r].inUse = true;
            return &regions[r];
        }
    }
 
    return NULL;
}
 
void
XMem_Destroy(XMem *xmem)
{
    uintptr_t off;
    PageEntry *entry;
 
    for (off = 0; off < xmem->length; off += PGSIZE) {
        PMap_SystemLookup(xmem->base + off, &entry, PGSIZE);
 
        // Compute DM
 
        // Free Page
    }
 
    //PMap_SystemUnmap(virt, pages);
}
 
uintptr_t
XMem_GetBase(XMem *xmem)
{
    return xmem->base;
}
 
uintptr_t
XMem_GetLength(XMem *xmem)
{
    return xmem->length;
}
 
bool
XMem_Allocate(XMem *xmem, uintptr_t length)
{
    uint64_t off;
 
    // We already allocated up to that size
    if (xmem->length > length)
        return true;
 
    // Allocation too long
    if (length > xmem->maxLength)
        return false;
 
    for (off = xmem->length; off < length; off += PGSIZE) {
        void *pg = PAlloc_AllocPage();
        if (pg == NULL)
            return false;
 
        PMap_SystemMap(DMVA2PA((uint64_t)pg), xmem->base + off, 1, 0);
 
        xmem->length += PGSIZE;
    }
 
    return true;
}
 
static void
Debug_XMemStats(int argc, const char *argv[])
{
    int r;
 
    kprintf("Region Nr: %16s %16s\n", "Base", "Length");
    for (r = 0; r < MAX_XMEM_REGIONS; r++)
    {
        if (regions[r].inUse) {
            kprintf("Region %2d: %016llx %016llx\n", r,
                    regions[r].base, regions[r].length);
        }
    }
}
 
REGISTER_DBGCMD(xmemstats, "XMem statistics", Debug_XMemStats);