/**
* Allocates one page.
*
* @param virtAddr The virtual address to which this page maybe mapped in
* the future.
*
* @returns Pointer to the allocated page, NULL on failure.
*/
static page_t *rtR0MemObjSolPageAlloc(caddr_t virtAddr)
{
u_offset_t offPage;
seg_t KernelSeg;
/*
* 16777215 terabytes of total memory for all VMs or
* restart 8000 1GB VMs 2147483 times until wraparound!
*/
mutex_enter(&g_OffsetMtx);
AssertCompileSize(u_offset_t, sizeof(uint64_t)); NOREF(RTASSERTVAR);
g_offPage = RT_ALIGN_64(g_offPage, PAGE_SIZE) + PAGE_SIZE;
offPage = g_offPage;
mutex_exit(&g_OffsetMtx);
KernelSeg.s_as = &kas;
page_t *pPage = page_create_va(&g_PageVnode, offPage, PAGE_SIZE, PG_WAIT | PG_NORELOC, &KernelSeg, virtAddr);
if (RT_LIKELY(pPage))
{
/*
* Lock this page into memory "long term" to prevent this page from being paged out
* when we drop the page lock temporarily (during free). Downgrade to a shared lock
* to prevent page relocation.
*/
page_pp_lock(pPage, 0 /* COW */, 1 /* Kernel */);
page_io_unlock(pPage);
page_downgrade(pPage);
Assert(PAGE_LOCKED_SE(pPage, SE_SHARED));
}
return pPage;
}
static void
less_pages(uint64_t base, uint64_t len)
{
uint64_t pa, end = base + len;
extern int kcage_on;
for (pa = base; pa < end; pa += PAGESIZE) {
pfn_t pfnum;
page_t *pp;
pfnum = (pfn_t)(pa >> PAGESHIFT);
if ((pp = page_numtopp_nolock(pfnum)) == NULL)
cmn_err(CE_PANIC, "missing pfnum %lx", pfnum);
/*
* must break up any large pages that may have
* constituent pages being utilized for
* prom_alloc()'s. page_reclaim() can't handle
* large pages.
*/
if (pp->p_szc != 0)
page_boot_demote(pp);
if (!PAGE_LOCKED(pp) && pp->p_lckcnt == 0) {
/*
* Ahhh yes, a prom page,
* suck it off the freelist,
* lock it, and hashin on prom_pages vp.
*/
if (page_trylock(pp, SE_EXCL) == 0)
cmn_err(CE_PANIC, "prom page locked");
(void) page_reclaim(pp, NULL);
/*
* vnode offsets on the prom_ppages vnode
* are page numbers (gack) for >32 bit
* physical memory machines.
*/
(void) page_hashin(pp, &promvp,
(offset_t)pfnum, NULL);
if (kcage_on) {
ASSERT(pp->p_szc == 0);
if (PP_ISNORELOC(pp) == 0) {
PP_SETNORELOC(pp);
PLCNT_XFER_NORELOC(pp);
}
}
(void) page_pp_lock(pp, 0, 1);
}
}
}
