void __init mmu_emu_init()

in sun3/mmu_emu.c [126:200]

• 49 lines of code
• 12 McCabe index (conditional complexity)

void __init mmu_emu_init(unsigned long bootmem_end)
{
	unsigned long seg, num;
	int i,j;

	memset(rom_pages, 0, sizeof(rom_pages));
	memset(pmeg_vaddr, 0, sizeof(pmeg_vaddr));
	memset(pmeg_alloc, 0, sizeof(pmeg_alloc));
	memset(pmeg_ctx, 0, sizeof(pmeg_ctx));

	/* pmeg align the end of bootmem, adding another pmeg,
	 * later bootmem allocations will likely need it */
	bootmem_end = (bootmem_end + (2 * SUN3_PMEG_SIZE)) & ~SUN3_PMEG_MASK;

	/* mark all of the pmegs used thus far as reserved */
	for (i=0; i < __pa(bootmem_end) / SUN3_PMEG_SIZE ; ++i)
		pmeg_alloc[i] = 2;


	/* I'm thinking that most of the top pmeg's are going to be
	   used for something, and we probably shouldn't risk it */
	for(num = 0xf0; num <= 0xff; num++)
		pmeg_alloc[num] = 2;

	/* liberate all existing mappings in the rest of kernel space */
	for(seg = bootmem_end; seg < 0x0f800000; seg += SUN3_PMEG_SIZE) {
		i = sun3_get_segmap(seg);

		if(!pmeg_alloc[i]) {
#ifdef DEBUG_MMU_EMU
			pr_info("freed:");
			print_pte_vaddr (seg);
#endif
			sun3_put_segmap(seg, SUN3_INVALID_PMEG);
		}
	}

	j = 0;
	for (num=0, seg=0x0F800000; seg<0x10000000; seg+=16*PAGE_SIZE) {
		if (sun3_get_segmap (seg) != SUN3_INVALID_PMEG) {
#ifdef DEBUG_PROM_MAPS
			for(i = 0; i < 16; i++) {
				pr_info("mapped:");
				print_pte_vaddr (seg + (i*PAGE_SIZE));
				break;
			}
#endif
			// the lowest mapping here is the end of our
			// vmalloc region
			if (!m68k_vmalloc_end)
				m68k_vmalloc_end = seg;

			// mark the segmap alloc'd, and reserve any
			// of the first 0xbff pages the hardware is
			// already using...  does any sun3 support > 24mb?
			pmeg_alloc[sun3_get_segmap(seg)] = 2;
		}
	}

	dvma_init();


	/* blank everything below the kernel, and we've got the base
	   mapping to start all the contexts off with... */
	for(seg = 0; seg < PAGE_OFFSET; seg += SUN3_PMEG_SIZE)
		sun3_put_segmap(seg, SUN3_INVALID_PMEG);

	set_fc(3);
	for(seg = 0; seg < 0x10000000; seg += SUN3_PMEG_SIZE) {
		i = sun3_get_segmap(seg);
		for(j = 1; j < CONTEXTS_NUM; j++)
			(*(romvec->pv_setctxt))(j, (void *)seg, i);
	}
	set_fc(USER_DATA);
}