static int pdt_mainloop()

in kernel/pdt.c [244:345]
82 lines of code
16 McCabe index (conditional complexity)

static int pdt_mainloop(void *unused)
{
	struct pdc_mem_read_pdt pdt_read_ret;
	struct pdc_pat_mem_read_pd_retinfo pat_pret __maybe_unused;
	unsigned long old_num_entries;
	unsigned long *bad_mem_ptr;
	int num, ret;

	for (;;) {
		set_current_state(TASK_INTERRUPTIBLE);

		old_num_entries = pdt_status.pdt_entries;

		schedule_timeout(pdt_poll_interval);
		if (kthread_should_stop())
			break;

		/* Do we have new PDT entries? */
		switch (pdt_type) {
		case PDT_PAT_NEW:
			ret = get_info_pat_new();
			break;
		case PDT_PAT_CELL:
			ret = get_info_pat_cell();
			break;
		default:
			ret = pdc_mem_pdt_info(&pdt_status);
			break;
		}

		if (ret != PDC_OK) {
			pr_warn("PDT: unexpected failure %d\n", ret);
			return -EINVAL;
		}

		/* if no new PDT entries, just wait again */
		num = pdt_status.pdt_entries - old_num_entries;
		if (num <= 0)
			continue;

		/* decrease poll interval in case we found memory errors */
		if (pdt_status.pdt_entries &&
			pdt_poll_interval == PDT_POLL_INTERVAL_DEFAULT)
			pdt_poll_interval = PDT_POLL_INTERVAL_SHORT;

		/* limit entries to get */
		if (num > MAX_PDT_ENTRIES) {
			num = MAX_PDT_ENTRIES;
			pdt_status.pdt_entries = old_num_entries + num;
		}

		/* get new entries */
		switch (pdt_type) {
#ifdef CONFIG_64BIT
		case PDT_PAT_CELL:
			if (pdt_status.pdt_entries > MAX_PDT_ENTRIES) {
				pr_crit("PDT: too many entries.\n");
				return -ENOMEM;
			}
			ret = pdc_pat_mem_read_cell_pdt(&pat_pret, pdt_entry,
				MAX_PDT_ENTRIES);
			bad_mem_ptr = &pdt_entry[old_num_entries];
			break;
		case PDT_PAT_NEW:
			ret = pdc_pat_mem_read_pd_pdt(&pat_pret,
				pdt_entry,
				num * sizeof(unsigned long),
				old_num_entries * sizeof(unsigned long));
			bad_mem_ptr = &pdt_entry[0];
			break;
#endif
		default:
			ret = pdc_mem_pdt_read_entries(&pdt_read_ret,
				pdt_entry);
			bad_mem_ptr = &pdt_entry[old_num_entries];
			break;
		}

		/* report and mark memory broken */
		while (num--) {
			unsigned long pde = *bad_mem_ptr++;

			report_mem_err(pde);

#ifdef CONFIG_MEMORY_FAILURE
			if ((pde & PDT_ADDR_PERM_ERR) ||
			    ((pde & PDT_ADDR_SINGLE_ERR) == 0))
				memory_failure(pde >> PAGE_SHIFT, 0);
			else
				soft_offline_page(pde >> PAGE_SHIFT, 0);
#else
			pr_crit("PDT: memory error at 0x%lx ignored.\n"
				"Rebuild kernel with CONFIG_MEMORY_FAILURE=y "
				"for real handling.\n",
				pde & PDT_ADDR_PHYS_MASK);
#endif

		}
	}

	return 0;
}