static int perf_write_image()

in kernel/perf.c [735:812]

• 58 lines of code
• 9 McCabe index (conditional complexity)

static int perf_write_image(uint64_t *memaddr)
{
	uint64_t buffer[MAX_RDR_WORDS];
	uint64_t *bptr;
	uint32_t dwords;
	const uint32_t *intrigue_rdr;
	const uint64_t *intrigue_bitmask;
	uint64_t tmp64;
	void __iomem *runway;
	const struct rdr_tbl_ent *tentry;
	int i;

	/* Clear out counters */
	if (perf_processor_interface == ONYX_INTF) {

		perf_rdr_clear(16);

		/* Toggle performance monitor */
		perf_intrigue_enable_perf_counters();
		perf_intrigue_disable_perf_counters();

		intrigue_rdr = perf_rdrs_U;
	} else {
		perf_rdr_clear(15);
		intrigue_rdr = perf_rdrs_W;
	}

	/* Write all RDRs */
	while (*intrigue_rdr != -1) {
		tentry = perf_rdr_get_entry(*intrigue_rdr);
		perf_rdr_read_ubuf(*intrigue_rdr, buffer);
		bptr   = &buffer[0];
		dwords = tentry->num_words;
		if (tentry->write_control) {
			intrigue_bitmask = &bitmask_array[tentry->write_control >> 3];
			while (dwords--) {
				tmp64 = *intrigue_bitmask & *memaddr++;
				tmp64 |= (~(*intrigue_bitmask++)) & *bptr;
				*bptr++ = tmp64;
			}
		} else {
			while (dwords--) {
				*bptr++ = *memaddr++;
			}
		}

		perf_rdr_write(*intrigue_rdr, buffer);
		intrigue_rdr++;
	}

	/*
	 * Now copy out the Runway stuff which is not in RDRs
	 */

	if (cpu_device == NULL)
	{
		printk(KERN_ERR "write_image: cpu_device not yet initialized!\n");
		return -1;
	}

	runway = ioremap(cpu_device->hpa.start, 4096);
	if (!runway) {
		pr_err("perf_write_image: ioremap failed!\n");
		return -ENOMEM;
	}

	/* Merge intrigue bits into Runway STATUS 0 */
	tmp64 = __raw_readq(runway + RUNWAY_STATUS) & 0xffecfffffffffffful;
	__raw_writeq(tmp64 | (*memaddr++ & 0x0013000000000000ul),
		     runway + RUNWAY_STATUS);

	/* Write RUNWAY DEBUG registers */
	for (i = 0; i < 8; i++) {
		__raw_writeq(*memaddr++, runway + RUNWAY_DEBUG);
	}

	return 0;
}