void build_copy_page()

in mm/page.c [424:612]


void build_copy_page(void)
{
	int off;
	u32 *buf = &__copy_page_start;
	struct uasm_label *l = labels;
	struct uasm_reloc *r = relocs;
	int i;
	static atomic_t run_once = ATOMIC_INIT(0);

	if (atomic_xchg(&run_once, 1)) {
		return;
	}

	memset(labels, 0, sizeof(labels));
	memset(relocs, 0, sizeof(relocs));

	set_prefetch_parameters();

	/*
	 * This algorithm makes the following assumptions:
	 *   - All prefetch biases are multiples of 8 words.
	 *   - The prefetch biases are less than one page.
	 *   - The store prefetch bias isn't greater than the load
	 *     prefetch bias.
	 */
	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);

	off = PAGE_SIZE - pref_bias_copy_load;
	if (off > 0xffff || !pref_bias_copy_load)
		pg_addiu(&buf, A2, A0, off);
	else
		uasm_i_ori(&buf, A2, A0, off);

	if (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) && cpu_is_r4600_v2_x())
		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));

	off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
				cache_line_size : 0;
	while (off) {
		build_copy_load_pref(&buf, -off);
		off -= cache_line_size;
	}
	off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
				cache_line_size : 0;
	while (off) {
		build_copy_store_pref(&buf, -off);
		off -= cache_line_size;
	}
	uasm_l_copy_pref_both(&l, buf);
	do {
		build_copy_load_pref(&buf, off);
		build_copy_load(&buf, T0, off);
		build_copy_load_pref(&buf, off + copy_word_size);
		build_copy_load(&buf, T1, off + copy_word_size);
		build_copy_load_pref(&buf, off + 2 * copy_word_size);
		build_copy_load(&buf, T2, off + 2 * copy_word_size);
		build_copy_load_pref(&buf, off + 3 * copy_word_size);
		build_copy_load(&buf, T3, off + 3 * copy_word_size);
		build_copy_store_pref(&buf, off);
		build_copy_store(&buf, T0, off);
		build_copy_store_pref(&buf, off + copy_word_size);
		build_copy_store(&buf, T1, off + copy_word_size);
		build_copy_store_pref(&buf, off + 2 * copy_word_size);
		build_copy_store(&buf, T2, off + 2 * copy_word_size);
		build_copy_store_pref(&buf, off + 3 * copy_word_size);
		build_copy_store(&buf, T3, off + 3 * copy_word_size);
		off += 4 * copy_word_size;
	} while (off < half_copy_loop_size);
	pg_addiu(&buf, A1, A1, 2 * off);
	pg_addiu(&buf, A0, A0, 2 * off);
	off = -off;
	do {
		build_copy_load_pref(&buf, off);
		build_copy_load(&buf, T0, off);
		build_copy_load_pref(&buf, off + copy_word_size);
		build_copy_load(&buf, T1, off + copy_word_size);
		build_copy_load_pref(&buf, off + 2 * copy_word_size);
		build_copy_load(&buf, T2, off + 2 * copy_word_size);
		build_copy_load_pref(&buf, off + 3 * copy_word_size);
		build_copy_load(&buf, T3, off + 3 * copy_word_size);
		build_copy_store_pref(&buf, off);
		build_copy_store(&buf, T0, off);
		build_copy_store_pref(&buf, off + copy_word_size);
		build_copy_store(&buf, T1, off + copy_word_size);
		build_copy_store_pref(&buf, off + 2 * copy_word_size);
		build_copy_store(&buf, T2, off + 2 * copy_word_size);
		build_copy_store_pref(&buf, off + 3 * copy_word_size);
		if (off == -(4 * copy_word_size))
			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
		build_copy_store(&buf, T3, off + 3 * copy_word_size);
		off += 4 * copy_word_size;
	} while (off < 0);

	if (pref_bias_copy_load - pref_bias_copy_store) {
		pg_addiu(&buf, A2, A0,
			 pref_bias_copy_load - pref_bias_copy_store);
		uasm_l_copy_pref_store(&l, buf);
		off = 0;
		do {
			build_copy_load(&buf, T0, off);
			build_copy_load(&buf, T1, off + copy_word_size);
			build_copy_load(&buf, T2, off + 2 * copy_word_size);
			build_copy_load(&buf, T3, off + 3 * copy_word_size);
			build_copy_store_pref(&buf, off);
			build_copy_store(&buf, T0, off);
			build_copy_store_pref(&buf, off + copy_word_size);
			build_copy_store(&buf, T1, off + copy_word_size);
			build_copy_store_pref(&buf, off + 2 * copy_word_size);
			build_copy_store(&buf, T2, off + 2 * copy_word_size);
			build_copy_store_pref(&buf, off + 3 * copy_word_size);
			build_copy_store(&buf, T3, off + 3 * copy_word_size);
			off += 4 * copy_word_size;
		} while (off < half_copy_loop_size);
		pg_addiu(&buf, A1, A1, 2 * off);
		pg_addiu(&buf, A0, A0, 2 * off);
		off = -off;
		do {
			build_copy_load(&buf, T0, off);
			build_copy_load(&buf, T1, off + copy_word_size);
			build_copy_load(&buf, T2, off + 2 * copy_word_size);
			build_copy_load(&buf, T3, off + 3 * copy_word_size);
			build_copy_store_pref(&buf, off);
			build_copy_store(&buf, T0, off);
			build_copy_store_pref(&buf, off + copy_word_size);
			build_copy_store(&buf, T1, off + copy_word_size);
			build_copy_store_pref(&buf, off + 2 * copy_word_size);
			build_copy_store(&buf, T2, off + 2 * copy_word_size);
			build_copy_store_pref(&buf, off + 3 * copy_word_size);
			if (off == -(4 * copy_word_size))
				uasm_il_bne(&buf, &r, A2, A0,
					    label_copy_pref_store);
			build_copy_store(&buf, T3, off + 3 * copy_word_size);
			off += 4 * copy_word_size;
		} while (off < 0);
	}

	if (pref_bias_copy_store) {
		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
		uasm_l_copy_nopref(&l, buf);
		off = 0;
		do {
			build_copy_load(&buf, T0, off);
			build_copy_load(&buf, T1, off + copy_word_size);
			build_copy_load(&buf, T2, off + 2 * copy_word_size);
			build_copy_load(&buf, T3, off + 3 * copy_word_size);
			build_copy_store(&buf, T0, off);
			build_copy_store(&buf, T1, off + copy_word_size);
			build_copy_store(&buf, T2, off + 2 * copy_word_size);
			build_copy_store(&buf, T3, off + 3 * copy_word_size);
			off += 4 * copy_word_size;
		} while (off < half_copy_loop_size);
		pg_addiu(&buf, A1, A1, 2 * off);
		pg_addiu(&buf, A0, A0, 2 * off);
		off = -off;
		do {
			build_copy_load(&buf, T0, off);
			build_copy_load(&buf, T1, off + copy_word_size);
			build_copy_load(&buf, T2, off + 2 * copy_word_size);
			build_copy_load(&buf, T3, off + 3 * copy_word_size);
			build_copy_store(&buf, T0, off);
			build_copy_store(&buf, T1, off + copy_word_size);
			build_copy_store(&buf, T2, off + 2 * copy_word_size);
			if (off == -(4 * copy_word_size))
				uasm_il_bne(&buf, &r, A2, A0,
					    label_copy_nopref);
			build_copy_store(&buf, T3, off + 3 * copy_word_size);
			off += 4 * copy_word_size;
		} while (off < 0);
	}

	uasm_i_jr(&buf, RA);
	uasm_i_nop(&buf);

	BUG_ON(buf > &__copy_page_end);

	uasm_resolve_relocs(relocs, labels);

	pr_debug("Synthesized copy page handler (%u instructions).\n",
		 (u32)(buf - &__copy_page_start));

	pr_debug("\t.set push\n");
	pr_debug("\t.set noreorder\n");
	for (i = 0; i < (buf - &__copy_page_start); i++)
		pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
	pr_debug("\t.set pop\n");
}