- /* IO coherency base - 0x8z */
- write_aux_reg(ARC_AUX_IO_COH_AP0_BASE, 0x80000);
- /* IO coherency aperture size - 512Mb: 0x8z-0xAz */
- write_aux_reg(ARC_AUX_IO_COH_AP0_SIZE, 0x11);
- /* Enable partial writes */
+ if (!is_power_of_2(ap_size) || ap_size < 4096)
+ panic("IOC Aperture size must be power of 2 and bigger 4Kib");
+
+ /*
+ * IOC Aperture size decoded as 2 ^ (SIZE + 2) KB,
+ * so setting 0x11 implies 512M, 0x12 implies 1G...
+ */
+ write_aux_reg(ARC_AUX_IO_COH_AP0_SIZE,
+ order_base_2(ap_size/1024) - 2);
+
+
+ /* IOC Aperture start must be aligned to the size of the aperture */
+ if (ap_base % ap_size != 0)
+ panic("IOC Aperture start must be aligned to the size of the aperture");
+
+ write_aux_reg(ARC_AUX_IO_COH_AP0_BASE, ap_base >> 12);