@@ -113,3 +113,79 @@ void __init rcar_gen2_timer_init(void)
#endif
clocksource_of_init();
}
+
+struct memory_reserve_config {
+ u64 reserved;
+ u64 base, size;
+};
+
+static int __init rcar_gen2_scan_mem(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+ const __be32 *reg, *endp;
+ int l;
+ struct memory_reserve_config *mrc = data;
+ u64 lpae_start = (u64)1 << 32;
+
+ /* We are scanning "memory" nodes only */
+ if (type == NULL) {
+ /*
+ * The longtrail doesn't have a device_type on the
+ * /memory node, so look for the node called /memory@0.
+ */
+ if (depth != 1 || strcmp(uname, "memory@0") != 0)
+ return 0;
+ } else if (strcmp(type, "memory") != 0)
+ return 0;
+
+ reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
+ if (reg == NULL)
+ reg = of_get_flat_dt_prop(node, "reg", &l);
+ if (reg == NULL)
+ return 0;
+
+ endp = reg + (l / sizeof(__be32));
+ while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
+ u64 base, size;
+
+ base = dt_mem_next_cell(dt_root_addr_cells, ®);
+ size = dt_mem_next_cell(dt_root_size_cells, ®);
+
+ if (base >= lpae_start)
+ continue;
+
+ if ((base + size) >= lpae_start)
+ size = lpae_start - base;
+
+ if (size < mrc->reserved)
+ continue;
+
+ if (base < mrc->base)
+ continue;
+
+ /* keep the area at top near the 32-bit legacy limit */
+ mrc->base = base + size - mrc->reserved;
+ mrc->size = mrc->reserved;
+ }
+
+ return 0;
+}
+
+struct cma *rcar_gen2_dma_contiguous;
+
+void __init rcar_gen2_reserve(void)
+{
+ struct memory_reserve_config mrc;
+
+ /* reserve 256 MiB at the top of the physical legacy 32-bit space */
+ memset(&mrc, 0, sizeof(mrc));
+ mrc.reserved = SZ_256M;
+
+ of_scan_flat_dt(rcar_gen2_scan_mem, &mrc);
+#ifdef CONFIG_DMA_CMA
+ if (mrc.size)
+ dma_contiguous_reserve_area(mrc.size, mrc.base, 0,
+ &rcar_gen2_dma_contiguous);
+#endif
+}