git: 8d5b63efd19c - main - dev/fdt: Add fdt_foreach_reserved_mem

From: Andrew Turner <andrew_at_FreeBSD.org>
Date: Tue, 08 Apr 2025 10:49:09 UTC
The branch main has been updated by andrew:

URL: https://cgit.FreeBSD.org/src/commit/?id=8d5b63efd19c9395eb9519145be4ba02406dc9b3

commit 8d5b63efd19c9395eb9519145be4ba02406dc9b3
Author:     Andrew Turner <andrew@FreeBSD.org>
AuthorDate: 2025-04-08 10:30:17 +0000
Commit:     Andrew Turner <andrew@FreeBSD.org>
CommitDate: 2025-04-08 10:48:28 +0000

    dev/fdt: Add fdt_foreach_reserved_mem
    
    As with fdt_foreach_mem_region add a function that calls a callback
    for each reserved memory region. This allows us to exclude this memory
    from the physical map in a way that is safe from overflowing a fixed
    array on the stack.
    
    Reviewed by:    imp
    Sponsored by:   Arm Ltd
    Differential Revision:  https://reviews.freebsd.org/D49698
---
 sys/dev/fdt/fdt_common.c | 38 ++++++++++++++++++++++++++++++++++++++
 sys/dev/fdt/fdt_common.h |  1 +
 2 files changed, 39 insertions(+)

diff --git a/sys/dev/fdt/fdt_common.c b/sys/dev/fdt/fdt_common.c
index 6c505ac2cd7c..e23878750bea 100644
--- a/sys/dev/fdt/fdt_common.c
+++ b/sys/dev/fdt/fdt_common.c
@@ -499,6 +499,44 @@ out:
 	return (rv);
 }
 
+int
+fdt_foreach_reserved_mem(fdt_mem_region_cb cb, void *arg)
+{
+	struct mem_region mr;
+	pcell_t reg[FDT_REG_CELLS];
+	phandle_t child, root;
+	int addr_cells, size_cells;
+	int rv;
+
+	root = OF_finddevice("/reserved-memory");
+	if (root == -1)
+		return (ENXIO);
+
+	if ((rv = fdt_addrsize_cells(root, &addr_cells, &size_cells)) != 0)
+		return (rv);
+
+	if (addr_cells + size_cells > FDT_REG_CELLS)
+		panic("Too many address and size cells %d %d", addr_cells,
+		    size_cells);
+
+	for (child = OF_child(root); child != 0; child = OF_peer(child)) {
+		if (!OF_hasprop(child, "no-map"))
+			continue;
+
+		rv = OF_getprop(child, "reg", reg, sizeof(reg));
+		if (rv <= 0)
+			/* XXX: Does a no-map of a dynamic range make sense? */
+			continue;
+
+		fdt_data_to_res(reg, addr_cells, size_cells,
+		    (u_long *)&mr.mr_start, (u_long *)&mr.mr_size);
+
+		cb(&mr, arg);
+	}
+
+	return (0);
+}
+
 int
 fdt_get_reserved_mem(struct mem_region *reserved, int *mreserved)
 {
diff --git a/sys/dev/fdt/fdt_common.h b/sys/dev/fdt/fdt_common.h
index f450d976dfe0..d1db7c0620fd 100644
--- a/sys/dev/fdt/fdt_common.h
+++ b/sys/dev/fdt/fdt_common.h
@@ -85,6 +85,7 @@ phandle_t fdt_find_compatible(phandle_t, const char *, int);
 phandle_t fdt_depth_search_compatible(phandle_t, const char *, int);
 int fdt_foreach_mem_region(fdt_mem_region_cb, void *);
 int fdt_get_mem_regions(struct mem_region *, int *, uint64_t *);
+int fdt_foreach_reserved_mem(fdt_mem_region_cb, void *);
 int fdt_get_reserved_mem(struct mem_region *, int *);
 int fdt_get_reserved_regions(struct mem_region *, int *);
 int fdt_get_phyaddr(phandle_t, device_t, int *, void **);