git: 28bc1919f5d4 - main - dev/fdt: Add fdt_foreach_reserved_region

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

URL: https://cgit.FreeBSD.org/src/commit/?id=28bc1919f5d42f699612f9335e25239bd30ed164

commit 28bc1919f5d42f699612f9335e25239bd30ed164
Author:     Andrew Turner <andrew@FreeBSD.org>
AuthorDate: 2025-04-08 10:30:24 +0000
Commit:     Andrew Turner <andrew@FreeBSD.org>
CommitDate: 2025-04-08 10:48:28 +0000

    dev/fdt: Add fdt_foreach_reserved_region
    
    As with fdt_foreach_mem_region add a function that calls a callback
    for each reserved memory region in /memreserve. 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/D49699
---
 sys/dev/fdt/fdt_common.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++
 sys/dev/fdt/fdt_common.h |  1 +
 2 files changed, 50 insertions(+)

diff --git a/sys/dev/fdt/fdt_common.c b/sys/dev/fdt/fdt_common.c
index e23878750bea..ba323ea56d96 100644
--- a/sys/dev/fdt/fdt_common.c
+++ b/sys/dev/fdt/fdt_common.c
@@ -442,6 +442,55 @@ fdt_get_phyaddr(phandle_t node, device_t dev, int *phy_addr, void **phy_sc)
 	return (0);
 }
 
+int
+fdt_foreach_reserved_region(fdt_mem_region_cb cb, void *arg)
+{
+	struct mem_region mr;
+	pcell_t reserve[FDT_REG_CELLS * FDT_MEM_REGIONS];
+	pcell_t *reservep;
+	phandle_t memory, root;
+	int addr_cells, size_cells;
+	int i, res_len, rv, tuple_size, tuples;
+
+	root = OF_finddevice("/");
+	memory = OF_finddevice("/memory");
+	if (memory == -1)
+		return (ENXIO);
+
+	if ((rv = fdt_addrsize_cells(OF_parent(memory), &addr_cells,
+	    &size_cells)) != 0)
+		return (rv);
+
+	if (addr_cells > 2)
+		return (ERANGE);
+
+	tuple_size = sizeof(pcell_t) * (addr_cells + size_cells);
+
+	res_len = OF_getproplen(root, "memreserve");
+	if (res_len <= 0 || res_len > sizeof(reserve))
+		return (ERANGE);
+
+	if (OF_getprop(root, "memreserve", reserve, res_len) <= 0)
+		return (ENXIO);
+
+	tuples = res_len / tuple_size;
+	reservep = (pcell_t *)&reserve;
+	for (i = 0; i < tuples; i++) {
+
+		rv = fdt_data_to_res(reservep, addr_cells, size_cells,
+			(u_long *)&mr.mr_start, (u_long *)&mr.mr_size);
+
+		if (rv != 0)
+			return (rv);
+
+		cb(&mr, arg);
+
+		reservep += addr_cells + size_cells;
+	}
+
+	return (0);
+}
+
 int
 fdt_get_reserved_regions(struct mem_region *mr, int *mrcnt)
 {
diff --git a/sys/dev/fdt/fdt_common.h b/sys/dev/fdt/fdt_common.h
index d1db7c0620fd..22842d0e6ae7 100644
--- a/sys/dev/fdt/fdt_common.h
+++ b/sys/dev/fdt/fdt_common.h
@@ -87,6 +87,7 @@ 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_foreach_reserved_region(fdt_mem_region_cb, void *);
 int fdt_get_reserved_regions(struct mem_region *, int *);
 int fdt_get_phyaddr(phandle_t, device_t, int *, void **);
 int fdt_get_range(phandle_t, int, u_long *, u_long *);