2121 .../arm/boot/compressed/fdt_check_mem_start.c | 48 ++++++++++++++++---
2222 1 file changed, 42 insertions(+), 6 deletions(-)
2323
24- diff --git a/arch/arm/boot/compressed/fdt_check_mem_start.c b/arch/arm/boot/compressed/fdt_check_mem_start.c
25- index 62450d824c3c..9291a2661bdf 100644
2624--- a/arch/arm/boot/compressed/fdt_check_mem_start.c
2725+++ b/arch/arm/boot/compressed/fdt_check_mem_start.c
28- @@ -55,16 +55,17 @@ static uint64_t get_val(const fdt32_t *cells, uint32_t ncells)
26+ @@ -55,16 +55,17 @@ static uint64_t get_val(const fdt32_t *c
2927 * DTB, and, if out-of-range, replace it by the real start address.
3028 * To preserve backwards compatibility (systems reserving a block of memory
3129 * at the start of physical memory, kdump, ...), the traditional method is
@@ -39,18 +37,18 @@ index 62450d824c3c..9291a2661bdf 100644
3937 {
4038- uint32_t addr_cells, size_cells, base;
4139+ uint32_t addr_cells, size_cells, usable_base, base;
42- uint32_t fdt_mem_start = 0xffffffff;
40+ uint32_t fdt_mem_start = 0xffffffff;
4341- const fdt32_t *reg, *endp;
4442- uint64_t size, end;
4543+ const fdt32_t *usable, *reg, *endp;
4644+ uint64_t size, usable_end, end;
47- const char *type;
48- int offset, len;
49-
50- @@ -80,6 +81,27 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
51- if (addr_cells > 2 || size_cells > 2)
52- return mem_start;
53-
45+ const char *type;
46+ int offset, len;
47+
48+ @@ -80,6 +81,27 @@ uint32_t fdt_check_mem_start(uint32_t me
49+ if (addr_cells > 2 || size_cells > 2)
50+ return mem_start;
51+
5452+ /*
5553+ * Usable memory in case of a crash dump kernel
5654+ * This property describes a limitation: memory within this range is
@@ -72,13 +70,13 @@ index 62450d824c3c..9291a2661bdf 100644
7270+ usable_end = usable_base + size;
7371+ }
7472+
75- /* Walk all memory nodes and regions */
76- for (offset = fdt_next_node(fdt, -1, NULL); offset >= 0;
77- offset = fdt_next_node(fdt, offset, NULL)) {
78- @@ -107,7 +129,20 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
79-
80- base = fdt32_ld(reg + addr_cells - 1);
81- end = base + size;
73+ /* Walk all memory nodes and regions */
74+ for (offset = fdt_next_node(fdt, -1, NULL); offset >= 0;
75+ offset = fdt_next_node(fdt, offset, NULL)) {
76+ @@ -107,7 +129,20 @@ uint32_t fdt_check_mem_start(uint32_t me
77+
78+ base = fdt32_ld(reg + addr_cells - 1);
79+ end = base + size;
8280- if (mem_start >= base && mem_start < end) {
8381+ if (usable) {
8482+ /*
@@ -94,18 +92,16 @@ index 62450d824c3c..9291a2661bdf 100644
9492+ if (end <= base)
9593+ continue;
9694+ } else if (mem_start >= base && mem_start < end) {
97- /* Calculated address is valid, use it */
98- return mem_start;
99- }
100- @@ -123,7 +158,8 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
101- }
102-
103- /*
95+ /* Calculated address is valid, use it */
96+ return mem_start;
97+ }
98+ @@ -123,7 +158,8 @@ uint32_t fdt_check_mem_start(uint32_t me
99+ }
100+
101+ /*
104102- * The calculated address is not usable.
105103+ * The calculated address is not usable, or was overridden by the
106104+ * "linux,usable-memory-range" property.
107- * Use the lowest usable physical memory address from the DTB instead,
108- * and make sure this is a multiple of 2 MiB for phys/virt patching.
109- */
110- - -
111- 2.35.1
105+ * Use the lowest usable physical memory address from the DTB instead,
106+ * and make sure this is a multiple of 2 MiB for phys/virt patching.
107+ */
0 commit comments