openwrt/target/linux/airoha/patches-5.15/0004-ARM-9124-1-uncompress-Parse-linux-usable-memory-rang.patch
Daniel Danzberger f32085fc0b airoha: Add new target platform
Airoha is a new ARM platform based on Cortex-A53 which has recently been
merged into linux-next.

Due to BootROM limitations on this platform, the Cortex-A53 can't run in
Aarch64 mode and code must be compiled for 32-Bit ARM.

This support is based mostly on those linux-next commits backported
for kernel 5.15.

Patches:
1 - platform support = linux-next
2 - clock driver = linux-next
3 - gpio driver = linux-next
4 - linux,usable-memory-range dts support = linux-next
5 - mtd spinand driver
6 - spi driver
7 - pci driver (kconfig only, uses mediatek PCI) = linux-next

Still missing:
- Ethernet driver
- Sysupgrade support

A.t.m there exists one subtarget EN7523 with only one evaluation
board.

The initramfs can be run with the following commands from u-boot:
-
u-boot> setenv bootfile \
	openwrt-airoha-airoha_en7523-evb-initramfs-kernel.bin
u-boot> tftpboot
u-boot> bootm 0x81800000
-

Signed-off-by: Daniel Danzberger <daniel@dd-wrt.com>
2022-09-05 11:12:32 +02:00

112 lines
4.0 KiB
Diff

From 48342ae751c797ac73ac9c894b3f312df18ffd21 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Wed, 15 Sep 2021 13:46:20 +0100
Subject: [PATCH] ARM: 9124/1: uncompress: Parse "linux,usable-memory-range" DT
property
Add support for parsing the "linux,usable-memory-range" DT property.
This property is used to describe the usable memory reserved for the
crash dump kernel, and thus makes the memory reservation explicit.
If present, Linux no longer needs to mask the program counter, and rely
on the "mem=" kernel parameter to obtain the start and size of usable
memory.
For backwards compatibility, the traditional method to derive the start
of memory is still used if "linux,usable-memory-range" is absent.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel Danzberger <daniel@dd-wrt.com>
---
.../arm/boot/compressed/fdt_check_mem_start.c | 48 ++++++++++++++++---
1 file changed, 42 insertions(+), 6 deletions(-)
diff --git a/arch/arm/boot/compressed/fdt_check_mem_start.c b/arch/arm/boot/compressed/fdt_check_mem_start.c
index 62450d824c3c..9291a2661bdf 100644
--- a/arch/arm/boot/compressed/fdt_check_mem_start.c
+++ b/arch/arm/boot/compressed/fdt_check_mem_start.c
@@ -55,16 +55,17 @@ static uint64_t get_val(const fdt32_t *cells, uint32_t ncells)
* DTB, and, if out-of-range, replace it by the real start address.
* To preserve backwards compatibility (systems reserving a block of memory
* at the start of physical memory, kdump, ...), the traditional method is
- * always used if it yields a valid address.
+ * used if it yields a valid address, unless the "linux,usable-memory-range"
+ * property is present.
*
* Return value: start address of physical memory to use
*/
uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
{
- uint32_t addr_cells, size_cells, base;
+ uint32_t addr_cells, size_cells, usable_base, base;
uint32_t fdt_mem_start = 0xffffffff;
- const fdt32_t *reg, *endp;
- uint64_t size, end;
+ const fdt32_t *usable, *reg, *endp;
+ uint64_t size, usable_end, end;
const char *type;
int offset, len;
@@ -80,6 +81,27 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
if (addr_cells > 2 || size_cells > 2)
return mem_start;
+ /*
+ * Usable memory in case of a crash dump kernel
+ * This property describes a limitation: memory within this range is
+ * only valid when also described through another mechanism
+ */
+ usable = get_prop(fdt, "/chosen", "linux,usable-memory-range",
+ (addr_cells + size_cells) * sizeof(fdt32_t));
+ if (usable) {
+ size = get_val(usable + addr_cells, size_cells);
+ if (!size)
+ return mem_start;
+
+ if (addr_cells > 1 && fdt32_ld(usable)) {
+ /* Outside 32-bit address space */
+ return mem_start;
+ }
+
+ usable_base = fdt32_ld(usable + addr_cells - 1);
+ usable_end = usable_base + size;
+ }
+
/* Walk all memory nodes and regions */
for (offset = fdt_next_node(fdt, -1, NULL); offset >= 0;
offset = fdt_next_node(fdt, offset, NULL)) {
@@ -107,7 +129,20 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
base = fdt32_ld(reg + addr_cells - 1);
end = base + size;
- if (mem_start >= base && mem_start < end) {
+ if (usable) {
+ /*
+ * Clip to usable range, which takes precedence
+ * over mem_start
+ */
+ if (base < usable_base)
+ base = usable_base;
+
+ if (end > usable_end)
+ end = usable_end;
+
+ if (end <= base)
+ continue;
+ } else if (mem_start >= base && mem_start < end) {
/* Calculated address is valid, use it */
return mem_start;
}
@@ -123,7 +158,8 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
}
/*
- * The calculated address is not usable.
+ * The calculated address is not usable, or was overridden by the
+ * "linux,usable-memory-range" property.
* Use the lowest usable physical memory address from the DTB instead,
* and make sure this is a multiple of 2 MiB for phys/virt patching.
*/
--
2.35.1