[PATCH] arm: apple: Fix mem layout

[Mark Kettenis]

The current approach for setting the environment variables that
describe the memory layout runs the risk of overlapping with
reserved memory regions. Use the lmb code to derive the addresses
for these variables instead.

Signed-off-by: Mark Kettenis <kettenis at openbsd.org>
---

Another candidate for 2022.04.  Not a regression either, but the
current code may end up randomly failing due to address space
randomization. The efi_loader bootpath seems to be unaffected, but
attempt to load a Linux kernel directly are more likely to fail.
Also tested widely by people using the Asahi Linux installer.

 arch/arm/mach-apple/board.c | 32 ++++++++++++++------------------
 1 file changed, 14 insertions(+), 18 deletions(-)

diff --git a/arch/arm/mach-apple/board.c b/arch/arm/mach-apple/board.c
index 54005f3adf..722dff1f64 100644
--- a/arch/arm/mach-apple/board.c
+++ b/arch/arm/mach-apple/board.c
@@ -6,6 +6,7 @@
 #include <common.h>
 #include <dm.h>
 #include <efi_loader.h>
+#include <lmb.h>
 
 #include <asm/armv8/mmu.h>
 #include <asm/global_data.h>
@@ -266,32 +267,27 @@ u64 get_page_table_size(void)
 	return SZ_256K;
 }
 
+#define KERNEL_COMP_SIZE	SZ_128M
+
 int board_late_init(void)
 {
-	unsigned long base;
-	unsigned long top;
+	struct lmb lmb;
 	u32 status = 0;
 
-	/* Reserve 4M each for scriptaddr and pxefile_addr_r at the top of RAM
-	 * at least 1M below the stack.
-	 */
-	top = gd->start_addr_sp - CONFIG_STACK_SIZE - SZ_8M - SZ_1M;
-	top = ALIGN_DOWN(top, SZ_8M);
-
-	status |= env_set_hex("scriptaddr", top + SZ_4M);
-	status |= env_set_hex("pxefile_addr_r", top);
+	lmb_init_and_reserve(&lmb, gd->bd, (void *)gd->fdt_blob);
 
 	/* somewhat based on the Linux Kernel boot requirements:
 	 * align by 2M and maximal FDT size 2M
 	 */
-	base = ALIGN(gd->ram_base, SZ_2M);
-
-	status |= env_set_hex("fdt_addr_r", base);
-	status |= env_set_hex("kernel_addr_r", base + SZ_2M);
-	status |= env_set_hex("ramdisk_addr_r", base + SZ_128M);
-	status |= env_set_hex("loadaddr", base + SZ_2G);
-	status |= env_set_hex("kernel_comp_addr_r", base + SZ_2G - SZ_128M);
-	status |= env_set_hex("kernel_comp_size", SZ_128M);
+	status |= env_set_hex("loadaddr", lmb_alloc(&lmb, SZ_1G, SZ_2M));
+	status |= env_set_hex("fdt_addr_r", lmb_alloc(&lmb, SZ_2M, SZ_2M));
+	status |= env_set_hex("kernel_addr_r", lmb_alloc(&lmb, SZ_128M, SZ_2M));
+	status |= env_set_hex("ramdisk_addr_r", lmb_alloc(&lmb, SZ_1G, SZ_2M));
+	status |= env_set_hex("kernel_comp_addr_r",
+			      lmb_alloc(&lmb, KERNEL_COMP_SIZE, SZ_2M));
+	status |= env_set_hex("kernel_comp_size", KERNEL_COMP_SIZE);
+	status |= env_set_hex("scriptaddr", lmb_alloc(&lmb, SZ_4M, SZ_2M));
+	status |= env_set_hex("pxefile_addr_r", lmb_alloc(&lmb, SZ_4M, SZ_2M));
 
 	if (status)
 		log_warning("late_init: Failed to set run time variables\n");
-- 
2.35.1