lmb: Add generic arch_lmb_reserve_generic()

The arc/arm/m68k/microblaze/mips/ppc arch_lmb_reserve() implementations
are all mostly the same, except for a couple of details. Implement a
generic arch_lmb_reserve_generic() function which can be parametrized
enough to cater for those differences between architectures. This can
also be parametrized enough so it can handle cases where U-Boot is not
relocated to the end of DRAM e.g. because there is some other reserved
memory past U-Boot (e.g. unmovable firmware for coprocessor), it is not
relocated at all, and other such use cases.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Alexey Brodkin <alexey.brodkin@synopsys.com>
Cc: Angelo Dureghello <angelo@sysam.it>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc: Hai Pham <hai.pham.ud@renesas.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Cc: Tom Rini <trini@konsulko.com>
Cc: Wolfgang Denk <wd@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>

2 files changed, 36 insertions, 0 deletions

diff --git a/include/lmb.h b/include/lmb.h
index 3c4afdf9f0..1984291132 100644
--- a/include/lmb.h
+++ b/include/lmb.h
@@ -122,6 +122,7 @@ lmb_size_bytes(struct lmb_region *type, unsigned long region_nr)
 
 void board_lmb_reserve(struct lmb *lmb);
 void arch_lmb_reserve(struct lmb *lmb);
+void arch_lmb_reserve_generic(struct lmb *lmb, ulong sp, ulong end, ulong align);
 
 /* Low level functions */
 
diff --git a/lib/lmb.c b/lib/lmb.c
index 7bd1255f7a..793647724c 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -12,6 +12,10 @@
 #include <log.h>
 #include <malloc.h>
 
+#include <asm/global_data.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
 #define LMB_ALLOC_ANYWHERE	0
 
 static void lmb_dump_region(struct lmb_region *rgn, char *name)
@@ -113,6 +117,37 @@ void lmb_init(struct lmb *lmb)
 	lmb->reserved.cnt = 0;
 }
 
+void arch_lmb_reserve_generic(struct lmb *lmb, ulong sp, ulong end, ulong align)
+{
+	ulong bank_end;
+	int bank;
+
+	/*
+	 * Reserve memory from aligned address below the bottom of U-Boot stack
+	 * until end of U-Boot area using LMB to prevent U-Boot from overwriting
+	 * that memory.
+	 */
+	debug("## Current stack ends at 0x%08lx ", sp);
+
+	/* adjust sp by 4K to be safe */
+	sp -= align;
+	for (bank = 0; bank < CONFIG_NR_DRAM_BANKS; bank++) {
+		if (!gd->bd->bi_dram[bank].size ||
+		    sp < gd->bd->bi_dram[bank].start)
+			continue;
+		/* Watch out for RAM at end of address space! */
+		bank_end = gd->bd->bi_dram[bank].start +
+			gd->bd->bi_dram[bank].size - 1;
+		if (sp > bank_end)
+			continue;
+		if (bank_end > end)
+			bank_end = end - 1;
+
+		lmb_reserve(lmb, sp, bank_end - sp + 1);
+		break;
+	}
+}
+
 static void lmb_reserve_common(struct lmb *lmb, void *fdt_blob)
 {
 	arch_lmb_reserve(lmb);