board: stm32mp1: reserve memory for OP-TEE in device tree

Add reserve memory for OP-TEE in U-Boot and in kernel device tree:
- no more reduce the DDR size in "memory" node:
  CONFIG_SYS_MEM_TOP_HIDE is no more used
- U-Boot device-tree defines the needed "reserved-memory" for OP-TEE
  and U-Boot should not use this reserved memory: board_get_usable_ram_top
  use lmb lib to found the first free region, the not reserved
  memory, enough to relocate U-Boot: the needed size of U-Boot
  is estimated with gd->mon_len + CONFIG_SYS_MALLOC_LEN.
- the optee node ("optee@...": firmware with compatible "linaro,optee-tz")
  and the associated "reserved-memory" are deactivated in kernel device
  tree when OP-TEE is not detected by U-Boot to prevent kernel issue
  (memory is reserved but not used, optee driver probe failed).

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>

arch/arm/dts/stm32mp157c-ed1.dts

@@ -70,6 +70,11 @@
 			reg = <0xe8000000 0x8000000>;
 			no-map;
 		};
+
+		optee@fe000000 {
+			reg = <0xfe000000 0x02000000>;
+			no-map;
+		};
 	};
 
 	aliases {

arch/arm/dts/stm32mp15xx-dkx.dtsi

@@ -58,6 +58,11 @@
 			reg = <0xd4000000 0x4000000>;
 			no-map;
 		};
+
+		optee@de000000 {
+			reg = <0xde000000 0x02000000>;
+			no-map;
+		};
 	};
 
 	led {

arch/arm/mach-stm32mp/dram_init.c

@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <dm.h>
+#include <lmb.h>
 #include <ram.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -31,3 +32,20 @@ int dram_init(void)
 
 	return 0;
 }
+
+ulong board_get_usable_ram_top(ulong total_size)
+{
+	phys_addr_t reg;
+	struct lmb lmb;
+
+	/* found enough not-reserved memory to relocated U-Boot */
+	lmb_init(&lmb);
+	lmb_add(&lmb, gd->ram_base, gd->ram_size);
+	boot_fdt_add_mem_rsv_regions(&lmb, (void *)gd->fdt_blob);
+	reg = lmb_alloc(&lmb, CONFIG_SYS_MALLOC_LEN + total_size, SZ_4K);
+
+	if (reg)
+		return ALIGN(reg + CONFIG_SYS_MALLOC_LEN + total_size, SZ_4K);
+
+	return gd->ram_top;
+}

arch/arm/mach-stm32mp/fdt.c

@@ -218,6 +218,26 @@ static void stm32_fdt_disable(void *fdt, int offset, u32 addr,
 		       string, addr, name);
 }
 
+static void stm32_fdt_disable_optee(void *blob)
+{
+	int off, node;
+
+	off = fdt_node_offset_by_compatible(blob, -1, "linaro,optee-tz");
+	if (off >= 0 && fdtdec_get_is_enabled(blob, off))
+		fdt_status_disabled(blob, off);
+
+	/* Disabled "optee@..." reserved-memory node */
+	off = fdt_path_offset(blob, "/reserved-memory/");
+	if (off < 0)
+		return;
+	for (node = fdt_first_subnode(blob, off);
+	     node >= 0;
+	     node = fdt_next_subnode(blob, node)) {
+		if (!strncmp(fdt_get_name(blob, node, NULL), "optee@", 6))
+			fdt_status_disabled(blob, node);
+	}
+}
+
 /*
  * This function is called right before the kernel is booted. "blob" is the
  * device tree that will be passed to the kernel.
@@ -302,5 +322,8 @@ int ft_system_setup(void *blob, bd_t *bd)
 				       "st,package", pkg, false);
 	}
 
+	if (!CONFIG_IS_ENABLED(STM32MP1_OPTEE))
+		stm32_fdt_disable_optee(blob);
+
 	return ret;
 }

include/configs/stm32mp1.h

@@ -23,10 +23,6 @@
 #define CONFIG_SYS_SDRAM_BASE			STM32_DDR_BASE
 #define CONFIG_SYS_INIT_SP_ADDR			CONFIG_SYS_TEXT_BASE
 
-#ifdef CONFIG_STM32MP1_OPTEE
-#define CONFIG_SYS_MEM_TOP_HIDE			SZ_32M
-#endif /* CONFIG_STM32MP1_OPTEE */
-
 /*
  * Console I/O buffer size
  */