[PATCH 3/3] board_f.c: Insure 16 alignment of start_addr_sp and reserved memory

[Heinrich Schuchardt]

On 1/9/20 6:11 PM, Patrick Delaunay wrote:
> Add a function reserve_sp() to reserved memory with 16 bits alignment

I guess this is a typo:

%s/bits/bytes/

Best regards

Heinrich

> after the stack pointer (gd->start_addr_sp) and use this new function
> in board_f.c to reserve all the memory area (malloc, board, gd, fdt,
> bootstage, stacks).
>
> This 16 byte alignment is needed for cast on struct pointer
> for the reserved memory, for example:
> + x86_64 ABI: https://reviews.llvm.org/D30049: 16 bytes
> + ARMv8 Instruction Set Overview: quad word, 16 bytes
>
> An other alignment value could be needed for other architecture.
>
> Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
> ---
>
>   common/board_f.c | 32 ++++++++++++++++++--------------
>   1 file changed, 18 insertions(+), 14 deletions(-)
>
> diff --git a/common/board_f.c b/common/board_f.c
> index e21f533634..0302ee4a6e 100644
> --- a/common/board_f.c
> +++ b/common/board_f.c
> @@ -470,6 +470,17 @@ static int reserve_uboot(void)
>   	return 0;
>   }
>
> +/*
> + * reserve after start_addr_sp the requested size and make the stack pointer
> + * 16-byte aligned, this alignment is needed for cast on the reserved memory
> + * ref = x86_64 ABI: https://reviews.llvm.org/D30049: 16 bytes
> + *     = ARMv8 Instruction Set Overview: quad word, 16 bytes
> + */
> +static unsigned long reserve_sp(size_t size)
> +{
> +	return ALIGN_DOWN(gd->start_addr_sp - size, 16);
> +}
> +
>   #ifdef CONFIG_SYS_NONCACHED_MEMORY
>   static int reserve_noncached(void)
>   {
> @@ -495,7 +506,7 @@ static int reserve_noncached(void)
>   /* reserve memory for malloc() area */
>   static int reserve_malloc(void)
>   {
> -	gd->start_addr_sp = gd->start_addr_sp - TOTAL_MALLOC_LEN;
> +	gd->start_addr_sp = reserve_sp(TOTAL_MALLOC_LEN);
>   	debug("Reserving %dk for malloc() at: %08lx\n",
>   	      TOTAL_MALLOC_LEN >> 10, gd->start_addr_sp);
>   #ifdef CONFIG_SYS_NONCACHED_MEMORY
> @@ -509,7 +520,7 @@ static int reserve_malloc(void)
>   static int reserve_board(void)
>   {
>   	if (!gd->bd) {
> -		gd->start_addr_sp -= sizeof(bd_t);
> +		gd->start_addr_sp = reserve_sp(sizeof(bd_t));
>   		gd->bd = (bd_t *)map_sysmem(gd->start_addr_sp, sizeof(bd_t));
>   		memset(gd->bd, '\0', sizeof(bd_t));
>   		debug("Reserving %zu Bytes for Board Info at: %08lx\n",
> @@ -528,7 +539,7 @@ static int setup_machine(void)
>
>   static int reserve_global_data(void)
>   {
> -	gd->start_addr_sp -= sizeof(gd_t);
> +	gd->start_addr_sp = reserve_sp(sizeof(gd_t));
>   	gd->new_gd = (gd_t *)map_sysmem(gd->start_addr_sp, sizeof(gd_t));
>   	debug("Reserving %zu Bytes for Global Data at: %08lx\n",
>   	      sizeof(gd_t), gd->start_addr_sp);
> @@ -546,7 +557,7 @@ static int reserve_fdt(void)
>   	if (gd->fdt_blob) {
>   		gd->fdt_size = ALIGN(fdt_totalsize(gd->fdt_blob) + 0x1000, 32);
>
> -		gd->start_addr_sp -= gd->fdt_size;
> +		gd->start_addr_sp = reserve_sp(gd->fdt_size);
>   		gd->new_fdt = map_sysmem(gd->start_addr_sp, gd->fdt_size);
>   		debug("Reserving %lu Bytes for FDT at: %08lx\n",
>   		      gd->fdt_size, gd->start_addr_sp);
> @@ -561,12 +572,7 @@ static int reserve_bootstage(void)
>   #ifdef CONFIG_BOOTSTAGE
>   	int size = bootstage_get_size();
>
> -	gd->start_addr_sp -= size;
> -	/*
> -	 * Insure that start_addr_sp is aligned down to reserve enough
> -	 * space for new_bootstage
> -	 */
> -	gd->start_addr_sp = ALIGN_DOWN(gd->start_addr_sp, 16);
> +	gd->start_addr_sp = reserve_sp(size);
>   	gd->new_bootstage = map_sysmem(gd->start_addr_sp, size);
>   	debug("Reserving %#x Bytes for bootstage at: %08lx\n", size,
>   	      gd->start_addr_sp);
> @@ -583,8 +589,7 @@ __weak int arch_reserve_stacks(void)
>   static int reserve_stacks(void)
>   {
>   	/* make stack pointer 16-byte aligned */
> -	gd->start_addr_sp -= 16;
> -	gd->start_addr_sp &= ~0xf;
> +	gd->start_addr_sp = reserve_sp(16);
>
>   	/*
>   	 * let the architecture-specific code tailor gd->start_addr_sp and
> @@ -596,8 +601,7 @@ static int reserve_stacks(void)
>   static int reserve_bloblist(void)
>   {
>   #ifdef CONFIG_BLOBLIST
> -	gd->start_addr_sp &= ~0xf;
> -	gd->start_addr_sp -= CONFIG_BLOBLIST_SIZE;
> +	gd->start_addr_sp = reserve_sp(CONFIG_BLOBLIST_SIZE);
>   	gd->new_bloblist = map_sysmem(gd->start_addr_sp, CONFIG_BLOBLIST_SIZE);
>   #endif
>
>