Re: [PATCH 3/4] ppc: bootm: relocate fdt to valid boot memory

[Sascha Hauer <s.hauer@pengutronix.de>]

On Fri, Sep 06, 2013 at 11:53:12AM +0100, Renaud Barbier wrote:
> For the MPC85xx family of SOCs Linux expects any boot firmware
> information to be passed in the first 64MiB of memory. This adds support
> to ensure that the device tree is relocated to a valid location if it is
> outside that address range.
> 
> For the other SOC family currently present in the ppc architecture, the
> default is not to relocate as at Linux startup the virtual address
> equals the physical address.
> 
> Signed-off-by: Renaud Barbier <renaud.barbier@ge.com>

Applied, thanks

Sascha

> ---
>  arch/ppc/include/asm/processor.h |  3 +++
>  arch/ppc/lib/ppclinux.c          | 49 +++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 51 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/ppc/include/asm/processor.h b/arch/ppc/include/asm/processor.h
> index 04cfb60..9145257 100644
> --- a/arch/ppc/include/asm/processor.h
> +++ b/arch/ppc/include/asm/processor.h
> @@ -966,8 +966,11 @@ struct cpu_type {
>  struct cpu_type *identify_cpu(u32 ver);
>  
>  #if defined(CONFIG_MPC85xx)
> +#define LINUX_TLB1_MAX_ADDR	((void *)(64 << 20))
>  #define CPU_TYPE_ENTRY(n, v, nc) \
>  	{ .name = #n, .soc_ver = SVR_##v, .num_cores = (nc), }
> +#else
> +#define LINUX_TLB1_MAX_ADDR	((void *)0xffffffff)
>  #endif
>  #ifndef CONFIG_MACH_SPECIFIC
>  extern int _machine;
> diff --git a/arch/ppc/lib/ppclinux.c b/arch/ppc/lib/ppclinux.c
> index ef69ead..7c30ac3 100644
> --- a/arch/ppc/lib/ppclinux.c
> +++ b/arch/ppc/lib/ppclinux.c
> @@ -4,12 +4,45 @@
>  #include <command.h>
>  #include <image.h>
>  #include <init.h>
> +#include <malloc.h>
>  #include <environment.h>
>  #include <asm/bitops.h>
> +#include <asm/processor.h>
>  #include <boot.h>
>  #include <errno.h>
>  #include <fs.h>
>  
> +static int bootm_relocate_fdt(void *addr, struct image_data *data)
> +{
> +	if (addr < LINUX_TLB1_MAX_ADDR) {
> +		/* The kernel is within  the boot TLB mapping.
> +		 * Put the DTB above if there is no space
> +		 * below.
> +		 */
> +		if (addr < (void *)data->oftree->totalsize) {
> +			addr = (void *)PAGE_ALIGN((phys_addr_t)addr +
> +					data->os->header.ih_size);
> +			addr += data->oftree->totalsize;
> +			if (addr < LINUX_TLB1_MAX_ADDR)
> +				addr = LINUX_TLB1_MAX_ADDR;
> +		}
> +	}
> +
> +	if (addr > LINUX_TLB1_MAX_ADDR) {
> +		pr_crit("Unable to relocate DTB to Linux TLB\n");
> +		return 1;
> +	}
> +
> +	addr = (void *)PAGE_ALIGN_DOWN((phys_addr_t)addr -
> +			data->oftree->totalsize);
> +	memcpy(addr, data->oftree, data->oftree->totalsize);
> +	free(data->oftree);
> +	data->oftree = addr;
> +
> +	pr_info("Relocating device tree to 0x%p\n", addr);
> +	return 0;
> +}
> +
>  static int do_bootm_linux(struct image_data *data)
>  {
>  	void	(*kernel)(void *, void *, unsigned long,
> @@ -24,6 +57,20 @@ static int do_bootm_linux(struct image_data *data)
>  		return -EINVAL;
>  	}
>  
> +	/* Relocate the device tree if outside the initial
> +	 * Linux mapped TLB.
> +	 */
> +	if (IS_ENABLED(CONFIG_MPC85xx)) {
> +		void *addr = data->oftree;
> +
> +		if ((addr + data->oftree->totalsize) > LINUX_TLB1_MAX_ADDR) {
> +			addr = (void *)data->os_address;
> +
> +			if (bootm_relocate_fdt(addr, data))
> +				goto error;
> +		}
> +	}
> +
>  	fdt_add_reserve_map(data->oftree);
>  
>  	kernel = (void *)(data->os_address + data->os_entry);
> @@ -40,7 +87,7 @@ static int do_bootm_linux(struct image_data *data)
>  
>  	reset_cpu(0);
>  
> -	/* not reached */
> +error:
>  	return -1;
>  }
>  
> -- 
> 1.8.3.4
> 
> 
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