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Commit 4d1f3f25 authored by Jimi Xenidis's avatar Jimi Xenidis Committed by Paul Mackerras
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[PATCH] powerpc: Auto reserve of device tree blob 



A devtree compiler (dtc) generated devtree blob is "relocatable" and so
does not contain a reserved_map entry for the blob itself.  This means
that if passed to Linux, Linux will not get lmb_reserve() the blob and
it could be over.  The following patch will explicitly reserve the
"blob" as it was given to us and stops prom_init.c from creating a
reserved mapping for the blob.

NOTE: that the dtc/kexec should not generate the blob reservation entry.
Although if they do, LMB reserver handles overlaps.

Signed-off-by: default avatar <jimix@watson.ibm.com>
Acked-by: default avatarMichael Neuling <mikey@neuling.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 1dc461f0

arch/powerpc/kernel/prom.c

+5 −0
Original line number Diff line number Diff line
@@ -1267,6 +1267,11 @@ static void __init early_reserve_mem(void) 


	reserve_map = (u64 *)(((unsigned long)initial_boot_params) +

					initial_boot_params->off_mem_rsvmap);



	/* before we do anything, lets reserve the dt blob */

	lmb_reserve(__pa((unsigned long)initial_boot_params),

		    initial_boot_params->totalsize);



#ifdef CONFIG_PPC32

	/* 

	 * Handle the case where we might be booting from an old kexec

arch/powerpc/kernel/prom_init.c

+4 −5
Original line number Diff line number Diff line
@@ -1950,11 +1950,7 @@ static void __init flatten_device_tree(void) 
	/* Version 16 is not backward compatible */

	hdr->last_comp_version = 0x10;



	/* Reserve the whole thing and copy the reserve map in, we

	 * also bump mem_reserve_cnt to cause further reservations to

	 * fail since it's too late.

	 */

	reserve_mem(RELOC(dt_header_start), hdr->totalsize);

	/* Copy the reserve map in */

	memcpy(rsvmap, RELOC(mem_reserve_map), sizeof(mem_reserve_map));



#ifdef DEBUG_PROM
@@ -1967,6 +1963,9 @@ static void __init flatten_device_tree(void) 
				    RELOC(mem_reserve_map)[i].size);

	}

#endif

	/* Bump mem_reserve_cnt to cause further reservations to fail

	 * since it's too late.

	 */

	RELOC(mem_reserve_cnt) = MEM_RESERVE_MAP_SIZE;



	prom_printf("Device tree strings 0x%x -> 0x%x\n",