Eric Lee / linux-smarc-t335x-v3.2

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Commit 7fea82ab1a74030f79a2adfac1af3d93b8638fc3

Authored by Olof Johansson
Committed by Paul Mackerras
1 parent 6f9aa72743
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

[PATCH] PPC64: Don't try to claim memory from OF at 1GB mark 

Some RS64-based machines (p620, F80, others) have problems with firmware
returning 0xdeadbeef instead of failure to allocations that end at the
1GB mark.

We have two options:
1. Detect the undocumented 0xdeadbeef return value and interpret it as
a failure.
2. Avoid allocating that high.

(2) is really the cleaner solution here. 768MB is plenty of room so use
that as the max alloc_top instead of 1GB.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Showing 1 changed file with 4 additions and 1 deletions Side-by-side Diff

arch/ppc64/kernel/prom_init.c
Diff comments   View file @ 7fea82a
... ... @@ -892,7 +892,10 @@
892 892 if ( RELOC(of_platform) == PLATFORM_PSERIES_LPAR )
893 893 RELOC(alloc_top) = RELOC(rmo_top);
894 894 else
895   - RELOC(alloc_top) = RELOC(rmo_top) = min(0x40000000ul, RELOC(ram_top));
  895 + /* Some RS64 machines have buggy firmware where claims up at 1GB
  896 + * fails. Cap at 768MB as a workaround. Still plenty of room.
  897 + */
  898 + RELOC(alloc_top) = RELOC(rmo_top) = min(0x30000000ul, RELOC(ram_top));
896 899  
897 900 prom_printf("memory layout at init:\n");
898 901 prom_printf(" memory_limit : %x (16 MB aligned)\n", RELOC(prom_memory_limit));