From: Olof Johansson Date: Mon, 29 Aug 2005 02:42:10 +0000 (-0500) Subject: [PATCH] PPC64: Don't try to claim memory from OF at 1GB mark X-Git-Tag: firefly_0821_release~42188^2~5 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7fea82ab1a74030f79a2adfac1af3d93b8638fc3;p=firefly-linux-kernel-4.4.55.git [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 Signed-off-by: Paul Mackerras --- diff --git a/arch/ppc64/kernel/prom_init.c b/arch/ppc64/kernel/prom_init.c index adcf972711fc..122283a1d39a 100644 --- a/arch/ppc64/kernel/prom_init.c +++ b/arch/ppc64/kernel/prom_init.c @@ -892,7 +892,10 @@ static void __init prom_init_mem(void) if ( RELOC(of_platform) == PLATFORM_PSERIES_LPAR ) RELOC(alloc_top) = RELOC(rmo_top); else - RELOC(alloc_top) = RELOC(rmo_top) = min(0x40000000ul, RELOC(ram_top)); + /* Some RS64 machines have buggy firmware where claims up at 1GB + * fails. Cap at 768MB as a workaround. Still plenty of room. + */ + RELOC(alloc_top) = RELOC(rmo_top) = min(0x30000000ul, RELOC(ram_top)); prom_printf("memory layout at init:\n"); prom_printf(" memory_limit : %x (16 MB aligned)\n", RELOC(prom_memory_limit));