| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2015 Timothy Pearson <tpearson@raptorengineeringinc.com>, Raptor Engineering |
| * Copyright (C) 2007 Advanced Micro Devices, Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <cpu/cpu.h> |
| #include <cpu/x86/msr.h> |
| #include <cpu/amd/mtrr.h> |
| |
| #include <cbmem.h> |
| |
| #include "ram_calc.h" |
| |
| #if !IS_ENABLED(CONFIG_LATE_CBMEM_INIT) |
| uint64_t get_uma_memory_size(uint64_t topmem) |
| { |
| uint64_t uma_size = 0; |
| if (IS_ENABLED(CONFIG_GFXUMA)) { |
| /* refer to UMA Size Consideration in 780 BDG. */ |
| if (topmem >= 0x40000000) /* 1GB and above system memory */ |
| uma_size = 0x10000000; /* 256M recommended UMA */ |
| |
| else if (topmem >= 0x20000000) /* 512M - 1023M system memory */ |
| uma_size = 0x8000000; /* 128M recommended UMA */ |
| |
| else if (topmem >= 0x10000000) /* 256M - 511M system memory */ |
| uma_size = 0x4000000; /* 64M recommended UMA */ |
| } |
| |
| return uma_size; |
| } |
| |
| void *cbmem_top(void) |
| { |
| uint32_t topmem = rdmsr(TOP_MEM).lo; |
| |
| return (void *) topmem - get_uma_memory_size(topmem); |
| } |
| #endif |