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Diffstat (limited to 'src/soc/intel/common/stack.c')
| -rw-r--r-- | src/soc/intel/common/stack.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/src/soc/intel/common/stack.c b/src/soc/intel/common/stack.c new file mode 100644 index 0000000000..0955b9751f --- /dev/null +++ b/src/soc/intel/common/stack.c @@ -0,0 +1,183 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2013 Google Inc. + * Copyright (C) 2015 Intel Corp. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <cbmem.h> +#include <console/console.h> +#include <cpu/x86/mtrr.h> +#include "memmap.h" +#include "romstage.h" +#include <soc/intel/common/util.h> +#include "stack.h" +#include <stdlib.h> + +const unsigned long romstage_ram_stack_size = CONFIG_ROMSTAGE_RAM_STACK_SIZE; + +/* + * Romstage needs quite a bit of stack for decompressing images since the lzma + * lib keeps its state on the stack during romstage. + */ +static unsigned long choose_top_of_stack(void) +{ + unsigned long stack_top; + + /* cbmem_add() does a find() before add(). */ + stack_top = (unsigned long)cbmem_add(CBMEM_ID_ROMSTAGE_RAM_STACK, + romstage_ram_stack_size); + stack_top += romstage_ram_stack_size; + return stack_top; +} + +/* + * setup_stack_and_mtrrs() determines the stack to use after + * cache-as-ram is torn down as well as the MTRR settings to use. + */ +void *setup_stack_and_mtrrs(void) +{ + size_t alignment; + uint32_t aligned_ram; + uint32_t mtrr_mask_upper; + uint32_t max_mtrrs; + uint32_t num_mtrrs; + uint32_t *slot; + unsigned long top_of_stack; + + /* Display the MTTRs */ + soc_display_mtrrs(); + + /* Top of stack needs to be aligned to a 8-byte boundary. */ + top_of_stack = choose_top_of_stack(); + slot = (void *)top_of_stack; + num_mtrrs = 0; + max_mtrrs = soc_get_variable_mtrr_count(NULL); + + /* + * The upper bits of the MTRR mask need to set according to the number + * of physical address bits. + */ + mtrr_mask_upper = (1 << ((cpuid_eax(0x80000008) & 0xff) - 32)) - 1; + alignment = mmap_region_granluarity(); + aligned_ram = ALIGN_DOWN(top_of_stack - romstage_ram_stack_size, + alignment); + + /* + * The order for each MTRR is value then base with upper 32-bits of + * each value coming before the lower 32-bits. The reasoning for + * this ordering is to create a stack layout like the following: + * + * +36: MTRR mask 1 63:32 + * +32: MTRR mask 1 31:0 + * +28: MTRR base 1 63:32 + * +24: MTRR base 1 31:0 + * +20: MTRR mask 0 63:32 + * +16: MTRR mask 0 31:0 + * +12: MTRR base 0 63:32 + * +8: MTRR base 0 31:0 + * +4: Number of MTRRs to setup (described above) + * +0: Number of variable MTRRs to clear + */ + + /* Cache RAM as WB from 0 -> CONFIG_RAMTOP. */ + slot = stack_push32(slot, mtrr_mask_upper); /* upper mask */ + slot = stack_push32(slot, ~(CONFIG_RAMTOP - 1) | MTRRphysMaskValid); + slot = stack_push32(slot, 0); /* upper base */ + slot = stack_push32(slot, 0 | MTRR_TYPE_WRBACK); + num_mtrrs++; + + /* + * +-------------------------+ Top of RAM (aligned) + * | System Management Mode | + * | code and data | Length: CONFIG_TSEG_SIZE + * | (TSEG) | + * +-------------------------+ SMM base (aligned) + * | | + * | Chipset Reserved Memory | Length: Multiple of CONFIG_TSEG_SIZE + * | | + * +-------------------------+ top_of_ram (aligned) + * | | + * | CBMEM Root | + * | | + * +-------------------------+ + * | | + * | FSP Reserved Memory | + * | | + * +-------------------------+ + * | | + * | Various CBMEM Entries | + * | | + * +-------------------------+ top_of_stack (8 byte aligned) + * | | + * | stack (CBMEM Entry) | + * | | + * +-------------------------+ + */ + + /* + * Cache the stack and the other CBMEM entries as well as part or all + * of the FSP reserved memory region. + */ + slot = stack_push32(slot, mtrr_mask_upper); /* upper mask */ + slot = stack_push32(slot, ~(alignment - 1) | MTRRphysMaskValid); + slot = stack_push32(slot, 0); /* upper base */ + slot = stack_push32(slot, aligned_ram | MTRR_TYPE_WRBACK); + num_mtrrs++; + +#if IS_ENABLED(CONFIG_HAVE_SMI_HANDLER) + void *smm_base; + size_t smm_size; + uint32_t tseg_base; + + /* + * Cache the TSEG region at the top of ram. This region is not + * restricted to SMM mode until SMM has been relocated. By setting + * the region to cacheable it provides faster access when relocating + * the SMM handler as well as using the TSEG region for other purposes. + */ + smm_region(&smm_base, &smm_size); + tseg_base = (uint32_t)smm_base; + slot = stack_push32(slot, mtrr_mask_upper); /* upper mask */ + slot = stack_push32(slot, ~(alignment - 1) | MTRRphysMaskValid); + slot = stack_push32(slot, 0); /* upper base */ + slot = stack_push32(slot, tseg_base | MTRR_TYPE_WRBACK); + num_mtrrs++; +#endif + + /* Cache the ROM as WP just below 4GiB. */ + slot = stack_push32(slot, mtrr_mask_upper); /* upper mask */ + slot = stack_push32(slot, ~(CONFIG_ROM_SIZE - 1) | MTRRphysMaskValid); + slot = stack_push32(slot, 0); /* upper base */ + slot = stack_push32(slot, ~(CONFIG_ROM_SIZE - 1) | MTRR_TYPE_WRPROT); + num_mtrrs++; + + /* Validate the MTRR usage */ + if (num_mtrrs > max_mtrrs) { + printk(BIOS_ERR, "MTRRs: max = %d, used = %d, available=%d", + max_mtrrs, num_mtrrs, max_mtrrs - num_mtrrs); + die("ERROR - MTRR use count incorrect!\n"); + } + + /* + * Save the number of MTRRs to setup and clear. Return the stack + * location pointing to the number of MTRRs. + */ + slot = stack_push32(slot, num_mtrrs); + slot = stack_push32(slot, max_mtrrs); + return slot; +} + |