New patch to review for coreboot: 0e64b4a haswell: romstage: pass stack pointer and MTRRs
Stefan Reinauer (stefan.reinauer@coreboot.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2755
-gerrit
commit 0e64b4a773edefeb528395636043f1d5f79ac362 Author: Aaron Durbin adurbin@chromium.org Date: Thu Feb 7 00:03:33 2013 -0600
haswell: romstage: pass stack pointer and MTRRs
Instead of hard coding the policy for the stack and MTRR values after the cache-as-ram is torn down, allow for the C code to pass those policies back to the cache-as-ram assembly file. That way, ramstage relocation can use a different stack as well as different MTRR policies.
Change-Id: Ied024d933f96a12ed0703c51c506586f4b50bd14 Signed-off-by: Aaron Durbin adurbin@chromium.org --- src/cpu/intel/haswell/cache_as_ram.inc | 51 ++++++++++-------- src/cpu/intel/haswell/haswell.h | 16 ++++++ src/cpu/intel/haswell/romstage.c | 95 +++++++++++++++++++++++++++++++--- 3 files changed, 133 insertions(+), 29 deletions(-)
diff --git a/src/cpu/intel/haswell/cache_as_ram.inc b/src/cpu/intel/haswell/cache_as_ram.inc index 72b4958..5fb5712 100644 --- a/src/cpu/intel/haswell/cache_as_ram.inc +++ b/src/cpu/intel/haswell/cache_as_ram.inc @@ -182,7 +182,11 @@ clear_mtrrs: before_romstage: post_code(0x29) /* Call romstage.c main function. */ - call main + call romstage_main + /* Save return value from romstage_main. It contains the stack to use + * after cache-as-ram is torn down. It also contains the information + * for setting up MTTRs. */ + movl %eax, %ebx
post_code(0x2f)
@@ -251,30 +255,34 @@ before_romstage:
post_code(0x38)
- /* Enable Write Back and Speculative Reads for the first MB - * and coreboot_ram. - */ - movl $MTRRphysBase_MSR(0), %ecx - movl $(0x00000000 | MTRR_TYPE_WRBACK), %eax - xorl %edx, %edx - wrmsr - movl $MTRRphysMask_MSR(0), %ecx - movl $(~(CONFIG_RAMTOP - 1) | MTRRphysMaskValid), %eax - movl $CPU_PHYSMASK_HI, %edx // 36bit address space - wrmsr + /* Setup stack as indicated by return value from ramstage_main(). */ + movl %ebx, %esp
- /* Enable Caching and speculative Reads for the - * complete ROM now that we actually have RAM. - */ - movl $MTRRphysBase_MSR(1), %ecx - movl $(0xffc00000 | MTRR_TYPE_WRPROT), %eax - xorl %edx, %edx + /* Get number of MTTRs. */ + popl %ebx + movl $MTRRphysBase_MSR(0), %ecx +1: + testl %ebx, %ebx + jz 1f + + /* Low 32 bits of MTTR base. */ + popl %eax + /* Upper 32 bits of MTTR base. */ + popl %edx + /* Write MTRR base. */ wrmsr - movl $MTRRphysMask_MSR(1), %ecx - movl $(~(4*1024*1024 - 1) | MTRRphysMaskValid), %eax - movl $CPU_PHYSMASK_HI, %edx + inc %ecx + /* Low 32 bits of MTTR mask. */ + popl %eax + /* Upper 32 bits of MTTR mask. */ + popl %edx + /* Write MTRR mask. */ wrmsr + inc %ecx
+ dec %ebx + jmp 1b +1: post_code(0x39)
/* And enable cache again after setting MTRRs. */ @@ -326,7 +334,6 @@ __main:
movl %ebp, %esi
- movl $ROMSTAGE_STACK, %esp movl %esp, %ebp pushl %esi call copy_and_run diff --git a/src/cpu/intel/haswell/haswell.h b/src/cpu/intel/haswell/haswell.h index 3ced0c0..7a55ef7 100644 --- a/src/cpu/intel/haswell/haswell.h +++ b/src/cpu/intel/haswell/haswell.h @@ -113,6 +113,22 @@ struct romstage_params { }; void mainboard_romstage_entry(unsigned long bist); void romstage_common(const struct romstage_params *params); +/* romstage_main is called from the cache-as-ram assembly file. The return + * value is the stack value to be used for romstage once cache-as-ram is + * torn down. The following values are pushed onto the stack to setup the + * MTRRs: + * +0: Number of MTRRs + * +4: MTTR base 0 31:0 + * +8: MTTR base 0 63:32 + * +12: MTTR mask 0 31:0 + * +16: MTTR mask 0 63:32 + * +20: MTTR base 1 31:0 + * +24: MTTR base 1 63:32 + * +28: MTTR mask 1 31:0 + * +32: MTTR mask 1 63:32 + * ... + */ +void * __attribute__((regparm(0))) romstage_main(unsigned long bist); #endif
#ifdef __SMM__ diff --git a/src/cpu/intel/haswell/romstage.c b/src/cpu/intel/haswell/romstage.c index 1d00af1..8b0e2cc 100644 --- a/src/cpu/intel/haswell/romstage.c +++ b/src/cpu/intel/haswell/romstage.c @@ -23,6 +23,8 @@ #include <arch/cpu.h> #include <cpu/x86/bist.h> #include <cpu/x86/msr.h> +#include <cpu/x86/mtrr.h> +#include <cpu/x86/stack.h> #include <lib.h> #include <timestamp.h> #include <arch/io.h> @@ -40,16 +42,90 @@ #include "southbridge/intel/lynxpoint/me.h"
-/* The cache-as-ram assembly file calls main() after setting up cache-as-ram. - * main() will then call the mainboards's mainboard_romstage_entry() function. - * That function then calls romstage_common() below. The reason for the back - * and forth is to provide common entry point from cache-as-ram while still - * allowing for code sharing. Because we can't use global variables the stack - * is used for allocations -- thus the need to call back and forth. */ +/* The cache-as-ram assembly file calls romstage_main() after setting up + * cache-as-ram. romstage_main() will then call the mainboards's + * mainboard_romstage_entry() function. That function then calls + * romstage_common() below. The reason for the back and forth is to provide + * common entry point from cache-as-ram while still allowing for code sharing. + * Because we can't use global variables the stack is used for allocations -- + * thus the need to call back and forth. */
-void main(unsigned long bist) + +static inline u32 *stack_push(u32 *stack, u32 value) +{ + stack = &stack[-1]; + *stack = value; + return stack; +} + +/* setup_romstage_stack_after_car() determines the stack to use after + * cache-as-ram is torn down as well as the MTRR settings to use. */ +static void *setup_romstage_stack_after_car(void) +{ + unsigned long top_of_stack; + int num_mtrrs; + u32 *slot; + u32 mtrr_mask_upper; + + /* Top of stack needs to be aligned to a 4-byte boundary. */ + top_of_stack = ROMSTAGE_STACK & ~3; + slot = (void *)top_of_stack; + num_mtrrs = 0; + + /* 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; + + /* The order for each MTTR 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: + * +0: Number of MTRRs + * +4: MTTR base 0 31:0 + * +8: MTTR base 0 63:32 + * +12: MTTR mask 0 31:0 + * +16: MTTR mask 0 63:32 + * +20: MTTR base 1 31:0 + * +24: MTTR base 1 63:32 + * +28: MTTR mask 1 31:0 + * +32: MTTR mask 1 63:32 + */ + + /* Cache the ROM as WP just below 4GiB. */ + slot = stack_push(slot, mtrr_mask_upper); /* upper mask */ + slot = stack_push(slot, ~(CONFIG_ROM_SIZE - 1) | MTRRphysMaskValid); + slot = stack_push(slot, 0); /* upper base */ + slot = stack_push(slot, ~(CONFIG_ROM_SIZE - 1) | MTRR_TYPE_WRPROT); + num_mtrrs++; + + /* Cache RAM as WB from 0 -> CONFIG_RAMTOP. */ + slot = stack_push(slot, mtrr_mask_upper); /* upper mask */ + slot = stack_push(slot, ~(CONFIG_RAMTOP - 1) | MTRRphysMaskValid); + slot = stack_push(slot, 0); /* upper base */ + slot = stack_push(slot, 0 | MTRR_TYPE_WRBACK); + num_mtrrs++; + + /* Cache 8MiB below the top of ram. On haswell systems the top of + * ram under 4GiB is the start of the TSEG region. It is required to + * be 8MiB aligned. Set this area as cacheable so it can be used later + * for ramstage before setting up the entire RAM as cacheable. */ + slot = stack_push(slot, mtrr_mask_upper); /* upper mask */ + slot = stack_push(slot, ~((8 << 20) - 1) | MTRRphysMaskValid); + slot = stack_push(slot, 0); /* upper base */ + slot = stack_push(slot, + (get_top_of_ram() - (8 << 20)) | MTRR_TYPE_WRBACK); + num_mtrrs++; + + /* Save the number of MTTRs to setup. Return the stack location + * pointing to the number of MTRRs. */ + slot = stack_push(slot, num_mtrrs); + + return slot; +} + +void * __attribute__((regparm(0))) romstage_main(unsigned long bist) { int i; + void *romstage_stack_after_car; const int num_guards = 4; const u32 stack_guard = 0xdeadbeef; u32 *stack_base = (void *)(CONFIG_DCACHE_RAM_BASE + @@ -69,10 +145,15 @@ void main(unsigned long bist) printk(BIOS_DEBUG, "Smashed stack detected in romstage!\n"); }
+ /* Get the stack to use after cache-as-ram is torn down. */ + romstage_stack_after_car = setup_romstage_stack_after_car(); + #if CONFIG_CONSOLE_CBMEM /* Keep this the last thing this function does. */ cbmemc_reinit(); #endif + + return romstage_stack_after_car; }
void romstage_common(const struct romstage_params *params)
-
Stefan Reinauer