diff options
author | Aaron Durbin <adurbin@chromium.org> | 2020-05-28 21:21:49 -0600 |
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committer | Aaron Durbin <adurbin@chromium.org> | 2020-06-02 16:09:58 +0000 |
commit | fa5eded303ac25c95ca4300ebfb4788c149bf2ab (patch) | |
tree | 2baed17b0f6e99b449c6ac93b81314cc633c4a45 /src/include/cpu/x86/mtrr.h | |
parent | a21eae0441209d596fd39ad6f394136c87b9ff91 (diff) |
cpu/x86/mtrr: add helper for setting multiple MTRRs
Introduce concept of var_mtrr_context object for tracking and
assigning MTRR values. The algorithm is lifted from postcar_loader
code, but it's generalized for different type of users: setting
MSRs explicitly or deferring to a particular caller's desired
actions.
BUG=b:155426691,b:155322763
Change-Id: Ic03b4b617196f04071093bbba4cf28d23fa482d8
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41849
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Diffstat (limited to 'src/include/cpu/x86/mtrr.h')
-rw-r--r-- | src/include/cpu/x86/mtrr.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/src/include/cpu/x86/mtrr.h b/src/include/cpu/x86/mtrr.h index 301ea3052d..c1ee51accf 100644 --- a/src/include/cpu/x86/mtrr.h +++ b/src/include/cpu/x86/mtrr.h @@ -110,6 +110,37 @@ void clear_all_var_mtrr(void); asmlinkage void display_mtrrs(void); +/* Variable MTRR structure to help track and set MTRRs prior to ramstage. This + and the following APIs can be used to set up more complex MTRR solutions + instead of open coding get_free_var_mtrr() and set_var_mtrr() or for determining + a future solution, such as postcar_loader. */ +struct var_mtrr_context { + uint32_t upper_mask; + int max_var_mtrrs; + int used_var_mtrrs; + void *arg; /* optional callback parameter */ +}; + +/* Returns 0-relative MTRR from context. Use MTRR_PHYS_BASE|MASK macros for calculating + MSR address value. */ +static inline int var_mtrr_context_current_mtrr(const struct var_mtrr_context *ctx) +{ + return ctx->used_var_mtrrs; +} + +/* Initialize var_mtrr_context object. Assumes all variable MTRRs are not yet used. */ +void var_mtrr_context_init(struct var_mtrr_context *ctx, void *arg); +/* Allocate a variable mtrr base and mask, calling the provided callback for each MTRR + MSR base-mask pair needed to accommodate the address and size request. + Returns < 0 on error and 0 on success. */ +int var_mtrr_set_with_cb(struct var_mtrr_context *ctx, + uintptr_t addr, size_t size, int type, + void (*callback)(const struct var_mtrr_context *ctx, + uintptr_t base_addr, size_t size, + msr_t base, msr_t mask)); +/* Same as var_mtrr_set_with_cb() but just write the MSRs directly. */ +int var_mtrr_set(struct var_mtrr_context *ctx, uintptr_t addr, size_t size, int type); + /* * Set the MTRRs using the data on the stack from setup_stack_and_mtrrs. * Return a new top_of_stack value which removes the setup_stack_and_mtrrs data. |