The following commit has been merged into the x86/mtrr branch of tip: Commit-ID: a4316603534cf7f4dcd9f9f1ed170257b987cca9 Gitweb: https://git.kernel.org/tip/a4316603534cf7f4dcd9f9f1ed170257b987cca9 Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Tue, 02 May 2023 14:09:27 +02:00 Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx> CommitterDate: Thu, 01 Jun 2023 15:04:33 +02:00 x86/mtrr: Add mtrr=debug command line option Add a new command line option "mtrr=debug" for getting debug output after building the new cache mode map. The output will include MTRR register values and the resulting map. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Tested-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230502120931.20719-13-jgross@xxxxxxxx Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> --- Documentation/admin-guide/kernel-parameters.txt | 4 +- arch/x86/kernel/cpu/mtrr/generic.c | 64 +++++++++++----- 2 files changed, 49 insertions(+), 19 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9e5bab2..44a87ad 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3423,6 +3423,10 @@ [HW] Make the MicroTouch USB driver use raw coordinates ('y', default) or cooked coordinates ('n') + mtrr=debug [X86] + Enable printing debug information related to MTRR + registers at boot time. + mtrr_chunk_size=nn[KMG] [X86] used for mtrr cleanup. It is largest continuous chunk that could hold holes aka. UC entries. diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index e0db6fc..852031e 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -41,6 +41,23 @@ struct cache_map { u64 fixed:1; }; +static bool mtrr_debug; + +static int __init mtrr_param_setup(char *str) +{ + int rc = 0; + + if (!str) + return -EINVAL; + if (!strcmp(str, "debug")) + mtrr_debug = true; + else + rc = -EINVAL; + + return rc; +} +early_param("mtrr", mtrr_param_setup); + /* * CACHE_MAP_MAX is the maximum number of memory ranges in cache_map, where * no 2 adjacent ranges have the same cache mode (those would be merged). @@ -515,6 +532,14 @@ void __init mtrr_build_map(void) pr_info("MTRR map: %u entries (%u fixed + %u variable; max %u), built from %u variable MTRRs\n", cache_map_n, cache_map_fixed, cache_map_n - cache_map_fixed, get_cache_map_size(), num_var_ranges + (mtrr_tom2 != 0)); + + if (mtrr_debug) { + for (i = 0; i < cache_map_n; i++) { + pr_info("%3u: %016llx-%016llx %s\n", i, + cache_map[i].start, cache_map[i].end - 1, + mtrr_attrib_to_str(cache_map[i].type)); + } + } } /* Copy the cache_map from __initdata memory to dynamically allocated one. */ @@ -721,8 +746,8 @@ static void __init print_fixed_last(void) if (!last_fixed_end) return; - pr_debug(" %05X-%05X %s\n", last_fixed_start, - last_fixed_end - 1, mtrr_attrib_to_str(last_fixed_type)); + pr_info(" %05X-%05X %s\n", last_fixed_start, + last_fixed_end - 1, mtrr_attrib_to_str(last_fixed_type)); last_fixed_end = 0; } @@ -760,10 +785,10 @@ static void __init print_mtrr_state(void) unsigned int i; int high_width; - pr_debug("MTRR default type: %s\n", - mtrr_attrib_to_str(mtrr_state.def_type)); + pr_info("MTRR default type: %s\n", + mtrr_attrib_to_str(mtrr_state.def_type)); if (mtrr_state.have_fixed) { - pr_debug("MTRR fixed ranges %sabled:\n", + pr_info("MTRR fixed ranges %sabled:\n", ((mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) && (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) ? "en" : "dis"); @@ -778,27 +803,27 @@ static void __init print_mtrr_state(void) /* tail */ print_fixed_last(); } - pr_debug("MTRR variable ranges %sabled:\n", - mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED ? "en" : "dis"); + pr_info("MTRR variable ranges %sabled:\n", + mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED ? "en" : "dis"); high_width = (boot_cpu_data.x86_phys_bits - (32 - PAGE_SHIFT) + 3) / 4; for (i = 0; i < num_var_ranges; ++i) { if (mtrr_state.var_ranges[i].mask_lo & MTRR_PHYSMASK_V) - pr_debug(" %u base %0*X%05X000 mask %0*X%05X000 %s\n", - i, - high_width, - mtrr_state.var_ranges[i].base_hi, - mtrr_state.var_ranges[i].base_lo >> 12, - high_width, - mtrr_state.var_ranges[i].mask_hi, - mtrr_state.var_ranges[i].mask_lo >> 12, - mtrr_attrib_to_str(mtrr_state.var_ranges[i].base_lo & + pr_info(" %u base %0*X%05X000 mask %0*X%05X000 %s\n", + i, + high_width, + mtrr_state.var_ranges[i].base_hi, + mtrr_state.var_ranges[i].base_lo >> 12, + high_width, + mtrr_state.var_ranges[i].mask_hi, + mtrr_state.var_ranges[i].mask_lo >> 12, + mtrr_attrib_to_str(mtrr_state.var_ranges[i].base_lo & MTRR_PHYSBASE_TYPE)); else - pr_debug(" %u disabled\n", i); + pr_info(" %u disabled\n", i); } if (mtrr_tom2) - pr_debug("TOM2: %016llx aka %lldM\n", mtrr_tom2, mtrr_tom2>>20); + pr_info("TOM2: %016llx aka %lldM\n", mtrr_tom2, mtrr_tom2>>20); } /* Grab all of the MTRR state for this CPU into *state */ @@ -833,7 +858,8 @@ bool __init get_mtrr_state(void) mtrr_tom2 &= 0xffffff800000ULL; } - print_mtrr_state(); + if (mtrr_debug) + print_mtrr_state(); mtrr_state_set = 1;