Re: [U-Boot] [PATCH 22/22] x86: Add an 'mtrr' command to list and adjust MTRRs

Hi Simon,

On Sun, Dec 28, 2014 at 10:20 AM, Simon Glass sjg@chromium.org wrote:

It is useful to be able to see the MTRR setup in U-Boot. Add a command to list the state of the variable MTRR registers and allow them to be changed.

Nice work! This will be a useful debug command.

Update the documentation to list some of the available commands.

This does not support fixed MTRRs as yet.

Signed-off-by: Simon Glass sjg@chromium.org

common/Makefile | 1 + common/cmd_mtrr.c | 138 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ doc/README.x86 | 18 ++++++- 3 files changed, 156 insertions(+), 1 deletion(-) create mode 100644 common/cmd_mtrr.c

diff --git a/common/Makefile b/common/Makefile index c668a2f..39e4e5f 100644 --- a/common/Makefile +++ b/common/Makefile @@ -135,6 +135,7 @@ obj-$(CONFIG_CMD_MMC) += cmd_mmc.o obj-$(CONFIG_CMD_MMC_SPI) += cmd_mmc_spi.o obj-$(CONFIG_MP) += cmd_mp.o obj-$(CONFIG_CMD_MTDPARTS) += cmd_mtdparts.o +obj-$(CONFIG_X86) += cmd_mtrr.o obj-$(CONFIG_CMD_NAND) += cmd_nand.o obj-$(CONFIG_CMD_NET) += cmd_net.o obj-$(CONFIG_CMD_ONENAND) += cmd_onenand.o diff --git a/common/cmd_mtrr.c b/common/cmd_mtrr.c new file mode 100644 index 0000000..7e0506b --- /dev/null +++ b/common/cmd_mtrr.c

Should we put cmd_mtrr.c to arch/x86/lib?

@@ -0,0 +1,138 @@ +/*

• • (C) Copyright 2014 Google, Inc
• • SPDX-License-Identifier: GPL-2.0+
• */

+#include <common.h> +#include <asm/msr.h> +#include <asm/mtrr.h>

+static const char *const mtrr_type_name[MTRR_TYPE_COUNT] = {

•   "Uncacheable",
  

•   "Combine",
  

•   "2",
  

•   "3",
  

•   "Through",
  

•   "Protect",
  

•   "Back",
  

+};

+static int do_mtrr_list(void) +{

•   int i;
  

•   printf("Reg Valid Write-type   %-16s %-16s %-16s\n", "Base   ||",
  

•          "Mask   ||", "Size   ||");
  

•   for (i = 0; i < MTRR_COUNT; i++) {
  

•           const char *type = "Invalid";
  

•           uint64_t base, mask, size;
  

•           bool valid;
  

•           base = native_read_msr(MTRR_PHYS_BASE_MSR(i));
  

•           mask = native_read_msr(MTRR_PHYS_MASK_MSR(i));
  

•           size = ~mask & ((1ULL << CONFIG_CPU_ADDR_BITS) - 1);
  

•           size |= (1 << 12) - 1;
  

•           size += 1;
  

•           valid = mask & MTRR_PHYS_MASK_VALID;
  

•           type = mtrr_type_name[base & MTRR_BASE_TYPE_MASK];
  

•           printf("%d   %-5s %-12s %016llx %016llx %016llx\n", i,
  

•                  valid ? "Y" : "N", type, base, mask, size);
  

•   }
  

•   return 0;
  

+}

+static int do_mtrr_set(uint reg, int argc, char * const argv[]) +{

•   const char *typename = argv[0];
  

•   struct mtrr_state state;
  

•   uint32_t start, size;
  

•   uint64_t base, mask;
  

•   int i, type = -1;
  

•   bool valid;
  

•   if (argc < 3)
  

•           return CMD_RET_USAGE;
  

•   for (i = 0; i < MTRR_TYPE_COUNT; i++) {
  

•           if (*typename == *mtrr_type_name[i])
  

•                   type = i;
  

•   }
  

•   if (type == -1) {
  

•           printf("Invalid type name %s\n", typename);
  

•           return CMD_RET_USAGE;
  

•   }
  

•   start = simple_strtoul(argv[1], NULL, 16);
  

•   size = simple_strtoul(argv[2], NULL, 16);
  

•   base = start | type;
  

•   valid = native_read_msr(MTRR_PHYS_MASK_MSR(reg)) & MTRR_PHYS_MASK_VALID;
  

•   mask = ~((uint64_t)size - 1);
  

•   mask &= (1ULL << CONFIG_CPU_ADDR_BITS) - 1;
  

•   if (valid)
  

•           mask |= MTRR_PHYS_MASK_VALID;
  

•   printf("base=%llx, mask=%llx\n", base, mask);
  

•   mtrr_open(&state);
  

•   wrmsrl(MTRR_PHYS_BASE_MSR(reg), base);
  

•   wrmsrl(MTRR_PHYS_MASK_MSR(reg), mask);
  

•   mtrr_close(&state);
  

•   return 0;
  

+}

+static int mtrr_set_valid(int reg, bool valid) +{

•   struct mtrr_state state;
  

•   uint64_t mask;
  

•   mtrr_open(&state);
  

•   mask = native_read_msr(MTRR_PHYS_MASK_MSR(reg));
  

•   if (valid)
  

•           mask |= MTRR_PHYS_MASK_VALID;
  

•   else
  

•           mask &= ~MTRR_PHYS_MASK_VALID;
  

•   wrmsrl(MTRR_PHYS_MASK_MSR(reg), mask);
  

•   mtrr_close(&state);
  

•   return 0;
  

+}

+static int do_mtrr(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) +{

•   const char *cmd;
  

•   uint reg;
  

•   cmd = argv[1];
  

•   if (argc < 2 || *cmd == 'l')
  

•           return do_mtrr_list();
  

•   argc -= 2;
  

•   argv += 2;
  

•   if (argc <= 0)
  

•           return CMD_RET_USAGE;
  

•   reg = simple_strtoul(argv[0], NULL, 16);
  

•   if (reg >= MTRR_COUNT) {
  

•           printf("Invalid register number\n");
  

•           return CMD_RET_USAGE;
  

•   }
  

•   if (*cmd == 'e')
  

•           return mtrr_set_valid(reg, true);
  

•   else if (*cmd == 'd')
  

•           return mtrr_set_valid(reg, false);
  

•   else if (*cmd == 's')
  

•           return do_mtrr_set(reg, argc - 1, argv + 1);
  

•   else
  

•           return CMD_RET_USAGE;
  

•   return 0;
  

+}

+U_BOOT_CMD(

•   mtrr,   6,      1,      do_mtrr,
  

•   "Use x86 memory type range registers (32-bit only)",
  

•   "[list]        - list current registers\n"
  

•   "set <reg> <type> <start> <size>   - set a register\n"
  

•   "\t<type> is Uncacheable, Combine, Through, Protect, Back\n"
  

•   "disable <reg>      - disable a register\n"
  

•   "ensable <reg>      - enable a register"
  

+); diff --git a/doc/README.x86 b/doc/README.x86 index 5fab044..6fbfb90 100644 --- a/doc/README.x86 +++ b/doc/README.x86 @@ -110,9 +110,25 @@ be turned on. Not every device on the board is configured via devie tree, but more and more devices will be added as time goes by. Check out the directory arch/x86/dts/ for these device tree source files.

+Useful Commands +---------------

+In keeping with the U-Boot philosophy of providing functions to check and +adjust internal settings, there are several x86-specific commands that may be +useful:

+hob - Display information about Firmware Support Package (FSP) Hand-off

•    Block. This is only available on platform which use FSP, mostly
  

use -> uses

•    Atom.
  

+iod - Display I/O memory +iow - Write I/O memory +mtrr - List and set the Memory Type Range Registers (MTRR). These are used to

•    tell the CPU whether memory is cacheable and if so the cache write
  

•    mode to use. U-Boot sets up some reasonable values but you can
  

•    adjust then with this command.
  

TODO List

-- MTRR support (for performance)

• Audio
• Chrome OS verified boot
• SMI and ACPI support, to provide platform info and facilities to Linux

--

Regards, Bin