soc/intel/common: Enable support to write protect SPI flash range

Write-protect SPI flash range provided by caller by using a free Flash
Protected Range (FPR) register. This expects SoC to define a callback
for providing information about the first FPR register address and
maximum number of FPRs supported.

BUG=chrome-os-partner:58896

Change-Id: I4e34ede8784e5587a5e08ffa10e20d2d14e20add
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/17115
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
This commit is contained in:
Furquan Shaikh 2016-10-24 15:23:40 -07:00 committed by Furquan Shaikh
parent 5817a15557
commit aedbfc8f09
5 changed files with 117 additions and 1 deletions

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@ -9,6 +9,10 @@ config CACHE_MRC_SETTINGS
bool "Save cached MRC settings"
default n
config SOC_INTEL_COMMON_SPI_PROTECT
bool
default n
if CACHE_MRC_SETTINGS
config MRC_SETTINGS_CACHE_BASE

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@ -19,6 +19,7 @@ postcar-y += util.c
ramstage-y += hda_verb.c
ramstage-$(CONFIG_CACHE_MRC_SETTINGS) += mrc_cache.c
ramstage-$(CONFIG_CACHE_MRC_SETTINGS) += nvm.c
ramstage-$(CONFIG_SOC_INTEL_COMMON_SPI_PROTECT) += spi.c
ramstage-$(CONFIG_SOC_INTEL_COMMON_LPSS_I2C) += lpss_i2c.c
ramstage-$(CONFIG_SOC_INTEL_COMMON_RESET) += reset.c
ramstage-y += util.c

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@ -20,9 +20,9 @@
#include <string.h>
#include <spi-generic.h>
#include <spi_flash.h>
#include <soc/spi.h>
#include <vendorcode/google/chromeos/chromeos.h>
#include "nvm.h"
#include "spi.h"
/* This module assumes the flash is memory mapped just below 4GiB in the
* address space for reading. Also this module assumes an area it erased

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@ -0,0 +1,66 @@
/*
* This file is part of the coreboot project.
*
* Copyright 2016 Google Inc.
*
* 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.
*/
#include <arch/io.h>
#include <console/console.h>
#include "spi.h"
/*
* Protect range of SPI flash defined by [start, start+size-1] using Flash
* Protected Range (FPR) register if available.
*/
int spi_flash_protect(u32 start, u32 size)
{
struct fpr_info fpr_info;
u32 end = start + size - 1;
u32 reg;
int fpr;
uintptr_t fpr_base;
if (spi_get_fpr_info(&fpr_info) == -1) {
printk(BIOS_ERR, "ERROR: FPR Info not found!\n");
return -1;
}
fpr_base = fpr_info.base;
/* Find first empty FPR */
for (fpr = 0; fpr < fpr_info.max; fpr++) {
reg = read32((void *)fpr_base);
if (reg == 0)
break;
fpr_base += sizeof(uint32_t);
}
if (fpr >= fpr_info.max) {
printk(BIOS_ERR, "ERROR: No SPI FPR free!\n");
return -1;
}
/* Set protected range base and limit */
reg = SPI_FPR(start, end) | SPI_FPR_WPE;
/* Set the FPR register and verify it is protected */
write32((void *)fpr_base, reg);
reg = read32((void *)fpr_base);
if (!(reg & SPI_FPR_WPE)) {
printk(BIOS_ERR, "ERROR: Unable to set SPI FPR %d\n", fpr);
return -1;
}
printk(BIOS_INFO, "%s: FPR %d is enabled for range 0x%08x-0x%08x\n",
__func__, fpr, start, end);
return 0;
}

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@ -0,0 +1,45 @@
/*
* This file is part of the coreboot project.
*
* Copyright 2016 Google Inc.
*
* 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.
*/
#define SPI_FPR_SHIFT 12
#define SPI_FPR_MASK 0x7fff
#define SPI_FPR_BASE_SHIFT 0
#define SPI_FPR_LIMIT_SHIFT 16
#define SPI_FPR_RPE (1 << 15) /* Read Protect */
#define SPI_FPR_WPE (1 << 31) /* Write Protect */
#define SPI_FPR(base, limit) \
(((((limit) >> SPI_FPR_SHIFT) & SPI_FPR_MASK) << SPI_FPR_LIMIT_SHIFT) |\
((((base) >> SPI_FPR_SHIFT) & SPI_FPR_MASK) << SPI_FPR_BASE_SHIFT))
struct fpr_info {
/* Offset of first FPR register */
uintptr_t base;
/* Maximum number of FPR registers */
uint8_t max;
};
/*
* SoC is expected to implement this function to provide address of first FPR
* register and max count of FPR registers.
*
* On success return 0 else -1.
*/
int spi_get_fpr_info(struct fpr_info *info);
/*
* Protect range of SPI flash defined by [start, start+size-1] using Flash
* Protected Range (FPR) register if available.
*/
int spi_flash_protect(u32 start, u32 size);