Nikolai Artemiev has uploaded this change for review.

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[RFC] writeprotect, cli_classic: delete old code, revise wp interface

This commit deletes most of the old writeprotect implementation as not
much of it can be adapted. It also revises the writeprotect interface to
increase consistency where possible and make it easier to expose through
libflashrom.

BUG=b:195381327,b:153800563
TEST=builds, all wp cmds tested at end of patch chain
BRANCH=none

Change-Id: I67e9b31f86465e5a8f7d3def637198671ee818a8
Signed-off-by: Nikolai Artemiev <nartemiev@google.com>
---
M cli_classic.c
M flash.h
M writeprotect.c
M writeprotect.h
4 files changed, 74 insertions(+), 423 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/74/58474/1
diff --git a/cli_classic.c b/cli_classic.c
index d69b798..447b3a0 100644
--- a/cli_classic.c
+++ b/cli_classic.c
@@ -128,6 +128,21 @@
return true;
}

+static int parse_wp_mode(const char *wp_mode_opt, enum wp_mode *mode)
+{
+ if (!wp_mode_opt || !strcasecmp("hardware", wp_mode_opt)) {
+ *mode = WP_MODE_HARDWARE;
+ } else if (!strcasecmp("power_cycle", wp_mode_opt)) {
+ *mode = WP_MODE_POWER_CYCLE;
+ } else if (!strcasecmp("permanent", wp_mode_opt)) {
+ *mode = WP_MODE_PERMANENT;
+ } else {
+ msg_gerr("Error: Invalid WP mode: \"%s\"\n", wp_mode_opt);
+ return 1;
+ }
+ return 0;
+}
+
static int parse_wp_range(unsigned int *start, unsigned int *len)
{
char *endptr = NULL, *token = NULL;
@@ -673,9 +688,12 @@
goto out_shutdown;
}

- if (!(read_it | write_it | verify_it | erase_it | flash_name | flash_size
- | set_wp_range | set_wp_region | set_wp_enable |
- set_wp_disable | wp_status | wp_list | extract_it)) {
+ bool any_wp_op =
+ set_wp_range | set_wp_region | set_wp_enable |
+ set_wp_disable | wp_status | wp_list;
+
+ if (!(read_it | write_it | verify_it | erase_it | flash_name | flash_size|
+ any_wp_op | extract_it)) {
msg_ginfo("No operations were specified.\n");
goto out_shutdown;
}
@@ -691,13 +709,10 @@
goto out_shutdown;
}

- struct wp *wp = fill_flash->chip->wp;
- if (set_wp_range || set_wp_region) {
- if (!wp || !wp->set_range) {
- msg_gerr("Error: write protect is not supported on this flash chip.\n");
- ret = 1;
- goto out_shutdown;
- }
+ if (any_wp_op && !wp_supported(fill_flash)) {
+ msg_gerr("Error: write protect is not supported on this flash chip.\n");
+ ret = 1;
+ goto out_shutdown;
}

if (flash_name) {
@@ -756,29 +771,19 @@
flashrom_layout_set(fill_flash, layout);

if (wp_status) {
- if (wp && wp->wp_status) {
- ret |= wp->wp_status(fill_flash);
- } else {
- msg_gerr("Error: write protect is not supported on this flash chip.\n");
- ret = 1;
- }
+ ret |= wp_print_status(fill_flash);
goto out_release;
}

/* Note: set_wp_disable should be done before setting the range */
if (set_wp_disable) {
- if (wp && wp->disable) {
- ret |= wp->disable(fill_flash);
- } else {
- msg_gerr("Error: write protect is not supported on this flash chip.\n");
- ret = 1;
- goto out_release;
- }
+ ret |= wp_set_mode(fill_flash, WP_MODE_DISABLED);
}

/* Note: set_wp_range must happen before set_wp_enable */
if (set_wp_range) {
- ret |= wp->set_range(fill_flash, wp_start, wp_len);
+ struct wp_range range = {0, wp_start, wp_len};
+ ret |= wp_set_range(fill_flash, range);
}

if (set_wp_region && wp_region) {
@@ -786,42 +791,23 @@
ret = 1;
goto out_release;
}
- ret |= wp->set_range(fill_flash, wp_start, wp_len);
- free(wp_region);
+ struct wp_range range = {0, wp_start, wp_len};
+ ret |= wp_set_range(fill_flash, range);
}

if (!ret && set_wp_enable) {
- enum wp_mode wp_mode;
-
- if (wp_mode_opt)
- wp_mode = get_wp_mode(wp_mode_opt);
- else
- wp_mode = WP_MODE_HARDWARE; /* default */
-
- if (wp_mode == WP_MODE_UNKNOWN) {
- msg_gerr("Error: Invalid WP mode: \"%s\"\n", wp_mode_opt);
+ enum wp_mode mode;
+ if (parse_wp_mode(wp_mode_opt, &mode)) {
ret = 1;
goto out_release;
}

- if (wp && wp->enable) {
- ret |= wp->enable(fill_flash, wp_mode);
- } else {
- msg_gerr("Error: write protect is not supported on this flash chip.\n");
- ret = 1;
- goto out_release;
- }
+ ret |= wp_set_mode(fill_flash, mode);
}

if (wp_list) {
msg_ginfo("Valid write protection ranges:\n");
- if (wp && wp->list_ranges) {
- ret |= wp->list_ranges(fill_flash);
- } else {
- msg_gerr("Error: write protect is not supported on this flash chip.\n");
- ret = 1;
- }
- goto out_release;
+ ret |= wp_list_ranges(fill_flash);
}

flashrom_flag_set(fill_flash, FLASHROM_FLAG_FORCE, !!force);
diff --git a/flash.h b/flash.h
index 3baa076..18e1a57 100644
--- a/flash.h
+++ b/flash.h
@@ -247,7 +247,6 @@
/* SPI specific options (TODO: Make it a union in case other bustypes get specific options.) */
uint8_t wrea_override; /**< override opcode for write extended address register */

- struct wp *wp;
};

typedef int (*chip_restore_fn_cb_t)(struct flashctx *flash, uint8_t status);
diff --git a/writeprotect.c b/writeprotect.c
index b26c121..1d907f6 100644
--- a/writeprotect.c
+++ b/writeprotect.c
@@ -15,380 +15,52 @@
*
*/

+#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#include <strings.h>

#include "flash.h"
-#include "flashchips.h"
#include "chipdrivers.h"
-#include "spi.h"
#include "writeprotect.h"

-/*
- * The following procedures rely on look-up tables to match the user-specified
- * range with the chip's supported ranges. This turned out to be the most
- * elegant approach since diferent flash chips use different levels of
- * granularity and methods to determine protected ranges. In other words,
- * be stupid and simple since clever arithmetic will not work for many chips.
- */
-
-struct wp_range {
- unsigned int start; /* starting address */
- unsigned int len; /* len */
-};
-
-enum bit_state {
- OFF = 0,
- ON = 1,
- X = -1 /* don't care. Must be bigger than max # of bp. */
-};
-
-/*
- * Generic write-protection schema for 25-series SPI flash chips. This assumes
- * there is a status register that contains one or more consecutive bits which
- * determine which address range is protected.
- */
-
-struct status_register_layout {
- int bp0_pos; /* position of BP0 */
- int bp_bits; /* number of block protect bits */
- int srp_pos; /* position of status register protect enable bit */
-};
-
-/*
- * The following ranges and functions are useful for representing the
- * writeprotect schema in which there are typically 5 bits of
- * relevant information stored in status register 1:
- * m.sec: This bit indicates the units (sectors vs. blocks)
- * m.tb: The top-bottom bit indicates if the affected range is at the top of
- * the flash memory's address space or at the bottom.
- * bp: Bitmask representing the number of affected sectors/blocks.
- */
-struct wp_range_descriptor {
- struct modifier_bits m;
- unsigned int bp; /* block protect bitfield */
- struct wp_range range;
-};
-
-struct wp_context {
- struct status_register_layout sr1; /* status register 1 */
- struct wp_range_descriptor *descrs;
-
- /*
- * Some chips store modifier bits in one or more special control
- * registers instead of the status register like many older SPI NOR
- * flash chips did. get_modifier_bits() and set_modifier_bits() will do
- * any chip-specific operations necessary to get/set these bit values.
- */
- int (*get_modifier_bits)(const struct flashctx *flash,
- struct modifier_bits *m);
- int (*set_modifier_bits)(const struct flashctx *flash,
- struct modifier_bits *m);
-};
-
-/*
- * Mask to extract write-protect enable and range bits
- * Status register 1:
- * SRP0: bit 7
- * range(BP2-BP0): bit 4-2
- * range(BP3-BP0): bit 5-2 (large chips)
- * Status register 2:
- * SRP1: bit 1
- */
-#define MASK_WP_AREA (0x9C)
-#define MASK_WP_AREA_LARGE (0x9C)
-#define MASK_WP2_AREA (0x01)
-
-static uint8_t do_read_status(const struct flashctx *flash)
+bool wp_supported(struct flashctx *flash)
{
- if (flash->chip->read_status)
- return flash->chip->read_status(flash);
- else
- return spi_read_status_register(flash);
+ /* TODO */
+ return false;
}

-static int do_write_status(const struct flashctx *flash, int status)
+int wp_get_range(struct flashctx *flash, struct wp_range *range)
{
- if (flash->chip->write_status)
- return flash->chip->write_status(flash, status);
- else
- return spi_write_status_register(flash, status);
+ /* TODO */
+ return 1;
}

-enum wp_mode get_wp_mode(const char *mode_str)
+int wp_set_range(struct flashctx *flash, const struct wp_range range)
{
- enum wp_mode wp_mode = WP_MODE_UNKNOWN;
-
- if (!strcasecmp(mode_str, "hardware"))
- wp_mode = WP_MODE_HARDWARE;
- else if (!strcasecmp(mode_str, "power_cycle"))
- wp_mode = WP_MODE_POWER_CYCLE;
- else if (!strcasecmp(mode_str, "permanent"))
- wp_mode = WP_MODE_PERMANENT;
-
- return wp_mode;
+ /* TODO */
+ return 1;
}

-/* Given a flash chip, this function returns its writeprotect info. */
-static int generic_range_table(const struct flashctx *flash,
- struct wp_context **wp,
- int *num_entries)
+int wp_get_mode(struct flashctx *flash, enum wp_mode *mode)
{
- *wp = NULL;
- *num_entries = 0;
-
- switch (flash->chip->manufacture_id) {
- default:
- msg_cerr("%s: flash vendor (0x%x) not found, aborting\n",
- __func__, flash->chip->manufacture_id);
- return -1;
- }
-
- return 0;
+ /* TODO */
+ return 1;
}

-static uint8_t generic_get_bp_mask(struct wp_context *wp)
+int wp_set_mode(struct flashctx *flash, enum wp_mode mode)
{
- return ((1 << (wp->sr1.bp0_pos + wp->sr1.bp_bits)) - 1) ^ \
- ((1 << wp->sr1.bp0_pos) - 1);
+ /* TODO */
+ return 1;
}

-static uint8_t generic_get_status_check_mask(struct wp_context *wp)
+int wp_list_ranges(struct flashctx *flash)
{
- return generic_get_bp_mask(wp) | 1 << wp->sr1.srp_pos;
+ /* TODO */
+ return 1;
}

-/* Given a [start, len], this function finds a block protect bit combination
- * (if possible) and sets the corresponding bits in "status". Remaining bits
- * are preserved. */
-static int generic_range_to_status(const struct flashctx *flash,
- unsigned int start, unsigned int len,
- uint8_t *status, uint8_t *check_mask)
+int wp_print_status(struct flashctx *flash)
{
- struct wp_context *wp;
- struct wp_range_descriptor *r;
- int i, range_found = 0, num_entries;
- uint8_t bp_mask;
-
- if (generic_range_table(flash, &wp, &num_entries))
- return -1;
-
- bp_mask = generic_get_bp_mask(wp);
-
- for (i = 0, r = &wp->descrs[0]; i < num_entries; i++, r++) {
- msg_cspew("comparing range 0x%x 0x%x / 0x%x 0x%x\n",
- start, len, r->range.start, r->range.len);
- if ((start == r->range.start) && (len == r->range.len)) {
- *status &= ~(bp_mask);
- *status |= r->bp << (wp->sr1.bp0_pos);
-
- if (wp->set_modifier_bits) {
- if (wp->set_modifier_bits(flash, &r->m) < 0) {
- msg_cerr("error setting modifier bits for range.\n");
- return -1;
- }
- }
-
- range_found = 1;
- break;
- }
- }
-
- if (!range_found) {
- msg_cerr("%s: matching range not found\n", __func__);
- return -1;
- }
-
- *check_mask = generic_get_status_check_mask(wp);
- return 0;
+ /* TODO */
+ return 1;
}
-
-static int generic_status_to_range(const struct flashctx *flash,
- const uint8_t sr1, unsigned int *start, unsigned int *len)
-{
- struct wp_context *wp;
- struct wp_range_descriptor *r;
- int num_entries, i, status_found = 0;
- uint8_t sr1_bp;
- struct modifier_bits m;
-
- if (generic_range_table(flash, &wp, &num_entries))
- return -1;
-
- /* modifier bits may be compared more than once, so get them here */
- if (wp->get_modifier_bits && wp->get_modifier_bits(flash, &m) < 0)
- return -1;
-
- sr1_bp = (sr1 >> wp->sr1.bp0_pos) & ((1 << wp->sr1.bp_bits) - 1);
-
- for (i = 0, r = &wp->descrs[0]; i < num_entries; i++, r++) {
- if (wp->get_modifier_bits) {
- if (memcmp(&m, &r->m, sizeof(m)))
- continue;
- }
- msg_cspew("comparing 0x%02x 0x%02x\n", sr1_bp, r->bp);
- if (sr1_bp == r->bp) {
- *start = r->range.start;
- *len = r->range.len;
- status_found = 1;
- break;
- }
- }
-
- if (!status_found) {
- msg_cerr("matching status not found\n");
- return -1;
- }
-
- return 0;
-}
-
-/* Given a [start, len], this function calls generic_range_to_status() to
- * convert it to flash-chip-specific range bits, then sets into status register.
- */
-static int generic_set_range(const struct flashctx *flash,
- unsigned int start, unsigned int len)
-{
- uint8_t status, expected, check_mask;
-
- status = do_read_status(flash);
- msg_cdbg("%s: old status: 0x%02x\n", __func__, status);
-
- expected = status; /* preserve non-bp bits */
- if (generic_range_to_status(flash, start, len, &expected, &check_mask))
- return -1;
-
- do_write_status(flash, expected);
-
- status = do_read_status(flash);
- msg_cdbg("%s: new status: 0x%02x\n", __func__, status);
- if ((status & check_mask) != (expected & check_mask)) {
- msg_cerr("expected=0x%02x, but actual=0x%02x. check mask=0x%02x\n",
- expected, status, check_mask);
- return 1;
- }
- return 0;
-}
-
-/* Set/clear the status regsiter write protect bit in SR1. */
-static int generic_set_srp0(const struct flashctx *flash, int enable)
-{
- uint8_t status, expected, check_mask;
- struct wp_context *wp;
- int num_entries;
-
- if (generic_range_table(flash, &wp, &num_entries))
- return -1;
-
- expected = do_read_status(flash);
- msg_cdbg("%s: old status: 0x%02x\n", __func__, expected);
-
- if (enable)
- expected |= 1 << wp->sr1.srp_pos;
- else
- expected &= ~(1 << wp->sr1.srp_pos);
-
- do_write_status(flash, expected);
-
- status = do_read_status(flash);
- msg_cdbg("%s: new status: 0x%02x\n", __func__, status);
-
- check_mask = generic_get_status_check_mask(wp);
- msg_cdbg("%s: check mask: 0x%02x\n", __func__, check_mask);
- if ((status & check_mask) != (expected & check_mask)) {
- msg_cerr("expected=0x%02x, but actual=0x%02x. check mask=0x%02x\n",
- expected, status, check_mask);
- return -1;
- }
-
- return 0;
-}
-
-static int generic_enable_writeprotect(const struct flashctx *flash,
- enum wp_mode wp_mode)
-{
- int ret;
-
- if (wp_mode != WP_MODE_HARDWARE) {
- msg_cerr("%s(): unsupported write-protect mode\n", __func__);
- return 1;
- }
-
- ret = generic_set_srp0(flash, 1);
- if (ret)
- msg_cerr("%s(): error=%d.\n", __func__, ret);
-
- return ret;
-}
-
-static int generic_disable_writeprotect(const struct flashctx *flash)
-{
- int ret;
-
- ret = generic_set_srp0(flash, 0);
- if (ret)
- msg_cerr("%s(): error=%d.\n", __func__, ret);
-
- return ret;
-}
-
-static int generic_list_ranges(const struct flashctx *flash)
-{
- struct wp_context *wp;
- struct wp_range_descriptor *r;
- int i, num_entries;
-
- if (generic_range_table(flash, &wp, &num_entries))
- return -1;
-
- r = &wp->descrs[0];
- for (i = 0; i < num_entries; i++) {
- msg_cinfo("start: 0x%06x, length: 0x%06x\n",
- r->range.start, r->range.len);
- r++;
- }
-
- return 0;
-}
-
-static int wp_context_status(const struct flashctx *flash)
-{
- uint8_t sr1;
- unsigned int start, len;
- int ret = 0;
- struct wp_context *wp;
- int num_entries, wp_en;
-
- if (generic_range_table(flash, &wp, &num_entries))
- return -1;
-
- sr1 = do_read_status(flash);
- wp_en = (sr1 >> wp->sr1.srp_pos) & 1;
-
- msg_cinfo("WP: status: 0x%04x\n", sr1);
- msg_cinfo("WP: status.srp0: %x\n", wp_en);
- /* FIXME: SRP1 is not really generic, but we probably should print
- * it anyway to have consistent output. #legacycruft */
- msg_cinfo("WP: status.srp1: %x\n", 0);
- msg_cinfo("WP: write protect is %s.\n",
- wp_en ? "enabled" : "disabled");
-
- msg_cinfo("WP: write protect range: ");
- if (generic_status_to_range(flash, sr1, &start, &len)) {
- msg_cinfo("(cannot resolve the range)\n");
- ret = -1;
- } else {
- msg_cinfo("start=0x%08x, len=0x%08x\n", start, len);
- }
-
- return ret;
-}
-
-struct wp wp_generic = {
- .list_ranges = generic_list_ranges,
- .set_range = generic_set_range,
- .enable = generic_enable_writeprotect,
- .disable = generic_disable_writeprotect,
- .wp_status = wp_context_status,
-};
diff --git a/writeprotect.h b/writeprotect.h
index bded4c8..db7f3aa 100644
--- a/writeprotect.h
+++ b/writeprotect.h
@@ -16,36 +16,30 @@
*/

#ifndef __WRITEPROTECT_H__
-#define __WRITEPROTECT_H__ 1
+#define __WRITEPROTECT_H__

enum wp_mode {
- WP_MODE_UNKNOWN = -1,
- WP_MODE_HARDWARE, /* hardware WP pin determines status */
- WP_MODE_POWER_CYCLE, /* WP active until power off/on cycle */
- WP_MODE_PERMANENT, /* status register permanently locked,
- WP permanently enabled */
+ WP_MODE_DISABLED,
+ WP_MODE_HARDWARE,
+ WP_MODE_POWER_CYCLE,
+ WP_MODE_PERMANENT,
};

-struct wp {
- int (*list_ranges)(const struct flashctx *flash);
- int (*set_range)(const struct flashctx *flash,
- unsigned int start, unsigned int len);
- int (*enable)(const struct flashctx *flash, enum wp_mode mode);
- int (*disable)(const struct flashctx *flash);
- int (*wp_status)(const struct flashctx *flash);
+struct wp_range {
+ uint32_t chip_len;
+ uint32_t start;
+ uint32_t len;
};

-extern struct wp wp_generic;
+bool wp_supported(struct flashctx *flash);

-enum wp_mode get_wp_mode(const char *mode_str);
+int wp_get_range(struct flashctx *flash, struct wp_range *range);
+int wp_set_range(struct flashctx *flash, struct wp_range range);

-/*
- * Generic write-protect stuff
- */
+int wp_get_mode(struct flashctx *flash, enum wp_mode *mode);
+int wp_set_mode(struct flashctx *flash, enum wp_mode mode);

-struct modifier_bits {
- int sec; /* if 1, bp bits describe sectors */
- int tb; /* value of top/bottom select bit */
-};
+int wp_list_ranges(struct flashctx *flash);
+int wp_print_status(struct flashctx *flash);

-#endif /* !__WRITEPROTECT_H__ */
+#endif

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Gerrit-Project: flashrom
Gerrit-Branch: master
Gerrit-Change-Id: I67e9b31f86465e5a8f7d3def637198671ee818a8
Gerrit-Change-Number: 58474
Gerrit-PatchSet: 1
Gerrit-Owner: Nikolai Artemiev <nartemiev@google.com>
Gerrit-MessageType: newchange