flashrom.c: Add functions for new erase selection algorithm

1) Add function to flatten out the addresses of the flash chip as per
the different erase functions. This function will return a list of
layouts which is dynamically allocated. So after use all the layouts as
well as the list itself should be freed. The free_erase_layout function
does that.

2) Add function to align start and end address of the region (in struct
walk_info) to some erase sector boundaries and modify the region start
and end addresses to match nearest erase sector boundaries. This
function will be used in the new algorithm for erase function selection.

3) Add function that returns a list of sectors (as seen by the first
erase function) that need erasing.

4) Add a function to call the erase algorithm.

Change-Id: Ic57ca1cca3d1646543f6b5939ba9c35db8d08256
Signed-off-by: Aarya Chaumal <aarya.chaumal@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/65844
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
Reviewed-by: Thomas Heijligen <src@posteo.de>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
---
M Makefile
A erasure_layout.c
A include/erasure_layout.h
M meson.build
4 files changed, 480 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 2ebd370..b37e807 100644
--- a/Makefile
+++ b/Makefile
@@ -388,7 +388,7 @@
 ###############################################################################
 # Library code.
 
-LIB_OBJS = libflashrom.o layout.o flashrom.o udelay.o parallel.o programmer.o programmer_table.o \
+LIB_OBJS = libflashrom.o layout.o erasure_layout.o flashrom.o udelay.o parallel.o programmer.o programmer_table.o \
 	helpers.o helpers_fileio.o ich_descriptors.o fmap.o platform/endian_$(ENDIAN).o platform/memaccess.o
 
 
diff --git a/erasure_layout.c b/erasure_layout.c
new file mode 100644
index 0000000..05376de
--- /dev/null
+++ b/erasure_layout.c
@@ -0,0 +1,406 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2022 Aarya Chaumal
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 <limits.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <string.h>
+
+#include "include/flash.h"
+#include "include/layout.h"
+#include "include/erasure_layout.h"
+
+static size_t calculate_block_count(const struct flashchip *chip, size_t eraser_idx)
+{
+	size_t block_count = 0;
+
+	chipoff_t addr = 0;
+	for (size_t i = 0; addr < chip->total_size * 1024; i++) {
+		const struct eraseblock *block = &chip->block_erasers[eraser_idx].eraseblocks[i];
+		block_count += block->count;
+		addr += block->size * block->count;
+	}
+
+	return block_count;
+}
+
+static void init_eraseblock(struct erase_layout *layout, size_t idx, size_t block_num,
+		chipoff_t start_addr, chipoff_t end_addr, size_t *sub_block_index)
+{
+	struct eraseblock_data *edata = &layout[idx].layout_list[block_num];
+	edata->start_addr = start_addr;
+	edata->end_addr = end_addr;
+	edata->selected = false;
+	edata->block_num = block_num;
+
+	if (!idx)
+		return;
+
+	edata->first_sub_block_index = *sub_block_index;
+	struct eraseblock_data *subedata = &layout[idx - 1].layout_list[*sub_block_index];
+	while (subedata->start_addr >= start_addr && subedata->end_addr <= end_addr &&
+		*sub_block_index < layout[idx-1].block_count) {
+		(*sub_block_index)++;
+		subedata++;
+	}
+	edata->last_sub_block_index = *sub_block_index - 1;
+}
+
+/*
+ * @brief Function to free the created erase_layout
+ *
+ * @param layout pointer to allocated layout
+ * @param erasefn_count number of erase functions for which the layout was created
+ *
+ */
+void free_erase_layout(struct erase_layout *layout, unsigned int erasefn_count)
+{
+	if (!layout)
+		return;
+	for (size_t i = 0; i < erasefn_count; i++) {
+		free(layout[i].layout_list);
+	}
+	free(layout);
+}
+
+/*
+ * @brief Function to create an erase layout
+ *
+ * @param	flashctx	flash context
+ * @param	e_layout	address to the pointer to store the layout
+ * @return	0 on success,
+ *		-1 if layout creation fails
+ *
+ * This function creates a layout of which erase functions erase which regions
+ * of the flash chip. This helps to optimally select the erase functions for
+ * erase/write operations.
+ */
+int create_erase_layout(struct flashctx *const flashctx, struct erase_layout **e_layout)
+{
+	const struct flashchip *chip = flashctx->chip;
+	const size_t erasefn_count = count_usable_erasers(flashctx);
+	struct erase_layout *layout = calloc(erasefn_count, sizeof(struct erase_layout));
+
+	if (!layout) {
+		msg_gerr("Out of memory!\n");
+		return -1;
+	}
+
+	if (!erasefn_count) {
+		msg_gerr("No erase functions supported\n");
+		return 0;
+	}
+
+	size_t layout_idx = 0;
+	for (size_t eraser_idx = 0; eraser_idx < NUM_ERASEFUNCTIONS; eraser_idx++) {
+		if (check_block_eraser(flashctx, eraser_idx, 0))
+			continue;
+
+		layout[layout_idx].eraser = &chip->block_erasers[eraser_idx];
+		const size_t block_count = calculate_block_count(flashctx->chip, eraser_idx);
+		size_t sub_block_index = 0;
+
+		layout[layout_idx].block_count = block_count;
+		layout[layout_idx].layout_list = (struct eraseblock_data *)calloc(block_count,
+									sizeof(struct eraseblock_data));
+
+		if (!layout[layout_idx].layout_list) {
+			free_erase_layout(layout, layout_idx);
+			return -1;
+		}
+
+		size_t block_num = 0;
+		chipoff_t start_addr = 0;
+
+		for (int i = 0; block_num < block_count;  i++) {
+			const struct eraseblock *block = &chip->block_erasers[eraser_idx].eraseblocks[i];
+
+			for (size_t num = 0; num < block->count; num++) {
+				chipoff_t end_addr = start_addr + block->size - 1;
+				init_eraseblock(layout, layout_idx, block_num,
+						start_addr, end_addr, &sub_block_index);
+				block_num += 1;
+				start_addr = end_addr + 1;
+			}
+		}
+		layout_idx++;
+	}
+
+	*e_layout = layout;
+	return layout_idx;
+}
+
+/*
+ * @brief	Function to align start and address of the region boundaries
+ *
+ * @param	layout	erase layout
+ * @param	flashctx	flash context
+ * @param	region_start	pointer to start address of the region to align
+ * @param	region_end	pointer to end address of the region to align
+ *
+ * This function aligns start and end address of the region (in struct walk_info)
+ * to some erase sector boundaries and modify the region start and end addresses
+ * to match nearest erase sector boundaries. This function will be used in the
+ * new algorithm for erase function selection.
+ */
+static void align_region(const struct erase_layout *layout, struct flashctx *const flashctx,
+			chipoff_t *region_start, chipoff_t *region_end)
+{
+	chipoff_t start_diff = UINT_MAX, end_diff = UINT_MAX;
+	const size_t erasefn_count = count_usable_erasers(flashctx);
+	for (size_t i = 0; i < erasefn_count; i++) {
+		for (size_t j = 0; j < layout[i].block_count; j++) {
+			const struct eraseblock_data *ll = &layout[i].layout_list[j];
+			if (ll->start_addr <= *region_start)
+				start_diff = (*region_start - ll->start_addr) > start_diff ?
+						start_diff : (*region_start - ll->start_addr);
+			if (ll->end_addr >= *region_end)
+				end_diff = (ll->end_addr - *region_end) > end_diff ?
+						end_diff : (ll->end_addr - *region_end);
+		}
+	}
+
+	if (start_diff) {
+		msg_cinfo("Region start not sector aligned! Extending start boundaries...\n");
+		*region_start = *region_start - start_diff;
+	}
+	if (end_diff) {
+		msg_cinfo("Region end not sector aligned! Extending end boundaries...\n");
+		*region_end = *region_end + end_diff;
+	}
+}
+
+/*
+ * @brief	Function to select the list of sectors that need erasing
+ *
+ * @param	flashctx	flash context
+ * @param	layout		erase layout
+ * @param	findex		index of the erase function
+ * @param	block_num	index of the block to erase according to the erase function index
+ * @param	curcontents	buffer containg the current contents of the flash
+ * @param	newcontents	buffer containg the new contents of the flash
+ * @param	rstart		start address of the region
+ * @rend	rend		end address of the region
+ */
+static void select_erase_functions(struct flashctx *flashctx, const struct erase_layout *layout,
+				size_t findex, size_t block_num, uint8_t *curcontents, uint8_t *newcontents,
+				chipoff_t rstart, chipoff_t rend)
+{
+	struct eraseblock_data *ll = &layout[findex].layout_list[block_num];
+	if (!findex) {
+		if (ll->start_addr >= rstart && ll->end_addr <= rend) {
+			chipoff_t start_addr = ll->start_addr;
+			chipoff_t end_addr = ll->end_addr;
+			const chipsize_t erase_len = end_addr - start_addr + 1;
+			const uint8_t erased_value = ERASED_VALUE(flashctx);
+			ll->selected = need_erase(curcontents + start_addr, newcontents + start_addr, erase_len,
+						flashctx->chip->gran, erased_value);
+		}
+	} else {
+		int count = 0;
+		const int sub_block_start = ll->first_sub_block_index;
+		const int sub_block_end = ll->last_sub_block_index;
+
+		for (int j = sub_block_start; j <= sub_block_end; j++) {
+			select_erase_functions(flashctx, layout, findex - 1, j, curcontents, newcontents,
+						rstart, rend);
+			if (layout[findex - 1].layout_list[j].selected)
+				count++;
+		}
+
+		const int total_blocks = sub_block_end - sub_block_start + 1;
+		if (count && count > total_blocks/2) {
+			if (ll->start_addr >= rstart && ll->end_addr <= rend) {
+				for (int j = sub_block_start; j <= sub_block_end; j++)
+					layout[findex - 1].layout_list[j].selected = false;
+				ll->selected = true;
+			}
+		}
+	}
+}
+
+/*
+ * @brief	wrapper to use the erase algorithm
+ *
+ * @param	flashctx	flash context
+ * @param	region_start	start address of the region
+ * @param	region_end	end address of the region
+ * @param       curcontents     buffer containg the current contents of the flash
+ * @param       newcontents     buffer containg the new contents of the flash
+ * @param	erase_layout	erase layout
+ * @param	all_skipped	pointer to the flag to chec if any block was erased
+ */
+int erase_write(struct flashctx *const flashctx, chipoff_t region_start, chipoff_t region_end,
+		uint8_t *curcontents, uint8_t *newcontents,
+		struct erase_layout *erase_layout, bool *all_skipped)
+{
+	const size_t erasefn_count = count_usable_erasers(flashctx);
+	int ret = 0;
+	size_t i;
+	chipoff_t old_start = region_start, old_end = region_end;
+	align_region(erase_layout, flashctx, &region_start, &region_end);
+
+	uint8_t *old_start_buf = NULL, *old_end_buf = NULL;
+	old_start_buf = (uint8_t *)malloc(old_start - region_start);
+	if (!old_start_buf) {
+		msg_cerr("Not enough memory!\n");
+		ret = -1;
+		goto _end;
+	}
+	old_end_buf = (uint8_t *)malloc(region_end - old_end);
+	if (!old_end_buf) {
+		msg_cerr("Not enough memory!\n");
+		ret = -1;
+		goto _end;
+	}
+
+	if (old_start - region_start) {
+		read_flash(flashctx, curcontents + region_start, region_start, old_start - region_start);
+		memcpy(old_start_buf, newcontents + region_start, old_start - region_start);
+		memcpy(newcontents + region_start, curcontents + region_start, old_start - region_start);
+	}
+	if (region_end - old_end) {
+		read_flash(flashctx, curcontents + old_end, old_end, region_end - old_end);
+		memcpy(old_end_buf, newcontents + old_end, region_end - old_end);
+		memcpy(newcontents + old_end, curcontents + old_end, region_end - old_end);
+	}
+
+	// select erase functions
+	for (i = 0; i < erase_layout[erasefn_count - 1].block_count; i++) {
+		if (erase_layout[erasefn_count - 1].layout_list[i].start_addr <= region_end &&
+			region_start <= erase_layout[erasefn_count - 1].layout_list[i].end_addr)
+			select_erase_functions(flashctx, erase_layout,
+						erasefn_count - 1, i,
+						curcontents, newcontents,
+						region_start, region_end);
+	}
+
+	for (i = 0; i < erasefn_count; i++) {
+		for (size_t j = 0; j < erase_layout[i].block_count; j++) {
+			if (!erase_layout[i].layout_list[j].selected)	continue;
+
+			// erase
+			chipoff_t start_addr = erase_layout[i].layout_list[j].start_addr;
+			unsigned int block_len = erase_layout[i].layout_list[j].end_addr - start_addr + 1;
+			const uint8_t erased_value = ERASED_VALUE(flashctx);
+			// execute erase
+			erasefunc_t *erasefn = lookup_erase_func_ptr(erase_layout[i].eraser);
+
+			if (!flashctx->flags.skip_unwritable_regions) {
+				if (check_for_unwritable_regions(flashctx, start_addr, block_len))
+					goto _end;
+			}
+
+			unsigned int len;
+			for (unsigned int addr = start_addr; addr < start_addr + block_len; addr += len) {
+				struct flash_region region;
+				get_flash_region(flashctx, addr, &region);
+
+				len = min(start_addr + block_len, region.end) - addr;
+
+				if (region.write_prot) {
+					msg_gdbg("%s: cannot erase inside %s "
+						"region (%#08x..%#08x), skipping range (%#08x..%#08x).\n",
+						 __func__, region.name,
+						 region.start, region.end - 1,
+						 addr, addr + len - 1);
+					free(region.name);
+					continue;
+				}
+
+				msg_gdbg("%s: %s region (%#08x..%#08x) is "
+					"writable, erasing range (%#08x..%#08x).\n",
+					 __func__, region.name,
+					 region.start, region.end - 1,
+					 addr, addr + len - 1);
+				free(region.name);
+
+				if (erasefn(flashctx, addr, len))
+					goto _end;
+				if (check_erased_range(flashctx, addr, len)) {
+					msg_cerr("ERASE FAILED!\n");
+					goto _end;
+				}
+			}
+
+			ret = erasefn(flashctx, start_addr, block_len);
+			if (ret) {
+				msg_cerr("Failed to execute erase command "
+					"for offset %#x to %#x.\n",
+					start_addr, start_addr + block_len);
+				ret = -1;
+				goto _end;
+			}
+
+			// adjust curcontents
+			memset(curcontents+start_addr, erased_value, block_len);
+			// after erase make it unselected again
+			erase_layout[i].layout_list[j].selected = false;
+			msg_cdbg("E(%x:%x)", start_addr, start_addr + block_len - 1);
+			// verify erase
+			ret = check_erased_range(flashctx, start_addr, block_len);
+			if (ret) {
+				msg_cerr("Verifying flash. Erase failed for range %#x : %#x, Abort.\n",
+					start_addr, start_addr + block_len - 1);
+				goto _end;
+			}
+
+			*all_skipped = false;
+		}
+	}
+
+	// write
+	unsigned int start_here = 0, len_here = 0, erase_len = region_end - region_start + 1;
+	while ((len_here = get_next_write(curcontents + region_start + start_here,
+					newcontents + region_start + start_here,
+					erase_len - start_here, &start_here,
+					flashctx->chip->gran))) {
+		// execute write
+		ret = write_flash(flashctx,
+				newcontents + region_start + start_here,
+				region_start + start_here, len_here);
+		if (ret) {
+			msg_cerr("Write failed at %#zx, Abort.\n", i);
+			ret = -1;
+			goto _end;
+		}
+
+		// adjust curcontents
+		memcpy(curcontents + region_start + start_here,
+			newcontents + region_start + start_here, len_here);
+		msg_cdbg("W(%x:%x)", region_start + start_here, region_start + start_here + len_here - 1);
+
+		*all_skipped = false;
+	}
+	// verify write
+	ret = verify_range(flashctx, newcontents + region_start, region_start, region_end - region_start);
+	if (ret) {
+		msg_cerr("Verifying flash. Write failed for range %#x : %#x, Abort.\n",
+			region_start, region_end);
+		goto _end;
+	}
+
+_end:
+	memcpy(newcontents + region_start, old_start_buf, old_start - region_start);
+	memcpy(newcontents + old_end, old_end_buf, region_end - old_end);
+
+	free(old_start_buf);
+	free(old_end_buf);
+
+	msg_cinfo("Erase/write done from %x to %x\n", region_start, region_end);
+	return ret;
+}
diff --git a/include/erasure_layout.h b/include/erasure_layout.h
new file mode 100644
index 0000000..b8b5f08
--- /dev/null
+++ b/include/erasure_layout.h
@@ -0,0 +1,41 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2022 Aarya Chaumal
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#ifndef __ERASURE_LAYOUT_H__
+#define __ERASURE_LAYOUT_H__ 1
+
+struct eraseblock_data {
+	chipoff_t start_addr;
+	chipoff_t end_addr;
+	bool selected;
+	size_t block_num;
+	size_t first_sub_block_index;
+	size_t last_sub_block_index;
+};
+
+struct erase_layout {
+	struct eraseblock_data* layout_list;
+	size_t block_count;
+	const struct block_eraser *eraser;
+};
+
+void free_erase_layout(struct erase_layout *layout, unsigned int erasefn_count);
+int create_erase_layout(struct flashctx *const flashctx, struct erase_layout **erase_layout);
+int erase_write(struct flashctx *const flashctx, chipoff_t region_start, chipoff_t region_end,
+		uint8_t* curcontents, uint8_t* newcontents,
+		struct erase_layout *erase_layout, bool *all_skipped);
+
+#endif		/* !__ERASURE_LAYOUT_H__ */
diff --git a/meson.build b/meson.build
index 57ac438..2575fe1 100644
--- a/meson.build
+++ b/meson.build
@@ -53,6 +53,7 @@
   'bitbang_spi.c',
   'edi.c',
   'en29lv640b.c',
+  'erasure_layout.c',
   'flashchips.c',
   'flashrom.c',
   'fmap.c',

