1 files changed, 299 insertions, 0 deletions

diff --git a/mboxd_flash.c b/mboxd_flash.c
new file mode 100644
index 0000000..5cd5868
--- /dev/null
+++ b/mboxd_flash.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (C) 2018 IBM Corp.
+
+#define _GNU_SOURCE
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <limits.h>
+#include <poll.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/timerfd.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <mtd/mtd-abi.h>
+
+#include "mbox.h"
+#include "common.h"
+#include "mboxd_flash.h"
+
+int init_flash_dev(struct mbox_context *context)
+{
+	char *filename = get_dev_mtd();
+	int fd, rc = 0;
+
+	if (!filename) {
+		MSG_ERR("Couldn't find the PNOR /dev/mtd partition\n");
+		return -1;
+	}
+
+	MSG_DBG("Opening %s\n", filename);
+
+	/* Open Flash Device */
+	fd = open(filename, O_RDWR);
+	if (fd < 0) {
+		MSG_ERR("Couldn't open %s with flags O_RDWR: %s\n",
+			filename, strerror(errno));
+		rc = -errno;
+		goto out;
+	}
+	context->fds[MTD_FD].fd = fd;
+
+	/* Read the Flash Info */
+	if (ioctl(fd, MEMGETINFO, &context->mtd_info) == -1) {
+		MSG_ERR("Couldn't get information about MTD: %s\n",
+			strerror(errno));
+		rc = -1;
+		goto out;
+	}
+
+	if (context->flash_size == 0) {
+		/*
+		 * PNOR images for current OpenPOWER systems are at most 64MB
+		 * despite the PNOR itself sometimes being as big as 128MB. To
+		 * ensure the image read from the PNOR is exposed in the LPC
+		 * address space at the location expected by the host firmware,
+		 * it is required that the image size be used for
+		 * context->flash_size, and not the size of the flash device.
+		 *
+		 * However, the test cases specify the flash size via special
+		 * test APIs (controlling flash behaviour) which don't have
+		 * access to the mbox context. Rather than requiring
+		 * error-prone assignments in every test case, we instead rely
+		 * on context->flash_size being set to the size reported by the
+		 * MEMINFO ioctl().
+		 *
+		 * As this case should never be hit in production (i.e. outside
+		 * the test environment), log an error. As a consequence, this
+		 * error is expected in the test case output.
+		 */
+		MSG_ERR("Flash size MUST be supplied on the commandline. However, continuing by assuming flash is %u bytes\n",
+				context->mtd_info.size);
+		context->flash_size = context->mtd_info.size;
+	}
+
+	/* We know the erase size so we can allocate the flash_erased bytemap */
+	context->erase_size_shift = log_2(context->mtd_info.erasesize);
+	context->flash_bmap = calloc(context->flash_size >>
+				     context->erase_size_shift,
+				     sizeof(*context->flash_bmap));
+	MSG_DBG("Flash erase size: 0x%.8x\n", context->mtd_info.erasesize);
+
+out:
+	free(filename);
+	return rc;
+}
+
+void free_flash_dev(struct mbox_context *context)
+{
+	free(context->flash_bmap);
+	close(context->fds[MTD_FD].fd);
+}
+
+/* Flash Functions */
+
+/*
+ * flash_is_erased() - Check if an offset into flash is erased
+ * @context:	The mbox context pointer
+ * @offset:	The flash offset to check (bytes)
+ *
+ * Return:	true if erased otherwise false
+ */
+static inline bool flash_is_erased(struct mbox_context *context,
+				   uint32_t offset)
+{
+	return context->flash_bmap[offset >> context->erase_size_shift]
+			== FLASH_ERASED;
+}
+
+/*
+ * set_flash_bytemap() - Set the flash erased bytemap
+ * @context:	The mbox context pointer
+ * @offset:	The flash offset to set (bytes)
+ * @count:	Number of bytes to set
+ * @val:	Value to set the bytemap to
+ *
+ * The flash bytemap only tracks the erased status at the erase block level so
+ * this will update the erased state for an (or many) erase blocks
+ *
+ * Return:	0 if success otherwise negative error code
+ */
+int set_flash_bytemap(struct mbox_context *context, uint32_t offset,
+		      uint32_t count, uint8_t val)
+{
+	if ((offset + count) > context->flash_size) {
+		return -MBOX_R_PARAM_ERROR;
+	}
+
+	MSG_DBG("Set flash bytemap @ 0x%.8x for 0x%.8x to %s\n",
+		offset, count, val ? "ERASED" : "DIRTY");
+	memset(context->flash_bmap + (offset >> context->erase_size_shift),
+	       val,
+	       align_up(count, 1 << context->erase_size_shift) >>
+	       context->erase_size_shift);
+
+	return 0;
+}
+
+/*
+ * erase_flash() - Erase the flash
+ * @context:	The mbox context pointer
+ * @offset:	The flash offset to erase (bytes)
+ * @size:	The number of bytes to erase
+ *
+ * Return:	0 on success otherwise negative error code
+ */
+int erase_flash(struct mbox_context *context, uint32_t offset, uint32_t count)
+{
+	const uint32_t erase_size = 1 << context->erase_size_shift;
+	struct erase_info_user erase_info = { 0 };
+	int rc;
+
+	MSG_DBG("Erase flash @ 0x%.8x for 0x%.8x\n", offset, count);
+
+	/*
+	 * We have an erased_bytemap for the flash so we want to avoid erasing
+	 * blocks which we already know to be erased. Look for runs of blocks
+	 * which aren't erased and erase the entire run at once to avoid how
+	 * often we have to call the erase ioctl. If the block is already
+	 * erased then there's nothing we need to do.
+	 */
+	while (count) {
+		if (!flash_is_erased(context, offset)) { /* Need to erase */
+			if (!erase_info.length) { /* Start of not-erased run */
+				erase_info.start = offset;
+			}
+			erase_info.length += erase_size;
+		} else if (erase_info.length) { /* Already erased|end of run? */
+			/* Erase the previous run which just ended */
+			MSG_DBG("Erase flash @ 0x%.8x for 0x%.8x\n",
+				erase_info.start, erase_info.length);
+			rc = ioctl(context->fds[MTD_FD].fd, MEMERASE,
+				   &erase_info);
+			if (rc < 0) {
+				MSG_ERR("Couldn't erase flash at 0x%.8x\n",
+						erase_info.start);
+				return -MBOX_R_SYSTEM_ERROR;
+			}
+			/* Mark ERASED where we just erased */
+			set_flash_bytemap(context, erase_info.start,
+					  erase_info.length, FLASH_ERASED);
+			erase_info.start = 0;
+			erase_info.length = 0;
+		}
+
+		offset += erase_size;
+		count -= erase_size;
+	}
+
+	if (erase_info.length) {
+		MSG_DBG("Erase flash @ 0x%.8x for 0x%.8x\n",
+			erase_info.start, erase_info.length);
+		rc = ioctl(context->fds[MTD_FD].fd, MEMERASE, &erase_info);
+		if (rc < 0) {
+			MSG_ERR("Couldn't erase flash at 0x%.8x\n",
+					erase_info.start);
+			return -MBOX_R_SYSTEM_ERROR;
+		}
+		/* Mark ERASED where we just erased */
+		set_flash_bytemap(context, erase_info.start, erase_info.length,
+				  FLASH_ERASED);
+	}
+
+	return 0;
+}
+
+#define CHUNKSIZE (64 * 1024)
+
+/*
+ * copy_flash() - Copy data from the flash device into a provided buffer
+ * @context:	The mbox context pointer
+ * @offset:	The flash offset to copy from (bytes)
+ * @mem:	The buffer to copy into (must be of atleast 'size' bytes)
+ * @size:	The number of bytes to copy
+ * Return:	Number of bytes copied on success, otherwise negative error
+ *		code. copy_flash will copy at most 'size' bytes, but it may
+ *		copy less.
+ */
+int64_t copy_flash(struct mbox_context *context, uint32_t offset, void *mem,
+		   uint32_t size)
+{
+	int32_t size_read;
+	void *start = mem;
+
+	MSG_DBG("Copy flash to %p for size 0x%.8x from offset 0x%.8x\n",
+		mem, size, offset);
+	if (lseek(context->fds[MTD_FD].fd, offset, SEEK_SET) != offset) {
+		MSG_ERR("Couldn't seek flash at pos: %u %s\n", offset,
+			strerror(errno));
+		return -MBOX_R_SYSTEM_ERROR;
+	}
+
+	do {
+		size_read = read(context->fds[MTD_FD].fd, mem,
+					  min_u32(CHUNKSIZE, size));
+		if (size_read < 0) {
+			MSG_ERR("Couldn't copy mtd into ram: %s\n",
+				strerror(errno));
+			return -MBOX_R_SYSTEM_ERROR;
+		}
+
+		size -= size_read;
+		mem += size_read;
+	} while (size && size_read);
+
+	return size_read ? mem - start : -MBOX_R_SYSTEM_ERROR;
+}
+
+/*
+ * write_flash() - Write the flash from a provided buffer
+ * @context:	The mbox context pointer
+ * @offset:	The flash offset to write to (bytes)
+ * @buf:	The buffer to write from (must be of atleast size)
+ * @size:	The number of bytes to write
+ *
+ * Return:	0 on success otherwise negative error code
+ */
+int write_flash(struct mbox_context *context, uint32_t offset, void *buf,
+		uint32_t count)
+{
+	uint32_t buf_offset = 0;
+	int rc;
+
+	MSG_DBG("Write flash @ 0x%.8x for 0x%.8x from %p\n", offset, count, buf);
+
+	if (lseek(context->fds[MTD_FD].fd, offset, SEEK_SET) != offset) {
+		MSG_ERR("Couldn't seek flash at pos: %u %s\n", offset,
+			strerror(errno));
+		return -MBOX_R_SYSTEM_ERROR;
+	}
+
+	while (count) {
+		rc = write(context->fds[MTD_FD].fd, buf + buf_offset, count);
+		if (rc < 0) {
+			MSG_ERR("Couldn't write to flash, write lost: %s\n",
+				strerror(errno));
+			return -MBOX_R_WRITE_ERROR;
+		}
+		/* Mark *NOT* erased where we just wrote */
+		set_flash_bytemap(context, offset + buf_offset, rc,
+				  FLASH_DIRTY);
+		count -= rc;
+		buf_offset += rc;
+	}
+
+	return 0;
+}