copy mass_storage driver from Kernel as initial version

Copy the mass_storage driver from Kernel source as initial version
of Motorola mass storage base.

Change-Id: I0d95b47de5c1463164843d9e8cebce06e9492e52
Signed-off-by: yanyh2 <yanyh2@motorola.com>
Reviewed-on: https://gerrit.mot.com/2053805
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Xiaojun Ji <jixj@motorola.com>
Reviewed-by: Jianqi Yang <yangj@motorola.com>
Reviewed-by: Yuecai Liu <liuyc20@motorola.com>
Submit-Approved: Jira Key

drivers/moto_f_mass_storage/Android.mk

@@ -0,0 +1,8 @@
+DLKM_DIR := motorola/kernel/modules
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := moto_f_mass_storage.ko
+LOCAL_MODULE_TAGS := optional
+LOCAL_MODULE_PATH := $(KERNEL_MODULES_OUT)
+include $(DLKM_DIR)/AndroidKernelModule.mk

drivers/moto_f_mass_storage/Kbuild

@@ -0,0 +1,6 @@
+# add -Wall to try to catch everything we can.
+EXTRA_CFLAGS += -Wall
+EXTRA_CFLAGS += -I$(ANDROID_BUILD_TOP)/motorola/kernel/modules/include
+
+moto_f_mass_storage-objs += f_mass_storage.o storage_common.o
+obj-m += moto_f_mass_storage.o

drivers/moto_f_mass_storage/Makefile

@@ -0,0 +1,14 @@
+all: modules
+
+modules:
+	$(MAKE) -C $(KERNEL_SRC) M=$(M) modules $(KBUILD_OPTIONS)
+
+modules_install:
+	$(MAKE) INSTALL_MOD_STRIP=1 -C $(KERNEL_SRC) M=$(M) modules_install
+
+%:
+	$(MAKE) -C $(KERNEL_SRC) M=$(M) $@ $(KBUILD_OPTIONS)
+
+clean:
+	rm -f *.o *.ko *.mod.c *.mod.o *~ .*.cmd Module.symvers
+	rm -rf .tmp_versions

drivers/moto_f_mass_storage/f_mass_storage.h

@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef USB_F_MASS_STORAGE_H
+#define USB_F_MASS_STORAGE_H
+
+#include <linux/usb/composite.h>
+#include "storage_common.h"
+
+struct fsg_module_parameters {
+	char		*file[FSG_MAX_LUNS];
+	bool		ro[FSG_MAX_LUNS];
+	bool		removable[FSG_MAX_LUNS];
+	bool		cdrom[FSG_MAX_LUNS];
+	bool		nofua[FSG_MAX_LUNS];
+
+	unsigned int	file_count, ro_count, removable_count, cdrom_count;
+	unsigned int	nofua_count;
+	unsigned int	luns;	/* nluns */
+	bool		stall;	/* can_stall */
+};
+
+#define _FSG_MODULE_PARAM_ARRAY(prefix, params, name, type, desc)	\
+	module_param_array_named(prefix ## name, params.name, type,	\
+				 &prefix ## params.name ## _count,	\
+				 S_IRUGO);				\
+	MODULE_PARM_DESC(prefix ## name, desc)
+
+#define _FSG_MODULE_PARAM(prefix, params, name, type, desc)		\
+	module_param_named(prefix ## name, params.name, type,		\
+			   S_IRUGO);					\
+	MODULE_PARM_DESC(prefix ## name, desc)
+
+#define __FSG_MODULE_PARAMETERS(prefix, params)				\
+	_FSG_MODULE_PARAM_ARRAY(prefix, params, file, charp,		\
+				"names of backing files or devices");	\
+	_FSG_MODULE_PARAM_ARRAY(prefix, params, ro, bool,		\
+				"true to force read-only");		\
+	_FSG_MODULE_PARAM_ARRAY(prefix, params, removable, bool,	\
+				"true to simulate removable media");	\
+	_FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool,		\
+				"true to simulate CD-ROM instead of disk"); \
+	_FSG_MODULE_PARAM_ARRAY(prefix, params, nofua, bool,		\
+				"true to ignore SCSI WRITE(10,12) FUA bit"); \
+	_FSG_MODULE_PARAM(prefix, params, luns, uint,			\
+			  "number of LUNs");				\
+	_FSG_MODULE_PARAM(prefix, params, stall, bool,			\
+			  "false to prevent bulk stalls")
+
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+
+#define FSG_MODULE_PARAMETERS(prefix, params)				\
+	__FSG_MODULE_PARAMETERS(prefix, params);			\
+	module_param_named(num_buffers, fsg_num_buffers, uint, S_IRUGO);\
+	MODULE_PARM_DESC(num_buffers, "Number of pipeline buffers")
+#else
+
+#define FSG_MODULE_PARAMETERS(prefix, params)				\
+	__FSG_MODULE_PARAMETERS(prefix, params)
+
+#endif
+
+struct fsg_common;
+
+/* FSF callback functions */
+struct fsg_lun_opts {
+	struct config_group group;
+	struct fsg_lun *lun;
+	int lun_id;
+};
+
+struct fsg_opts {
+	struct fsg_common *common;
+	struct usb_function_instance func_inst;
+	struct fsg_lun_opts lun0;
+	struct config_group *default_groups[2];
+	bool no_configfs; /* for legacy gadgets */
+
+	/*
+	 * Read/write access to configfs attributes is handled by configfs.
+	 *
+	 * This is to protect the data from concurrent access by read/write
+	 * and create symlink/remove symlink.
+	 */
+	struct mutex			lock;
+	int				refcnt;
+};
+
+struct fsg_lun_config {
+	const char *filename;
+	char ro;
+	char removable;
+	char cdrom;
+	char nofua;
+	char inquiry_string[INQUIRY_STRING_LEN];
+};
+
+struct fsg_config {
+	unsigned nluns;
+	struct fsg_lun_config luns[FSG_MAX_LUNS];
+
+	/* Callback functions. */
+	const struct fsg_operations	*ops;
+	/* Gadget's private data. */
+	void			*private_data;
+
+	const char *vendor_name;		/*  8 characters or less */
+	const char *product_name;		/* 16 characters or less */
+
+	char			can_stall;
+	unsigned int		fsg_num_buffers;
+};
+
+static inline struct fsg_opts *
+fsg_opts_from_func_inst(const struct usb_function_instance *fi)
+{
+	return container_of(fi, struct fsg_opts, func_inst);
+}
+
+void fsg_common_set_sysfs(struct fsg_common *common, bool sysfs);
+
+int fsg_common_set_num_buffers(struct fsg_common *common, unsigned int n);
+
+void fsg_common_free_buffers(struct fsg_common *common);
+
+int fsg_common_set_cdev(struct fsg_common *common,
+			struct usb_composite_dev *cdev, bool can_stall);
+
+void fsg_common_remove_lun(struct fsg_lun *lun);
+
+void fsg_common_remove_luns(struct fsg_common *common);
+
+int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
+			  unsigned int id, const char *name,
+			  const char **name_pfx);
+
+int fsg_common_create_luns(struct fsg_common *common, struct fsg_config *cfg);
+
+void fsg_common_set_inquiry_string(struct fsg_common *common, const char *vn,
+				   const char *pn);
+
+void fsg_config_from_params(struct fsg_config *cfg,
+			    const struct fsg_module_parameters *params,
+			    unsigned int fsg_num_buffers);
+
+#endif /* USB_F_MASS_STORAGE_H */

drivers/moto_f_mass_storage/storage_common.c

@@ -0,0 +1,522 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * storage_common.c -- Common definitions for mass storage functionality
+ *
+ * Copyright (C) 2003-2008 Alan Stern
+ * Copyeight (C) 2009 Samsung Electronics
+ * Author: Michal Nazarewicz (mina86@mina86.com)
+ */
+
+/*
+ * This file requires the following identifiers used in USB strings to
+ * be defined (each of type pointer to char):
+ *  - fsg_string_interface    -- name of the interface
+ */
+
+/*
+ * When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
+ * sets the number of pipeline buffers (length of the fsg_buffhd array).
+ * The valid range of num_buffers is: num >= 2 && num <= 4.
+ */
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/usb/composite.h>
+
+#include "storage_common.h"
+
+/* There is only one interface. */
+
+struct usb_interface_descriptor fsg_intf_desc = {
+	.bLength =		sizeof fsg_intf_desc,
+	.bDescriptorType =	USB_DT_INTERFACE,
+
+	.bNumEndpoints =	2,		/* Adjusted during fsg_bind() */
+	.bInterfaceClass =	USB_CLASS_MASS_STORAGE,
+	.bInterfaceSubClass =	USB_SC_SCSI,	/* Adjusted during fsg_bind() */
+	.bInterfaceProtocol =	USB_PR_BULK,	/* Adjusted during fsg_bind() */
+	.iInterface =		FSG_STRING_INTERFACE,
+};
+EXPORT_SYMBOL_GPL(fsg_intf_desc);
+
+/*
+ * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
+ * interrupt-in.
+ */
+
+struct usb_endpoint_descriptor fsg_fs_bulk_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	/* wMaxPacketSize set by autoconfiguration */
+};
+EXPORT_SYMBOL_GPL(fsg_fs_bulk_in_desc);
+
+struct usb_endpoint_descriptor fsg_fs_bulk_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	/* wMaxPacketSize set by autoconfiguration */
+};
+EXPORT_SYMBOL_GPL(fsg_fs_bulk_out_desc);
+
+struct usb_descriptor_header *fsg_fs_function[] = {
+	(struct usb_descriptor_header *) &fsg_intf_desc,
+	(struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
+	(struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
+	NULL,
+};
+EXPORT_SYMBOL_GPL(fsg_fs_function);
+
+
+/*
+ * USB 2.0 devices need to expose both high speed and full speed
+ * descriptors, unless they only run at full speed.
+ *
+ * That means alternate endpoint descriptors (bigger packets).
+ */
+struct usb_endpoint_descriptor fsg_hs_bulk_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+EXPORT_SYMBOL_GPL(fsg_hs_bulk_in_desc);
+
+struct usb_endpoint_descriptor fsg_hs_bulk_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+	.bInterval =		1,	/* NAK every 1 uframe */
+};
+EXPORT_SYMBOL_GPL(fsg_hs_bulk_out_desc);
+
+
+struct usb_descriptor_header *fsg_hs_function[] = {
+	(struct usb_descriptor_header *) &fsg_intf_desc,
+	(struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
+	(struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
+	NULL,
+};
+EXPORT_SYMBOL_GPL(fsg_hs_function);
+
+struct usb_endpoint_descriptor fsg_ss_bulk_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_desc);
+
+struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
+	.bLength =		sizeof(fsg_ss_bulk_in_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+
+	/*.bMaxBurst =		DYNAMIC, */
+};
+EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_comp_desc);
+
+struct usb_endpoint_descriptor fsg_ss_bulk_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_desc);
+
+struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
+	.bLength =		sizeof(fsg_ss_bulk_in_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+
+	/*.bMaxBurst =		DYNAMIC, */
+};
+EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_comp_desc);
+
+struct usb_descriptor_header *fsg_ss_function[] = {
+	(struct usb_descriptor_header *) &fsg_intf_desc,
+	(struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
+	(struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
+	(struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
+	(struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
+	NULL,
+};
+EXPORT_SYMBOL_GPL(fsg_ss_function);
+
+
+ /*-------------------------------------------------------------------------*/
+
+/*
+ * If the next two routines are called while the gadget is registered,
+ * the caller must own fsg->filesem for writing.
+ */
+
+void fsg_lun_close(struct fsg_lun *curlun)
+{
+	if (curlun->filp) {
+		LDBG(curlun, "close backing file\n");
+		fput(curlun->filp);
+		curlun->filp = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(fsg_lun_close);
+
+int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
+{
+	int				ro;
+	struct file			*filp = NULL;
+	int				rc = -EINVAL;
+	struct inode			*inode = NULL;
+	loff_t				size;
+	loff_t				num_sectors;
+	loff_t				min_sectors;
+	unsigned int			blkbits;
+	unsigned int			blksize;
+
+	/* R/W if we can, R/O if we must */
+	ro = curlun->initially_ro;
+	if (!ro) {
+		filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
+		if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
+			ro = 1;
+	}
+	if (ro)
+		filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
+	if (IS_ERR(filp)) {
+		LINFO(curlun, "unable to open backing file: %s\n", filename);
+		return PTR_ERR(filp);
+	}
+
+	if (!(filp->f_mode & FMODE_WRITE))
+		ro = 1;
+
+	inode = file_inode(filp);
+	if ((!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
+		LINFO(curlun, "invalid file type: %s\n", filename);
+		goto out;
+	}
+
+	/*
+	 * If we can't read the file, it's no good.
+	 * If we can't write the file, use it read-only.
+	 */
+	if (!(filp->f_mode & FMODE_CAN_READ)) {
+		LINFO(curlun, "file not readable: %s\n", filename);
+		goto out;
+	}
+	if (!(filp->f_mode & FMODE_CAN_WRITE))
+		ro = 1;
+
+	size = i_size_read(inode->i_mapping->host);
+	if (size < 0) {
+		LINFO(curlun, "unable to find file size: %s\n", filename);
+		rc = (int) size;
+		goto out;
+	}
+
+	if (curlun->cdrom) {
+		blksize = 2048;
+		blkbits = 11;
+	} else if (inode->i_bdev) {
+		blksize = bdev_logical_block_size(inode->i_bdev);
+		blkbits = blksize_bits(blksize);
+	} else {
+		blksize = 512;
+		blkbits = 9;
+	}
+
+	num_sectors = size >> blkbits; /* File size in logic-block-size blocks */
+	min_sectors = 1;
+	if (curlun->cdrom) {
+		min_sectors = 300;	/* Smallest track is 300 frames */
+		if (num_sectors >= 256*60*75) {
+			num_sectors = 256*60*75 - 1;
+			LINFO(curlun, "file too big: %s\n", filename);
+			LINFO(curlun, "using only first %d blocks\n",
+					(int) num_sectors);
+		}
+	}
+	if (num_sectors < min_sectors) {
+		LINFO(curlun, "file too small: %s\n", filename);
+		rc = -ETOOSMALL;
+		goto out;
+	}
+
+	if (fsg_lun_is_open(curlun))
+		fsg_lun_close(curlun);
+
+	curlun->blksize = blksize;
+	curlun->blkbits = blkbits;
+	curlun->ro = ro;
+	curlun->filp = filp;
+	curlun->file_length = size;
+	curlun->num_sectors = num_sectors;
+	LDBG(curlun, "open backing file: %s\n", filename);
+	return 0;
+
+out:
+	fput(filp);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(fsg_lun_open);
+
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Sync the file data, don't bother with the metadata.
+ * This code was copied from fs/buffer.c:sys_fdatasync().
+ */
+int fsg_lun_fsync_sub(struct fsg_lun *curlun)
+{
+	struct file	*filp = curlun->filp;
+
+	if (curlun->ro || !filp)
+		return 0;
+	return vfs_fsync(filp, 1);
+}
+EXPORT_SYMBOL_GPL(fsg_lun_fsync_sub);
+
+void store_cdrom_address(u8 *dest, int msf, u32 addr)
+{
+	if (msf) {
+		/* Convert to Minutes-Seconds-Frames */
+		addr >>= 2;		/* Convert to 2048-byte frames */
+		addr += 2*75;		/* Lead-in occupies 2 seconds */
+		dest[3] = addr % 75;	/* Frames */
+		addr /= 75;
+		dest[2] = addr % 60;	/* Seconds */
+		addr /= 60;
+		dest[1] = addr;		/* Minutes */
+		dest[0] = 0;		/* Reserved */
+	} else {
+		/* Absolute sector */
+		put_unaligned_be32(addr, dest);
+	}
+}
+EXPORT_SYMBOL_GPL(store_cdrom_address);
+
+/*-------------------------------------------------------------------------*/
+
+
+ssize_t fsg_show_ro(struct fsg_lun *curlun, char *buf)
+{
+	return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
+				  ? curlun->ro
+				  : curlun->initially_ro);
+}
+EXPORT_SYMBOL_GPL(fsg_show_ro);
+
+ssize_t fsg_show_nofua(struct fsg_lun *curlun, char *buf)
+{
+	return sprintf(buf, "%u\n", curlun->nofua);
+}
+EXPORT_SYMBOL_GPL(fsg_show_nofua);
+
+ssize_t fsg_show_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+		      char *buf)
+{
+	char		*p;
+	ssize_t		rc;
+
+	down_read(filesem);
+	if (fsg_lun_is_open(curlun)) {	/* Get the complete pathname */
+		p = file_path(curlun->filp, buf, PAGE_SIZE - 1);
+		if (IS_ERR(p))
+			rc = PTR_ERR(p);
+		else {
+			rc = strlen(p);
+			memmove(buf, p, rc);
+			buf[rc] = '\n';		/* Add a newline */
+			buf[++rc] = 0;
+		}
+	} else {				/* No file, return 0 bytes */
+		*buf = 0;
+		rc = 0;
+	}
+	up_read(filesem);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(fsg_show_file);
+
+ssize_t fsg_show_cdrom(struct fsg_lun *curlun, char *buf)
+{
+	return sprintf(buf, "%u\n", curlun->cdrom);
+}
+EXPORT_SYMBOL_GPL(fsg_show_cdrom);
+
+ssize_t fsg_show_removable(struct fsg_lun *curlun, char *buf)
+{
+	return sprintf(buf, "%u\n", curlun->removable);
+}
+EXPORT_SYMBOL_GPL(fsg_show_removable);
+
+ssize_t fsg_show_inquiry_string(struct fsg_lun *curlun, char *buf)
+{
+	return sprintf(buf, "%s\n", curlun->inquiry_string);
+}
+EXPORT_SYMBOL_GPL(fsg_show_inquiry_string);
+
+/*
+ * The caller must hold fsg->filesem for reading when calling this function.
+ */
+static ssize_t _fsg_store_ro(struct fsg_lun *curlun, bool ro)
+{
+	if (fsg_lun_is_open(curlun)) {
+		LDBG(curlun, "read-only status change prevented\n");
+		return -EBUSY;
+	}
+
+	curlun->ro = ro;
+	curlun->initially_ro = ro;
+	LDBG(curlun, "read-only status set to %d\n", curlun->ro);
+
+	return 0;
+}
+
+ssize_t fsg_store_ro(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+		     const char *buf, size_t count)
+{
+	ssize_t		rc;
+	bool		ro;
+
+	rc = strtobool(buf, &ro);
+	if (rc)
+		return rc;
+
+	/*
+	 * Allow the write-enable status to change only while the
+	 * backing file is closed.
+	 */
+	down_read(filesem);
+	rc = _fsg_store_ro(curlun, ro);
+	if (!rc)
+		rc = count;
+	up_read(filesem);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(fsg_store_ro);
+
+ssize_t fsg_store_nofua(struct fsg_lun *curlun, const char *buf, size_t count)
+{
+	bool		nofua;
+	int		ret;
+
+	ret = strtobool(buf, &nofua);
+	if (ret)
+		return ret;
+
+	/* Sync data when switching from async mode to sync */
+	if (!nofua && curlun->nofua)
+		fsg_lun_fsync_sub(curlun);
+
+	curlun->nofua = nofua;
+
+	return count;
+}
+EXPORT_SYMBOL_GPL(fsg_store_nofua);
+
+ssize_t fsg_store_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+		       const char *buf, size_t count)
+{
+	int		rc = 0;
+
+	if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
+		LDBG(curlun, "eject attempt prevented\n");
+		return -EBUSY;				/* "Door is locked" */
+	}
+
+	/* Remove a trailing newline */
+	if (count > 0 && buf[count-1] == '\n')
+		((char *) buf)[count-1] = 0;		/* Ugh! */
+
+	/* Load new medium */
+	down_write(filesem);
+	if (count > 0 && buf[0]) {
+		/* fsg_lun_open() will close existing file if any. */
+		rc = fsg_lun_open(curlun, buf);
+		if (rc == 0)
+			curlun->unit_attention_data =
+					SS_NOT_READY_TO_READY_TRANSITION;
+	} else if (fsg_lun_is_open(curlun)) {
+		fsg_lun_close(curlun);
+		curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
+	}
+	up_write(filesem);
+	return (rc < 0 ? rc : count);
+}
+EXPORT_SYMBOL_GPL(fsg_store_file);
+
+ssize_t fsg_store_cdrom(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+			const char *buf, size_t count)
+{
+	bool		cdrom;
+	int		ret;
+
+	ret = strtobool(buf, &cdrom);
+	if (ret)
+		return ret;
+
+	down_read(filesem);
+	ret = cdrom ? _fsg_store_ro(curlun, true) : 0;
+
+	if (!ret) {
+		curlun->cdrom = cdrom;
+		ret = count;
+	}
+	up_read(filesem);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fsg_store_cdrom);
+
+ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf,
+			    size_t count)
+{
+	bool		removable;
+	int		ret;
+
+	ret = strtobool(buf, &removable);
+	if (ret)
+		return ret;
+
+	curlun->removable = removable;
+
+	return count;
+}
+EXPORT_SYMBOL_GPL(fsg_store_removable);
+
+ssize_t fsg_store_inquiry_string(struct fsg_lun *curlun, const char *buf,
+				 size_t count)
+{
+	const size_t len = min(count, sizeof(curlun->inquiry_string));
+
+	if (len == 0 || buf[0] == '\n') {
+		curlun->inquiry_string[0] = 0;
+	} else {
+		snprintf(curlun->inquiry_string,
+			 sizeof(curlun->inquiry_string), "%-28s", buf);
+		if (curlun->inquiry_string[len-1] == '\n')
+			curlun->inquiry_string[len-1] = ' ';
+	}
+
+	return count;
+}
+EXPORT_SYMBOL_GPL(fsg_store_inquiry_string);
+
+MODULE_LICENSE("GPL");

drivers/moto_f_mass_storage/storage_common.h

@@ -0,0 +1,223 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef USB_STORAGE_COMMON_H
+#define USB_STORAGE_COMMON_H
+
+#include <linux/device.h>
+#include <linux/usb/storage.h>
+#include <scsi/scsi.h>
+#include <asm/unaligned.h>
+
+#ifndef DEBUG
+#undef VERBOSE_DEBUG
+#undef DUMP_MSGS
+#endif /* !DEBUG */
+
+#ifdef VERBOSE_DEBUG
+#define VLDBG	LDBG
+#else
+#define VLDBG(lun, fmt, args...) do { } while (0)
+#endif /* VERBOSE_DEBUG */
+
+#define _LMSG(func, lun, fmt, args...)					\
+	do {								\
+		if ((lun)->name_pfx && *(lun)->name_pfx)		\
+			func("%s/%s: " fmt, *(lun)->name_pfx,		\
+				 (lun)->name, ## args);			\
+		else							\
+			func("%s: " fmt, (lun)->name, ## args);		\
+	} while (0)
+
+#define LDBG(lun, fmt, args...)		_LMSG(pr_debug, lun, fmt, ## args)
+#define LERROR(lun, fmt, args...)	_LMSG(pr_err, lun, fmt, ## args)
+#define LWARN(lun, fmt, args...)	_LMSG(pr_warn, lun, fmt, ## args)
+#define LINFO(lun, fmt, args...)	_LMSG(pr_info, lun, fmt, ## args)
+
+
+#ifdef DUMP_MSGS
+
+#  define dump_msg(fsg, /* const char * */ label,			\
+		   /* const u8 * */ buf, /* unsigned */ length)		\
+do {									\
+	if (length < 512) {						\
+		DBG(fsg, "%s, length %u:\n", label, length);		\
+		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,	\
+			       16, 1, buf, length, 0);			\
+	}								\
+} while (0)
+
+#  define dump_cdb(fsg) do { } while (0)
+
+#else
+
+#  define dump_msg(fsg, /* const char * */ label, \
+		   /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
+
+#  ifdef VERBOSE_DEBUG
+
+#    define dump_cdb(fsg)						\
+	print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,	\
+		       16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0)		\
+
+#  else
+
+#    define dump_cdb(fsg) do { } while (0)
+
+#  endif /* VERBOSE_DEBUG */
+
+#endif /* DUMP_MSGS */
+
+/* Length of a SCSI Command Data Block */
+#define MAX_COMMAND_SIZE	16
+
+/* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
+#define SS_NO_SENSE				0
+#define SS_COMMUNICATION_FAILURE		0x040800
+#define SS_INVALID_COMMAND			0x052000
+#define SS_INVALID_FIELD_IN_CDB			0x052400
+#define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE	0x052100
+#define SS_LOGICAL_UNIT_NOT_SUPPORTED		0x052500
+#define SS_MEDIUM_NOT_PRESENT			0x023a00
+#define SS_MEDIUM_REMOVAL_PREVENTED		0x055302
+#define SS_NOT_READY_TO_READY_TRANSITION	0x062800
+#define SS_RESET_OCCURRED			0x062900
+#define SS_SAVING_PARAMETERS_NOT_SUPPORTED	0x053900
+#define SS_UNRECOVERED_READ_ERROR		0x031100
+#define SS_WRITE_ERROR				0x030c02
+#define SS_WRITE_PROTECTED			0x072700
+
+#define SK(x)		((u8) ((x) >> 16))	/* Sense Key byte, etc. */
+#define ASC(x)		((u8) ((x) >> 8))
+#define ASCQ(x)		((u8) (x))
+
+/*
+ * Vendor (8 chars), product (16 chars), release (4 hexadecimal digits) and NUL
+ * byte
+ */
+#define INQUIRY_STRING_LEN ((size_t) (8 + 16 + 4 + 1))
+
+struct fsg_lun {
+	struct file	*filp;
+	loff_t		file_length;
+	loff_t		num_sectors;
+
+	unsigned int	initially_ro:1;
+	unsigned int	ro:1;
+	unsigned int	removable:1;
+	unsigned int	cdrom:1;
+	unsigned int	prevent_medium_removal:1;
+	unsigned int	registered:1;
+	unsigned int	info_valid:1;
+	unsigned int	nofua:1;
+
+	u32		sense_data;
+	u32		sense_data_info;
+	u32		unit_attention_data;
+
+	unsigned int	blkbits; /* Bits of logical block size
+						       of bound block device */
+	unsigned int	blksize; /* logical block size of bound block device */
+	struct device	dev;
+	const char	*name;		/* "lun.name" */
+	const char	**name_pfx;	/* "function.name" */
+	char		inquiry_string[INQUIRY_STRING_LEN];
+};
+
+static inline bool fsg_lun_is_open(struct fsg_lun *curlun)
+{
+	return curlun->filp != NULL;
+}
+
+/* Default size of buffer length. */
+#define FSG_BUFLEN	((u32)16384)
+
+/* Maximal number of LUNs supported in mass storage function */
+#define FSG_MAX_LUNS	16
+
+enum fsg_buffer_state {
+	BUF_STATE_SENDING = -2,
+	BUF_STATE_RECEIVING,
+	BUF_STATE_EMPTY = 0,
+	BUF_STATE_FULL
+};
+
+struct fsg_buffhd {
+	void				*buf;
+	enum fsg_buffer_state		state;
+	struct fsg_buffhd		*next;
+
+	/*
+	 * The NetChip 2280 is faster, and handles some protocol faults
+	 * better, if we don't submit any short bulk-out read requests.
+	 * So we will record the intended request length here.
+	 */
+	unsigned int			bulk_out_intended_length;
+
+	struct usb_request		*inreq;
+	struct usb_request		*outreq;
+};
+
+enum fsg_state {
+	FSG_STATE_NORMAL,
+	FSG_STATE_ABORT_BULK_OUT,
+	FSG_STATE_PROTOCOL_RESET,
+	FSG_STATE_CONFIG_CHANGE,
+	FSG_STATE_EXIT,
+	FSG_STATE_TERMINATED
+};
+
+enum data_direction {
+	DATA_DIR_UNKNOWN = 0,
+	DATA_DIR_FROM_HOST,
+	DATA_DIR_TO_HOST,
+	DATA_DIR_NONE
+};
+
+static inline struct fsg_lun *fsg_lun_from_dev(struct device *dev)
+{
+	return container_of(dev, struct fsg_lun, dev);
+}
+
+enum {
+	FSG_STRING_INTERFACE
+};
+
+extern struct usb_interface_descriptor fsg_intf_desc;
+
+extern struct usb_endpoint_descriptor fsg_fs_bulk_in_desc;
+extern struct usb_endpoint_descriptor fsg_fs_bulk_out_desc;
+extern struct usb_descriptor_header *fsg_fs_function[];
+
+extern struct usb_endpoint_descriptor fsg_hs_bulk_in_desc;
+extern struct usb_endpoint_descriptor fsg_hs_bulk_out_desc;
+extern struct usb_descriptor_header *fsg_hs_function[];
+
+extern struct usb_endpoint_descriptor fsg_ss_bulk_in_desc;
+extern struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc;
+extern struct usb_endpoint_descriptor fsg_ss_bulk_out_desc;
+extern struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc;
+extern struct usb_descriptor_header *fsg_ss_function[];
+
+void fsg_lun_close(struct fsg_lun *curlun);
+int fsg_lun_open(struct fsg_lun *curlun, const char *filename);
+int fsg_lun_fsync_sub(struct fsg_lun *curlun);
+void store_cdrom_address(u8 *dest, int msf, u32 addr);
+ssize_t fsg_show_ro(struct fsg_lun *curlun, char *buf);
+ssize_t fsg_show_nofua(struct fsg_lun *curlun, char *buf);
+ssize_t fsg_show_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+		      char *buf);
+ssize_t fsg_show_inquiry_string(struct fsg_lun *curlun, char *buf);
+ssize_t fsg_show_cdrom(struct fsg_lun *curlun, char *buf);
+ssize_t fsg_show_removable(struct fsg_lun *curlun, char *buf);
+ssize_t fsg_store_ro(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+		     const char *buf, size_t count);
+ssize_t fsg_store_nofua(struct fsg_lun *curlun, const char *buf, size_t count);
+ssize_t fsg_store_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+		       const char *buf, size_t count);
+ssize_t fsg_store_cdrom(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+			const char *buf, size_t count);
+ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf,
+			    size_t count);
+ssize_t fsg_store_inquiry_string(struct fsg_lun *curlun, const char *buf,
+				 size_t count);
+
+#endif /* USB_STORAGE_COMMON_H */