]> git.karo-electronics.de Git - karo-tx-linux.git/commitdiff
xshm: XSHM Configuration data handling
authorSjur Brændeland <sjur.brandeland@stericsson.com>
Fri, 9 Dec 2011 11:00:18 +0000 (12:00 +0100)
committerLinus Walleij <linus.walleij@stericsson.com>
Sun, 18 Dec 2011 21:05:28 +0000 (22:05 +0100)
This patch implements the configuration handling:
- reception of gen-netlink requests from user-space.
- calculating address of where to put information in shared memory, i.e
  the offset of: IPC-TOC, channel-descriptors, read/write indexes for each
  directional channel, and data area of each channel.
- formatting of the shared memory area, so modem can read out configuration
  data.
- Creation of configuration data given to the XSHM drivers: xshm_chr and
  caif_xshm.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
drivers/xshm/xshm_boot.c [new file with mode: 0644]

diff --git a/drivers/xshm/xshm_boot.c b/drivers/xshm/xshm_boot.c
new file mode 100644 (file)
index 0000000..5e61d53
--- /dev/null
@@ -0,0 +1,1150 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2011
+ * Author:     Sjur Brændeland / sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": %s :" fmt, __func__
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+#include <linux/crc-ccitt.h>
+#include <linux/kdev_t.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>
+#include "xshm_ipctoc.h"
+#include <linux/xshm/xshm_dev.h>
+#include <linux/xshm/xshm_netlink.h>
+#include <linux/c2c_genio.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sjur Brændland <sjur.brandeland@stericsson.com>");
+
+#define XSHM_VERSION   0x1
+#define XSHM_SUBVER    0x0
+#define TOC_SZ         512
+#define IMG_MAX_SZ     65536
+#define XSHM_ALIGNMT   sizeof(u32)
+#define XSHM_MIN_CHSZ 3
+#define XSHM_PAYL_ALIGN max(32, L1_CACHE_BYTES)
+#define STE_BOOTIMG_NAME "ste-bootimg.bin"
+
+#define GET_OFFSET(base, ptr) (((u8 *)(ptr)) - ((u8 *)(base)))
+#define OFFS2PTR(base, offs) ((void *) ((u8 *)base + offs))
+#define LEOFFS2PTR(base, offs) ((void *) ((u8 *)base + le32_to_cpu(offs)))
+
+/* Structure use in debug mode for integrity checking */
+struct ipctoc_hash {
+       u16 img_hash;
+       u16 ch_hash;
+       u16 ch_size;
+};
+
+struct xshm_modem {
+       bool config_error;
+       bool commited;
+       bool registered;
+       bool addr_set;
+       u32 modem_bootimg_size;
+       void *shm_start;
+       u32 channels;
+       struct xshm_channel *channel[XSHM_MAX_CHANNELS + 1];
+       struct xshm_ipctoc *ipctoc;
+       bool gennetl_reg;
+};
+
+static unsigned long xshm_start;
+module_param(xshm_start, ulong, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(xshm_start, "Address for memory shared by host/modem.");
+
+static unsigned long xshm_c2c_bootaddr;
+module_param(xshm_c2c_bootaddr, ulong, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(xshm_c2c_bootaddr,
+                       "Address given to modem (through GENI register)");
+
+static long xshm_size;
+module_param(xshm_size, long, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(xshm_size, "Size of SHM area");
+
+#ifdef DEBUG
+
+/* In debug mode we pad around all payload area in order to detect overwrite */
+#define MAGIC_PAD_LEN 32
+#define MAGIC_PAD 0xbc
+
+/* Verify a magic-pad area */
+static inline bool padok(void *mag)
+{
+       u32 *p = mag, v = 0xbcbcbcbc;
+       int i;
+
+       for (i = 0; i < 8; i++)
+               if (*p++ != v)
+                       return false;
+       return true;
+}
+
+/* Insert a magic-pad area */
+static inline void add_magic_pad(u32 *offset, void *base)
+{
+       if (*offset < xshm_size)
+               memset(base + *offset, MAGIC_PAD, MAGIC_PAD_LEN);
+       *offset += MAGIC_PAD_LEN;
+}
+
+/* Abuse the pad area to create a checksum of the ipc-toc and descriptors */
+static inline void store_checksum(struct xshm_modem *modem, u32 size)
+{
+       struct ipctoc_hash *hash = (void *)modem->ipctoc;
+       --hash;
+       hash->img_hash =
+               crc_ccitt(0xffff, (u8 *) modem->shm_start,
+                               modem->modem_bootimg_size);
+       hash->ch_hash = crc_ccitt(0xffff, (u8 *) modem->ipctoc, size);
+       hash->ch_size = size;
+}
+
+/* Verify that shm config has not been accidently tampered. */
+static inline bool ok_checksum(struct xshm_modem *modem,
+                               struct xshm_ipctoc *ipctoc)
+{
+       struct ipctoc_hash *hash = (void *) ipctoc;
+       u16 new_hash, new_imghash;
+       int i;
+       u8 *p;
+
+       if (!modem->commited)
+               return false;
+
+       for (i = 0; i < modem->channels; i++) {
+               struct xshm_ipctoc_channel *ch;
+
+               ch = LEOFFS2PTR(modem->shm_start,
+                               ipctoc->channel_offsets[i].rx);
+               p = LEOFFS2PTR(modem->shm_start, ch->ipc);
+               if (!padok(p - MAGIC_PAD_LEN))
+                       return false;
+               p = LEOFFS2PTR(modem->shm_start, ch->offset);
+               if (!padok(p - MAGIC_PAD_LEN))
+                       return false;
+               ch = LEOFFS2PTR(modem->shm_start,
+                               ipctoc->channel_offsets[i].tx);
+               p = LEOFFS2PTR(modem->shm_start, ch->ipc);
+               if (!padok(p - MAGIC_PAD_LEN))
+                       return false;
+               p = LEOFFS2PTR(modem->shm_start, ch->offset);
+               if (!padok(p - MAGIC_PAD_LEN))
+                       return false;
+       }
+
+       --hash;
+       new_hash = crc_ccitt(0xffff, (u8 *) ipctoc, hash->ch_size);
+       new_imghash =
+               crc_ccitt(0xffff, (u8 *) modem->shm_start,
+                               modem->modem_bootimg_size);
+       pr_debug("Hash result:size:%d chksm:%u/%u img:%u/%u\n",
+                       hash->ch_size, hash->ch_hash, new_hash,
+                       hash->img_hash, new_imghash);
+       return hash->ch_hash == new_hash && hash->img_hash == new_imghash;
+}
+
+static inline void init_data(void *shm_start, u32 offset,
+                               int ch, u32 size)
+{
+       memset((u8 *)shm_start + offset, ch + 1, size);
+}
+#else
+#define MAGIC_PAD_LEN 0
+static inline void add_magic_pad(u32 *offset, void *base)
+{
+}
+static inline void store_checksum(struct xshm_modem *modem, u32 size)
+{
+}
+static inline bool ok_checksum(struct xshm_modem *modem, void *ipctoc)
+{
+       return true;
+}
+static inline void init_data(struct xshm_modem *modem, u32 offs, int ch,
+                               u32 size)
+{
+}
+#endif
+
+/* write_to_shm - Write SHM Channel descriptors to SHM.
+ *
+ * Based on the configuration data channel configuration
+ * is written to the shared memory area.
+ * This is the data layout:
+ *
+ * +------------+  <---- xshm_start
+ * |   TOC     |
+ * +------------+
+ * | Boot IMG  |
+ * +------------+ <---- rw_start
+ * | RW Data   |
+ * +------------+
+ * | RW Buf idx |
+ * +------------+ <---- ipctoc
+ * | IPC TOC   |
+ * +------------+
+ * | RW Ch Decr |
+ * +------------+ <---- ro_start
+ * | RO Ch Decr |
+ * +------------+
+ * | RO Buf idx |
+ * +------------+
+ * | RO Data   |
+ * +------------+
+ */
+
+static int write_to_shm(struct xshm_modem *modem)
+{
+       int i, pri, bitno;
+       u32 offset, ro_start, rw_start, ipctoc_offs, ipcro_offs;
+       bool found;
+       struct xshm_ipctoc_channel *ch;
+       struct toc_entry *toc_entry;
+       struct xshm_bufidx *bix;
+
+       /*
+        * Find where to put IPC-TOC by adding up
+        * the size of Payload buffers pluss buf-indices
+        */
+       ipctoc_offs = ALIGN(modem->modem_bootimg_size, XSHM_PAYL_ALIGN);
+       rw_start = ipctoc_offs;
+       for (i = 0; i < modem->channels; i++) {
+               int n = modem->channel[i]->tx.buffers;
+               ipctoc_offs += MAGIC_PAD_LEN;
+               ipctoc_offs += offsetof(struct xshm_bufidx, size[n + 2]);
+               ipctoc_offs = ALIGN(ipctoc_offs, XSHM_PAYL_ALIGN);
+               ipctoc_offs += MAGIC_PAD_LEN;
+               ipctoc_offs += modem->channel[i]->tx.ch_size;
+               ipctoc_offs = ALIGN(ipctoc_offs, XSHM_PAYL_ALIGN);
+       }
+       add_magic_pad(&ipctoc_offs, modem->shm_start);
+       pr_debug("IPC toc @ %08x\n", ipctoc_offs);
+
+       /*
+        * Allocate the IPC-TOC and, initiatlize it.
+        * The IPC toc will be located after the RW Data and
+        * buffer indices.
+        */
+       offset = ipctoc_offs;
+       modem->ipctoc = OFFS2PTR(modem->shm_start, ipctoc_offs);
+       modem->ipctoc->magic[0] = XSHM_IPCTOC_MAGIC1;
+       modem->ipctoc->magic[1] = XSHM_IPCTOC_MAGIC2;
+       modem->ipctoc->version = XSHM_VERSION;
+       modem->ipctoc->subver = XSHM_SUBVER;
+       memset(modem->ipctoc->channel_offsets, 0,
+               sizeof(modem->ipctoc->channel_offsets));
+
+       /* Find start of first channel descriptor */
+       offset += sizeof(struct xshm_ipctoc);
+
+       /*
+        * Allocate the location for the RW Channel descriptors.
+        * It will be located after the IPC-TOC.
+        */
+       offset = ALIGN(offset, XSHM_ALIGNMT);
+       for (i = 0; i < modem->channels; i++) {
+               pr_debug("Channel descriptor %d RW @ 0x%08x\n", i, offset);
+               modem->ipctoc->channel_offsets[i].tx = cpu_to_le32(offset);
+               offset += sizeof(struct xshm_ipctoc_channel);
+               offset = ALIGN(offset, XSHM_ALIGNMT);
+               if (offset > xshm_size)
+                       goto badsize;
+       }
+       ro_start = offset;
+
+       /*
+        * Allocate the location for the RO Channel descriptors.
+        * It will be located after the RW Channels.
+        */
+       for (i = 0; i < modem->channels; i++) {
+               pr_debug("Channel descriptor %d RO @ 0x%08x\n", i, offset);
+               modem->ipctoc->channel_offsets[i].rx = cpu_to_le32(offset);
+               offset += sizeof(struct xshm_ipctoc_channel);
+               offset = ALIGN(offset, XSHM_ALIGNMT);
+               if (offset > xshm_size)
+                       goto badsize;
+       }
+
+       /*
+        * Allocate the location for the RO Buffer Indices.
+        * It will be located after the RO Channels.
+        */
+       offset = ALIGN(offset, XSHM_PAYL_ALIGN);
+       ipcro_offs = offset;
+       for (i = 0; i < modem->channels; i++) {
+               int n = modem->channel[i]->rx.buffers;
+               ch = LEOFFS2PTR(modem->shm_start,
+                               modem->ipctoc->channel_offsets[i].rx);
+               add_magic_pad(&offset, modem->shm_start);
+               ch->ipc = cpu_to_le32(offset);
+
+               bix = OFFS2PTR(modem->shm_start, offset);
+               bix->read_index = cpu_to_le32(0);
+               bix->write_index = cpu_to_le32(0);
+               bix->state = cpu_to_le32(XSHM_CLOSED);
+               bix->size[0] = cpu_to_le32(0);
+
+               pr_debug("IPC RO[%d] @: 0x%08x\n",  i, offset);
+               offset += offsetof(struct xshm_bufidx, size[n + 2]);
+               offset = ALIGN(offset, XSHM_PAYL_ALIGN);
+               if (offset > xshm_size)
+                       goto badsize;
+       }
+
+       /*
+        * Allocate RO Data Area. This will located after
+        * the RO Buffer Indices at the end of the Share Memory
+        * area.
+        */
+       offset = ALIGN(offset, XSHM_PAYL_ALIGN);
+       for (i = 0; i < modem->channels; i++) {
+               u8 align;
+               u32 size;
+               ch = LEOFFS2PTR(modem->shm_start,
+                               modem->ipctoc->channel_offsets[i].rx);
+               add_magic_pad(&offset, modem->shm_start);
+               ch->offset = cpu_to_le32(offset);
+
+               BUILD_BUG_ON(sizeof(ch->mode) != 1);
+               ch->mode = modem->channel[i]->mode & XSHM_MODE_MASK;
+               ch->buffers = cpu_to_le32(modem->channel[i]->rx.buffers);
+               align = rounddown_pow_of_two(modem->channel[i]->rx.alignment);
+               ch->alignment = align;
+               ch->packets = modem->channel[i]->rx.packets;
+               ch->mtu = modem->channel[i]->rx.mtu;
+               size = modem->channel[i]->tx.ch_size;
+               if (modem->channel[i]->mode & XSHM_PACKET_MODE) {
+                       u32 buf_size;
+                       buf_size = size / modem->channel[i]->tx.buffers;
+                       buf_size = rounddown(buf_size, align);
+                       size = buf_size * modem->channel[i]->tx.buffers;
+               }
+               pr_debug("Buffer area RO for Channel[%d] at: 0x%08x size:%d\n",
+                               i, offset, size);
+               ch->size = cpu_to_le32(size);
+
+               init_data(modem->shm_start, offset, i,
+                               modem->channel[i]->rx.ch_size);
+               offset += modem->channel[i]->rx.ch_size;
+               offset = ALIGN(offset, XSHM_PAYL_ALIGN);
+               if (offset > xshm_size)
+                       goto badsize;
+       }
+
+       /*
+        * Allocate RW Data Area. This will located in the beginning
+        * just after the Modem Boot Image.
+        */
+       offset = rw_start;
+       for (i = 0; i < modem->channels; i++) {
+               u8 align;
+               u32 size;
+               ch = LEOFFS2PTR(modem->shm_start,
+                               modem->ipctoc->channel_offsets[i].tx);
+               add_magic_pad(&offset, modem->shm_start);
+               ch->offset = cpu_to_le32(offset);
+               init_data(modem->shm_start, offset, i,
+                               modem->channel[i]->tx.ch_size);
+               ch->mode = modem->channel[i]->mode &
+                               XSHM_MODE_MASK;
+               ch->buffers = cpu_to_le32(modem->channel[i]->tx.buffers);
+               align = rounddown_pow_of_two(modem->channel[i]->rx.alignment);
+               ch->alignment = align;
+               ch->packets = modem->channel[i]->rx.packets;
+               ch->mtu = modem->channel[i]->rx.mtu;
+               size = modem->channel[i]->tx.ch_size;
+               if (modem->channel[i]->mode & XSHM_PACKET_MODE) {
+                       u32 buf_size;
+                       buf_size = size / modem->channel[i]->tx.buffers;
+                       buf_size = rounddown(buf_size, align);
+                       size = buf_size * modem->channel[i]->tx.buffers;
+               }
+               ch->size = cpu_to_le32(size);
+               pr_debug("Buffer area RW for Channel[%d] at: 0x%08x size:%d\n",
+                               i, offset, size);
+               offset += modem->channel[i]->tx.ch_size;
+               offset = ALIGN(offset, XSHM_PAYL_ALIGN);
+               if (offset > ro_start)
+                       goto badsize;
+       }
+
+       /*
+        * Allocate RW IPC Area. This will located after RW data area,
+        * just before the IPC-TOC.
+        */
+       offset = ALIGN(offset, XSHM_PAYL_ALIGN);
+       for (i = 0; i < modem->channels; i++) {
+               int n = modem->channel[i]->tx.buffers;
+               ch = LEOFFS2PTR(modem->shm_start,
+                               modem->ipctoc->channel_offsets[i].tx);
+               add_magic_pad(&offset, modem->shm_start);
+               ch->ipc = cpu_to_le32(offset);
+               bix = OFFS2PTR(modem->shm_start, offset);
+               bix->read_index = cpu_to_le32(0);
+               bix->write_index = cpu_to_le32(0);
+               bix->state = cpu_to_le32(XSHM_CLOSED);
+               bix->size[0] = cpu_to_le32(0);
+
+               pr_debug("IPC RW[%d] @: 0x%08x\n",  i, offset);
+               offset += offsetof(struct xshm_bufidx, size[n + 2]);
+               offset = ALIGN(offset, XSHM_PAYL_ALIGN);
+               if (offset > xshm_size)
+                       goto badsize;
+       }
+
+       /* Allocate genio bits for each channel according to priority*/
+       bitno = 0;
+       for (pri = 0; pri < 8; pri++) {
+               for (i = 0; i < modem->channels; i++) {
+                       if (modem->channel[i]->priority == pri) {
+                               ch = LEOFFS2PTR(modem->shm_start,
+                                       modem->ipctoc->channel_offsets[i].tx);
+                               ch->write_bit = cpu_to_le16(bitno * 4);
+                               ch->read_bit = cpu_to_le16(bitno * 4 + 2);
+                               ch = LEOFFS2PTR(modem->shm_start,
+                                       modem->ipctoc->channel_offsets[i].rx);
+                               ch->write_bit = cpu_to_le16(bitno * 4 + 1);
+                               ch->read_bit = cpu_to_le16(bitno * 4 + 3);
+                               bitno++;
+                       }
+               }
+       }
+
+       /*
+        * The Master TOC points out the boot images for the modem,
+        * Use the first avilable entry in the toc to write the pointer,
+        * to the IPC-TOC defined above.
+        */
+       found = false;
+       for (toc_entry = modem->shm_start, i = 0; i < 16; i++, toc_entry++)
+               if (toc_entry->start == cpu_to_le32(0xffffffff)) {
+                       pr_debug("IPCTOC address written into Master TOC"
+                                       " @ 0x%08x\n", i * 32);
+                       toc_entry->start =
+                               cpu_to_le32(GET_OFFSET(modem->shm_start,
+                                                       modem->ipctoc));
+                       toc_entry->size = cpu_to_le32(0);
+                       toc_entry->flags = cpu_to_le32(0);
+                       toc_entry->entry_point = cpu_to_le32(0);
+                       toc_entry->load_addr = cpu_to_le32(0xffffffff);
+                       memset(toc_entry->name, 0, sizeof(toc_entry->name));
+                       sprintf(toc_entry->name, "ipc-toc");
+                       found = true;
+                       break;
+               }
+       if (!found) {
+               pr_debug("Cannot insert IPC-TOC in toc\n");
+               goto bad_config;
+       }
+
+       store_checksum(modem, ipcro_offs - ipctoc_offs);
+
+       return 0;
+
+badsize:
+       pr_debug("IPCTOC not enough space offset (size:0x%lx offset:0x%x\n",
+                       xshm_size, offset);
+       return -ENOSPC;
+
+bad_config:
+       pr_debug("IPCTOC bad configuration data\n");
+       return -EINVAL;
+}
+
+static int xshm_verify_config(struct xshm_modem *modem,
+                               struct xshm_channel *xcfg)
+{
+       int j;
+
+       if ((xcfg->mode & XSHM_MODE_MASK) != XSHM_PACKET_MODE &&
+                       (xcfg->mode & XSHM_MODE_MASK) != XSHM_STREAM_MODE) {
+               pr_debug("Bad config:"
+                               "channel mode must be set\n");
+               return -EINVAL;
+       }
+       if (xcfg->mode & XSHM_PACKET_MODE && xcfg->rx.buffers < 2) {
+               pr_debug("Bad config:minimum 2 buffers "
+                               "must be set for packet mode\n");
+               return -EINVAL;
+       }
+
+       if (xcfg->rx.ch_size < XSHM_MIN_CHSZ) {
+               pr_debug("Bad config:"
+                               "Channel size must be larger than %d\n",
+                               XSHM_MIN_CHSZ);
+               return -EINVAL;
+       }
+
+       if (xcfg->mode & XSHM_PACKET_MODE) {
+               if (xcfg->tx.buffers < 2) {
+                       pr_debug("Bad config:"
+                               "buffers must be minimum 2 packet mode\n");
+                       return -EINVAL;
+               }
+               if (xcfg->tx.packets < 1) {
+                       pr_debug("Bad config:"
+                               "packets must be set for packet mode\n");
+                       return -EINVAL;
+               }
+       }
+
+       if (xcfg->tx.ch_size < XSHM_MIN_CHSZ) {
+               pr_debug("Bad config:"
+                               "Channel size must be larger than %d\n",
+                               XSHM_MIN_CHSZ);
+               return -EINVAL;
+       }
+
+       if (xcfg->name[0] == '\0') {
+               pr_debug("Channel must be named\n");
+               return -EINVAL;
+       }
+       for (j = 0; j < modem->channels; j++) {
+               struct xshm_channel *xcfg2 = modem->channel[j];
+               if (xcfg != xcfg2 && strcmp(xcfg->name, xcfg2->name) == 0) {
+                       pr_debug("Channels has same name:%s\n",
+                                        xcfg->name);
+                       return -EINVAL;
+               }
+       }
+       return 0;
+}
+
+static int verify_config(struct xshm_modem *modem)
+{
+       int i;
+
+       if (modem->channels == 0) {
+               pr_debug("Bad config: minimum one channel must be defined\n");
+               return -EINVAL;
+       }
+       for (i = 0; i < modem->channels; i++) {
+               int err = xshm_verify_config(modem, modem->channel[i]);
+               if (err)
+                       return err;
+       }
+       return 0;
+}
+
+/*
+ * Create Configuration data for the xshm devices.
+ */
+static void create_devs(struct xshm_modem *modem)
+{
+       int i;
+
+       for (i = 0; i < modem->channels; i++) {
+               struct xshm_bufidx *buf_rx, *buf_tx;
+               struct xshm_ipctoc_channel *ch_rx, *ch_tx;
+               struct xshm_channel *xcfg = modem->channel[i];
+               ch_rx = LEOFFS2PTR(modem->shm_start,
+                               modem->ipctoc->channel_offsets[i].rx);
+               buf_rx = LEOFFS2PTR(modem->shm_start, ch_rx->ipc);
+               ch_tx = LEOFFS2PTR(modem->shm_start,
+                               modem->ipctoc->channel_offsets[i].tx);
+               buf_tx = LEOFFS2PTR(modem->shm_start, ch_tx->ipc);
+
+               /*
+                * Due to restricted read-only access
+                * we swap positions for read/write
+                * pointers.
+                */
+               xcfg->tx.write = &buf_tx->write_index;
+               xcfg->tx.read = &buf_rx->read_index;
+
+               xcfg->rx.write = &buf_rx->write_index;
+               xcfg->rx.read = &buf_tx->read_index;
+
+               xcfg->rx.addr = LEOFFS2PTR(modem->shm_start, ch_rx->offset);
+               xcfg->tx.addr = LEOFFS2PTR(modem->shm_start, ch_tx->offset);
+               xcfg->rx.state = &buf_rx->state;
+               xcfg->tx.state = &buf_tx->state;
+               xcfg->tx.buf_size = buf_tx->size;
+               xcfg->rx.buf_size = buf_rx->size;
+
+               xcfg->rx.xfer_bit = le16_to_cpu(ch_rx->write_bit);
+               xcfg->tx.xfer_bit = le16_to_cpu(ch_tx->write_bit);
+               xcfg->rx.xfer_done_bit = le16_to_cpu(ch_rx->read_bit);
+               xcfg->tx.xfer_done_bit = le16_to_cpu(ch_tx->read_bit);
+
+               if (xcfg->mode & XSHM_PAIR_MODE) {
+                       struct xshm_channel *pair;
+                       pr_debug("Channel[%d] is in PAIR mode\n", i);
+                       if (i < 1) {
+                               pr_debug("No channel to pair with\n");
+                               continue;
+                       }
+                       /* Cross couple rx/tx on the pair */
+                       pair = modem->channel[i - 1];
+
+                       /* Copy everything but the kobj which is at the end */
+                       memcpy(&xcfg->tx, &pair->rx,
+                                       offsetof(struct xshm_udchannel, kobj));
+                       memcpy(&xcfg->rx, &pair->tx,
+                                       offsetof(struct xshm_udchannel, kobj));
+               } else if (xcfg->mode & XSHM_LOOP_MODE) {
+                       pr_debug("Channel[%d] is in LOOP mode\n", i);
+                       /*
+                        * Connect rx/tx in a pair. Copy everything,
+                        * but the kobj which is at the end
+                        */
+                       memcpy(&xcfg->tx, &xcfg->rx,
+                                       offsetof(struct xshm_udchannel, kobj));
+               }
+
+               pr_devel("RX[%d] wi:%p ri:%p\n", i, xcfg->rx.read,
+                               xcfg->rx.write);
+               pr_devel("TX[%d] wi:%p ri:%p\n", i, xcfg->tx.read,
+                               xcfg->tx.write);
+       }
+}
+
+struct xshm_modem *modem;
+
+struct xshm_modem *get_modem(struct sk_buff *skb, struct genl_info *info)
+{
+       return modem;
+}
+
+static int do_commit(struct xshm_modem *modem)
+{
+       int err;
+
+       if (modem->config_error) {
+               pr_devel("config error detected\n");
+               return -EINVAL;
+       }
+
+       if (modem->commited) {
+               pr_devel("already commited\n");
+               modem->config_error = true;
+               return -EINVAL;
+       }
+       err = verify_config(modem);
+       if (err) {
+               pr_devel("bad config\n");
+               modem->config_error = true;
+               return err;
+       }
+       err = write_to_shm(modem);
+       if (err) {
+               pr_devel("writei to SHM failed\n");
+               modem->config_error = true;
+               return err;
+       }
+       modem->commited = true;
+       create_devs(modem);
+       return 0;
+}
+
+static int do_register(struct xshm_modem *modem)
+{
+       int err;
+
+       if (!modem->commited || modem->registered || modem->config_error) {
+               pr_devel("bad sequence of requests\n");
+               modem->config_error = true;
+               return -EINVAL;
+       }
+
+       err = verify_config(modem);
+       if (err) {
+               modem->config_error = true;
+               pr_devel("bad config\n");
+               return err;
+       }
+       modem->registered = true;
+
+       xshm_register_devices(modem->channel, modem->channels);
+
+       return 0;
+}
+
+static void do_reset(struct xshm_modem *modem)
+{
+       int i;
+
+       xshm_reset();
+       modem->config_error = false;
+       modem->registered = false;
+       modem->commited = false;
+       modem->addr_set = false;
+       modem->modem_bootimg_size = TOC_SZ;
+       for (i = 0; i < modem->channels; i++) {
+               kfree(modem->channel[i]);
+               modem->channel[i] = NULL;
+       }
+       modem->channels = 0;
+}
+
+static int do_set_addr(struct xshm_modem *modem)
+{
+       int err;
+       if (!modem->commited || modem->addr_set || modem->config_error) {
+               pr_devel("bad sequence of requests\n");
+               modem->config_error = true;
+               return -EINVAL;
+       }
+       err = verify_config(modem);
+       if (err) {
+               modem->config_error = true;
+               pr_devel("bad config\n");
+               return err;
+       }
+       modem->addr_set = true;
+       return genio_set_shm_addr(xshm_c2c_bootaddr, genio_ipc_ready_cb);
+}
+
+static int copy_name(const char *src, char *d, size_t count)
+{
+       const char *s, *end = src + count;
+       for (s = src; *s && s < end; s++, d++)
+               if (*s == '\0' || *s == '\n')
+                       break;
+               else if (!isalnum(*s)) {
+                       pr_debug("Illegal chr:'%c' in name:'%s'\n", *s, src);
+                       return -EINVAL;
+               } else if (s - src >= XSHM_NAMESZ - 1) {
+                       pr_debug("Name '%s'too long\n", src);
+                       return -EINVAL;
+               } else
+                       *d = *s;
+       *d = '\0';
+
+       return count;
+}
+
+/* XSHM Generic NETLINK family */
+static struct genl_family xshm_gnl_family = {
+       .id = GENL_ID_GENERATE,
+       .hdrsize = 0,
+       .name = "XSHM",
+       .version = XSHM_PROTO_VERSION,
+       .maxattr = XSHM_A_MAX,
+};
+
+/* XSHM Netlink attribute policy */
+static const struct nla_policy xshm_genl_policy[XSHM_A_MAX + 1] = {
+       [XSHM_A_VERSION] = { .type = NLA_U8 },
+       [XSHM_A_SUB_VERSION] = { .type = NLA_U8 },
+       [__XSHM_A_FLAGS] = { .type = NLA_U32 },
+       [XSHM_A_NAME] = { .type = NLA_NUL_STRING, .len = XSHM_NAMESZ},
+       [XSHM_A_RX_CHANNEL] = { .type = NLA_NESTED },
+       [XSHM_A_TX_CHANNEL] = { .type = NLA_NESTED },
+       [XSHM_A_PRIORITY] = { .type = NLA_U8 },
+       [XSHM_A_LATENCY] = { .type = NLA_U8 },
+};
+
+/* Policy for uni-directional attributes for stream */
+static const struct nla_policy stream_policy[XSHM_A_MAX + 1] = {
+       [XSHM_A_CHANNEL_SIZE] = { .type = NLA_U32 },
+};
+
+/* Policy for uni-directional attributes for packet */
+static const struct nla_policy packet_policy[XSHM_A_MAX + 1] = {
+       [XSHM_A_CHANNEL_SIZE] = { .type = NLA_U32 },
+       [XSHM_A_CHANNEL_BUFFERS] = { .type = NLA_U32 },
+       [XSHM_A_MTU] = { .type = NLA_U16 },
+       [XSHM_A_ALIGNMENT] = { .type = NLA_U8 },
+       [XSHM_A_PACKETS] = { .type = NLA_U8 },
+};
+
+static int xshm_add_udchannel(struct xshm_udchannel *chn, int attr,
+                       struct genl_info *info, struct nla_policy const *policy)
+{
+       struct nlattr *nla;
+       int nla_rem;
+
+       if (!info->attrs[attr])
+               return -EINVAL;
+
+       if (nla_validate_nested(info->attrs[attr],
+                                       XSHM_A_MAX,
+                                       policy) != 0) {
+               pr_info("Invalid RX channel attributes\n");
+               return -EINVAL;
+       }
+
+       nla_for_each_nested(nla, info->attrs[attr], nla_rem) {
+
+               if (nla_type(nla) == XSHM_A_CHANNEL_SIZE)
+                       chn->ch_size = nla_get_u32(nla);
+
+               if (nla_type(nla) == XSHM_A_CHANNEL_BUFFERS)
+                       chn->buffers = nla_get_u32(nla);
+
+               if (nla_type(nla) == XSHM_A_MTU)
+                       chn->mtu = nla_get_u16(nla);
+
+               if (nla_type(nla) == XSHM_A_PACKETS)
+                       chn->packets = nla_get_u8(nla);
+
+               if (nla_type(nla) == XSHM_A_ALIGNMENT) {
+                       chn->alignment = nla_get_u8(nla);
+                       chn->alignment = rounddown_pow_of_two(chn->alignment);
+               }
+
+       }
+       return 0;
+}
+
+static int xshm_add_channel(struct xshm_channel *cfg, struct genl_info *info,
+                       int mode)
+{
+       int len, err;
+       struct nla_policy const *policy;
+       char name[XSHM_NAMESZ];
+
+       policy = (mode == XSHM_PACKET_MODE) ? packet_policy : stream_policy;
+
+       if (info->attrs[XSHM_A_VERSION]) {
+               u8 version;
+               u8 sub_version;
+
+               version = nla_get_u8(info->attrs[XSHM_A_VERSION]);
+               if (!info->attrs[XSHM_A_SUB_VERSION])
+                       return -EINVAL;
+               sub_version = nla_get_u8(info->attrs[XSHM_A_SUB_VERSION]);
+               if (version != 1 || sub_version != 0) {
+                       pr_info("Bad version or sub_version\n");
+                       return -EINVAL;
+               }
+       }
+
+       if (!info->attrs[XSHM_A_NAME]) {
+               pr_debug("Name not specified\n");
+               return -EINVAL;
+       }
+
+       len = nla_strlcpy(name, info->attrs[XSHM_A_NAME],
+                       XSHM_NAMESZ);
+
+       if (len > XSHM_NAMESZ)
+               return -EINVAL;
+
+       err = copy_name(name, cfg->name, sizeof(name));
+       if (err < 0)
+               return err;
+
+       cfg->excl_group = 1;
+       if (info->attrs[XSHM_A_EXCL_GROUP])
+               cfg->excl_group = nla_get_u8(info->attrs[XSHM_A_EXCL_GROUP]);
+
+       err = xshm_add_udchannel(&cfg->rx, XSHM_A_RX_CHANNEL, info, policy);
+
+       if (err)
+               return err;
+       err = xshm_add_udchannel(&cfg->tx, XSHM_A_TX_CHANNEL, info, policy);
+
+       if (err)
+               return err;
+
+       if (info->attrs[XSHM_A_PRIORITY]) {
+               cfg->priority = nla_get_u8(info->attrs[XSHM_A_PRIORITY]);
+               /* silently fixup bad value */
+               if (cfg->priority > 7)
+                       cfg->priority = 0;
+       }
+
+       if (info->attrs[XSHM_A_LATENCY])
+               cfg->latency = nla_get_u8(info->attrs[XSHM_A_LATENCY]);
+
+       if (info->attrs[__XSHM_A_FLAGS])
+               cfg->mode |= nla_get_u32(info->attrs[__XSHM_A_FLAGS]);
+
+
+       return 0;
+}
+
+static int do_reply(struct genl_info *info, int result)
+{
+       struct sk_buff *msg;
+       int err;
+       void *reply;
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (msg == NULL)
+               return -ENOMEM;
+
+       reply = genlmsg_put_reply(msg, info, &xshm_gnl_family, 0, result);
+       if (reply == NULL) {
+               kfree_skb(msg);
+               return -EMSGSIZE;
+       }
+
+       genlmsg_end(msg, reply);
+       err = genlmsg_reply(msg, info);
+       return err;
+}
+
+static int xshm_add_ch(struct sk_buff *skb, struct genl_info *info, int mode)
+{
+       int err;
+       struct xshm_channel *cfg;
+       struct xshm_modem *modem = get_modem(skb, info);
+       if (!modem)
+               return -EINVAL;
+
+       if (modem->channels + 1 > XSHM_MAX_CHANNELS) {
+               pr_debug("Too many channels added\n");
+               return -EINVAL;
+       }
+
+
+       cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
+       if (cfg == NULL)
+               return -ENOMEM;
+
+       cfg->mode = mode;
+       err = xshm_add_channel(cfg, info, mode);
+       if (err)
+               goto error;
+
+       modem->channel[modem->channels] = cfg;
+       ++modem->channels;
+
+       err = xshm_verify_config(modem, cfg);
+       if (err)
+               goto error;
+
+       err = do_reply(info, 0);
+       if (err)
+               goto error;
+       return err;
+
+error:
+       --modem->channels;
+       kfree(cfg);
+       return err;
+}
+
+static int xshm_add_packet_ch(struct sk_buff *skb, struct genl_info *info)
+{
+       return xshm_add_ch(skb, info, XSHM_PACKET_MODE);
+}
+
+static int xshm_add_stream_ch(struct sk_buff *skb, struct genl_info *info)
+{
+       return xshm_add_ch(skb, info, XSHM_STREAM_MODE);
+}
+
+
+static int xshm_c_commit(struct sk_buff *skb, struct genl_info *info)
+{
+       struct xshm_modem *modem = get_modem(skb, info);
+       int err;
+       if (!modem)
+               return -EINVAL;
+
+       err = do_commit(modem);
+       if (!err)
+               do_reply(info, 0);
+       return err;
+}
+
+static int xshm_c_register(struct sk_buff *skb, struct genl_info *info)
+{
+       int err;
+       struct xshm_modem *modem = get_modem(skb, info);
+       if (!modem)
+               return -EINVAL;
+
+       err = do_register(modem);
+       if (!err)
+               do_reply(info, 0);
+       return err;
+}
+
+static int xshm_c_set_addr(struct sk_buff *skb, struct genl_info *info)
+{
+       int err;
+       struct xshm_modem *modem = get_modem(skb, info);
+       if (!modem)
+               return -EINVAL;
+
+       err = do_set_addr(modem);
+       if (!err)
+               do_reply(info, 0);
+       return err;
+}
+
+static int xshm_c_reset(struct sk_buff *skb, struct genl_info *info)
+{
+       struct xshm_modem *modem = get_modem(skb, info);
+       if (!modem)
+               return -EINVAL;
+
+       do_reset(modem);
+       do_reply(info, 0);
+       return 0;
+}
+
+static int xshm_c_verify(struct sk_buff *skb, struct genl_info *info)
+{
+       int err;
+       struct xshm_modem *modem = get_modem(skb, info);
+       if (!modem)
+               return -EINVAL;
+
+       err = verify_config(modem);
+       if (!err)
+               do_reply(info, 0);
+       return err;
+}
+
+static struct genl_ops xshm_genl_ops[] = {
+       {
+       .cmd = XSHM_C_ADD_STREAM_CHANNEL,
+       .flags = GENL_ADMIN_PERM,
+       .policy = xshm_genl_policy,
+       .doit = xshm_add_stream_ch,
+       .dumpit = NULL,
+       },
+       {
+       .cmd = XSHM_C_ADD_PACKET_CHANNEL,
+       .flags = GENL_ADMIN_PERM,
+       .policy = xshm_genl_policy,
+       .doit = xshm_add_packet_ch,
+       .dumpit = NULL,
+       },
+       {
+       .cmd = XSHM_C_COMMIT,
+       .flags = GENL_ADMIN_PERM,
+       .doit = xshm_c_commit,
+       .dumpit = NULL,
+       },
+       {
+       .cmd = XSHM_C_REGISTER,
+       .flags = GENL_ADMIN_PERM,
+       .doit = xshm_c_register,
+       .dumpit = NULL,
+       },
+       {
+       .cmd = XSHM_C_SET_ADDR,
+       .flags = GENL_ADMIN_PERM,
+       .doit = xshm_c_set_addr,
+       .dumpit = NULL,
+       },
+       {
+       .cmd = XSHM_C_RESET,
+       .flags = GENL_ADMIN_PERM,
+       .doit = xshm_c_reset,
+       .dumpit = NULL,
+       },
+       {
+       .cmd = __XSHM_C_VERIFY,
+       .flags = GENL_ADMIN_PERM,
+       .doit = xshm_c_verify,
+       .dumpit = NULL,
+       },
+
+};
+
+
+static void xshm_firmware(const struct firmware *fw, void *context)
+{
+       struct xshm_modem *modem = context;
+
+       if (fw == NULL) {
+               pr_warn("No boot-img provided\n");
+               return;
+       }
+
+       if (modem->commited) {
+               pr_warn("Received firmware too late in modem boot\n");
+               return;
+       }
+
+       pr_debug("recevied firmware\n");
+       memcpy(modem->shm_start, fw->data, fw->size);
+}
+
+/* Initialize boot handling and create sysfs entries*/
+int __init xshm_boot_init(void)
+{
+       int err = -EINVAL;
+       bool xshm_fake = false;
+
+       modem = kzalloc(sizeof(struct xshm_modem), GFP_KERNEL);
+       if (modem == NULL)
+               return -ENOMEM;
+
+       /* Negative xshm_size indicates module test without real SHM */
+       if (xshm_size < 0) {
+               xshm_fake = true;
+               xshm_size = abs(xshm_size);
+       }
+
+       if (xshm_size < TOC_SZ)
+               goto bad_config;
+
+       if (xshm_fake) {
+               modem->shm_start = kzalloc(xshm_size, GFP_KERNEL);
+               err = -ENOMEM;
+               if (!modem->shm_start)
+                       goto error;
+               xshm_start = (unsigned long) modem->shm_start;
+               memset(modem->shm_start, 0xaa, xshm_size);
+       } else {
+               if (xshm_start == 0)
+                       goto bad_config;
+               modem->shm_start = ioremap(xshm_start, xshm_size);
+       }
+
+       /* Initiate the Master TOC to 0xff for the first 512 bytes */
+       if (xshm_size > TOC_SZ)
+               memset(modem->shm_start, 0xff, TOC_SZ);
+
+       modem->modem_bootimg_size = TOC_SZ;
+
+       pr_debug("Boot image addr: %p size:%d\n", modem->shm_start,
+                       modem->modem_bootimg_size);
+
+       err = genl_register_family_with_ops(&xshm_gnl_family,
+               xshm_genl_ops, ARRAY_SIZE(xshm_genl_ops));
+       if (err)
+               goto error;
+
+       modem->gennetl_reg = 1;
+
+       err = xshm_request_firmware(modem, THIS_MODULE,
+                       STE_BOOTIMG_NAME, xshm_firmware);
+       if (err)
+               goto error;
+
+       return err;
+error:
+       pr_debug("initialization failed\n");
+
+       if (xshm_fake)
+               kfree(modem->shm_start);
+       return err;
+bad_config:
+       pr_err("Bad module configuration:"
+                       " xshm_base_address:%lu xshm_size:%lu err:%d\n",
+                       xshm_start, xshm_size, err);
+       /* Buildin module should not return error */
+       return -EINVAL;
+}
+
+void __exit xshm_boot_exit(void)
+{
+
+       if (modem->gennetl_reg)
+               genl_unregister_family(&xshm_gnl_family);
+       modem->gennetl_reg = 0;
+}
+module_init(xshm_boot_init);
+module_exit(xshm_boot_exit);