diff options
author | David Vrabel <david.vrabel@csr.com> | 2008-09-17 16:34:09 +0100 |
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committer | David Vrabel <dv02@dv02pc01.europe.root.pri> | 2008-09-17 16:54:24 +0100 |
commit | 8cc13a09474bb30d15dbf449767bb6d0198a8bf8 (patch) | |
tree | 2423388e0a7e9bca0c6e6f7edd5f492887d38160 /drivers/uwb/drp-avail.c | |
parent | 22d203ecef9b0cc1fa8d8f64c935b451ca7d1022 (diff) | |
download | kernel_samsung_tuna-8cc13a09474bb30d15dbf449767bb6d0198a8bf8.zip kernel_samsung_tuna-8cc13a09474bb30d15dbf449767bb6d0198a8bf8.tar.gz kernel_samsung_tuna-8cc13a09474bb30d15dbf449767bb6d0198a8bf8.tar.bz2 |
uwb: add the UWB stack (reservation manager)
DRP and reservation management.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Diffstat (limited to 'drivers/uwb/drp-avail.c')
-rw-r--r-- | drivers/uwb/drp-avail.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/drivers/uwb/drp-avail.c b/drivers/uwb/drp-avail.c new file mode 100644 index 0000000..3febd85 --- /dev/null +++ b/drivers/uwb/drp-avail.c @@ -0,0 +1,288 @@ +/* + * Ultra Wide Band + * DRP availability management + * + * Copyright (C) 2005-2006 Intel Corporation + * Reinette Chatre <reinette.chatre@intel.com> + * Copyright (C) 2008 Cambridge Silicon Radio Ltd. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * + * Manage DRP Availability (the MAS available for DRP + * reservations). Thus: + * + * - Handle DRP Availability Change notifications + * + * - Allow the reservation manager to indicate MAS reserved/released + * by local (owned by/targeted at the radio controller) + * reservations. + * + * - Based on the two sources above, generate a DRP Availability IE to + * be included in the beacon. + * + * See also the documentation for struct uwb_drp_avail. + */ + +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/bitmap.h> +#include "uwb-internal.h" + +/** + * uwb_drp_avail_init - initialize an RC's MAS availability + * + * All MAS are available initially. The RC will inform use which + * slots are used for the BP (it may change in size). + */ +void uwb_drp_avail_init(struct uwb_rc *rc) +{ + bitmap_fill(rc->drp_avail.global, UWB_NUM_MAS); + bitmap_fill(rc->drp_avail.local, UWB_NUM_MAS); + bitmap_fill(rc->drp_avail.pending, UWB_NUM_MAS); +} + +/* + * Determine MAS available for new local reservations. + * + * avail = global & local & pending + */ +static void uwb_drp_available(struct uwb_rc *rc, struct uwb_mas_bm *avail) +{ + bitmap_and(avail->bm, rc->drp_avail.global, rc->drp_avail.local, UWB_NUM_MAS); + bitmap_and(avail->bm, avail->bm, rc->drp_avail.pending, UWB_NUM_MAS); +} + +/** + * uwb_drp_avail_reserve_pending - reserve MAS for a new reservation + * @rc: the radio controller + * @mas: the MAS to reserve + * + * Returns 0 on success, or -EBUSY if the MAS requested aren't available. + */ +int uwb_drp_avail_reserve_pending(struct uwb_rc *rc, struct uwb_mas_bm *mas) +{ + struct uwb_mas_bm avail; + + uwb_drp_available(rc, &avail); + if (!bitmap_subset(mas->bm, avail.bm, UWB_NUM_MAS)) + return -EBUSY; + + bitmap_andnot(rc->drp_avail.pending, rc->drp_avail.pending, mas->bm, UWB_NUM_MAS); + return 0; +} + +/** + * uwb_drp_avail_reserve - reserve MAS for an established reservation + * @rc: the radio controller + * @mas: the MAS to reserve + */ +void uwb_drp_avail_reserve(struct uwb_rc *rc, struct uwb_mas_bm *mas) +{ + bitmap_or(rc->drp_avail.pending, rc->drp_avail.pending, mas->bm, UWB_NUM_MAS); + bitmap_andnot(rc->drp_avail.local, rc->drp_avail.local, mas->bm, UWB_NUM_MAS); + rc->drp_avail.ie_valid = false; +} + +/** + * uwb_drp_avail_release - release MAS from a pending or established reservation + * @rc: the radio controller + * @mas: the MAS to release + */ +void uwb_drp_avail_release(struct uwb_rc *rc, struct uwb_mas_bm *mas) +{ + bitmap_or(rc->drp_avail.local, rc->drp_avail.local, mas->bm, UWB_NUM_MAS); + bitmap_or(rc->drp_avail.pending, rc->drp_avail.pending, mas->bm, UWB_NUM_MAS); + rc->drp_avail.ie_valid = false; +} + +/** + * uwb_drp_avail_ie_update - update the DRP Availability IE + * @rc: the radio controller + * + * avail = global & local + */ +void uwb_drp_avail_ie_update(struct uwb_rc *rc) +{ + struct uwb_mas_bm avail; + + bitmap_and(avail.bm, rc->drp_avail.global, rc->drp_avail.local, UWB_NUM_MAS); + + rc->drp_avail.ie.hdr.element_id = UWB_IE_DRP_AVAILABILITY; + rc->drp_avail.ie.hdr.length = UWB_NUM_MAS / 8; + uwb_mas_bm_copy_le(rc->drp_avail.ie.bmp, &avail); + rc->drp_avail.ie_valid = true; +} + +/** + * Create an unsigned long from a buffer containing a byte stream. + * + * @array: pointer to buffer + * @itr: index of buffer from where we start + * @len: the buffer's remaining size may not be exact multiple of + * sizeof(unsigned long), @len is the length of buffer that needs + * to be converted. This will be sizeof(unsigned long) or smaller + * (BUG if not). If it is smaller then we will pad the remaining + * space of the result with zeroes. + */ +static +unsigned long get_val(u8 *array, size_t itr, size_t len) +{ + unsigned long val = 0; + size_t top = itr + len; + + BUG_ON(len > sizeof(val)); + + while (itr < top) { + val <<= 8; + val |= array[top - 1]; + top--; + } + val <<= 8 * (sizeof(val) - len); /* padding */ + return val; +} + +/** + * Initialize bitmap from data buffer. + * + * The bitmap to be converted could come from a IE, for example a + * DRP Availability IE. + * From ECMA-368 1.0 [16.8.7]: " + * octets: 1 1 N * (0 to 32) + * Element ID Length (=N) DRP Availability Bitmap + * + * The DRP Availability Bitmap field is up to 256 bits long, one + * bit for each MAS in the superframe, where the least-significant + * bit of the field corresponds to the first MAS in the superframe + * and successive bits correspond to successive MASs." + * + * The DRP Availability bitmap is in octets from 0 to 32, so octet + * 32 contains bits for MAS 1-8, etc. If the bitmap is smaller than 32 + * octets, the bits in octets not included at the end of the bitmap are + * treated as zero. In this case (when the bitmap is smaller than 32 + * octets) the MAS represented range from MAS 1 to MAS (size of bitmap) + * with the last octet still containing bits for MAS 1-8, etc. + * + * For example: + * F00F0102 03040506 0708090A 0B0C0D0E 0F010203 + * ^^^^ + * |||| + * |||| + * |||\LSB of byte is MAS 9 + * ||\MSB of byte is MAS 16 + * |\LSB of first byte is MAS 1 + * \ MSB of byte is MAS 8 + * + * An example of this encoding can be found in ECMA-368 Annex-D [Table D.11] + * + * The resulting bitmap will have the following mapping: + * bit position 0 == MAS 1 + * bit position 1 == MAS 2 + * ... + * bit position (UWB_NUM_MAS - 1) == MAS UWB_NUM_MAS + * + * @bmp_itr: pointer to bitmap (can be declared with DECLARE_BITMAP) + * @buffer: pointer to buffer containing bitmap data in big endian + * format (MSB first) + * @buffer_size:number of bytes with which bitmap should be initialized + */ +static +void buffer_to_bmp(unsigned long *bmp_itr, void *_buffer, + size_t buffer_size) +{ + u8 *buffer = _buffer; + size_t itr, len; + unsigned long val; + + itr = 0; + while (itr < buffer_size) { + len = buffer_size - itr >= sizeof(val) ? + sizeof(val) : buffer_size - itr; + val = get_val(buffer, itr, len); + bmp_itr[itr / sizeof(val)] = val; + itr += sizeof(val); + } +} + + +/** + * Extract DRP Availability bitmap from the notification. + * + * The notification that comes in contains a bitmap of (UWB_NUM_MAS / 8) bytes + * We convert that to our internal representation. + */ +static +int uwbd_evt_get_drp_avail(struct uwb_event *evt, unsigned long *bmp) +{ + struct device *dev = &evt->rc->uwb_dev.dev; + struct uwb_rc_evt_drp_avail *drp_evt; + int result = -EINVAL; + + /* Is there enough data to decode the event? */ + if (evt->notif.size < sizeof(*drp_evt)) { + dev_err(dev, "DRP Availability Change: Not enough " + "data to decode event [%zu bytes, %zu " + "needed]\n", evt->notif.size, sizeof(*drp_evt)); + goto error; + } + drp_evt = container_of(evt->notif.rceb, struct uwb_rc_evt_drp_avail, rceb); + buffer_to_bmp(bmp, drp_evt->bmp, UWB_NUM_MAS/8); + result = 0; +error: + return result; +} + + +/** + * Process an incoming DRP Availability notification. + * + * @evt: Event information (packs the actual event data, which + * radio controller it came to, etc). + * + * @returns: 0 on success (so uwbd() frees the event buffer), < 0 + * on error. + * + * According to ECMA-368 1.0 [16.8.7], bits set to ONE indicate that + * the MAS slot is available, bits set to ZERO indicate that the slot + * is busy. + * + * So we clear available slots, we set used slots :) + * + * The notification only marks non-availability based on the BP and + * received DRP IEs that are not for this radio controller. A copy of + * this bitmap is needed to generate the real availability (which + * includes local and pending reservations). + * + * The DRP Availability IE that this radio controller emits will need + * to be updated. + */ +int uwbd_evt_handle_rc_drp_avail(struct uwb_event *evt) +{ + int result; + struct uwb_rc *rc = evt->rc; + DECLARE_BITMAP(bmp, UWB_NUM_MAS); + + result = uwbd_evt_get_drp_avail(evt, bmp); + if (result < 0) + return result; + + mutex_lock(&rc->rsvs_mutex); + bitmap_copy(rc->drp_avail.global, bmp, UWB_NUM_MAS); + rc->drp_avail.ie_valid = false; + mutex_unlock(&rc->rsvs_mutex); + + uwb_rsv_sched_update(rc); + + return 0; +} |