The files has name bh, but it is not really a standard Linux bottom half. SDIO interface does not support asyncronous non-blocking i/o, so serving code was implemented as a realtime thread. Some effort is ongoing to convert the thread to a realtime workqueue and start/stop it on interface start/stop. Signed-off-by: Dmitry Tarnyagin <dmitry.tarnyagin@xxxxxxxxxxxxxx> --- drivers/staging/cw1200/bh.c | 619 +++++++++++++++++++++++++++++++++++++++++++ drivers/staging/cw1200/bh.h | 30 ++ 2 files changed, 649 insertions(+), 0 deletions(-) create mode 100644 drivers/staging/cw1200/bh.c create mode 100644 drivers/staging/cw1200/bh.h diff --git a/drivers/staging/cw1200/bh.c b/drivers/staging/cw1200/bh.c new file mode 100644 index 0000000..2f78e60 --- /dev/null +++ b/drivers/staging/cw1200/bh.c @@ -0,0 +1,619 @@ +/* + * Device handling thread implementation for mac80211 ST-Ericsson CW1200 drivers + * + * Copyright (c) 2010, ST-Ericsson + * Author: Dmitry Tarnyagin <dmitry.tarnyagin@xxxxxxxxxxxxxx> + * + * Based on: + * ST-Ericsson UMAC CW1200 driver, which is + * Copyright (c) 2010, ST-Ericsson + * Author: Ajitpal Singh <ajitpal.singh@xxxxxxxxxxxxxx> + * + * 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. + */ + +#include <net/mac80211.h> +#include <linux/kthread.h> + +#include "cw1200.h" +#include "bh.h" +#include "hwio.h" +#include "wsm.h" +#include "sbus.h" +#include "debug.h" + +#if defined(CONFIG_CW1200_BH_DEBUG) +#define bh_printk(...) printk(__VA_ARGS__) +#else +#define bh_printk(...) +#endif + +static int cw1200_bh(void *arg); + +/* TODO: Verify these numbers with WSM specification. */ +#define DOWNLOAD_BLOCK_SIZE_WR (0x1000 - 4) +/* an SPI message cannot be bigger than (2"12-1)*2 bytes + * "*2" to cvt to bytes */ +#define MAX_SZ_RD_WR_BUFFERS (DOWNLOAD_BLOCK_SIZE_WR*2) +#define PIGGYBACK_CTRL_REG (2) +#define EFFECTIVE_BUF_SIZE (MAX_SZ_RD_WR_BUFFERS - PIGGYBACK_CTRL_REG) + +/* Suspend state privates */ +enum cw1200_bh_pm_state { + CW1200_BH_RESUMED = 0, + CW1200_BH_SUSPEND, + CW1200_BH_SUSPENDED, + CW1200_BH_RESUME, +}; + +typedef int (*cw1200_wsm_handler)(struct cw1200_common *priv, + u8 *data, size_t size); + + +int cw1200_register_bh(struct cw1200_common *priv) +{ + int err = 0; + struct sched_param param = { .sched_priority = 1 }; + bh_printk(KERN_DEBUG "[BH] register.\n"); + BUG_ON(priv->bh_thread); + atomic_set(&priv->bh_rx, 0); + atomic_set(&priv->bh_tx, 0); + atomic_set(&priv->bh_term, 0); + atomic_set(&priv->bh_suspend, CW1200_BH_RESUMED); + priv->buf_id_tx = 0; + priv->buf_id_rx = 0; + init_waitqueue_head(&priv->bh_wq); + init_waitqueue_head(&priv->bh_evt_wq); + priv->bh_thread = kthread_create(&cw1200_bh, priv, "cw1200_bh"); + if (IS_ERR(priv->bh_thread)) { + err = PTR_ERR(priv->bh_thread); + priv->bh_thread = NULL; + } else { + WARN_ON(sched_setscheduler(priv->bh_thread, + SCHED_FIFO, ¶m)); +#ifdef HAS_PUT_TASK_STRUCT + get_task_struct(priv->bh_thread); +#endif + wake_up_process(priv->bh_thread); + } + return err; +} + +void cw1200_unregister_bh(struct cw1200_common *priv) +{ + struct task_struct *thread = priv->bh_thread; + if (WARN_ON(!thread)) + return; + + priv->bh_thread = NULL; + bh_printk(KERN_DEBUG "[BH] unregister.\n"); + atomic_add(1, &priv->bh_term); + wake_up(&priv->bh_wq); + kthread_stop(thread); +#ifdef HAS_PUT_TASK_STRUCT + put_task_struct(thread); +#endif +} + +void cw1200_irq_handler(struct cw1200_common *priv) +{ + bh_printk(KERN_DEBUG "[BH] irq.\n"); + if (/* WARN_ON */(priv->bh_error)) + return; + + if (atomic_add_return(1, &priv->bh_rx) == 1) + wake_up(&priv->bh_wq); +} + +void cw1200_bh_wakeup(struct cw1200_common *priv) +{ + bh_printk(KERN_DEBUG "[BH] wakeup.\n"); + if (WARN_ON(priv->bh_error)) + return; + + if (atomic_add_return(1, &priv->bh_tx) == 1) + wake_up(&priv->bh_wq); +} + +int cw1200_bh_suspend(struct cw1200_common *priv) +{ + bh_printk(KERN_DEBUG "[BH] suspend.\n"); + if (WARN_ON(priv->bh_error)) + return 0; + + atomic_set(&priv->bh_suspend, CW1200_BH_SUSPEND); + wake_up(&priv->bh_wq); + return wait_event_timeout(priv->bh_evt_wq, priv->bh_error || + (CW1200_BH_SUSPENDED == atomic_read(&priv->bh_suspend)), + 1 * HZ) ? 0 : -ETIMEDOUT; +} + +int cw1200_bh_resume(struct cw1200_common *priv) +{ + bh_printk(KERN_DEBUG "[BH] resume.\n"); + if (WARN_ON(priv->bh_error)) + return 0; + + atomic_set(&priv->bh_suspend, CW1200_BH_RESUME); + wake_up(&priv->bh_wq); + return wait_event_timeout(priv->bh_evt_wq, priv->bh_error || + (CW1200_BH_RESUMED == atomic_read(&priv->bh_suspend)), + 1 * HZ) ? 0 : -ETIMEDOUT; +} + +static inline void wsm_alloc_tx_buffer(struct cw1200_common *priv) +{ + ++priv->hw_bufs_used; +} + +int wsm_release_tx_buffer(struct cw1200_common *priv, int count) +{ + int ret = 0; + int hw_bufs_used = priv->hw_bufs_used; + + priv->hw_bufs_used -= count; + if (WARN_ON(priv->hw_bufs_used < 0)) + ret = -1; + else if (hw_bufs_used >= priv->wsm_caps.numInpChBufs) + ret = 1; + if (!priv->hw_bufs_used) + wake_up(&priv->bh_evt_wq); + return ret; +} + +static struct sk_buff *cw1200_get_skb(struct cw1200_common *priv, size_t len) +{ + struct sk_buff *skb; + size_t alloc_len = (len > SDIO_BLOCK_SIZE) ? len : SDIO_BLOCK_SIZE; + + if (len > SDIO_BLOCK_SIZE || !priv->skb_cache) { + skb = dev_alloc_skb(alloc_len + + WSM_TX_EXTRA_HEADROOM + + 8 /* TKIP IV */ + + 12 /* TKIP ICV + MIC */ + - 2 /* Piggyback */); + /* In AP mode RXed SKB can be looped back as a broadcast. + * Here we reserve enough space for headers. */ + skb_reserve(skb, WSM_TX_EXTRA_HEADROOM + + 8 /* TKIP IV */ + - WSM_RX_EXTRA_HEADROOM); + } else { + skb = priv->skb_cache; + priv->skb_cache = NULL; + } + return skb; +} + +static void cw1200_put_skb(struct cw1200_common *priv, struct sk_buff *skb) +{ + if (priv->skb_cache) + dev_kfree_skb(skb); + else + priv->skb_cache = skb; +} + +static int cw1200_bh_read_ctrl_reg(struct cw1200_common *priv, + u16 *ctrl_reg) +{ + int ret; + + ret = cw1200_reg_read_16(priv, + ST90TDS_CONTROL_REG_ID, ctrl_reg); + if (ret) { + ret = cw1200_reg_read_16(priv, + ST90TDS_CONTROL_REG_ID, ctrl_reg); + if (ret) + printk(KERN_ERR + "[BH] Failed to read control register.\n"); + } + + return ret; +} + +static int cw1200_device_wakeup(struct cw1200_common *priv) +{ + u16 ctrl_reg; + int ret; + + bh_printk(KERN_DEBUG "[BH] Device wakeup.\n"); + + /* To force the device to be always-on, the host sets WLAN_UP to 1 */ + ret = cw1200_reg_write_16(priv, ST90TDS_CONTROL_REG_ID, + ST90TDS_CONT_WUP_BIT); + if (WARN_ON(ret)) + return ret; + + ret = cw1200_bh_read_ctrl_reg(priv, &ctrl_reg); + if (WARN_ON(ret)) + return ret; + + /* If the device returns WLAN_RDY as 1, the device is active and will + * remain active. */ + if (ctrl_reg & ST90TDS_CONT_RDY_BIT) { + bh_printk(KERN_DEBUG "[BH] Device awake.\n"); + return 1; + } + + return 0; +} + +/* Must be called from BH thraed. */ +void cw1200_enable_powersave(struct cw1200_common *priv, + bool enable) +{ + bh_printk(KERN_DEBUG "[BH] Powerave is %s.\n", + enable ? "enabled" : "disabled"); + priv->powersave_enabled = enable; +} + +static int cw1200_bh(void *arg) +{ + struct cw1200_common *priv = arg; + struct sk_buff *skb_rx = NULL; + size_t read_len = 0; + int rx, tx, term, suspend; + struct wsm_hdr *wsm; + size_t wsm_len; + int wsm_id; + u8 wsm_seq; + int rx_resync = 1; + u16 ctrl_reg = 0; + int tx_allowed; + int pending_tx = 0; + int tx_burst; + int rx_burst = 0; + long status; +#if defined(CONFIG_CW1200_WSM_DUMPS) + size_t wsm_dump_max = -1; +#endif + u32 dummy; + + for (;;) { + if (!priv->hw_bufs_used + && priv->powersave_enabled + && !priv->device_can_sleep) + status = 1 * HZ; + else if (priv->hw_bufs_used) + /* Interrupt loss detection */ + status = 1 * HZ; + else + status = MAX_SCHEDULE_TIMEOUT; + + /* Dummy Read for SDIO retry mechanism*/ + if (((atomic_read(&priv->bh_rx) == 0) && + (atomic_read(&priv->bh_tx) == 0))) + cw1200_reg_read(priv, ST90TDS_CONFIG_REG_ID, + &dummy, sizeof(dummy)); +#if defined(CONFIG_CW1200_WSM_DUMPS_SHORT) + wsm_dump_max = priv->wsm_dump_max_size; +#endif /* CONFIG_CW1200_WSM_DUMPS_SHORT */ + + status = wait_event_interruptible_timeout(priv->bh_wq, ({ + rx = atomic_xchg(&priv->bh_rx, 0); + tx = atomic_xchg(&priv->bh_tx, 0); + term = atomic_xchg(&priv->bh_term, 0); + suspend = pending_tx ? + 0 : atomic_read(&priv->bh_suspend); + (rx || tx || term || suspend || priv->bh_error); + }), status); + + if (status < 0 || term || priv->bh_error) + break; + + if (!status && priv->hw_bufs_used) { + unsigned long timestamp = jiffies; + long timeout; + bool pending = false; + int i; + + wiphy_warn(priv->hw->wiphy, "Missed interrupt?\n"); + rx = 1; + + /* Get a timestamp of "oldest" frame */ + for (i = 0; i < 4; ++i) + pending |= cw1200_queue_get_xmit_timestamp( + &priv->tx_queue[i], + ×tamp); + + /* Check if frame transmission is timed out. + * Add an extra second with respect to possible + * interrupt loss. */ + timeout = timestamp + + WSM_CMD_LAST_CHANCE_TIMEOUT + + 1 * HZ - + jiffies; + + /* And terminate BH tread if the frame is "stuck" */ + if (pending && timeout < 0) { + wiphy_warn(priv->hw->wiphy, + "Timeout waiting for TX confirm.\n"); + break; + } + +#if defined(CONFIG_CW1200_DUMP_ON_ERROR) + BUG_ON(1); +#endif /* CONFIG_CW1200_DUMP_ON_ERROR */ + } else if (!status) { + bh_printk(KERN_DEBUG "[BH] Device wakedown.\n"); + WARN_ON(cw1200_reg_write_16(priv, + ST90TDS_CONTROL_REG_ID, 0)); + priv->device_can_sleep = true; + continue; + } else if (suspend) { + bh_printk(KERN_DEBUG "[BH] Device suspend.\n"); + if (priv->powersave_enabled) { + WARN_ON(cw1200_reg_write_16(priv, + ST90TDS_CONTROL_REG_ID, 0)); + priv->device_can_sleep = true; + } + + atomic_set(&priv->bh_suspend, CW1200_BH_SUSPENDED); + wake_up(&priv->bh_evt_wq); + status = wait_event_interruptible(priv->bh_wq, + CW1200_BH_RESUME == atomic_read( + &priv->bh_suspend)); + if (status < 0) { + wiphy_err(priv->hw->wiphy, + "%s: Failed to wait for resume: %ld.\n", + __func__, status); + break; + } + bh_printk(KERN_DEBUG "[BH] Device resume.\n"); + atomic_set(&priv->bh_suspend, CW1200_BH_RESUMED); + wake_up(&priv->bh_evt_wq); + atomic_add(1, &priv->bh_rx); + continue; + } + + tx += pending_tx; + pending_tx = 0; + + if (rx) { + size_t alloc_len; + u8 *data; + + if (WARN_ON(cw1200_bh_read_ctrl_reg( + priv, &ctrl_reg))) + break; +rx: + read_len = (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK) * 2; + if (!read_len) { + rx_burst = 0; + goto tx; + } + + if (WARN_ON((read_len < sizeof(struct wsm_hdr)) || + (read_len > EFFECTIVE_BUF_SIZE))) { + printk(KERN_DEBUG "Invalid read len: %ld", + read_len); + break; + } + + /* Add SIZE of PIGGYBACK reg (CONTROL Reg) + * to the NEXT Message length + 2 Bytes for SKB */ + read_len = read_len + 2; + +#if defined(CONFIG_CW1200_NON_POWER_OF_TWO_BLOCKSIZES) + alloc_len = priv->sbus_ops->align_size( + priv->sbus_priv, read_len); +#else /* CONFIG_CW1200_NON_POWER_OF_TWO_BLOCKSIZES */ + /* Platform's SDIO workaround */ + alloc_len = read_len & ~(SDIO_BLOCK_SIZE - 1); + if (read_len & (SDIO_BLOCK_SIZE - 1)) + alloc_len += SDIO_BLOCK_SIZE; +#endif /* CONFIG_CW1200_NON_POWER_OF_TWO_BLOCKSIZES */ + + /* Check if not exceeding CW1200 capabilities */ + if (WARN_ON_ONCE(alloc_len > EFFECTIVE_BUF_SIZE)) { + printk(KERN_DEBUG "Read aligned len: %ld\n", + alloc_len); + } + + skb_rx = cw1200_get_skb(priv, alloc_len); + if (WARN_ON(!skb_rx)) + break; + + skb_trim(skb_rx, 0); + skb_put(skb_rx, read_len); + data = skb_rx->data; + if (WARN_ON(!data)) + break; + + if (WARN_ON(cw1200_data_read(priv, data, alloc_len))) + break; + + /* Piggyback */ + ctrl_reg = __le16_to_cpu( + ((__le16 *)data)[alloc_len / 2 - 1]); + + wsm = (struct wsm_hdr *)data; + wsm_len = __le32_to_cpu(wsm->len); + if (WARN_ON(wsm_len > read_len)) + break; + +#if defined(CONFIG_CW1200_WSM_DUMPS) + if (unlikely(priv->wsm_enable_wsm_dumps)) + print_hex_dump_bytes("<-- ", + DUMP_PREFIX_NONE, + data, min(wsm_len, wsm_dump_max)); +#endif /* CONFIG_CW1200_WSM_DUMPS */ + + wsm_id = __le32_to_cpu(wsm->id) & 0xFFF; + wsm_seq = (__le32_to_cpu(wsm->id) >> 13) & 7; + + skb_trim(skb_rx, wsm_len); + + if (unlikely(wsm_id == 0x0800)) { + wsm_handle_exception(priv, + &data[sizeof(*wsm)], + wsm_len - sizeof(*wsm)); + break; + } else if (unlikely(!rx_resync)) { + if (WARN_ON(wsm_seq != priv->wsm_rx_seq)) { +#if defined(CONFIG_CW1200_DUMP_ON_ERROR) + BUG_ON(1); +#endif /* CONFIG_CW1200_DUMP_ON_ERROR */ + break; + } + } + priv->wsm_rx_seq = (wsm_seq + 1) & 7; + rx_resync = 0; + + if (wsm_id & 0x0400) { + int rc = wsm_release_tx_buffer(priv, 1); + if (WARN_ON(rc < 0)) + break; + else if (rc > 0) + tx = 1; + } + + /* cw1200_wsm_rx takes care on SKB livetime */ + if (WARN_ON(wsm_handle_rx(priv, wsm_id, wsm, &skb_rx))) + break; + + if (skb_rx) { + cw1200_put_skb(priv, skb_rx); + skb_rx = NULL; + } + + read_len = 0; + + if (rx_burst) { + cw1200_debug_rx_burst(priv); + --rx_burst; + goto rx; + } + } + +tx: + BUG_ON(priv->hw_bufs_used > priv->wsm_caps.numInpChBufs); + tx_burst = priv->wsm_caps.numInpChBufs - priv->hw_bufs_used; + tx_allowed = tx_burst > 0; + + if (tx && tx_allowed) { + size_t tx_len; + u8 *data; + int ret; + + if (priv->device_can_sleep) { + ret = cw1200_device_wakeup(priv); + if (WARN_ON(ret < 0)) + break; + else if (ret) + priv->device_can_sleep = false; + else { + /* Wait for "awake" interrupt */ + pending_tx = tx; + continue; + } + } + + wsm_alloc_tx_buffer(priv); + ret = wsm_get_tx(priv, &data, &tx_len, &tx_burst); + if (ret <= 0) { + wsm_release_tx_buffer(priv, 1); + if (WARN_ON(ret < 0)) + break; + } else { + wsm = (struct wsm_hdr *)data; + BUG_ON(tx_len < sizeof(*wsm)); + BUG_ON(__le32_to_cpu(wsm->len) != tx_len); + +#if 0 /* count is not implemented */ + if (ret > 1) + atomic_add(1, &priv->bh_tx); +#else + atomic_add(1, &priv->bh_tx); +#endif + + +#if defined(CONFIG_CW1200_NON_POWER_OF_TWO_BLOCKSIZES) + tx_len = priv->sbus_ops->align_size( + priv->sbus_priv, tx_len); +#else /* CONFIG_CW1200_NON_POWER_OF_TWO_BLOCKSIZES */ + /* HACK!!! Platform limitation. + * It is also supported by upper layer: + * there is always enough space at the + * end of the buffer. */ + if (tx_len & (SDIO_BLOCK_SIZE - 1)) { + tx_len &= ~(SDIO_BLOCK_SIZE - 1); + tx_len += SDIO_BLOCK_SIZE; + } +#endif /* CONFIG_CW1200_NON_POWER_OF_TWO_BLOCKSIZES */ + + /* Check if not exceeding CW1200 + capabilities */ + if (WARN_ON_ONCE( + tx_len > EFFECTIVE_BUF_SIZE)) { + printk(KERN_DEBUG "Write aligned len:" + " %ld\n", tx_len); + } + + wsm->id &= __cpu_to_le32( + ~WSM_TX_SEQ(WSM_TX_SEQ_MAX)); + wsm->id |= cpu_to_le32( + WSM_TX_SEQ(priv->wsm_tx_seq)); + + if (WARN_ON(cw1200_data_write(priv, + data, tx_len))) { + wsm_release_tx_buffer(priv, 1); + break; + } + +#if defined(CONFIG_CW1200_WSM_DUMPS) + if (unlikely(priv->wsm_enable_wsm_dumps)) + print_hex_dump_bytes("--> ", + DUMP_PREFIX_NONE, + data, + min_t(size_t, + __le32_to_cpu(wsm->len), + wsm_dump_max)); +#endif /* CONFIG_CW1200_WSM_DUMPS */ + + wsm_txed(priv, data); + priv->wsm_tx_seq = (priv->wsm_tx_seq + 1) & + WSM_TX_SEQ_MAX; + + if (tx_burst > 1) { + cw1200_debug_tx_burst(priv); + ++rx_burst; + goto tx; + } + } + } + + if (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK) + goto rx; + } + + if (skb_rx) { + cw1200_put_skb(priv, skb_rx); + skb_rx = NULL; + } + + + if (!term) { + cw1200_dbg(CW1200_DBG_ERROR, "[BH] Fatal error, exitting.\n"); +#if defined(CONFIG_CW1200_DUMP_ON_ERROR) + BUG_ON(1); +#endif /* CONFIG_CW1200_DUMP_ON_ERROR */ + priv->bh_error = 1; + /* TODO: schedule_work(recovery) */ +#ifndef HAS_PUT_TASK_STRUCT + /* The only reason of having this stupid code here is + * that __put_task_struct is not exported by kernel. */ + for (;;) { + int status = wait_event_interruptible(priv->bh_wq, ({ + term = atomic_xchg(&priv->bh_term, 0); + (term); + })); + + if (status || term) + break; + } +#endif + } + return 0; +} diff --git a/drivers/staging/cw1200/bh.h b/drivers/staging/cw1200/bh.h new file mode 100644 index 0000000..ea4598a --- /dev/null +++ b/drivers/staging/cw1200/bh.h @@ -0,0 +1,30 @@ +/* + * Device handling thread interface for mac80211 ST-Ericsson CW1200 drivers + * + * Copyright (c) 2010, ST-Ericsson + * Author: Dmitry Tarnyagin <dmitry.tarnyagin@xxxxxxxxxxxxxx> + * + * 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. + */ + +#ifndef CW1200_BH_H +#define CW1200_BH_H + +/* extern */ struct cw1200_common; + +#define SDIO_BLOCK_SIZE (512) + +int cw1200_register_bh(struct cw1200_common *priv); +void cw1200_unregister_bh(struct cw1200_common *priv); +void cw1200_irq_handler(struct cw1200_common *priv); +void cw1200_bh_wakeup(struct cw1200_common *priv); +int cw1200_bh_suspend(struct cw1200_common *priv); +int cw1200_bh_resume(struct cw1200_common *priv); +/* Must be called from BH thread. */ +void cw1200_enable_powersave(struct cw1200_common *priv, + bool enable); +int wsm_release_tx_buffer(struct cw1200_common *priv, int count); + +#endif /* CW1200_BH_H */ -- 1.7.9 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html