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Diffstat (limited to 'drivers/atm/ambassador.c')
| -rw-r--r-- | drivers/atm/ambassador.c | 2400 |
1 files changed, 0 insertions, 2400 deletions
diff --git a/drivers/atm/ambassador.c b/drivers/atm/ambassador.c deleted file mode 100644 index c039b8a4fefe..000000000000 --- a/drivers/atm/ambassador.c +++ /dev/null @@ -1,2400 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - Madge Ambassador ATM Adapter driver. - Copyright (C) 1995-1999 Madge Networks Ltd. - -*/ - -/* * dedicated to the memory of Graham Gordon 1971-1998 * */ - -#include <linux/module.h> -#include <linux/types.h> -#include <linux/pci.h> -#include <linux/kernel.h> -#include <linux/init.h> -#include <linux/ioport.h> -#include <linux/atmdev.h> -#include <linux/delay.h> -#include <linux/interrupt.h> -#include <linux/poison.h> -#include <linux/bitrev.h> -#include <linux/mutex.h> -#include <linux/firmware.h> -#include <linux/ihex.h> -#include <linux/slab.h> - -#include <linux/atomic.h> -#include <asm/io.h> -#include <asm/byteorder.h> - -#include "ambassador.h" - -#define maintainer_string "Giuliano Procida at Madge Networks <gprocida@madge.com>" -#define description_string "Madge ATM Ambassador driver" -#define version_string "1.2.4" - -static inline void __init show_version (void) { - printk ("%s version %s\n", description_string, version_string); -} - -/* - - Theory of Operation - - I Hardware, detection, initialisation and shutdown. - - 1. Supported Hardware - - This driver is for the PCI ATMizer-based Ambassador card (except - very early versions). It is not suitable for the similar EISA "TR7" - card. Commercially, both cards are known as Collage Server ATM - adapters. - - The loader supports image transfer to the card, image start and few - other miscellaneous commands. - - Only AAL5 is supported with vpi = 0 and vci in the range 0 to 1023. - - The cards are big-endian. - - 2. Detection - - Standard PCI stuff, the early cards are detected and rejected. - - 3. Initialisation - - The cards are reset and the self-test results are checked. The - microcode image is then transferred and started. This waits for a - pointer to a descriptor containing details of the host-based queues - and buffers and various parameters etc. Once they are processed - normal operations may begin. The BIA is read using a microcode - command. - - 4. Shutdown - - This may be accomplished either by a card reset or via the microcode - shutdown command. Further investigation required. - - 5. Persistent state - - The card reset does not affect PCI configuration (good) or the - contents of several other "shared run-time registers" (bad) which - include doorbell and interrupt control as well as EEPROM and PCI - control. The driver must be careful when modifying these registers - not to touch bits it does not use and to undo any changes at exit. - - II Driver software - - 0. Generalities - - The adapter is quite intelligent (fast) and has a simple interface - (few features). VPI is always zero, 1024 VCIs are supported. There - is limited cell rate support. UBR channels can be capped and ABR - (explicit rate, but not EFCI) is supported. There is no CBR or VBR - support. - - 1. Driver <-> Adapter Communication - - Apart from the basic loader commands, the driver communicates - through three entities: the command queue (CQ), the transmit queue - pair (TXQ) and the receive queue pairs (RXQ). These three entities - are set up by the host and passed to the microcode just after it has - been started. - - All queues are host-based circular queues. They are contiguous and - (due to hardware limitations) have some restrictions as to their - locations in (bus) memory. They are of the "full means the same as - empty so don't do that" variety since the adapter uses pointers - internally. - - The queue pairs work as follows: one queue is for supply to the - adapter, items in it are pending and are owned by the adapter; the - other is the queue for return from the adapter, items in it have - been dealt with by the adapter. The host adds items to the supply - (TX descriptors and free RX buffer descriptors) and removes items - from the return (TX and RX completions). The adapter deals with out - of order completions. - - Interrupts (card to host) and the doorbell (host to card) are used - for signalling. - - 1. CQ - - This is to communicate "open VC", "close VC", "get stats" etc. to - the adapter. At most one command is retired every millisecond by the - card. There is no out of order completion or notification. The - driver needs to check the return code of the command, waiting as - appropriate. - - 2. TXQ - - TX supply items are of variable length (scatter gather support) and - so the queue items are (more or less) pointers to the real thing. - Each TX supply item contains a unique, host-supplied handle (the skb - bus address seems most sensible as this works for Alphas as well, - there is no need to do any endian conversions on the handles). - - TX return items consist of just the handles above. - - 3. RXQ (up to 4 of these with different lengths and buffer sizes) - - RX supply items consist of a unique, host-supplied handle (the skb - bus address again) and a pointer to the buffer data area. - - RX return items consist of the handle above, the VC, length and a - status word. This just screams "oh so easy" doesn't it? - - Note on RX pool sizes: - - Each pool should have enough buffers to handle a back-to-back stream - of minimum sized frames on a single VC. For example: - - frame spacing = 3us (about right) - - delay = IRQ lat + RX handling + RX buffer replenish = 20 (us) (a guess) - - min number of buffers for one VC = 1 + delay/spacing (buffers) - - delay/spacing = latency = (20+2)/3 = 7 (buffers) (rounding up) - - The 20us delay assumes that there is no need to sleep; if we need to - sleep to get buffers we are going to drop frames anyway. - - In fact, each pool should have enough buffers to support the - simultaneous reassembly of a separate frame on each VC and cope with - the case in which frames complete in round robin cell fashion on - each VC. - - Only one frame can complete at each cell arrival, so if "n" VCs are - open, the worst case is to have them all complete frames together - followed by all starting new frames together. - - desired number of buffers = n + delay/spacing - - These are the extreme requirements, however, they are "n+k" for some - "k" so we have only the constant to choose. This is the argument - rx_lats which current defaults to 7. - - Actually, "n ? n+k : 0" is better and this is what is implemented, - subject to the limit given by the pool size. - - 4. Driver locking - - Simple spinlocks are used around the TX and RX queue mechanisms. - Anyone with a faster, working method is welcome to implement it. - - The adapter command queue is protected with a spinlock. We always - wait for commands to complete. - - A more complex form of locking is used around parts of the VC open - and close functions. There are three reasons for a lock: 1. we need - to do atomic rate reservation and release (not used yet), 2. Opening - sometimes involves two adapter commands which must not be separated - by another command on the same VC, 3. the changes to RX pool size - must be atomic. The lock needs to work over context switches, so we - use a semaphore. - - III Hardware Features and Microcode Bugs - - 1. Byte Ordering - - *%^"$&%^$*&^"$(%^$#&^%$(&#%$*(&^#%!"!"!*! - - 2. Memory access - - All structures that are not accessed using DMA must be 4-byte - aligned (not a problem) and must not cross 4MB boundaries. - - There is a DMA memory hole at E0000000-E00000FF (groan). - - TX fragments (DMA read) must not cross 4MB boundaries (would be 16MB - but for a hardware bug). - - RX buffers (DMA write) must not cross 16MB boundaries and must - include spare trailing bytes up to the next 4-byte boundary; they - will be written with rubbish. - - The PLX likes to prefetch; if reading up to 4 u32 past the end of - each TX fragment is not a problem, then TX can be made to go a - little faster by passing a flag at init that disables a prefetch - workaround. We do not pass this flag. (new microcode only) - - Now we: - . Note that alloc_skb rounds up size to a 16byte boundary. - . Ensure all areas do not traverse 4MB boundaries. - . Ensure all areas do not start at a E00000xx bus address. - (I cannot be certain, but this may always hold with Linux) - . Make all failures cause a loud message. - . Discard non-conforming SKBs (causes TX failure or RX fill delay). - . Discard non-conforming TX fragment descriptors (the TX fails). - In the future we could: - . Allow RX areas that traverse 4MB (but not 16MB) boundaries. - . Segment TX areas into some/more fragments, when necessary. - . Relax checks for non-DMA items (ignore hole). - . Give scatter-gather (iovec) requirements using ???. (?) - - 3. VC close is broken (only for new microcode) - - The VC close adapter microcode command fails to do anything if any - frames have been received on the VC but none have been transmitted. - Frames continue to be reassembled and passed (with IRQ) to the - driver. - - IV To Do List - - . Fix bugs! - - . Timer code may be broken. - - . Deal with buggy VC close (somehow) in microcode 12. - - . Handle interrupted and/or non-blocking writes - is this a job for - the protocol layer? - - . Add code to break up TX fragments when they span 4MB boundaries. - - . Add SUNI phy layer (need to know where SUNI lives on card). - - . Implement a tx_alloc fn to (a) satisfy TX alignment etc. and (b) - leave extra headroom space for Ambassador TX descriptors. - - . Understand these elements of struct atm_vcc: recvq (proto?), - sleep, callback, listenq, backlog_quota, reply and user_back. - - . Adjust TX/RX skb allocation to favour IP with LANE/CLIP (configurable). - - . Impose a TX-pending limit (2?) on each VC, help avoid TX q overflow. - - . Decide whether RX buffer recycling is or can be made completely safe; - turn it back on. It looks like Werner is going to axe this. - - . Implement QoS changes on open VCs (involves extracting parts of VC open - and close into separate functions and using them to make changes). - - . Hack on command queue so that someone can issue multiple commands and wait - on the last one (OR only "no-op" or "wait" commands are waited for). - - . Eliminate need for while-schedule around do_command. - -*/ - -static void do_housekeeping (struct timer_list *t); -/********** globals **********/ - -static unsigned short debug = 0; -static unsigned int cmds = 8; -static unsigned int txs = 32; -static unsigned int rxs[NUM_RX_POOLS] = { 64, 64, 64, 64 }; -static unsigned int rxs_bs[NUM_RX_POOLS] = { 4080, 12240, 36720, 65535 }; -static unsigned int rx_lats = 7; -static unsigned char pci_lat = 0; - -static const unsigned long onegigmask = -1 << 30; - -/********** access to adapter **********/ - -static inline void wr_plain (const amb_dev * dev, size_t addr, u32 data) { - PRINTD (DBG_FLOW|DBG_REGS, "wr: %08zx <- %08x", addr, data); -#ifdef AMB_MMIO - dev->membase[addr / sizeof(u32)] = data; -#else - outl (data, dev->iobase + addr); -#endif -} - -static inline u32 rd_plain (const amb_dev * dev, size_t addr) { -#ifdef AMB_MMIO - u32 data = dev->membase[addr / sizeof(u32)]; -#else - u32 data = inl (dev->iobase + addr); -#endif - PRINTD (DBG_FLOW|DBG_REGS, "rd: %08zx -> %08x", addr, data); - return data; -} - -static inline void wr_mem (const amb_dev * dev, size_t addr, u32 data) { - __be32 be = cpu_to_be32 (data); - PRINTD (DBG_FLOW|DBG_REGS, "wr: %08zx <- %08x b[%08x]", addr, data, be); -#ifdef AMB_MMIO - dev->membase[addr / sizeof(u32)] = be; -#else - outl (be, dev->iobase + addr); -#endif -} - -static inline u32 rd_mem (const amb_dev * dev, size_t addr) { -#ifdef AMB_MMIO - __be32 be = dev->membase[addr / sizeof(u32)]; -#else - __be32 be = inl (dev->iobase + addr); -#endif - u32 data = be32_to_cpu (be); - PRINTD (DBG_FLOW|DBG_REGS, "rd: %08zx -> %08x b[%08x]", addr, data, be); - return data; -} - -/********** dump routines **********/ - -static inline void dump_registers (const amb_dev * dev) { -#ifdef DEBUG_AMBASSADOR - if (debug & DBG_REGS) { - size_t i; - PRINTD (DBG_REGS, "reading PLX control: "); - for (i = 0x00; i < 0x30; i += sizeof(u32)) - rd_mem (dev, i); - PRINTD (DBG_REGS, "reading mailboxes: "); - for (i = 0x40; i < 0x60; i += sizeof(u32)) - rd_mem (dev, i); - PRINTD (DBG_REGS, "reading doorb irqev irqen reset:"); - for (i = 0x60; i < 0x70; i += sizeof(u32)) - rd_mem (dev, i); - } -#else - (void) dev; -#endif - return; -} - -static inline void dump_loader_block (volatile loader_block * lb) { -#ifdef DEBUG_AMBASSADOR - unsigned int i; - PRINTDB (DBG_LOAD, "lb @ %p; res: %d, cmd: %d, pay:", - lb, be32_to_cpu (lb->result), be32_to_cpu (lb->command)); - for (i = 0; i < MAX_COMMAND_DATA; ++i) - PRINTDM (DBG_LOAD, " %08x", be32_to_cpu (lb->payload.data[i])); - PRINTDE (DBG_LOAD, ", vld: %08x", be32_to_cpu (lb->valid)); -#else - (void) lb; -#endif - return; -} - -static inline void dump_command (command * cmd) { -#ifdef DEBUG_AMBASSADOR - unsigned int i; - PRINTDB (DBG_CMD, "cmd @ %p, req: %08x, pars:", - cmd, /*be32_to_cpu*/ (cmd->request)); - for (i = 0; i < 3; ++i) - PRINTDM (DBG_CMD, " %08x", /*be32_to_cpu*/ (cmd->args.par[i])); - PRINTDE (DBG_CMD, ""); -#else - (void) cmd; -#endif - return; -} - -static inline void dump_skb (char * prefix, unsigned int vc, struct sk_buff * skb) { -#ifdef DEBUG_AMBASSADOR - unsigned int i; - unsigned char * data = skb->data; - PRINTDB (DBG_DATA, "%s(%u) ", prefix, vc); - for (i=0; i<skb->len && i < 256;i++) - PRINTDM (DBG_DATA, "%02x ", data[i]); - PRINTDE (DBG_DATA,""); -#else - (void) prefix; - (void) vc; - (void) skb; -#endif - return; -} - -/********** check memory areas for use by Ambassador **********/ - -/* see limitations under Hardware Features */ - -static int check_area (void * start, size_t length) { - // assumes length > 0 - const u32 fourmegmask = -1 << 22; - const u32 twofivesixmask = -1 << 8; - const u32 starthole = 0xE0000000; - u32 startaddress = virt_to_bus (start); - u32 lastaddress = startaddress+length-1; - if ((startaddress ^ lastaddress) & fourmegmask || - (startaddress & twofivesixmask) == starthole) { - PRINTK (KERN_ERR, "check_area failure: [%x,%x] - mail maintainer!", - startaddress, lastaddress); - return -1; - } else { - return 0; - } -} - -/********** free an skb (as per ATM device driver documentation) **********/ - -static void amb_kfree_skb (struct sk_buff * skb) { - if (ATM_SKB(skb)->vcc->pop) { - ATM_SKB(skb)->vcc->pop (ATM_SKB(skb)->vcc, skb); - } else { - dev_kfree_skb_any (skb); - } -} - -/********** TX completion **********/ - -static void tx_complete (amb_dev * dev, tx_out * tx) { - tx_simple * tx_descr = bus_to_virt (tx->handle); - struct sk_buff * skb = tx_descr->skb; - - PRINTD (DBG_FLOW|DBG_TX, "tx_complete %p %p", dev, tx); - - // VC layer stats - atomic_inc(&ATM_SKB(skb)->vcc->stats->tx); - - // free the descriptor - kfree (tx_descr); - - // free the skb - amb_kfree_skb (skb); - - dev->stats.tx_ok++; - return; -} - -/********** RX completion **********/ - -static void rx_complete (amb_dev * dev, rx_out * rx) { - struct sk_buff * skb = bus_to_virt (rx->handle); - u16 vc = be16_to_cpu (rx->vc); - // unused: u16 lec_id = be16_to_cpu (rx->lec_id); - u16 status = be16_to_cpu (rx->status); - u16 rx_len = be16_to_cpu (rx->length); - - PRINTD (DBG_FLOW|DBG_RX, "rx_complete %p %p (len=%hu)", dev, rx, rx_len); - - // XXX move this in and add to VC stats ??? - if (!status) { - struct atm_vcc * atm_vcc = dev->rxer[vc]; - dev->stats.rx.ok++; - - if (atm_vcc) { - - if (rx_len <= atm_vcc->qos.rxtp.max_sdu) { - - if (atm_charge (atm_vcc, skb->truesize)) { - - // prepare socket buffer - ATM_SKB(skb)->vcc = atm_vcc; - skb_put (skb, rx_len); - - dump_skb ("<<<", vc, skb); - - // VC layer stats - atomic_inc(&atm_vcc->stats->rx); - __net_timestamp(skb); - // end of our responsibility - atm_vcc->push (atm_vcc, skb); - return; - - } else { - // someone fix this (message), please! - PRINTD (DBG_INFO|DBG_RX, "dropped thanks to atm_charge (vc %hu, truesize %u)", vc, skb->truesize); - // drop stats incremented in atm_charge - } - - } else { - PRINTK (KERN_INFO, "dropped over-size frame"); - // should we count this? - atomic_inc(&atm_vcc->stats->rx_drop); - } - - } else { - PRINTD (DBG_WARN|DBG_RX, "got frame but RX closed for channel %hu", vc); - // this is an adapter bug, only in new version of microcode - } - - } else { - dev->stats.rx.error++; - if (status & CRC_ERR) - dev->stats.rx.badcrc++; - if (status & LEN_ERR) - dev->stats.rx.toolong++; - if (status & ABORT_ERR) - dev->stats.rx.aborted++; - if (status & UNUSED_ERR) - dev->stats.rx.unused++; - } - - dev_kfree_skb_any (skb); - return; -} - -/* - - Note on queue handling. - - Here "give" and "take" refer to queue entries and a queue (pair) - rather than frames to or from the host or adapter. Empty frame - buffers are given to the RX queue pair and returned unused or - containing RX frames. TX frames (well, pointers to TX fragment - lists) are given to the TX queue pair, completions are returned. - -*/ - -/********** command queue **********/ - -// I really don't like this, but it's the best I can do at the moment - -// also, the callers are responsible for byte order as the microcode -// sometimes does 16-bit accesses (yuk yuk yuk) - -static int command_do (amb_dev * dev, command * cmd) { - amb_cq * cq = &dev->cq; - volatile amb_cq_ptrs * ptrs = &cq->ptrs; - command * my_slot; - - PRINTD (DBG_FLOW|DBG_CMD, "command_do %p", dev); - - if (test_bit (dead, &dev->flags)) - return 0; - - spin_lock (&cq->lock); - - // if not full... - if (cq->pending < cq->maximum) { - // remember my slot for later - my_slot = ptrs->in; - PRINTD (DBG_CMD, "command in slot %p", my_slot); - - dump_command (cmd); - - // copy command in - *ptrs->in = *cmd; - cq->pending++; - ptrs->in = NEXTQ (ptrs->in, ptrs->start, ptrs->limit); - - // mail the command - wr_mem (dev, offsetof(amb_mem, mb.adapter.cmd_address), virt_to_bus (ptrs->in)); - - if (cq->pending > cq->high) - cq->high = cq->pending; - spin_unlock (&cq->lock); - - // these comments were in a while-loop before, msleep removes the loop - // go to sleep - // PRINTD (DBG_CMD, "wait: sleeping %lu for command", timeout); - msleep(cq->pending); - - // wait for my slot to be reached (all waiters are here or above, until...) - while (ptrs->out != my_slot) { - PRINTD (DBG_CMD, "wait: command slot (now at %p)", ptrs->out); - set_current_state(TASK_UNINTERRUPTIBLE); - schedule(); - } - - // wait on my slot (... one gets to its slot, and... ) - while (ptrs->out->request != cpu_to_be32 (SRB_COMPLETE)) { - PRINTD (DBG_CMD, "wait: command slot completion"); - set_current_state(TASK_UNINTERRUPTIBLE); - schedule(); - } - - PRINTD (DBG_CMD, "command complete"); - // update queue (... moves the queue along to the next slot) - spin_lock (&cq->lock); - cq->pending--; - // copy command out - *cmd = *ptrs->out; - ptrs->out = NEXTQ (ptrs->out, ptrs->start, ptrs->limit); - spin_unlock (&cq->lock); - - return 0; - } else { - cq->filled++; - spin_unlock (&cq->lock); - return -EAGAIN; - } - -} - -/********** TX queue pair **********/ - -static int tx_give (amb_dev * dev, tx_in * tx) { - amb_txq * txq = &dev->txq; - unsigned long flags; - - PRINTD (DBG_FLOW|DBG_TX, "tx_give %p", dev); - - if (test_bit (dead, &dev->flags)) - return 0; - - spin_lock_irqsave (&txq->lock, flags); - - if (txq->pending < txq->maximum) { - PRINTD (DBG_TX, "TX in slot %p", txq->in.ptr); - - *txq->in.ptr = *tx; - txq->pending++; - txq->in.ptr = NEXTQ (txq->in.ptr, txq->in.start, txq->in.limit); - // hand over the TX and ring the bell - wr_mem (dev, offsetof(amb_mem, mb.adapter.tx_address), virt_to_bus (txq->in.ptr)); - wr_mem (dev, offsetof(amb_mem, doorbell), TX_FRAME); - - if (txq->pending > txq->high) - txq->high = txq->pending; - spin_unlock_irqrestore (&txq->lock, flags); - return 0; - } else { - txq->filled++; - spin_unlock_irqrestore (&txq->lock, flags); - return -EAGAIN; - } -} - -static int tx_take (amb_dev * dev) { - amb_txq * txq = &dev->txq; - unsigned long flags; - - PRINTD (DBG_FLOW|DBG_TX, "tx_take %p", dev); - - spin_lock_irqsave (&txq->lock, flags); - - if (txq->pending && txq->out.ptr->handle) { - // deal with TX completion - tx_complete (dev, txq->out.ptr); - // mark unused again - txq->out.ptr->handle = 0; - // remove item - txq->pending--; - txq->out.ptr = NEXTQ (txq->out.ptr, txq->out.start, txq->out.limit); - - spin_unlock_irqrestore (&txq->lock, flags); - return 0; - } else { - - spin_unlock_irqrestore (&txq->lock, flags); - return -1; - } -} - -/********** RX queue pairs **********/ - -static int rx_give (amb_dev * dev, rx_in * rx, unsigned char pool) { - amb_rxq * rxq = &dev->rxq[pool]; - unsigned long flags; - - PRINTD (DBG_FLOW|DBG_RX, "rx_give %p[%hu]", dev, pool); - - spin_lock_irqsave (&rxq->lock, flags); - - if (rxq->pending < rxq->maximum) { - PRINTD (DBG_RX, "RX in slot %p", rxq->in.ptr); - - *rxq->in.ptr = *rx; - rxq->pending++; - rxq->in.ptr = NEXTQ (rxq->in.ptr, rxq->in.start, rxq->in.limit); - // hand over the RX buffer - wr_mem (dev, offsetof(amb_mem, mb.adapter.rx_address[pool]), virt_to_bus (rxq->in.ptr)); - - spin_unlock_irqrestore (&rxq->lock, flags); - return 0; - } else { - spin_unlock_irqrestore (&rxq->lock, flags); - return -1; - } -} - -static int rx_take (amb_dev * dev, unsigned char pool) { - amb_rxq * rxq = &dev->rxq[pool]; - unsigned long flags; - - PRINTD (DBG_FLOW|DBG_RX, "rx_take %p[%hu]", dev, pool); - - spin_lock_irqsave (&rxq->lock, flags); - - if (rxq->pending && (rxq->out.ptr->status || rxq->out.ptr->length)) { - // deal with RX completion - rx_complete (dev, rxq->out.ptr); - // mark unused again - rxq->out.ptr->status = 0; - rxq->out.ptr->length = 0; - // remove item - rxq->pending--; - rxq->out.ptr = NEXTQ (rxq->out.ptr, rxq->out.start, rxq->out.limit); - - if (rxq->pending < rxq->low) - rxq->low = rxq->pending; - spin_unlock_irqrestore (&rxq->lock, flags); - return 0; - } else { - if (!rxq->pending && rxq->buffers_wanted) - rxq->emptied++; - spin_unlock_irqrestore (&rxq->lock, flags); - return -1; - } -} - -/********** RX Pool handling **********/ - -/* pre: buffers_wanted = 0, post: pending = 0 */ -static void drain_rx_pool (amb_dev * dev, unsigned char pool) { - amb_rxq * rxq = &dev->rxq[pool]; - - PRINTD (DBG_FLOW|DBG_POOL, "drain_rx_pool %p %hu", dev, pool); - - if (test_bit (dead, &dev->flags)) - return; - - /* we are not quite like the fill pool routines as we cannot just - remove one buffer, we have to remove all of them, but we might as - well pretend... */ - if (rxq->pending > rxq->buffers_wanted) { - command cmd; - cmd.request = cpu_to_be32 (SRB_FLUSH_BUFFER_Q); - cmd.args.flush.flags = cpu_to_be32 (pool << SRB_POOL_SHIFT); - while (command_do (dev, &cmd)) - schedule(); - /* the pool may also be emptied via the interrupt handler */ - while (rxq->pending > rxq->buffers_wanted) - if (rx_take (dev, pool)) - schedule(); - } - - return; -} - -static void drain_rx_pools (amb_dev * dev) { - unsigned char pool; - - PRINTD (DBG_FLOW|DBG_POOL, "drain_rx_pools %p", dev); - - for (pool = 0; pool < NUM_RX_POOLS; ++pool) - drain_rx_pool (dev, pool); -} - -static void fill_rx_pool (amb_dev * dev, unsigned char pool, - gfp_t priority) -{ - rx_in rx; - amb_rxq * rxq; - - PRINTD (DBG_FLOW|DBG_POOL, "fill_rx_pool %p %hu %x", dev, pool, priority); - - if (test_bit (dead, &dev->flags)) - return; - - rxq = &dev->rxq[pool]; - while (rxq->pending < rxq->maximum && rxq->pending < rxq->buffers_wanted) { - - struct sk_buff * skb = alloc_skb (rxq->buffer_size, priority); - if (!skb) { - PRINTD (DBG_SKB|DBG_POOL, "failed to allocate skb for RX pool %hu", pool); - return; - } - if (check_area (skb->data, skb->truesize)) { - dev_kfree_skb_any (skb); - return; - } - // cast needed as there is no %? for pointer differences - PRINTD (DBG_SKB, "allocated skb at %p, head %p, area %li", - skb, skb->head, (long) skb_end_offset(skb)); - rx.handle = virt_to_bus (skb); - rx.host_address = cpu_to_be32 (virt_to_bus (skb->data)); - if (rx_give (dev, &rx, pool)) - dev_kfree_skb_any (skb); - - } - - return; -} - -// top up all RX pools -static void fill_rx_pools (amb_dev * dev) { - unsigned char pool; - - PRINTD (DBG_FLOW|DBG_POOL, "fill_rx_pools %p", dev); - - for (pool = 0; pool < NUM_RX_POOLS; ++pool) - fill_rx_pool (dev, pool, GFP_ATOMIC); - - return; -} - -/********** enable host interrupts **********/ - -static void interrupts_on (amb_dev * dev) { - wr_plain (dev, offsetof(amb_mem, interrupt_control), - rd_plain (dev, offsetof(amb_mem, interrupt_control)) - | AMB_INTERRUPT_BITS); -} - -/********** disable host interrupts **********/ - -static void interrupts_off (amb_dev * dev) { - wr_plain (dev, offsetof(amb_mem, interrupt_control), - rd_plain (dev, offsetof(amb_mem, interrupt_control)) - &~ AMB_INTERRUPT_BITS); -} - -/********** interrupt handling **********/ - -static irqreturn_t interrupt_handler(int irq, void *dev_id) { - amb_dev * dev = dev_id; - - PRINTD (DBG_IRQ|DBG_FLOW, "interrupt_handler: %p", dev_id); - - { - u32 interrupt = rd_plain (dev, offsetof(amb_mem, interrupt)); - - // for us or someone else sharing the same interrupt - if (!interrupt) { - PRINTD (DBG_IRQ, "irq not for me: %d", irq); - return IRQ_NONE; - } - - // definitely for us - PRINTD (DBG_IRQ, "FYI: interrupt was %08x", interrupt); - wr_plain (dev, offsetof(amb_mem, interrupt), -1); - } - - { - unsigned int irq_work = 0; - unsigned char pool; - for (pool = 0; pool < NUM_RX_POOLS; ++pool) - while (!rx_take (dev, pool)) - ++irq_work; - while (!tx_take (dev)) - ++irq_work; - - if (irq_work) { - fill_rx_pools (dev); - - PRINTD (DBG_IRQ, "work done: %u", irq_work); - } else { - PRINTD (DBG_IRQ|DBG_WARN, "no work done"); - } - } - - PRINTD (DBG_IRQ|DBG_FLOW, "interrupt_handler done: %p", dev_id); - return IRQ_HANDLED; -} - -/********** make rate (not quite as much fun as Horizon) **********/ - -static int make_rate (unsigned int rate, rounding r, - u16 * bits, unsigned int * actual) { - unsigned char exp = -1; // hush gcc - unsigned int man = -1; // hush gcc - - PRINTD (DBG_FLOW|DBG_QOS, "make_rate %u", rate); - - // rates in cells per second, ITU format (nasty 16-bit floating-point) - // given 5-bit e and 9-bit m: - // rate = EITHER (1+m/2^9)*2^e OR 0 - // bits = EITHER 1<<14 | e<<9 | m OR 0 - // (bit 15 is "reserved", bit 14 "non-zero") - // smallest rate is 0 (special representation) - // largest rate is (1+511/512)*2^31 = 4290772992 (< 2^32-1) - // smallest non-zero rate is (1+0/512)*2^0 = 1 (> 0) - // simple algorithm: - // find position of top bit, this gives e - // remove top bit and shift (rounding if feeling clever) by 9-e - - // ucode bug: please don't set bit 14! so 0 rate not representable - - if (rate > 0xffc00000U) { - // larger than largest representable rate - - if (r == round_up) { - return -EINVAL; - } else { - exp = 31; - man = 511; - } - - } else if (rate) { - // representable rate - - exp = 31; - man = rate; - - // invariant: rate = man*2^(exp-31) - while (!(man & (1<<31))) { - exp = exp - 1; - man = man<<1; - } - - // man has top bit set - // rate = (2^31+(man-2^31))*2^(exp-31) - // rate = (1+(man-2^31)/2^31)*2^exp - man = man<<1; - man &= 0xffffffffU; // a nop on 32-bit systems - // rate = (1+man/2^32)*2^exp - - // exp is in the range 0 to 31, man is in the range 0 to 2^32-1 - // time to lose significance... we want m in the range 0 to 2^9-1 - // rounding presents a minor problem... we first decide which way - // we are rounding (based on given rounding direction and possibly - // the bits of the mantissa that are to be discarded). - - switch (r) { - case round_down: { - // just truncate - man = man>>(32-9); - break; - } - case round_up: { - // check all bits that we are discarding - if (man & (~0U>>9)) { - man = (man>>(32-9)) + 1; - if (man == (1<<9)) { - // no need to check for round up outside of range - man = 0; - exp += 1; - } - } else { - man = (man>>(32-9)); - } - break; - } - case round_nearest: { - // check msb that we are discarding - if (man & (1<<(32-9-1))) { - man = (man>>(32-9)) + 1; - if (man == (1<<9)) { - // no need to check for round up outside of range - man = 0; - exp += 1; - } - } else { - man = (man>>(32-9)); - } - break; - } - } - - } else { - // zero rate - not representable - - if (r == round_down) { - return -EINVAL; - } else { - exp = 0; - man = 0; - } - - } - - PRINTD (DBG_QOS, "rate: man=%u, exp=%hu", man, exp); - - if (bits) - *bits = /* (1<<14) | */ (exp<<9) | man; - - if (actual) - *actual = (exp >= 9) - ? (1 << exp) + (man << (exp-9)) - : (1 << exp) + ((man + (1<<(9-exp-1))) >> (9-exp)); - - return 0; -} - -/********** Linux ATM Operations **********/ - -// some are not yet implemented while others do not make sense for -// this device - -/********** Open a VC **********/ - -static int amb_open (struct atm_vcc * atm_vcc) -{ - int error; - - struct atm_qos * qos; - struct atm_trafprm * txtp; - struct atm_trafprm * rxtp; - u16 tx_rate_bits = -1; // hush gcc - u16 tx_vc_bits = -1; // hush gcc - u16 tx_frame_bits = -1; // hush gcc - - amb_dev * dev = AMB_DEV(atm_vcc->dev); - amb_vcc * vcc; - unsigned char pool = -1; // hush gcc - short vpi = atm_vcc->vpi; - int vci = atm_vcc->vci; - - PRINTD (DBG_FLOW|DBG_VCC, "amb_open %x %x", vpi, vci); - -#ifdef ATM_VPI_UNSPEC - // UNSPEC is deprecated, remove this code eventually - if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) { - PRINTK (KERN_WARNING, "rejecting open with unspecified VPI/VCI (deprecated)"); - return -EINVAL; - } -#endif - - if (!(0 <= vpi && vpi < (1<<NUM_VPI_BITS) && - 0 <= vci && vci < (1<<NUM_VCI_BITS))) { - PRINTD (DBG_WARN|DBG_VCC, "VPI/VCI out of range: %hd/%d", vpi, vci); - return -EINVAL; - } - - qos = &atm_vcc->qos; - - if (qos->aal != ATM_AAL5) { - PRINTD (DBG_QOS, "AAL not supported"); - return -EINVAL; - } - - // traffic parameters - - PRINTD (DBG_QOS, "TX:"); - txtp = &qos->txtp; - if (txtp->traffic_class != ATM_NONE) { - switch (txtp->traffic_class) { - case ATM_UBR: { - // we take "the PCR" as a rate-cap - int pcr = atm_pcr_goal (txtp); - if (!pcr) { - // no rate cap - tx_rate_bits = 0; - tx_vc_bits = TX_UBR; - tx_frame_bits = TX_FRAME_NOTCAP; - } else { - rounding r; - if (pcr < 0) { - r = round_down; - pcr = -pcr; - } else { - r = round_up; - } - error = make_rate (pcr, r, &tx_rate_bits, NULL); - if (error) - return error; - tx_vc_bits = TX_UBR_CAPPED; - tx_frame_bits = TX_FRAME_CAPPED; - } - break; - } -#if 0 - case ATM_ABR: { - pcr = atm_pcr_goal (txtp); - PRINTD (DBG_QOS, "pcr goal = %d", pcr); - break; - } -#endif - default: { - // PRINTD (DBG_QOS, "request for non-UBR/ABR denied"); - PRINTD (DBG_QOS, "request for non-UBR denied"); - return -EINVAL; - } - } - PRINTD (DBG_QOS, "tx_rate_bits=%hx, tx_vc_bits=%hx", - tx_rate_bits, tx_vc_bits); - } - - PRINTD (DBG_QOS, "RX:"); - rxtp = &qos->rxtp; - if (rxtp->traffic_class == ATM_NONE) { - // do nothing - } else { - // choose an RX pool (arranged in increasing size) - for (pool = 0; pool < NUM_RX_POOLS; ++pool) - if ((unsigned int) rxtp->max_sdu <= dev->rxq[pool].buffer_size) { - PRINTD (DBG_VCC|DBG_QOS|DBG_POOL, "chose pool %hu (max_sdu %u <= %u)", - pool, rxtp->max_sdu, dev->rxq[pool].buffer_size); - break; - } - if (pool == NUM_RX_POOLS) { - PRINTD (DBG_WARN|DBG_VCC|DBG_QOS|DBG_POOL, - "no pool suitable for VC (RX max_sdu %d is too large)", - rxtp->max_sdu); - return -EINVAL; - } - - switch (rxtp->traffic_class) { - case ATM_UBR: { - break; - } -#if 0 |