Commit 9dd441e4 authored by Alex Elder's avatar Alex Elder Committed by David S. Miller

soc: qcom: ipa: GSI transactions

This patch implements GSI transactions.  A GSI transaction is a
structure that represents a single request (consisting of one or
more TREs) sent to the GSI hardware.  The last TRE in a transaction
includes a flag requesting that the GSI interrupt the AP to notify
that it has completed.

TREs are executed and completed strictly in order.  For this reason,
the completion of a single TRE implies that all previous TREs (in
particular all of those "earlier" in a transaction) have completed.

Whenever there is a need to send a request (a set of TREs) to the
IPA, a GSI transaction is allocated, specifying the number of TREs
that will be required.  Details of the request (e.g. transfer offsets
and length) are represented by in a Linux scatterlist array that is
incorporated in the transaction structure.

Once all commands (TREs) are added to a transaction it is committed.
When the hardware signals that the request has completed, a callback
function allows for cleanup or followup activity to be performed
before the transaction is freed.
Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c3f398b1
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
* Copyright (C) 2019-2020 Linaro Ltd.
*/
#include <linux/types.h>
#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/refcount.h>
#include <linux/scatterlist.h>
#include <linux/dma-direction.h>
#include "gsi.h"
#include "gsi_private.h"
#include "gsi_trans.h"
#include "ipa_gsi.h"
#include "ipa_data.h"
#include "ipa_cmd.h"
/**
* DOC: GSI Transactions
*
* A GSI transaction abstracts the behavior of a GSI channel by representing
* everything about a related group of IPA commands in a single structure.
* (A "command" in this sense is either a data transfer or an IPA immediate
* command.) Most details of interaction with the GSI hardware are managed
* by the GSI transaction core, allowing users to simply describe commands
* to be performed. When a transaction has completed a callback function
* (dependent on the type of endpoint associated with the channel) allows
* cleanup of resources associated with the transaction.
*
* To perform a command (or set of them), a user of the GSI transaction
* interface allocates a transaction, indicating the number of TREs required
* (one per command). If sufficient TREs are available, they are reserved
* for use in the transaction and the allocation succeeds. This way
* exhaustion of the available TREs in a channel ring is detected
* as early as possible. All resources required to complete a transaction
* are allocated at transaction allocation time.
*
* Commands performed as part of a transaction are represented in an array
* of Linux scatterlist structures. This array is allocated with the
* transaction, and its entries are initialized using standard scatterlist
* functions (such as sg_set_buf() or skb_to_sgvec()).
*
* Once a transaction's scatterlist structures have been initialized, the
* transaction is committed. The caller is responsible for mapping buffers
* for DMA if necessary, and this should be done *before* allocating
* the transaction. Between a successful allocation and commit of a
* transaction no errors should occur.
*
* Committing transfers ownership of the entire transaction to the GSI
* transaction core. The GSI transaction code formats the content of
* the scatterlist array into the channel ring buffer and informs the
* hardware that new TREs are available to process.
*
* The last TRE in each transaction is marked to interrupt the AP when the
* GSI hardware has completed it. Because transfers described by TREs are
* performed strictly in order, signaling the completion of just the last
* TRE in the transaction is sufficient to indicate the full transaction
* is complete.
*
* When a transaction is complete, ipa_gsi_trans_complete() is called by the
* GSI code into the IPA layer, allowing it to perform any final cleanup
* required before the transaction is freed.
*/
/* Hardware values representing a transfer element type */
enum gsi_tre_type {
GSI_RE_XFER = 0x2,
GSI_RE_IMMD_CMD = 0x3,
};
/* An entry in a channel ring */
struct gsi_tre {
__le64 addr; /* DMA address */
__le16 len_opcode; /* length in bytes or enum IPA_CMD_* */
__le16 reserved;
__le32 flags; /* TRE_FLAGS_* */
};
/* gsi_tre->flags mask values (in CPU byte order) */
#define TRE_FLAGS_CHAIN_FMASK GENMASK(0, 0)
#define TRE_FLAGS_IEOB_FMASK GENMASK(8, 8)
#define TRE_FLAGS_IEOT_FMASK GENMASK(9, 9)
#define TRE_FLAGS_BEI_FMASK GENMASK(10, 10)
#define TRE_FLAGS_TYPE_FMASK GENMASK(23, 16)
int gsi_trans_pool_init(struct gsi_trans_pool *pool, size_t size, u32 count,
u32 max_alloc)
{
void *virt;
#ifdef IPA_VALIDATE
if (!size || size % 8)
return -EINVAL;
if (count < max_alloc)
return -EINVAL;
if (!max_alloc)
return -EINVAL;
#endif /* IPA_VALIDATE */
/* By allocating a few extra entries in our pool (one less
* than the maximum number that will be requested in a
* single allocation), we can always satisfy requests without
* ever worrying about straddling the end of the pool array.
* If there aren't enough entries starting at the free index,
* we just allocate free entries from the beginning of the pool.
*/
virt = kcalloc(count + max_alloc - 1, size, GFP_KERNEL);
if (!virt)
return -ENOMEM;
pool->base = virt;
/* If the allocator gave us any extra memory, use it */
pool->count = ksize(pool->base) / size;
pool->free = 0;
pool->max_alloc = max_alloc;
pool->size = size;
pool->addr = 0; /* Only used for DMA pools */
return 0;
}
void gsi_trans_pool_exit(struct gsi_trans_pool *pool)
{
kfree(pool->base);
memset(pool, 0, sizeof(*pool));
}
/* Allocate the requested number of (zeroed) entries from the pool */
/* Home-grown DMA pool. This way we can preallocate and use the tre_count
* to guarantee allocations will succeed. Even though we specify max_alloc
* (and it can be more than one), we only allow allocation of a single
* element from a DMA pool.
*/
int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,
size_t size, u32 count, u32 max_alloc)
{
size_t total_size;
dma_addr_t addr;
void *virt;
#ifdef IPA_VALIDATE
if (!size || size % 8)
return -EINVAL;
if (count < max_alloc)
return -EINVAL;
if (!max_alloc)
return -EINVAL;
#endif /* IPA_VALIDATE */
/* Don't let allocations cross a power-of-two boundary */
size = __roundup_pow_of_two(size);
total_size = (count + max_alloc - 1) * size;
/* The allocator will give us a power-of-2 number of pages. But we
* can't guarantee that, so request it. That way we won't waste any
* memory that would be available beyond the required space.
*/
total_size = get_order(total_size) << PAGE_SHIFT;
virt = dma_alloc_coherent(dev, total_size, &addr, GFP_KERNEL);
if (!virt)
return -ENOMEM;
pool->base = virt;
pool->count = total_size / size;
pool->free = 0;
pool->size = size;
pool->max_alloc = max_alloc;
pool->addr = addr;
return 0;
}
void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool)
{
dma_free_coherent(dev, pool->size, pool->base, pool->addr);
memset(pool, 0, sizeof(*pool));
}
/* Return the byte offset of the next free entry in the pool */
static u32 gsi_trans_pool_alloc_common(struct gsi_trans_pool *pool, u32 count)
{
u32 offset;
/* assert(count > 0); */
/* assert(count <= pool->max_alloc); */
/* Allocate from beginning if wrap would occur */
if (count > pool->count - pool->free)
pool->free = 0;
offset = pool->free * pool->size;
pool->free += count;
memset(pool->base + offset, 0, count * pool->size);
return offset;
}
/* Allocate a contiguous block of zeroed entries from a pool */
void *gsi_trans_pool_alloc(struct gsi_trans_pool *pool, u32 count)
{
return pool->base + gsi_trans_pool_alloc_common(pool, count);
}
/* Allocate a single zeroed entry from a DMA pool */
void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr)
{
u32 offset = gsi_trans_pool_alloc_common(pool, 1);
*addr = pool->addr + offset;
return pool->base + offset;
}
/* Return the pool element that immediately follows the one given.
* This only works done if elements are allocated one at a time.
*/
void *gsi_trans_pool_next(struct gsi_trans_pool *pool, void *element)
{
void *end = pool->base + pool->count * pool->size;
/* assert(element >= pool->base); */
/* assert(element < end); */
/* assert(pool->max_alloc == 1); */
element += pool->size;
return element < end ? element : pool->base;
}
/* Map a given ring entry index to the transaction associated with it */
static void gsi_channel_trans_map(struct gsi_channel *channel, u32 index,
struct gsi_trans *trans)
{
/* Note: index *must* be used modulo the ring count here */
channel->trans_info.map[index % channel->tre_ring.count] = trans;
}
/* Return the transaction mapped to a given ring entry */
struct gsi_trans *
gsi_channel_trans_mapped(struct gsi_channel *channel, u32 index)
{
/* Note: index *must* be used modulo the ring count here */
return channel->trans_info.map[index % channel->tre_ring.count];
}
/* Return the oldest completed transaction for a channel (or null) */
struct gsi_trans *gsi_channel_trans_complete(struct gsi_channel *channel)
{
return list_first_entry_or_null(&channel->trans_info.complete,
struct gsi_trans, links);
}
/* Move a transaction from the allocated list to the pending list */
static void gsi_trans_move_pending(struct gsi_trans *trans)
{
struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
struct gsi_trans_info *trans_info = &channel->trans_info;
spin_lock_bh(&trans_info->spinlock);
list_move_tail(&trans->links, &trans_info->pending);
spin_unlock_bh(&trans_info->spinlock);
}
/* Move a transaction and all of its predecessors from the pending list
* to the completed list.
*/
void gsi_trans_move_complete(struct gsi_trans *trans)
{
struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
struct gsi_trans_info *trans_info = &channel->trans_info;
struct list_head list;
spin_lock_bh(&trans_info->spinlock);
/* Move this transaction and all predecessors to completed list */
list_cut_position(&list, &trans_info->pending, &trans->links);
list_splice_tail(&list, &trans_info->complete);
spin_unlock_bh(&trans_info->spinlock);
}
/* Move a transaction from the completed list to the polled list */
void gsi_trans_move_polled(struct gsi_trans *trans)
{
struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
struct gsi_trans_info *trans_info = &channel->trans_info;
spin_lock_bh(&trans_info->spinlock);
list_move_tail(&trans->links, &trans_info->polled);
spin_unlock_bh(&trans_info->spinlock);
}
/* Reserve some number of TREs on a channel. Returns true if successful */
static bool
gsi_trans_tre_reserve(struct gsi_trans_info *trans_info, u32 tre_count)
{
int avail = atomic_read(&trans_info->tre_avail);
int new;
do {
new = avail - (int)tre_count;
if (unlikely(new < 0))
return false;
} while (!atomic_try_cmpxchg(&trans_info->tre_avail, &avail, new));
return true;
}
/* Release previously-reserved TRE entries to a channel */
static void
gsi_trans_tre_release(struct gsi_trans_info *trans_info, u32 tre_count)
{
atomic_add(tre_count, &trans_info->tre_avail);
}
/* Allocate a GSI transaction on a channel */
struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
u32 tre_count,
enum dma_data_direction direction)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
struct gsi_trans_info *trans_info;
struct gsi_trans *trans;
/* assert(tre_count <= gsi_channel_trans_tre_max(gsi, channel_id)); */
trans_info = &channel->trans_info;
/* We reserve the TREs now, but consume them at commit time.
* If there aren't enough available, we're done.
*/
if (!gsi_trans_tre_reserve(trans_info, tre_count))
return NULL;
/* Allocate and initialize non-zero fields in the the transaction */
trans = gsi_trans_pool_alloc(&trans_info->pool, 1);
trans->gsi = gsi;
trans->channel_id = channel_id;
trans->tre_count = tre_count;
init_completion(&trans->completion);
/* Allocate the scatterlist and (if requested) info entries. */
trans->sgl = gsi_trans_pool_alloc(&trans_info->sg_pool, tre_count);
sg_init_marker(trans->sgl, tre_count);
trans->direction = direction;
spin_lock_bh(&trans_info->spinlock);
list_add_tail(&trans->links, &trans_info->alloc);
spin_unlock_bh(&trans_info->spinlock);
refcount_set(&trans->refcount, 1);
return trans;
}
/* Free a previously-allocated transaction (used only in case of error) */
void gsi_trans_free(struct gsi_trans *trans)
{
struct gsi_trans_info *trans_info;
if (!refcount_dec_and_test(&trans->refcount))
return;
trans_info = &trans->gsi->channel[trans->channel_id].trans_info;
spin_lock_bh(&trans_info->spinlock);
list_del(&trans->links);
spin_unlock_bh(&trans_info->spinlock);
ipa_gsi_trans_release(trans);
/* Releasing the reserved TREs implicitly frees the sgl[] and
* (if present) info[] arrays, plus the transaction itself.
*/
gsi_trans_tre_release(trans_info, trans->tre_count);
}
/* Add an immediate command to a transaction */
void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size,
dma_addr_t addr, enum dma_data_direction direction,
enum ipa_cmd_opcode opcode)
{
struct ipa_cmd_info *info;
u32 which = trans->used++;
struct scatterlist *sg;
/* assert(which < trans->tre_count); */
/* Set the page information for the buffer. We also need to fill in
* the DMA address for the buffer (something dma_map_sg() normally
* does).
*/
sg = &trans->sgl[which];
sg_set_buf(sg, buf, size);
sg_dma_address(sg) = addr;
info = &trans->info[which];
info->opcode = opcode;
info->direction = direction;
}
/* Add a page transfer to a transaction. It will fill the only TRE. */
int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size,
u32 offset)
{
struct scatterlist *sg = &trans->sgl[0];
int ret;
/* assert(trans->tre_count == 1); */
/* assert(!trans->used); */
sg_set_page(sg, page, size, offset);
ret = dma_map_sg(trans->gsi->dev, sg, 1, trans->direction);
if (!ret)
return -ENOMEM;
trans->used++; /* Transaction now owns the (DMA mapped) page */
return 0;
}
/* Add an SKB transfer to a transaction. No other TREs will be used. */
int gsi_trans_skb_add(struct gsi_trans *trans, struct sk_buff *skb)
{
struct scatterlist *sg = &trans->sgl[0];
u32 used;
int ret;
/* assert(trans->tre_count == 1); */
/* assert(!trans->used); */
/* skb->len will not be 0 (checked early) */
ret = skb_to_sgvec(skb, sg, 0, skb->len);
if (ret < 0)
return ret;
used = ret;
ret = dma_map_sg(trans->gsi->dev, sg, used, trans->direction);
if (!ret)
return -ENOMEM;
trans->used += used; /* Transaction now owns the (DMA mapped) skb */
return 0;
}
/* Compute the length/opcode value to use for a TRE */
static __le16 gsi_tre_len_opcode(enum ipa_cmd_opcode opcode, u32 len)
{
return opcode == IPA_CMD_NONE ? cpu_to_le16((u16)len)
: cpu_to_le16((u16)opcode);
}
/* Compute the flags value to use for a given TRE */
static __le32 gsi_tre_flags(bool last_tre, bool bei, enum ipa_cmd_opcode opcode)
{
enum gsi_tre_type tre_type;
u32 tre_flags;
tre_type = opcode == IPA_CMD_NONE ? GSI_RE_XFER : GSI_RE_IMMD_CMD;
tre_flags = u32_encode_bits(tre_type, TRE_FLAGS_TYPE_FMASK);
/* Last TRE contains interrupt flags */
if (last_tre) {
/* All transactions end in a transfer completion interrupt */
tre_flags |= TRE_FLAGS_IEOT_FMASK;
/* Don't interrupt when outbound commands are acknowledged */
if (bei)
tre_flags |= TRE_FLAGS_BEI_FMASK;
} else { /* All others indicate there's more to come */
tre_flags |= TRE_FLAGS_CHAIN_FMASK;
}
return cpu_to_le32(tre_flags);
}
static void gsi_trans_tre_fill(struct gsi_tre *dest_tre, dma_addr_t addr,
u32 len, bool last_tre, bool bei,
enum ipa_cmd_opcode opcode)
{
struct gsi_tre tre;
tre.addr = cpu_to_le64(addr);
tre.len_opcode = gsi_tre_len_opcode(opcode, len);
tre.reserved = 0;
tre.flags = gsi_tre_flags(last_tre, bei, opcode);
/* ARM64 can write 16 bytes as a unit with a single instruction.
* Doing the assignment this way is an attempt to make that happen.
*/
*dest_tre = tre;
}
/**
* __gsi_trans_commit() - Common GSI transaction commit code
* @trans: Transaction to commit
* @ring_db: Whether to tell the hardware about these queued transfers
*
* Formats channel ring TRE entries based on the content of the scatterlist.
* Maps a transaction pointer to the last ring entry used for the transaction,
* so it can be recovered when it completes. Moves the transaction to the
* pending list. Finally, updates the channel ring pointer and optionally
* rings the doorbell.
*/
static void __gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
{
struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
struct gsi_ring *ring = &channel->tre_ring;
enum ipa_cmd_opcode opcode = IPA_CMD_NONE;
bool bei = channel->toward_ipa;
struct ipa_cmd_info *info;
struct gsi_tre *dest_tre;
struct scatterlist *sg;
u32 byte_count = 0;
u32 avail;
u32 i;
/* assert(trans->used > 0); */
/* Consume the entries. If we cross the end of the ring while
* filling them we'll switch to the beginning to finish.
* If there is no info array we're doing a simple data
* transfer request, whose opcode is IPA_CMD_NONE.
*/
info = trans->info ? &trans->info[0] : NULL;
avail = ring->count - ring->index % ring->count;
dest_tre = gsi_ring_virt(ring, ring->index);
for_each_sg(trans->sgl, sg, trans->used, i) {
bool last_tre = i == trans->used - 1;
dma_addr_t addr = sg_dma_address(sg);
u32 len = sg_dma_len(sg);
byte_count += len;
if (!avail--)
dest_tre = gsi_ring_virt(ring, 0);
if (info)
opcode = info++->opcode;
gsi_trans_tre_fill(dest_tre, addr, len, last_tre, bei, opcode);
dest_tre++;
}
ring->index += trans->used;
if (channel->toward_ipa) {
/* We record TX bytes when they are sent */
trans->len = byte_count;
trans->trans_count = channel->trans_count;
trans->byte_count = channel->byte_count;
channel->trans_count++;
channel->byte_count += byte_count;
}
/* Associate the last TRE with the transaction */
gsi_channel_trans_map(channel, ring->index - 1, trans);
gsi_trans_move_pending(trans);
/* Ring doorbell if requested, or if all TREs are allocated */
if (ring_db || !atomic_read(&channel->trans_info.tre_avail)) {
/* Report what we're handing off to hardware for TX channels */
if (channel->toward_ipa)
gsi_channel_tx_queued(channel);
gsi_channel_doorbell(channel);
}
}
/* Commit a GSI transaction */
void gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
{
if (trans->used)
__gsi_trans_commit(trans, ring_db);
else
gsi_trans_free(trans);
}
/* Commit a GSI transaction and wait for it to complete */
void gsi_trans_commit_wait(struct gsi_trans *trans)
{
if (!trans->used)
goto out_trans_free;
refcount_inc(&trans->refcount);
__gsi_trans_commit(trans, true);
wait_for_completion(&trans->completion);
out_trans_free:
gsi_trans_free(trans);
}
/* Commit a GSI transaction and wait for it to complete, with timeout */
int gsi_trans_commit_wait_timeout(struct gsi_trans *trans,
unsigned long timeout)
{
unsigned long timeout_jiffies = msecs_to_jiffies(timeout);
unsigned long remaining = 1; /* In case of empty transaction */
if (!trans->used)
goto out_trans_free;
refcount_inc(&trans->refcount);
__gsi_trans_commit(trans, true);
remaining = wait_for_completion_timeout(&trans->completion,
timeout_jiffies);
out_trans_free:
gsi_trans_free(trans);
return remaining ? 0 : -ETIMEDOUT;
}
/* Process the completion of a transaction; called while polling */
void gsi_trans_complete(struct gsi_trans *trans)
{
/* If the entire SGL was mapped when added, unmap it now */
if (trans->direction != DMA_NONE)
dma_unmap_sg(trans->gsi->dev, trans->sgl, trans->used,
trans->direction);
ipa_gsi_trans_complete(trans);
complete(&trans->completion);
gsi_trans_free(trans);
}
/* Cancel a channel's pending transactions */
void gsi_channel_trans_cancel_pending(struct gsi_channel *channel)
{
struct gsi_trans_info *trans_info = &channel->trans_info;
struct gsi_trans *trans;
bool cancelled;
/* channel->gsi->mutex is held by caller */
spin_lock_bh(&trans_info->spinlock);
cancelled = !list_empty(&trans_info->pending);
list_for_each_entry(trans, &trans_info->pending, links)
trans->cancelled = true;
list_splice_tail_init(&trans_info->pending, &trans_info->complete);
spin_unlock_bh(&trans_info->spinlock);
/* Schedule NAPI polling to complete the cancelled transactions */
if (cancelled)
napi_schedule(&channel->napi);
}
/* Issue a command to read a single byte from a channel */
int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
struct gsi_ring *ring = &channel->tre_ring;
struct gsi_trans_info *trans_info;
struct gsi_tre *dest_tre;
trans_info = &channel->trans_info;
/* First reserve the TRE, if possible */
if (!gsi_trans_tre_reserve(trans_info, 1))
return -EBUSY;
/* Now fill the the reserved TRE and tell the hardware */
dest_tre = gsi_ring_virt(ring, ring->index);
gsi_trans_tre_fill(dest_tre, addr, 1, true, false, IPA_CMD_NONE);
ring->index++;
gsi_channel_doorbell(channel);
return 0;
}
/* Mark a gsi_trans_read_byte() request done */
void gsi_trans_read_byte_done(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
gsi_trans_tre_release(&channel->trans_info, 1);
}
/* Initialize a channel's GSI transaction info */
int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
struct gsi_trans_info *trans_info;
u32 tre_max;
int ret;
/* Ensure the size of a channel element is what's expected */
BUILD_BUG_ON(sizeof(struct gsi_tre) != GSI_RING_ELEMENT_SIZE);
/* The map array is used to determine what transaction is associated
* with a TRE that the hardware reports has completed. We need one
* map entry per TRE.
*/
trans_info = &channel->trans_info;
trans_info->map = kcalloc(channel->tre_count, sizeof(*trans_info->map),
GFP_KERNEL);
if (!trans_info->map)
return -ENOMEM;
/* We can't use more TREs than there are available in the ring.
* This limits the number of transactions that can be oustanding.
* Worst case is one TRE per transaction (but we actually limit
* it to something a little less than that). We allocate resources
* for transactions (including transaction structures) based on
* this maximum number.
*/
tre_max = gsi_channel_tre_max(channel->gsi, channel_id);
/* Transactions are allocated one at a time. */
ret = gsi_trans_pool_init(&trans_info->pool, sizeof(struct gsi_trans),
tre_max, 1);
if (ret)
goto err_kfree;
/* A transaction uses a scatterlist array to represent the data
* transfers implemented by the transaction. Each scatterlist
* element is used to fill a single TRE when the transaction is
* committed. So we need as many scatterlist elements as the
* maximum number of TREs that can be outstanding.
*
* All TREs in a transaction must fit within the channel's TLV FIFO.
* A transaction on a channel can allocate as many TREs as that but
* no more.
*/
ret = gsi_trans_pool_init(&trans_info->sg_pool,
sizeof(struct scatterlist),
tre_max, channel->tlv_count);
if (ret)
goto err_trans_pool_exit;
/* Finally, the tre_avail field is what ultimately limits the number
* of outstanding transactions and their resources. A transaction
* allocation succeeds only if the TREs available are sufficient for
* what the transaction might need. Transaction resource pools are
* sized based on the maximum number of outstanding TREs, so there
* will always be resources available if there are TREs available.
*/
atomic_set(&trans_info->tre_avail, tre_max);
spin_lock_init(&trans_info->spinlock);
INIT_LIST_HEAD(&trans_info->alloc);
INIT_LIST_HEAD(&trans_info->pending);
INIT_LIST_HEAD(&trans_info->complete);
INIT_LIST_HEAD(&trans_info->polled);
return 0;
err_trans_pool_exit:
gsi_trans_pool_exit(&trans_info->pool);
err_kfree:
kfree(trans_info->map);
dev_err(gsi->dev, "error %d initializing channel %u transactions\n",
ret, channel_id);
return ret;
}
/* Inverse of gsi_channel_trans_init() */
void gsi_channel_trans_exit(struct gsi_channel *channel)
{
struct gsi_trans_info *trans_info = &channel->trans_info;
gsi_trans_pool_exit(&trans_info->sg_pool);
gsi_trans_pool_exit(&trans_info->pool);
kfree(trans_info->map);
}
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
* Copyright (C) 2019-2020 Linaro Ltd.
*/
#ifndef _GSI_TRANS_H_
#define _GSI_TRANS_H_
#include <linux/types.h>
#include <linux/refcount.h>
#include <linux/completion.h>
#include <linux/dma-direction.h>
#include "ipa_cmd.h"
struct scatterlist;
struct device;
struct sk_buff;
struct gsi;
struct gsi_trans;
struct gsi_trans_pool;
/**
* struct gsi_trans - a GSI transaction
*
* Most fields in this structure for internal use by the transaction core code:
* @links: Links for channel transaction lists by state
* @gsi: GSI pointer
* @channel_id: Channel number transaction is associated with
* @cancelled: If set by the core code, transaction was cancelled
* @tre_count: Number of TREs reserved for this transaction
* @used: Number of TREs *used* (could be less than tre_count)
* @len: Total # of transfer bytes represented in sgl[] (set by core)
* @data: Preserved but not touched by the core transaction code
* @sgl: An array of scatter/gather entries managed by core code
* @info: Array of command information structures (command channel)
* @direction: DMA transfer direction (DMA_NONE for commands)
* @refcount: Reference count used for destruction
* @completion: Completed when the transaction completes
* @byte_count: TX channel byte count recorded when transaction committed
* @trans_count: Channel transaction count when committed (for BQL accounting)
*
* The size used for some fields in this structure were chosen to ensure
* the full structure size is no larger than 128 bytes.
*/
struct gsi_trans {
struct list_head links; /* gsi_channel lists */
struct gsi *gsi;
u8 channel_id;
bool cancelled; /* true if transaction was cancelled */
u8 tre_count; /* # TREs requested */
u8 used; /* # entries used in sgl[] */
u32 len; /* total # bytes across sgl[] */
void *data;
struct scatterlist *sgl;
struct ipa_cmd_info *info; /* array of entries, or null */
enum dma_data_direction direction;
refcount_t refcount;
struct completion completion;
u64 byte_count; /* channel byte_count when committed */
u64 trans_count; /* channel trans_count when committed */
};
/**
* gsi_trans_pool_init() - Initialize a pool of structures for transactions
* @gsi: GSI pointer
* @size: Size of elements in the pool
* @count: Minimum number of elements in the pool
* @max_alloc: Maximum number of elements allocated at a time from pool
*
* @Return: 0 if successful, or a negative error code
*/
int gsi_trans_pool_init(struct gsi_trans_pool *pool, size_t size, u32 count,
u32 max_alloc);
/**
* gsi_trans_pool_alloc() - Allocate one or more elements from a pool
* @pool: Pool pointer
* @count: Number of elements to allocate from the pool
*
* @Return: Virtual address of element(s) allocated from the pool
*/
void *gsi_trans_pool_alloc(struct gsi_trans_pool *pool, u32 count);
/**
* gsi_trans_pool_exit() - Inverse of gsi_trans_pool_init()
* @pool: Pool pointer
*/
void gsi_trans_pool_exit(struct gsi_trans_pool *pool);
/**
* gsi_trans_pool_init_dma() - Initialize a pool of DMA-able structures
* @dev: Device used for DMA
* @pool: Pool pointer
* @size: Size of elements in the pool
* @count: Minimum number of elements in the pool
* @max_alloc: Maximum number of elements allocated at a time from pool
*
* @Return: 0 if successful, or a negative error code
*
* Structures in this pool reside in DMA-coherent memory.
*/
int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,
size_t size, u32 count, u32 max_alloc);
/**
* gsi_trans_pool_alloc_dma() - Allocate an element from a DMA pool
* @pool: DMA pool pointer
* @addr: DMA address "handle" associated with the allocation
*
* @Return: Virtual address of element allocated from the pool
*
* Only one element at a time may be allocated from a DMA pool.
*/
void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr);
/**
* gsi_trans_pool_exit() - Inverse of gsi_trans_pool_init()
* @pool: Pool pointer
*/
void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool);
/**
* gsi_channel_trans_alloc() - Allocate a GSI transaction on a channel
* @gsi: GSI pointer
* @channel_id: Channel the transaction is associated with
* @tre_count: Number of elements in the transaction
* @direction: DMA direction for entire SGL (or DMA_NONE)
*
* @Return: A GSI transaction structure, or a null pointer if all
* available transactions are in use
*/
struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
u32 tre_count,
enum dma_data_direction direction);
/**
* gsi_trans_free() - Free a previously-allocated GSI transaction
* @trans: Transaction to be freed
*/
void gsi_trans_free(struct gsi_trans *trans);
/**
* gsi_trans_cmd_add() - Add an immediate command to a transaction
* @trans: Transaction
* @buf: Buffer pointer for command payload
* @size: Number of bytes in buffer
* @addr: DMA address for payload
* @direction: Direction of DMA transfer (or DMA_NONE if none required)
* @opcode: IPA immediate command opcode
*/
void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size,
dma_addr_t addr, enum dma_data_direction direction,
enum ipa_cmd_opcode opcode);
/**
* gsi_trans_page_add() - Add a page transfer to a transaction
* @trans: Transaction
* @page: Page pointer
* @size: Number of bytes (starting at offset) to transfer
* @offset: Offset within page for start of transfer
*/
int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size,
u32 offset);
/**
* gsi_trans_skb_add() - Add a socket transfer to a transaction
* @trans: Transaction
* @skb: Socket buffer for transfer (outbound)
*
* @Return: 0, or -EMSGSIZE if socket data won't fit in transaction.
*/
int gsi_trans_skb_add(struct gsi_trans *trans, struct sk_buff *skb);
/**
* gsi_trans_commit() - Commit a GSI transaction
* @trans: Transaction to commit
* @ring_db: Whether to tell the hardware about these queued transfers
*/
void gsi_trans_commit(struct gsi_trans *trans, bool ring_db);
/**
* gsi_trans_commit_wait() - Commit a GSI transaction and wait for it
* to complete
* @trans: Transaction to commit
*/
void gsi_trans_commit_wait(struct gsi_trans *trans);
/**
* gsi_trans_commit_wait_timeout() - Commit a GSI transaction and wait for
* it to complete, with timeout
* @trans: Transaction to commit
* @timeout: Timeout period (in milliseconds)
*/
int gsi_trans_commit_wait_timeout(struct gsi_trans *trans,
unsigned long timeout);
/**
* gsi_trans_read_byte() - Issue a single byte read TRE on a channel
* @gsi: GSI pointer
* @channel_id: Channel on which to read a byte
* @addr: DMA address into which to transfer the one byte
*
* This is not a transaction operation at all. It's defined here because
* it needs to be done in coordination with other transaction activity.
*/
int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr);
/**
* gsi_trans_read_byte_done() - Clean up after a single byte read TRE
* @gsi: GSI pointer
* @channel_id: Channel on which byte was read
*
* This function needs to be called to signal that the work related
* to reading a byte initiated by gsi_trans_read_byte() is complete.
*/
void gsi_trans_read_byte_done(struct gsi *gsi, u32 channel_id);
#endif /* _GSI_TRANS_H_ */
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