[PATCH v2 14/15] crypto: iaa - Add irq support for the crypto async interface

Tom Zanussi
2023-03-28T15:38:42Z

The existing iaa crypto async support provides an implementation that
satisfies the interface but does so in a synchronous manner - it fills
and submits the IDXD descriptor and then waits for it to complete
before returning. This isn't a problem at the moment, since all
existing callers (e.g. zswap) wrap any asynchronous callees in a
synchronous wrapper anyway.

This change makes the iaa crypto async implementation truly
asynchronous: it fills and submits the IDXD descriptor, then returns
immediately with -EINPROGRESS. It also sets the descriptor's 'request
completion irq' bit and sets up a callback with the IDXD driver which
is called when the operation completes and the irq fires. The
existing callers such as zswap use synchronous wrappers to deal with
-EINPROGRESS and so work as expected without any changes.

This mode can be enabled by writing 'async_irq' to the sync_mode
iaa_crypto driver attribute:

echo async_irq > /sys/bus/dsa/drivers/crypto/sync_mode

Async mode without interrupts (caller must poll) can be enabled by
writing 'async' to it:

echo async > /sys/bus/dsa/drivers/crypto/sync_mode

The default sync mode can be enabled by writing 'sync' to it:

echo sync > /sys/bus/dsa/drivers/crypto/sync_mode

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
drivers/crypto/intel/iaa/iaa_crypto_main.c | 224 ++++++++++++++++++++-
1 file changed, 222 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c b/drivers/crypto/intel/iaa/iaa_crypto_main.c
index b6d41642f0dd..7a2c0ed80108 100644
--- a/drivers/crypto/intel/iaa/iaa_crypto_main.c
+++ b/drivers/crypto/intel/iaa/iaa_crypto_main.c
@@ -116,6 +116,102 @@ static ssize_t verify_compress_store(struct device_driver *driver,
}
static DRIVER_ATTR_RW(verify_compress);

+/*
+ * The iaa crypto driver supports three 'sync' methods determining how
+ * compressions and decompressions are performed:
+ *
+ * - sync: the compression or decompression completes before
+ * returning. This is the mode used by the async crypto
+ * interface when the sync mode is set to 'sync' and by
+ * the sync crypto interface regardless of setting.
+ *
+ * - async: the compression or decompression is submitted and returns
+ * immediately. Completion interrupts are not used so
+ * the caller is responsible for polling the descriptor
+ * for completion. This mode is applicable to only the
+ * async crypto interface and is ignored for anything
+ * else.
+ *
+ * - async_irq: the compression or decompression is submitted and
+ * returns immediately. Completion interrupts are
+ * enabled so the caller can wait for the completion and
+ * yield to other threads. When the compression or
+ * decompression completes, the completion is signaled
+ * and the caller awakened. This mode is applicable to
+ * only the async crypto interface and is ignored for
+ * anything else.
+ *
+ * These modes can be set using the iaa_crypto sync_mode driver
+ * attribute.
+ */
+
+/* Use async mode */
+static bool async_mode;
+/* Use interrupts */
+static bool use_irq;
+
+/**
+ * set_iaa_sync_mode - Set IAA sync mode
+ * @name: The name of the sync mode
+ *
+ * Make the IAA sync mode named @name the current sync mode used by
+ * compression/decompression.
+ */
+
+static int set_iaa_sync_mode(const char *name)
+{
+ int ret = 0;
+
+ if (sysfs_streq(name, "sync")) {
+ async_mode = false;
+ use_irq = false;
+ } else if (sysfs_streq(name, "async")) {
+ async_mode = true;
+ use_irq = false;
+ } else if (sysfs_streq(name, "async_irq")) {
+ async_mode = true;
+ use_irq = true;
+ } else {
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static ssize_t sync_mode_show(struct device_driver *driver, char *buf)
+{
+ int ret = 0;
+
+ if (!async_mode && !use_irq)
+ ret = sprintf(buf, "%s\n", "sync");
+ else if (async_mode && !use_irq)
+ ret = sprintf(buf, "%s\n", "async");
+ else if (async_mode && use_irq)
+ ret = sprintf(buf, "%s\n", "async_irq");
+
+ return ret;
+}
+
+static ssize_t sync_mode_store(struct device_driver *driver,
+ const char *buf, size_t count)
+{
+ int ret = -EBUSY;
+
+ mutex_lock(&iaa_devices_lock);
+
+ if (iaa_crypto_enabled)
+ goto out;
+
+ ret = set_iaa_sync_mode(buf);
+ if (ret == 0)
+ ret = count;
+out:
+ mutex_unlock(&iaa_devices_lock);
+
+ return ret;
+}
+static DRIVER_ATTR_RW(sync_mode);
+
static struct iaa_compression_mode *iaa_compression_modes[IAA_COMP_MODES_MAX];
static int active_compression_mode;

@@ -1033,6 +1129,72 @@ static inline int check_completion(struct device *dev,
return ret;
}

+static int iaa_compress_verify(struct crypto_tfm *tfm, struct acomp_req *req,
+ struct idxd_wq *wq,
+ dma_addr_t src_addr, unsigned int slen,
+ dma_addr_t dst_addr, unsigned int *dlen,
+ u32 compression_crc);
+
+static void iaa_desc_complete(struct idxd_desc *idxd_desc,
+ enum idxd_complete_type comp_type,
+ bool free_desc, void *__ctx,
+ u32 *status)
+{
+ struct crypto_ctx *ctx = __ctx;
+ struct idxd_device *idxd;
+ struct iaa_wq *iaa_wq;
+ struct pci_dev *pdev;
+ struct device *dev;
+ int ret, err = 0;
+
+ iaa_wq = idxd_desc->wq->private_data;
+ idxd = iaa_wq->iaa_device->idxd;
+ pdev = idxd->pdev;
+ dev = &pdev->dev;
+
+ dev_dbg(dev, "%s: compression mode %s,"
+ " ctx->src_addr %llx, ctx->dst_addr %llx\n", __func__,
+ iaa_wq->iaa_device->active_compression_mode->name,
+ ctx->src_addr, ctx->dst_addr);
+
+ ret = check_completion(dev, idxd_desc->iax_completion,
+ ctx->compress, false);
+ if (ret) {
+ dev_dbg(dev, "%s: check_completion failed ret=%d\n", __func__, ret);
+ err = -EIO;
+ goto err;
+ }
+
+ ctx->req->dlen = idxd_desc->iax_completion->output_size;
+
+ if (ctx->compress && iaa_verify_compress) {
+ u32 compression_crc;
+
+ compression_crc = idxd_desc->iax_completion->crc;
+ dma_sync_sg_for_device(dev, ctx->req->dst, 1, DMA_FROM_DEVICE);
+ dma_sync_sg_for_device(dev, ctx->req->src, 1, DMA_TO_DEVICE);
+ ret = iaa_compress_verify(ctx->tfm, ctx->req, iaa_wq->wq, ctx->src_addr,
+ ctx->req->slen, ctx->dst_addr, &ctx->req->dlen,
+ compression_crc);
+ if (ret) {
+ dev_dbg(dev, "%s: compress verify failed ret=%d\n", __func__, ret);
+ err = -EIO;
+ }
+ }
+err:
+ if (ctx->req->base.complete)
+ acomp_request_complete(ctx->req, err);
+
+ dma_unmap_sg(dev, ctx->req->dst, sg_nents(ctx->req->dst), DMA_FROM_DEVICE);
+ dma_unmap_sg(dev, ctx->req->src, sg_nents(ctx->req->src), DMA_TO_DEVICE);
+
+ if (ret != 0)
+ dev_dbg(dev, "asynchronous compress failed ret=%d\n", ret);
+
+ if (free_desc)
+ idxd_free_desc(idxd_desc->wq, idxd_desc);
+}
+
static int iaa_compress(struct crypto_tfm *tfm, struct acomp_req *req,
struct idxd_wq *wq,
dma_addr_t src_addr, unsigned int slen,
@@ -1075,6 +1237,22 @@ static int iaa_compress(struct crypto_tfm *tfm, struct acomp_req *req,
desc->src2_size = sizeof(struct aecs_comp_table_record);
desc->completion_addr = idxd_desc->compl_dma;

+ if (use_irq) {
+ desc->flags |= IDXD_OP_FLAG_RCI;
+
+ idxd_desc->crypto.req = req;
+ idxd_desc->crypto.tfm = tfm;
+ idxd_desc->crypto.src_addr = src_addr;
+ idxd_desc->crypto.dst_addr = dst_addr;
+ idxd_desc->crypto.compress = true;
+
+ dev_dbg(dev, "%s use_async_irq: compression mode %s,"
+ " src_addr %llx, dst_addr %llx\n", __func__,
+ iaa_wq->iaa_device->active_compression_mode->name,
+ src_addr, dst_addr);
+ } else if (async_mode && !disable_async)
+ req->base.data = idxd_desc;
+
dev_dbg(dev, "%s: compression mode %s,"
" desc->src1_addr %llx, desc->src1_size %d,"
" desc->dst_addr %llx, desc->max_dst_size %d,"
@@ -1089,6 +1267,12 @@ static int iaa_compress(struct crypto_tfm *tfm, struct acomp_req *req,
goto err;
}

+ if (async_mode && !disable_async) {
+ ret = -EINPROGRESS;
+ dev_dbg(dev, "%s: returning -EINPROGRESS\n", __func__);
+ goto out;
+ }
+
ret = check_completion(dev, idxd_desc->iax_completion, true, false);
if (ret) {
dev_dbg(dev, "check_completion failed ret=%d\n", ret);
@@ -1099,7 +1283,8 @@ static int iaa_compress(struct crypto_tfm *tfm, struct acomp_req *req,

*compression_crc = idxd_desc->iax_completion->crc;

- idxd_free_desc(wq, idxd_desc);
+ if (!async_mode)
+ idxd_free_desc(wq, idxd_desc);
out:
return ret;
err:
@@ -1246,6 +1431,22 @@ static int iaa_decompress(struct crypto_tfm *tfm, struct acomp_req *req,
desc->flags |= IDXD_OP_FLAG_RD_SRC2_AECS;
}

+ if (use_irq && !disable_async) {
+ desc->flags |= IDXD_OP_FLAG_RCI;
+
+ idxd_desc->crypto.req = req;
+ idxd_desc->crypto.tfm = tfm;
+ idxd_desc->crypto.src_addr = src_addr;
+ idxd_desc->crypto.dst_addr = dst_addr;
+ idxd_desc->crypto.compress = false;
+
+ dev_dbg(dev, "%s: use_async_irq compression mode %s,"
+ " src_addr %llx, dst_addr %llx\n", __func__,
+ iaa_wq->iaa_device->active_compression_mode->name,
+ src_addr, dst_addr);
+ } else if (async_mode && !disable_async)
+ req->base.data = idxd_desc;
+
dev_dbg(dev, "%s: decompression mode %s,"
" desc->src1_addr %llx, desc->src1_size %d,"
" desc->dst_addr %llx, desc->max_dst_size %d,"
@@ -1260,6 +1461,12 @@ static int iaa_decompress(struct crypto_tfm *tfm, struct acomp_req *req,
goto err;
}

+ if (async_mode && !disable_async) {
+ ret = -EINPROGRESS;
+ dev_dbg(dev, "%s: returning -EINPROGRESS\n", __func__);
+ goto out;
+ }
+
ret = check_completion(dev, idxd_desc->iax_completion, false, false);
if (ret) {
dev_dbg(dev, "check_completion failed ret=%d\n", ret);
@@ -1268,7 +1475,8 @@ static int iaa_decompress(struct crypto_tfm *tfm, struct acomp_req *req,

*dlen = idxd_desc->iax_completion->output_size;

- idxd_free_desc(wq, idxd_desc);
+ if (!async_mode)
+ idxd_free_desc(wq, idxd_desc);
out:
return ret;
err:
@@ -1675,6 +1883,7 @@ static struct idxd_device_driver iaa_crypto_driver = {
.remove = iaa_crypto_remove,
.name = IDXD_SUBDRIVER_NAME,
.type = dev_types,
+ .desc_complete = iaa_desc_complete,
};

static int __init iaa_crypto_init_module(void)
@@ -1691,6 +1900,13 @@ static int __init iaa_crypto_init_module(void)
goto out;
}

+ ret = driver_create_file(&iaa_crypto_driver.drv,
+ &driver_attr_sync_mode);
+ if (ret) {
+ pr_debug("IAA sync mode attr creation failed\n");
+ goto err_attr_create;
+ }
+
ret = driver_create_file(&iaa_crypto_driver.drv,
&driver_attr_compression_mode);
if (ret) {
@@ -1723,6 +1939,8 @@ static int __init iaa_crypto_init_module(void)
return ret;

err_compression_mode:
+ driver_remove_file(&iaa_crypto_driver.drv,
+ &driver_attr_sync_mode);
driver_remove_file(&iaa_crypto_driver.drv,
&driver_attr_compression_mode);
driver_remove_file(&iaa_crypto_driver.drv,
@@ -1735,6 +1953,8 @@ static int __init iaa_crypto_init_module(void)

static void __exit iaa_crypto_cleanup_module(void)
{
+ driver_remove_file(&iaa_crypto_driver.drv,
+ &driver_attr_sync_mode);
driver_remove_file(&iaa_crypto_driver.drv,
&driver_attr_compression_mode);
driver_remove_file(&iaa_crypto_driver.drv,
--
2.34.1