drivers/crypto/inside-secure/safexcel_ring.c

Source file repositories/reference/linux-study-clean/drivers/crypto/inside-secure/safexcel_ring.c

File Facts

System
Linux kernel
Corpus path
drivers/crypto/inside-secure/safexcel_ring.c
Extension
.c
Size
6791 bytes
Lines
255
Domain
Driver Families
Bucket
drivers/crypto
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2017 Marvell
 *
 * Antoine Tenart <antoine.tenart@free-electrons.com>
 */

#include <linux/dma-mapping.h>
#include <linux/spinlock.h>

#include "safexcel.h"

int safexcel_init_ring_descriptors(struct safexcel_crypto_priv *priv,
				   struct safexcel_desc_ring *cdr,
				   struct safexcel_desc_ring *rdr)
{
	int i;
	struct safexcel_command_desc *cdesc;
	dma_addr_t atok;

	/* Actual command descriptor ring */
	cdr->offset = priv->config.cd_offset;
	cdr->base = dmam_alloc_coherent(priv->dev,
					cdr->offset * EIP197_DEFAULT_RING_SIZE,
					&cdr->base_dma, GFP_KERNEL);
	if (!cdr->base)
		return -ENOMEM;
	cdr->write = cdr->base;
	cdr->base_end = cdr->base + cdr->offset * (EIP197_DEFAULT_RING_SIZE - 1);
	cdr->read = cdr->base;

	/* Command descriptor shadow ring for storing additional token data */
	cdr->shoffset = priv->config.cdsh_offset;
	cdr->shbase = dmam_alloc_coherent(priv->dev,
					  cdr->shoffset *
					  EIP197_DEFAULT_RING_SIZE,
					  &cdr->shbase_dma, GFP_KERNEL);
	if (!cdr->shbase)
		return -ENOMEM;
	cdr->shwrite = cdr->shbase;
	cdr->shbase_end = cdr->shbase + cdr->shoffset *
					(EIP197_DEFAULT_RING_SIZE - 1);

	/*
	 * Populate command descriptors with physical pointers to shadow descs.
	 * Note that we only need to do this once if we don't overwrite them.
	 */
	cdesc = cdr->base;
	atok = cdr->shbase_dma;
	for (i = 0; i < EIP197_DEFAULT_RING_SIZE; i++) {
		cdesc->atok_lo = lower_32_bits(atok);
		cdesc->atok_hi = upper_32_bits(atok);
		cdesc = (void *)cdesc + cdr->offset;
		atok += cdr->shoffset;
	}

	rdr->offset = priv->config.rd_offset;
	/* Use shoffset for result token offset here */
	rdr->shoffset = priv->config.res_offset;
	rdr->base = dmam_alloc_coherent(priv->dev,
					rdr->offset * EIP197_DEFAULT_RING_SIZE,
					&rdr->base_dma, GFP_KERNEL);
	if (!rdr->base)
		return -ENOMEM;
	rdr->write = rdr->base;
	rdr->base_end = rdr->base + rdr->offset  * (EIP197_DEFAULT_RING_SIZE - 1);
	rdr->read = rdr->base;

	return 0;
}

inline int safexcel_select_ring(struct safexcel_crypto_priv *priv)
{
	return (atomic_inc_return(&priv->ring_used) % priv->config.rings);
}

static void *safexcel_ring_next_cwptr(struct safexcel_crypto_priv *priv,
				     struct safexcel_desc_ring *ring,
				     bool first,
				     struct safexcel_token **atoken)
{
	void *ptr = ring->write;

	if (first)
		*atoken = ring->shwrite;

	if ((ring->write == ring->read - ring->offset) ||
	    (ring->read == ring->base && ring->write == ring->base_end))
		return ERR_PTR(-ENOMEM);

Annotation

Implementation Notes