path: root/drivers/crypto/nx/nx-842-pseries.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Driver for IBM Power 842 compression accelerator
 *
 * Copyright (C) IBM Corporation, 2012
 *
 * Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
 *          Seth Jennings <sjenning@linux.vnet.ibm.com>
 */

#include <asm/vio.h>

#include "nx-842.h"
#include "nx_csbcpb.h" /* struct nx_csbcpb */

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Robert Jennings <rcj@linux.vnet.ibm.com>");
MODULE_DESCRIPTION("842 H/W Compression driver for IBM Power processors");
MODULE_ALIAS_CRYPTO("842");
MODULE_ALIAS_CRYPTO("842-nx");

static struct nx842_constraints nx842_pseries_constraints = {
	.alignment =	DDE_BUFFER_ALIGN,
	.multiple =	DDE_BUFFER_LAST_MULT,
	.minimum =	DDE_BUFFER_LAST_MULT,
	.maximum =	PAGE_SIZE, /* dynamic, max_sync_size */
};

static int check_constraints(unsigned long buf, unsigned int *len, bool in)
{
	if (!IS_ALIGNED(buf, nx842_pseries_constraints.alignment)) {
		pr_debug("%s buffer 0x%lx not aligned to 0x%x\n",
			 in ? "input" : "output", buf,
			 nx842_pseries_constraints.alignment);
		return -EINVAL;
	}
	if (*len % nx842_pseries_constraints.multiple) {
		pr_debug("%s buffer len 0x%x not multiple of 0x%x\n",
			 in ? "input" : "output", *len,
			 nx842_pseries_constraints.multiple);
		if (in)
			return -EINVAL;
		*len = round_down(*len, nx842_pseries_constraints.multiple);
	}
	if (*len < nx842_pseries_constraints.minimum) {
		pr_debug("%s buffer len 0x%x under minimum 0x%x\n",
			 in ? "input" : "output", *len,
			 nx842_pseries_constraints.minimum);
		return -EINVAL;
	}
	if (*len > nx842_pseries_constraints.maximum) {
		pr_debug("%s buffer len 0x%x over maximum 0x%x\n",
			 in ? "input" : "output", *len,
			 nx842_pseries_constraints.maximum);
		if (in)
			return -EINVAL;
		*len = nx842_pseries_constraints.maximum;
	}
	return 0;
}

/* I assume we need to align the CSB? */
#define WORKMEM_ALIGN	(256)

struct nx842_workmem {
	/* scatterlist */
	char slin[4096];
	char slout[4096];
	/* coprocessor status/parameter block */
	struct nx_csbcpb csbcpb;

	char padding[WORKMEM_ALIGN];
} __aligned(WORKMEM_ALIGN);

/* Macros for fields within nx_csbcpb */
/* Check the valid bit within the csbcpb valid field */
#define NX842_CSBCBP_VALID_CHK(x) (x & BIT_MASK(7))

/* CE macros operate on the completion_extension field bits in the csbcpb.
 * CE0 0=full completion, 1=partial completion
 * CE1 0=CE0 indicates completion, 1=termination (output may be modified)
 * CE2 0=processed_bytes is source bytes, 1=processed_bytes is target bytes */
#define NX842_CSBCPB_CE0(x)	(x & BIT_MASK(7))
#define NX842_CSBCPB_CE1(x)	(x & BIT_MASK(6))
#define NX842_CSBCPB_CE2(x)	(x & BIT_MASK(5))

/* The NX unit accepts data only on 4K page boundaries */
#define NX842_HW_PAGE_SIZE	(4096)
#define NX842_HW_PAGE_MASK	(~(NX842_HW_PAGE_SIZE-1))

struct ibm_nx842_counters {
	atomic64_t comp_complete;
	atomic64_t comp_failed;
	atomic64_t decomp_complete;
	atomic64_t decomp_failed;
	atomic64_t swdecomp;
	atomic64_t comp_times[32];
	atomic64_t decomp_times[32];
};

static struct nx842_devdata {
	struct vio_dev *vdev;
	struct device *dev;
	struct ibm_nx842_counters *counters;
	unsigned int max_sg_len;
	unsigned int max_sync_size;
	unsigned int max_sync_sg;
} __rcu *devdata;
static DEFINE_SPINLOCK(devdata_mutex);

#define NX842_COUNTER_INC(_x) \
static inline void nx842_inc_##_x( \
	const struct nx842_devdata *dev) { \
	if (dev) \
		atomic64_inc(&dev->counters->_x); \
}
NX842_COUNTER_INC(comp_complete);
NX842_COUNTER_INC(comp_failed);
NX842_COUNTER_INC(decomp_complete);
NX842_COUNTER_INC(decomp_failed);
NX842_COUNTER_INC(swdecomp);

#define NX842_HIST_SLOTS 16

static void ibm_nx842_incr_hist(atomic64_t *times, unsigned int time)
{
	int bucket = fls(time);

	if (bucket)
		bucket = min((NX842_HIST_SLOTS - 1), bucket - 1);

	atomic64_inc(&times[bucket]);
}

/* NX unit operation flags */
#define NX842_OP_COMPRESS	0x0
#define NX842_OP_CRC		0x1
#define NX842_OP_DECOMPRESS	0x2
#define NX842_OP_COMPRESS_CRC   (NX842_OP_COMPRESS | NX842_OP_CRC)
#define NX842_OP_DECOMPRESS_CRC (NX842_OP_DECOMPRESS | NX842_OP_CRC)
#define NX842_OP_ASYNC		(1<<23)
#define NX842_OP_NOTIFY		(1<<22)
#define NX842_OP_NOTIFY_INT(x)	((x & 0xff)<<8)

static unsigned long nx842_get_desired_dma(struct vio_dev *viodev)
{
	/* No use of DMA mappings within the driver. */
	return 0;
}

struct nx842_slentry {
	__be64 ptr; /* Real address (use __pa()) */
	__be64 len;
};

/* pHyp scatterlist entry */
struct nx842_scatterlist {
	int entry_nr; /* number of slentries */
	struct nx842_slentry *entries; /* ptr to array of slentries */
};

/* Does not include sizeof(entry_nr) in the size */
static inline unsigned long nx842_get_scatterlist_size(
				struct nx842_scatterlist *sl)
{
	return sl->entry_nr * sizeof(struct nx842_slentry);
}

static int nx842_build_scatterlist(unsigned long buf, int len,
			struct nx842_scatterlist *sl)
{
	unsigned long entrylen;
	struct nx842