path: root/drivers/crypto/nx/nx-common-powernv.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Driver for IBM PowerNV compression accelerator
 *
 * Copyright (C) 2015 Dan Streetman, IBM Corp
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "nx-842.h"

#include <linux/timer.h>

#include <asm/prom.h>
#include <asm/icswx.h>
#include <asm/vas.h>
#include <asm/reg.h>
#include <asm/opal-api.h>
#include <asm/opal.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
MODULE_DESCRIPTION("H/W Compression driver for IBM PowerNV processors");
MODULE_ALIAS_CRYPTO("842");
MODULE_ALIAS_CRYPTO("842-nx");

#define WORKMEM_ALIGN	(CRB_ALIGN)
#define CSB_WAIT_MAX	(5000) /* ms */
#define VAS_RETRIES	(10)

struct nx842_workmem {
	/* Below fields must be properly aligned */
	struct coprocessor_request_block crb; /* CRB_ALIGN align */
	struct data_descriptor_entry ddl_in[DDL_LEN_MAX]; /* DDE_ALIGN align */
	struct data_descriptor_entry ddl_out[DDL_LEN_MAX]; /* DDE_ALIGN align */
	/* Above fields must be properly aligned */

	ktime_t start;

	char padding[WORKMEM_ALIGN]; /* unused, to allow alignment */
} __packed __aligned(WORKMEM_ALIGN);

struct nx_coproc {
	unsigned int chip_id;
	unsigned int ct;	/* Can be 842 or GZIP high/normal*/
	unsigned int ci;	/* Coprocessor instance, used with icswx */
	struct {
		struct vas_window *rxwin;
		int id;
	} vas;
	struct list_head list;
};

/*
 * Send the request to NX engine on the chip for the corresponding CPU
 * where the process is executing. Use with VAS function.
 */
static DEFINE_PER_CPU(struct vas_window *, cpu_txwin);

/* no cpu hotplug on powernv, so this list never changes after init */
static LIST_HEAD(nx_coprocs);
static unsigned int nx842_ct;	/* used in icswx function */

/*
 * Using same values as in skiboot or coprocessor type representing
 * in NX workbook.
 */
#define NX_CT_GZIP	(2)	/* on P9 and later */
#define NX_CT_842	(3)

static int (*nx842_powernv_exec)(const unsigned char *in,
				unsigned int inlen, unsigned char *out,
				unsigned int *outlenp, void *workmem, int fc);

/**
 * setup_indirect_dde - Setup an indirect DDE
 *
 * The DDE is setup with the the DDE count, byte count, and address of
 * first direct DDE in the list.
 */
static void setup_indirect_dde(struct data_descriptor_entry *dde,
			       struct data_descriptor_entry *ddl,
			       unsigned int dde_count, unsigned int byte_count)
{
	dde->flags = 0;
	dde->count = dde_count;
	dde->index = 0;
	dde->length = cpu_to_be32(byte_count);
	dde->address = cpu_to_be64(nx842_get_pa(ddl));
}

/**
 * setup_direct_dde - Setup single DDE from buffer
 *
 * The DDE is setup with the buffer and length.  The buffer must be properly
 * aligned.  The used length is returned.
 * Returns:
 *   N    Successfully set up DDE with N bytes
 */
static unsigned int setup_direct_dde(struct data_descriptor_entry *dde,
				     unsigned long pa, unsigned int len)
{
	unsigned int l = min_t(unsigned int, len, LEN_ON_PAGE(pa));

	dde->flags = 0;
	dde->count = 0;
	dde->index = 0;
	dde->length = cpu_to_be32(l);
	dde->address = cpu_to_be64(pa);

	return l;
}

/**
 * setup_ddl - Setup DDL from buffer
 *
 * Returns:
 *   0		Successfully set up DDL
 */
static int setup_ddl(struct data_descriptor_entry *dde,
		     struct data_descriptor_entry *ddl,
		     unsigned char *buf, unsigned int len,
		     bool in)
{
	unsigned long pa = nx842_get_pa(buf);
	int i, ret, total_len = len;

	if (!IS_ALIGNED(pa, DDE_BUFFER_ALIGN)) {
		pr_debug("%s buffer pa 0x%lx not 0x%x-byte aligned\n",
			 in ? "input" : "output", pa, DDE_BUFFER_ALIGN);
		return -EINVAL;
	}

	/* only need to check last mult; since buffer must be
	 * DDE_BUFFER_ALIGN aligned, and that is a multiple of
	 * DDE_BUFFER_SIZE_MULT, and pre-last page DDE buffers
	 * are guaranteed a multiple of DDE_BUFFER_SIZE_MULT.
	 */
	if (len % DDE_BUFFER_LAST_MULT) {
		pr_debug("%s buffer len 0x%x not a multiple of 0x%x\n",
			 in ? "input" : "output", len, DDE_BUFFER_LAST_MULT);
		if (in)
			return -EINVAL;
		len = round_down(len, DDE_BUFFER_LAST_MULT);
	}

	/* use a single direct DDE */
	if (len <= LEN_ON_PAGE(pa)) {
		ret = setup_direct_dde(dde, pa, len);
		WARN_ON(ret < len);
		return 0;
	}

	/* use the DDL */
	for (i = 0; i < DDL_LEN_MAX && len > 0; i++) {
		ret = setup_direct_dde(&ddl[i], pa, len);
		buf += ret;
		len -= ret;
		pa = nx842_get_pa(buf);
	}