crypto: nx - add PowerNV platform NX-842 driver

Add driver for NX-842 hardware on the PowerNV platform.

This allows the use of the 842 compression hardware coprocessor on
the PowerNV platform.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

7 files changed, 741 insertions, 12 deletions

diff --git a/drivers/crypto/nx/Kconfig b/drivers/crypto/nx/Kconfig
index 34013f7d46c8..ee9e25956241 100644
--- a/drivers/crypto/nx/Kconfig
+++ b/drivers/crypto/nx/Kconfig
@@ -40,4 +40,14 @@ config CRYPTO_DEV_NX_COMPRESS_PSERIES
           algorithm.  This supports NX hardware on the pSeries platform.
           If you choose 'M' here, this module will be called nx_compress_pseries.
 
+config CRYPTO_DEV_NX_COMPRESS_POWERNV
+        tristate "Compression acceleration support on PowerNV platform"
+        depends on PPC_POWERNV
+        default y
+        help
+          Support for PowerPC Nest (NX) compression acceleration. This
+          module supports acceleration for compressing memory with the 842
+          algorithm.  This supports NX hardware on the PowerNV platform.
+          If you choose 'M' here, this module will be called nx_compress_powernv.
+
 endif
diff --git a/drivers/crypto/nx/Makefile b/drivers/crypto/nx/Makefile
index 5d9f4bc15209..6619787423b3 100644
--- a/drivers/crypto/nx/Makefile
+++ b/drivers/crypto/nx/Makefile
@@ -12,5 +12,7 @@ nx-crypto-objs := nx.o \
 
 obj-$(CONFIG_CRYPTO_DEV_NX_COMPRESS) += nx-compress.o
 obj-$(CONFIG_CRYPTO_DEV_NX_COMPRESS_PSERIES) += nx-compress-pseries.o
+obj-$(CONFIG_CRYPTO_DEV_NX_COMPRESS_POWERNV) += nx-compress-powernv.o
 nx-compress-objs := nx-842.o
 nx-compress-pseries-objs := nx-842-pseries.o
+nx-compress-powernv-objs := nx-842-powernv.o
diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
new file mode 100644
index 000000000000..6a9fb8b2d05b
--- /dev/null
+++ b/drivers/crypto/nx/nx-842-powernv.c
@@ -0,0 +1,625 @@
+/*
+ * Driver for IBM PowerNV 842 compression accelerator
+ *
+ * Copyright (C) 2015 Dan Streetman, IBM Corp
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "nx-842.h"
+
+#include <linux/timer.h>
+
+#include <asm/prom.h>
+#include <asm/icswx.h>
+
+#define MODULE_NAME NX842_POWERNV_MODULE_NAME
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
+MODULE_DESCRIPTION("842 H/W Compression driver for IBM PowerNV processors");
+
+#define WORKMEM_ALIGN   (CRB_ALIGN)
+#define CSB_WAIT_MAX    (5000) /* ms */
+
+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 nx842_coproc {
+        unsigned int chip_id;
+        unsigned int ct;
+        unsigned int ci;
+        struct list_head list;
+};
+
+/* no cpu hotplug on powernv, so this list never changes after init */
+static LIST_HEAD(nx842_coprocs);
+static unsigned int nx842_ct;
+
+/**
+ * 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);
+        }
+
+        if (len > 0) {
+                pr_debug("0x%x total %s bytes 0x%x too many for DDL.\n",
+                         total_len, in ? "input" : "output", len);
+                if (in)
+                        return -EMSGSIZE;
+                total_len -= len;
+        }
+        setup_indirect_dde(dde, ddl, i, total_len);
+
+        return 0;
+}
+
+#define CSB_ERR(csb, msg, ...)                                  \
+        pr_err("ERROR: " msg " : %02x %02x %02x %02x %08x\n",   \
+               ##__VA_ARGS__, (csb)->flags,                     \
+               (csb)->cs, (csb)->cc, (csb)->ce,                 \
+               be32_to_cpu((csb)->count))
+
+#define CSB_ERR_ADDR(csb, msg, ...)                             \
+        CSB_ERR(csb, msg " at %lx", ##__VA_ARGS__,              \
+                (unsigned long)be64_to_cpu((csb)->address))
+
+/**
+ * wait_for_csb
+ */
+static int wait_for_csb(struct nx842_workmem *wmem,
+                        struct coprocessor_status_block *csb)
+{
+        ktime_t start = wmem->start, now = ktime_get();
+        ktime_t timeout = ktime_add_ms(start, CSB_WAIT_MAX);
+
+        while (!(ACCESS_ONCE(csb->flags) & CSB_V)) {
+                cpu_relax();
+                now = ktime_get();
+                if (ktime_after(now, timeout))
+                        break;
+        }
+
+        /* hw has updated csb and output buffer */
+        barrier();
+
+        /* check CSB flags */
+        if (!(csb->flags & CSB_V)) {
+                CSB_ERR(csb, "CSB still not valid after %ld us, giving up",
+                        (long)ktime_us_delta(now, start));
+                return -ETIMEDOUT;
+        }
+        if (csb->flags & CSB_F) {
+                CSB_ERR(csb, "Invalid CSB format");
+                return -EPROTO;
+        }
+        if (csb->flags & CSB_CH) {
+                CSB_ERR(csb, "Invalid CSB chaining state");
+                return -EPROTO;
+        }
+
+        /* verify CSB completion sequence is 0 */
+        if (csb->cs) {
+                CSB_ERR(csb, "Invalid CSB completion sequence");
+                return -EPROTO;
+        }
+
+        /* check CSB Completion Code */
+        switch (csb->cc) {
+        /* no error */
+        case CSB_CC_SUCCESS:
+                break;
+        case CSB_CC_TPBC_GT_SPBC:
+                /* not an error, but the compressed data is
+                 * larger than the uncompressed data :(
+                 */
+                break;
+
+        /* input data errors */
+        case CSB_CC_OPERAND_OVERLAP:
+                /* input and output buffers overlap */
+                CSB_ERR(csb, "Operand Overlap error");
+                return -EINVAL;
+        case CSB_CC_INVALID_OPERAND:
+                CSB_ERR(csb, "Invalid operand");
+                return -EINVAL;
+        case CSB_CC_NOSPC:
+                /* output buffer too small */
+                return -ENOSPC;
+        case CSB_CC_ABORT:
+                CSB_ERR(csb, "Function aborted");
+                return -EINTR;
+        case CSB_CC_CRC_MISMATCH:
+                CSB_ERR(csb, "CRC mismatch");
+                return -EINVAL;
+        case CSB_CC_TEMPL_INVALID:
+                CSB_ERR(csb, "Compressed data template invalid");
+                return -EINVAL;
+        case CSB_CC_TEMPL_OVERFLOW:
+                CSB_ERR(csb, "Compressed data template shows data past end");
+                return -EINVAL;
+
+        /* these should not happen */
+        case CSB_CC_INVALID_ALIGN:
+                /* setup_ddl should have detected this */
+                CSB_ERR_ADDR(csb, "Invalid alignment");
+                return -EINVAL;
+        case CSB_CC_DATA_LENGTH:
+                /* setup_ddl should have detected this */
+                CSB_ERR(csb, "Invalid data length");
+                return -EINVAL;
+        case CSB_CC_WR_TRANSLATION:
+        case CSB_CC_TRANSLATION:
+        case CSB_CC_TRANSLATION_DUP1:
+        case CSB_CC_TRANSLATION_DUP2:
+        case CSB_CC_TRANSLATION_DUP3:
+        case CSB_CC_TRANSLATION_DUP4:
+        case CSB_CC_TRANSLATION_DUP5:
+        case CSB_CC_TRANSLATION_DUP6:
+                /* should not happen, we use physical addrs */
+                CSB_ERR_ADDR(csb, "Translation error");
+                return -EPROTO;
+        case CSB_CC_WR_PROTECTION:
+        case CSB_CC_PROTECTION:
+        case CSB_CC_PROTECTION_DUP1:
+        case CSB_CC_PROTECTION_DUP2:
+        case CSB_CC_PROTECTION_DUP3:
+        case CSB_CC_PROTECTION_DUP4:
+        case CSB_CC_PROTECTION_DUP5:
+        case CSB_CC_PROTECTION_DUP6:
+                /* should not happen, we use physical addrs */
+                CSB_ERR_ADDR(csb, "Protection error");
+                return -EPROTO;
+        case CSB_CC_PRIVILEGE:
+                /* shouldn't happen, we're in HYP mode */
+                CSB_ERR(csb, "Insufficient Privilege error");
+                return -EPROTO;
+        case CSB_CC_EXCESSIVE_DDE:
+                /* shouldn't happen, setup_ddl doesn't use many dde's */
+                CSB_ERR(csb, "Too many DDEs in DDL");
+                return -EINVAL;
+        case CSB_CC_TRANSPORT:
+                /* shouldn't happen, we setup CRB correctly */
+                CSB_ERR(csb, "Invalid CRB");
+                return -EINVAL;
+        case CSB_CC_SEGMENTED_DDL:
+                /* shouldn't happen, setup_ddl creates DDL right */
+                CSB_ERR(csb, "Segmented DDL error");
+                return -EINVAL;
+        case CSB_CC_DDE_OVERFLOW:
+                /* shouldn't happen, setup_ddl creates DDL right */
+                CSB_ERR(csb, "DDE overflow error");
+                return -EINVAL;
+        case CSB_CC_SESSION:
+                /* should not happen with ICSWX */
+                CSB_ERR(csb, "Session violation error");
+                return -EPROTO;
+        case CSB_CC_CHAIN:
+                /* should not happen, we don't use chained CRBs */
+                CSB_ERR(csb, "Chained CRB error");
+                return -EPROTO;
+        case CSB_CC_SEQUENCE:
+                /* should not happen, we don't use chained CRBs */
+                CSB_ERR(csb, "CRB seqeunce number error");
+                return -EPROTO;
+        case CSB_CC_UNKNOWN_CODE:
+                CSB_ERR(csb, "Unknown subfunction code");
+                return -EPROTO;
+
+        /* hardware errors */
+        case CSB_CC_RD_EXTERNAL:
+        case CSB_CC_RD_EXTERNAL_DUP1:
+        case CSB_CC_RD_EXTERNAL_DUP2:
+        case CSB_CC_RD_EXTERNAL_DUP3:
+                CSB_ERR_ADDR(csb, "Read error outside coprocessor");
+                return -EPROTO;
+        case CSB_CC_WR_EXTERNAL:
+                CSB_ERR_ADDR(csb, "Write error outside coprocessor");
+                return -EPROTO;
+        case CSB_CC_INTERNAL:
+                CSB_ERR(csb, "Internal error in coprocessor");
+                return -EPROTO;
+        case CSB_CC_PROVISION:
+                CSB_ERR(csb, "Storage provision error");
+                return -EPROTO;
+        case CSB_CC_HW:
+                CSB_ERR(csb, "Correctable hardware error");
+                return -EPROTO;
+
+        default:
+                CSB_ERR(csb, "Invalid CC %d", csb->cc);
+                return -EPROTO;
+        }
+
+        /* check Completion Extension state */
+        if (csb->ce & CSB_CE_TERMINATION) {
+                CSB_ERR(csb, "CSB request was terminated");
+                return -EPROTO;
+        }
+        if (csb->ce & CSB_CE_INCOMPLETE) {
+                CSB_ERR(csb, "CSB request not complete");
+                return -EPROTO;
+        }
+        if (!(csb->ce & CSB_CE_TPBC)) {
+                CSB_ERR(csb, "TPBC not provided, unknown target length");
+                return -EPROTO;
+        }
+
+        /* successful completion */
+        pr_debug_ratelimited("Processed %u bytes in %lu us\n", csb->count,
+                             (unsigned long)ktime_us_delta(now, start));
+
+        return 0;
+}
+
+/**
+ * nx842_powernv_function - compress/decompress data using the 842 algorithm
+ *
+ * (De)compression provided by the NX842 coprocessor on IBM PowerNV systems.
+ * This compresses or decompresses the provided input buffer into the provided
+ * output buffer.
+ *
+ * Upon return from this function @outlen contains the length of the
+ * output data.  If there is an error then @outlen will be 0 and an
+ * error will be specified by the return code from this function.
+ *
+ * The @workmem buffer should only be used by one function call at a time.
+ *
+ * @in: input buffer pointer
+ * @inlen: input buffer size
+ * @out: output buffer pointer
+ * @outlenp: output buffer size pointer
+ * @workmem: working memory buffer pointer, must be at least NX842_MEM_COMPRESS
+ * @fc: function code, see CCW Function Codes in nx-842.h
+ *
+ * Returns:
+ *   0          Success, output of length @outlenp stored in the buffer at @out
+ *   -ENODEV    Hardware unavailable
+ *   -ENOSPC    Output buffer is to small
+ *   -EMSGSIZE  Input buffer too large
+ *   -EINVAL    buffer constraints do not fix nx842_constraints
+ *   -EPROTO    hardware error during operation
+ *   -ETIMEDOUT hardware did not complete operation in reasonable time
+ *   -EINTR     operation was aborted
+ */
+static int nx842_powernv_function(const unsigned char *in, unsigned int inlen,
+                                  unsigned char *out, unsigned int *outlenp,
+                                  void *workmem, int fc)
+{
+        struct coprocessor_request_block *crb;
+        struct coprocessor_status_block *csb;
+        struct nx842_workmem *wmem;
+        int ret;
+        u64 csb_addr;
+        u32 ccw;
+        unsigned int outlen = *outlenp;
+
+        wmem = PTR_ALIGN(workmem, WORKMEM_ALIGN);
+
+        *outlenp = 0;
+
+        /* shoudn't happen, we don't load without a coproc */
+        if (!nx842_ct) {
+                pr_err_ratelimited("coprocessor CT is 0");
+                return -ENODEV;
+        }
+
+        crb = &wmem->crb;
+        csb = &crb->csb;
+
+        /* Clear any previous values */
+        memset(crb, 0, sizeof(*crb));
+
+        /* set up DDLs */
+        ret = setup_ddl(&crb->source, wmem->ddl_in,
+                        (unsigned char *)in, inlen, true);
+        if (ret)
+                return ret;
+        ret = setup_ddl(&crb->target, wmem->ddl_out,
+                        out, outlen, false);
+        if (ret)
+                return ret;
+
+        /* set up CCW */
+        ccw = 0;
+        ccw = SET_FIELD(ccw, CCW_CT, nx842_ct);
+        ccw = SET_FIELD(ccw, CCW_CI_842, 0); /* use 0 for hw auto-selection */
+        ccw = SET_FIELD(ccw, CCW_FC_842, fc);
+
+        /* set up CRB's CSB addr */
+        csb_addr = nx842_get_pa(csb) & CRB_CSB_ADDRESS;
+        csb_addr |= CRB_CSB_AT; /* Addrs are phys */
+        crb->csb_addr = cpu_to_be64(csb_addr);
+
+        wmem->start = ktime_get();
+
+        /* do ICSWX */
+        ret = icswx(cpu_to_be32(ccw), crb);
+
+        pr_debug_ratelimited("icswx CR %x ccw %x crb->ccw %x\n", ret,
+                             (unsigned int)ccw,
+                             (unsigned int)be32_to_cpu(crb->ccw));
+
+        switch (ret) {
+        case ICSWX_INITIATED:
+                ret = wait_for_csb(wmem, csb);
+                break;
+        case ICSWX_BUSY:
+                pr_debug_ratelimited("842 Coprocessor busy\n");
+                ret = -EBUSY;
+                break;
+        case ICSWX_REJECTED:
+                pr_err_ratelimited("ICSWX rejected\n");
+                ret = -EPROTO;
+                break;
+        default:
+                pr_err_ratelimited("Invalid ICSWX return code %x\n", ret);
+                ret = -EPROTO;
+                break;
+        }
+
+        if (!ret)
+                *outlenp = be32_to_cpu(csb->count);
+
+        return ret;
+}
+
+/**
+ * nx842_powernv_compress - Compress data using the 842 algorithm
+ *
+ * Compression provided by the NX842 coprocessor on IBM PowerNV systems.
+ * The input buffer is compressed and the result is stored in the
+ * provided output buffer.
+ *
+ * Upon return from this function @outlen contains the length of the
+ * compressed data.  If there is an error then @outlen will be 0 and an
+ * error will be specified by the return code from this function.
+ *
+ * @in: input buffer pointer
+ * @inlen: input buffer size
+ * @out: output buffer pointer
+ * @outlenp: output buffer size pointer
+ * @workmem: working memory buffer pointer, must be at least NX842_MEM_COMPRESS
+ *
+ * Returns: see @nx842_powernv_function()
+ */
+static int nx842_powernv_compress(const unsigned char *in, unsigned int inlen,
+                                  unsigned char *out, unsigned int *outlenp,
+                                  void *wmem)
+{
+        return nx842_powernv_function(in, inlen, out, outlenp,
+                                      wmem, CCW_FC_842_COMP_NOCRC);
+}
+
+/**
+ * nx842_powernv_decompress - Decompress data using the 842 algorithm
+ *
+ * Decompression provided by the NX842 coprocessor on IBM PowerNV systems.
+ * The input buffer is decompressed and the result is stored in the
+ * provided output buffer.
+ *
+ * Upon return from this function @outlen contains the length of the
+ * decompressed data.  If there is an error then @outlen will be 0 and an
+ * error will be specified by the return code from this function.
+ *
+ * @in: input buffer pointer
+ * @inlen: input buffer size
+ * @out: output buffer pointer
+ * @outlenp: output buffer size pointer
+ * @workmem: working memory buffer pointer, must be at least NX842_MEM_COMPRESS
+ *
+ * Returns: see @nx842_powernv_function()
+ */
+static int nx842_powernv_decompress(const unsigned char *in, unsigned int inlen,
+                                    unsigned char *out, unsigned int *outlenp,
+                                    void *wmem)
+{
+        return nx842_powernv_function(in, inlen, out, outlenp,
+                                      wmem, CCW_FC_842_DECOMP_NOCRC);
+}
+
+static int __init nx842_powernv_probe(struct device_node *dn)
+{
+        struct nx842_coproc *coproc;
+        struct property *ct_prop, *ci_prop;
+        unsigned int ct, ci;
+        int chip_id;
+
+        chip_id = of_get_ibm_chip_id(dn);
+        if (chip_id < 0) {
+                pr_err("ibm,chip-id missing\n");
+                return -EINVAL;
+        }
+        ct_prop = of_find_property(dn, "ibm,842-coprocessor-type", NULL);
+        if (!ct_prop) {
+                pr_err("ibm,842-coprocessor-type missing\n");
+                return -EINVAL;
+        }
+        ct = be32_to_cpu(*(unsigned int *)ct_prop->value);
+        ci_prop = of_find_property(dn, "ibm,842-coprocessor-instance", NULL);
+        if (!ci_prop) {
+                pr_err("ibm,842-coprocessor-instance missing\n");
+                return -EINVAL;
+        }
+        ci = be32_to_cpu(*(unsigned int *)ci_prop->value);
+
+        coproc = kmalloc(sizeof(*coproc), GFP_KERNEL);
+        if (!coproc)
+                return -ENOMEM;
+
+        coproc->chip_id = chip_id;
+        coproc->ct = ct;
+        coproc->ci = ci;
+        INIT_LIST_HEAD(&coproc->list);
+        list_add(&coproc->list, &nx842_coprocs);
+
+        pr_info("coprocessor found on chip %d, CT %d CI %d\n", chip_id, ct, ci);
+
+        if (!nx842_ct)
+                nx842_ct = ct;
+        else if (nx842_ct != ct)
+                pr_err("NX842 chip %d, CT %d != first found CT %d\n",
+                       chip_id, ct, nx842_ct);
+
+        return 0;
+}
+
+static struct nx842_constraints nx842_powernv_constraints = {
+        .alignment =    DDE_BUFFER_ALIGN,
+        .multiple =     DDE_BUFFER_LAST_MULT,
+        .minimum =      DDE_BUFFER_LAST_MULT,
+        .maximum =      (DDL_LEN_MAX - 1) * PAGE_SIZE,
+};
+
+static struct nx842_driver nx842_powernv_driver = {
+        .owner =        THIS_MODULE,
+        .constraints =  &nx842_powernv_constraints,
+        .compress =     nx842_powernv_compress,
+        .decompress =   nx842_powernv_decompress,
+};
+
+static __init int nx842_powernv_init(void)
+{
+        struct device_node *dn;
+
+        /* verify workmem size/align restrictions */
+        BUILD_BUG_ON(sizeof(struct nx842_workmem) > NX842_MEM_COMPRESS);
+        BUILD_BUG_ON(WORKMEM_ALIGN % CRB_ALIGN);
+        BUILD_BUG_ON(CRB_ALIGN % DDE_ALIGN);
+        BUILD_BUG_ON(CRB_SIZE % DDE_ALIGN);
+        /* verify buffer size/align restrictions */
+        BUILD_BUG_ON(PAGE_SIZE % DDE_BUFFER_ALIGN);
+        BUILD_BUG_ON(DDE_BUFFER_ALIGN % DDE_BUFFER_SIZE_MULT);
+        BUILD_BUG_ON(DDE_BUFFER_SIZE_MULT % DDE_BUFFER_LAST_MULT);
+
+        pr_info("loading\n");
+
+        for_each_compatible_node(dn, NULL, NX842_POWERNV_COMPAT_NAME)
+                nx842_powernv_probe(dn);
+
+        if (!nx842_ct) {
+                pr_err("no coprocessors found\n");
+                return -ENODEV;
+        }
+
+        nx842_register_driver(&nx842_powernv_driver);
+
+        pr_info("loaded\n");
+
+        return 0;
+}
+module_init(nx842_powernv_init);
+
+static void __exit nx842_powernv_exit(void)
+{
+        struct nx842_coproc *coproc, *n;
+
+        nx842_unregister_driver(&nx842_powernv_driver);
+
+        list_for_each_entry_safe(coproc, n, &nx842_coprocs, list) {
+                list_del(&coproc->list);
+                kfree(coproc);
+        }
+
+        pr_info("unloaded\n");
+}
+module_exit(nx842_powernv_exit);
diff --git a/drivers/crypto/nx/nx-842-pseries.c b/drivers/crypto/nx/nx-842-pseries.c
index cb481d81df06..6db99924652c 100644
--- a/drivers/crypto/nx/nx-842-pseries.c
+++ b/drivers/crypto/nx/nx-842-pseries.c
@@ -160,15 +160,6 @@ static inline unsigned long nx842_get_scatterlist_size(
         return sl->entry_nr * sizeof(struct nx842_slentry);
 }
 
-static inline unsigned long nx842_get_pa(void *addr)
-{
-        if (is_vmalloc_addr(addr))
-                return page_to_phys(vmalloc_to_page(addr))
-                       + offset_in_page(addr);
-        else
-                return __pa(addr);
-}
-
 static int nx842_build_scatterlist(unsigned long buf, int len,
                         struct nx842_scatterlist *sl)
 {
diff --git a/drivers/crypto/nx/nx-842.c b/drivers/crypto/nx/nx-842.c
index 160fe2d97336..bf2823ceaf4e 100644
--- a/drivers/crypto/nx/nx-842.c
+++ b/drivers/crypto/nx/nx-842.c
@@ -164,7 +164,9 @@ static __init int nx842_init(void)
 {
         pr_info("loading\n");
 
-        if (of_find_compatible_node(NULL, NULL, NX842_PSERIES_COMPAT_NAME))
+        if (of_find_compatible_node(NULL, NULL, NX842_POWERNV_COMPAT_NAME))
+                request_module_nowait(NX842_POWERNV_MODULE_NAME);
+        else if (of_find_compatible_node(NULL, NULL, NX842_PSERIES_COMPAT_NAME))
                 request_module_nowait(NX842_PSERIES_MODULE_NAME);
         else
                 pr_err("no nx842 driver found.\n");
diff --git a/drivers/crypto/nx/nx-842.h b/drivers/crypto/nx/nx-842.h
index c6ceb0f1d04c..84b15b7448bb 100644
--- a/drivers/crypto/nx/nx-842.h
+++ b/drivers/crypto/nx/nx-842.h
@@ -5,9 +5,104 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/nx842.h>
+#include <linux/sw842.h>
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/ratelimit.h>
+
+/* Restrictions on Data Descriptor List (DDL) and Entry (DDE) buffers
+ *
+ * From NX P8 workbook, sec 4.9.1 "842 details"
+ *   Each DDE buffer is 128 byte aligned
+ *   Each DDE buffer size is a multiple of 32 bytes (except the last)
+ *   The last DDE buffer size is a multiple of 8 bytes
+ */
+#define DDE_BUFFER_ALIGN        (128)
+#define DDE_BUFFER_SIZE_MULT    (32)
+#define DDE_BUFFER_LAST_MULT    (8)
+
+/* Arbitrary DDL length limit
+ * Allows max buffer size of MAX-1 to MAX pages
+ * (depending on alignment)
+ */
+#define DDL_LEN_MAX             (17)
+
+/* CCW 842 CI/FC masks
+ * NX P8 workbook, section 4.3.1, figure 4-6
+ * "CI/FC Boundary by NX CT type"
+ */
+#define CCW_CI_842              (0x00003ff8)
+#define CCW_FC_842              (0x00000007)
+
+/* CCW Function Codes (FC) for 842
+ * NX P8 workbook, section 4.9, table 4-28
+ * "Function Code Definitions for 842 Memory Compression"
+ */
+#define CCW_FC_842_COMP_NOCRC   (0)
+#define CCW_FC_842_COMP_CRC     (1)
+#define CCW_FC_842_DECOMP_NOCRC (2)
+#define CCW_FC_842_DECOMP_CRC   (3)
+#define CCW_FC_842_MOVE         (4)
+
+/* CSB CC Error Types for 842
+ * NX P8 workbook, section 4.10.3, table 4-30
+ * "Reported Error Types Summary Table"
+ */
+/* These are all duplicates of existing codes defined in icswx.h. */
+#define CSB_CC_TRANSLATION_DUP1 (80)
+#define CSB_CC_TRANSLATION_DUP2 (82)
+#define CSB_CC_TRANSLATION_DUP3 (84)
+#define CSB_CC_TRANSLATION_DUP4 (86)
+#define CSB_CC_TRANSLATION_DUP5 (92)
+#define CSB_CC_TRANSLATION_DUP6 (94)
+#define CSB_CC_PROTECTION_DUP1  (81)
+#define CSB_CC_PROTECTION_DUP2  (83)
+#define CSB_CC_PROTECTION_DUP3  (85)
+#define CSB_CC_PROTECTION_DUP4  (87)
+#define CSB_CC_PROTECTION_DUP5  (93)
+#define CSB_CC_PROTECTION_DUP6  (95)
+#define CSB_CC_RD_EXTERNAL_DUP1 (89)
+#define CSB_CC_RD_EXTERNAL_DUP2 (90)
+#define CSB_CC_RD_EXTERNAL_DUP3 (91)
+/* These are specific to NX */
+/* 842 codes */
+#define CSB_CC_TPBC_GT_SPBC     (64) /* no error, but >1 comp ratio */
+#define CSB_CC_CRC_MISMATCH     (65) /* decomp crc mismatch */
+#define CSB_CC_TEMPL_INVALID    (66) /* decomp invalid template value */
+#define CSB_CC_TEMPL_OVERFLOW   (67) /* decomp template shows data after end */
+/* sym crypt codes */
+#define CSB_CC_DECRYPT_OVERFLOW (64)
+/* asym crypt codes */
+#define CSB_CC_MINV_OVERFLOW    (128)
+/* These are reserved for hypervisor use */
+#define CSB_CC_HYP_RESERVE_START        (240)
+#define CSB_CC_HYP_RESERVE_END          (253)
+#define CSB_CC_HYP_NO_HW                (254)
+#define CSB_CC_HYP_HANG_ABORTED         (255)
+
+/* CCB Completion Modes (CM) for 842
+ * NX P8 workbook, section 4.3, figure 4-5
+ * "CRB Details - Normal Cop_Req (CL=00, C=1)"
+ */
+#define CCB_CM_EXTRA_WRITE      (CCB_CM0_ALL_COMPLETIONS & CCB_CM12_STORE)
+#define CCB_CM_INTERRUPT        (CCB_CM0_ALL_COMPLETIONS & CCB_CM12_INTERRUPT)
+
+#define LEN_ON_PAGE(pa)         (PAGE_SIZE - ((pa) & ~PAGE_MASK))
+
+static inline unsigned long nx842_get_pa(void *addr)
+{
+        if (!is_vmalloc_addr(addr))
+                return __pa(addr);
+
+        return page_to_phys(vmalloc_to_page(addr)) + offset_in_page(addr);
+}
+
+/* Get/Set bit fields */
+#define MASK_LSH(m)             (__builtin_ffsl(m) - 1)
+#define GET_FIELD(v, m)         (((v) & (m)) >> MASK_LSH(m))
+#define SET_FIELD(v, m, val)    (((v) & ~(m)) | (((val) << MASK_LSH(m)) & (m)))
 
 struct nx842_driver {
         struct module *owner;
@@ -27,6 +122,8 @@ void nx842_unregister_driver(struct nx842_driver *driver);
 
 
 /* To allow the main nx-compress module to load platform module */
+#define NX842_POWERNV_MODULE_NAME       "nx-compress-powernv"
+#define NX842_POWERNV_COMPAT_NAME       "ibm,power-nx"
 #define NX842_PSERIES_MODULE_NAME       "nx-compress-pseries"
 #define NX842_PSERIES_COMPAT_NAME       "ibm,compression"
 
diff --git a/include/linux/nx842.h b/include/linux/nx842.h
index aa1a97e90dea..4ddf68d9c0d4 100644
--- a/include/linux/nx842.h
+++ b/include/linux/nx842.h
@@ -1,9 +1,11 @@
 #ifndef __NX842_H__
 #define __NX842_H__
 
-#define __NX842_PSERIES_MEM_COMPRESS    ((PAGE_SIZE * 2) + 10240)
+#define __NX842_PSERIES_MEM_COMPRESS    (10240)
+#define __NX842_POWERNV_MEM_COMPRESS    (1024)
 
-#define NX842_MEM_COMPRESS      __NX842_PSERIES_MEM_COMPRESS
+#define NX842_MEM_COMPRESS      (max_t(unsigned int,                    \
+        __NX842_PSERIES_MEM_COMPRESS, __NX842_POWERNV_MEM_COMPRESS))
 
 struct nx842_constraints {
         int alignment;