Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1135 insertions, 0 deletions

diff --git a/drivers/crypto/nx/nx-common-powernv.c b/drivers/crypto/nx/nx-common-powernv.c
new file mode 100644
index 0000000000..8c859872c1
--- /dev/null
+++ b/drivers/crypto/nx/nx-common-powernv.c
@@ -0,0 +1,1135 @@
+// 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 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))
+
+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 (!(READ_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;
+	case CSB_CC_EXCEED_BYTE_COUNT:	/* P9 or later */
+		/*
+		 * DDE byte count exceeds the limit specified in Maximum
+		 * byte count register.
+		 */
+		CSB_ERR(csb, "DDE byte count exceeds the limit");
+		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:
+	case CSB_CC_INVALID_CRB:	/* P9 or later */
+		/* shouldn't happen, we setup CRB correctly */
+		CSB_ERR(csb, "Invalid CRB");
+		return -EINVAL;
+	case CSB_CC_INVALID_DDE:	/* P9 or later */
+		/*
+		 * shouldn't happen, setup_direct/indirect_dde creates
+		 * DDE right
+		 */
+		CSB_ERR(csb, "Invalid DDE");
+		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 sequence 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;
+	case CSB_CC_HW_EXPIRED_TIMER:	/* P9 or later */
+		CSB_ERR(csb, "Job did not finish within allowed time");
+		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",
+			     be32_to_cpu(csb->count),
+			     (unsigned long)ktime_us_delta(now, start));
+
+	return 0;
+}
+
+static int nx842_config_crb(const unsigned char *in, unsigned int inlen,
+			unsigned char *out, unsigned int outlen,
+			struct nx842_workmem *wmem)
+{
+	struct coprocessor_request_block *crb;
+	struct coprocessor_status_block *csb;
+	u64 csb_addr;
+	int ret;
+
+	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 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);
+
+	return 0;
+}
+
+/**
+ * nx842_exec_icswx - 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, size determined by
+ *           nx842_powernv_driver.workmem_size
+ * @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_exec_icswx(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;
+	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;
+	}
+
+	ret = nx842_config_crb(in, inlen, out, outlen, wmem);
+	if (ret)
+		return ret;
+
+	crb = &wmem->crb;
+	csb = &crb->csb;
+
+	/* set up CCW */
+	ccw = 0;
+	ccw = SET_FIELD(CCW_CT, ccw, nx842_ct);
+	ccw = SET_FIELD(CCW_CI_842, ccw, 0); /* use 0 for hw auto-selection */
+	ccw = SET_FIELD(CCW_FC_842, ccw, fc);
+
+	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));
+
+	/*
+	 * NX842 coprocessor sets 3rd bit in CR register with XER[S0].
+	 * XER[S0] is the integer summary overflow bit which is nothing
+	 * to do NX. Since this bit can be set with other return values,
+	 * mask this bit.
+	 */
+	ret &= ~ICSWX_XERS0;
+
+	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;
+	}
+
+	if (!ret)
+		*outlenp = be32_to_cpu(csb->count);
+
+	return ret;
+}
+
+/**
+ * nx842_exec_vas - 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, size determined by
+ *           nx842_powernv_driver.workmem_size
+ * @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_exec_vas(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;
+	struct vas_window *txwin;
+	int ret, i = 0;
+	u32 ccw;
+	unsigned int outlen = *outlenp;
+
+	wmem = PTR_ALIGN(workmem, WORKMEM_ALIGN);
+
+	*outlenp = 0;
+
+	crb = &wmem->crb;
+	csb = &crb->csb;
+
+	ret = nx842_config_crb(in, inlen, out, outlen, wmem);
+	if (ret)
+		return ret;
+
+	ccw = 0;
+	ccw = SET_FIELD(CCW_FC_842, ccw, fc);
+	crb->ccw = cpu_to_be32(ccw);
+
+	do {
+		wmem->start = ktime_get();
+		preempt_disable();
+		txwin = this_cpu_read(cpu_txwin);
+
+		/*
+		 * VAS copy CRB into L2 cache. Refer <asm/vas.h>.
+		 * @crb and @offset.
+		 */
+		vas_copy_crb(crb, 0);
+
+		/*
+		 * VAS paste previously copied CRB to NX.
+		 * @txwin, @offset and @last (must be true).
+		 */
+		ret = vas_paste_crb(txwin, 0, 1);
+		preempt_enable();
+		/*
+		 * Retry copy/paste function for VAS failures.
+		 */
+	} while (ret && (i++ < VAS_RETRIES));
+
+	if (ret) {
+		pr_err_ratelimited("VAS copy/paste failed\n");
+		return ret;
+	}
+
+	ret = wait_for_csb(wmem, csb);
+	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
+ * @wmem: working memory buffer pointer, size determined by
+ *        nx842_powernv_driver.workmem_size
+ *
+ * Returns: see @nx842_powernv_exec()
+ */
+static int nx842_powernv_compress(const unsigned char *in, unsigned int inlen,
+				  unsigned char *out, unsigned int *outlenp,
+				  void *wmem)
+{
+	return nx842_powernv_exec(in, inlen, out, outlenp,
+				      wmem, CCW_FC_842_COMP_CRC);
+}
+
+/**
+ * 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
+ * @wmem: working memory buffer pointer, size determined by
+ *        nx842_powernv_driver.workmem_size
+ *
+ * Returns: see @nx842_powernv_exec()
+ */
+static int nx842_powernv_decompress(const unsigned char *in, unsigned int inlen,
+				    unsigned char *out, unsigned int *outlenp,
+				    void *wmem)
+{
+	return nx842_powernv_exec(in, inlen, out, outlenp,
+				      wmem, CCW_FC_842_DECOMP_CRC);
+}
+
+static inline void nx_add_coprocs_list(struct nx_coproc *coproc,
+					int chipid)
+{
+	coproc->chip_id = chipid;
+	INIT_LIST_HEAD(&coproc->list);
+	list_add(&coproc->list, &nx_coprocs);
+}
+
+static struct vas_window *nx_alloc_txwin(struct nx_coproc *coproc)
+{
+	struct vas_window *txwin = NULL;
+	struct vas_tx_win_attr txattr;
+
+	/*
+	 * Kernel requests will be high priority. So open send
+	 * windows only for high priority RxFIFO entries.
+	 */
+	vas_init_tx_win_attr(&txattr, coproc->ct);
+	txattr.lpid = 0;	/* lpid is 0 for kernel requests */
+
+	/*
+	 * Open a VAS send window which is used to send request to NX.
+	 */
+	txwin = vas_tx_win_open(coproc->vas.id, coproc->ct, &txattr);
+	if (IS_ERR(txwin))
+		pr_err("ibm,nx-842: Can not open TX window: %ld\n",
+				PTR_ERR(txwin));
+
+	return txwin;
+}
+
+/*
+ * Identify chip ID for each CPU, open send wndow for the corresponding NX
+ * engine and save txwin in percpu cpu_txwin.
+ * cpu_txwin is used in copy/paste operation for each compression /
+ * decompression request.
+ */
+static int nx_open_percpu_txwins(void)
+{
+	struct nx_coproc *coproc, *n;
+	unsigned int i, chip_id;
+
+	for_each_possible_cpu(i) {
+		struct vas_window *txwin = NULL;
+
+		chip_id = cpu_to_chip_id(i);
+
+		list_for_each_entry_safe(coproc, n, &nx_coprocs, list) {
+			/*
+			 * Kernel requests use only high priority FIFOs. So
+			 * open send windows for these FIFOs.
+			 * GZIP is not supported in kernel right now.
+			 */
+
+			if (coproc->ct != VAS_COP_TYPE_842_HIPRI)
+				continue;
+
+			if (coproc->chip_id == chip_id) {
+				txwin = nx_alloc_txwin(coproc);
+				if (IS_ERR(txwin))
+					return PTR_ERR(txwin);
+
+				per_cpu(cpu_txwin, i) = txwin;
+				break;
+			}
+		}
+
+		if (!per_cpu(cpu_txwin, i)) {
+			/* shouldn't happen, Each chip will have NX engine */
+			pr_err("NX engine is not available for CPU %d\n", i);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int __init nx_set_ct(struct nx_coproc *coproc, const char *priority,
+				int high, int normal)
+{
+	if (!strcmp(priority, "High"))
+		coproc->ct = high;
+	else if (!strcmp(priority, "Normal"))
+		coproc->ct = normal;
+	else {
+		pr_err("Invalid RxFIFO priority value\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
+					int vasid, int type, int *ct)
+{
+	struct vas_window *rxwin = NULL;
+	struct vas_rx_win_attr rxattr;
+	u32 lpid, pid, tid, fifo_size;
+	struct nx_coproc *coproc;
+	u64 rx_fifo;
+	const char *priority;
+	int ret;
+
+	ret = of_property_read_u64(dn, "rx-fifo-address", &rx_fifo);
+	if (ret) {
+		pr_err("Missing rx-fifo-address property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(dn, "rx-fifo-size", &fifo_size);
+	if (ret) {
+		pr_err("Missing rx-fifo-size property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(dn, "lpid", &lpid);
+	if (ret) {
+		pr_err("Missing lpid property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(dn, "pid", &pid);
+	if (ret) {
+		pr_err("Missing pid property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(dn, "tid", &tid);
+	if (ret) {
+		pr_err("Missing tid property\n");
+		return ret;
+	}
+
+	ret = of_property_read_string(dn, "priority", &priority);
+	if (ret) {
+		pr_err("Missing priority property\n");
+		return ret;
+	}
+
+	coproc = kzalloc(sizeof(*coproc), GFP_KERNEL);
+	if (!coproc)
+		return -ENOMEM;
+
+	if (type == NX_CT_842)
+		ret = nx_set_ct(coproc, priority, VAS_COP_TYPE_842_HIPRI,
+			VAS_COP_TYPE_842);
+	else if (type == NX_CT_GZIP)
+		ret = nx_set_ct(coproc, priority, VAS_COP_TYPE_GZIP_HIPRI,
+				VAS_COP_TYPE_GZIP);
+
+	if (ret)
+		goto err_out;
+
+	vas_init_rx_win_attr(&rxattr, coproc->ct);
+	rxattr.rx_fifo = rx_fifo;
+	rxattr.rx_fifo_size = fifo_size;
+	rxattr.lnotify_lpid = lpid;
+	rxattr.lnotify_pid = pid;
+	rxattr.lnotify_tid = tid;
+	/*
+	 * Maximum RX window credits can not be more than #CRBs in
+	 * RxFIFO. Otherwise, can get checkstop if RxFIFO overruns.
+	 */
+	rxattr.wcreds_max = fifo_size / CRB_SIZE;
+
+	/*
+	 * Open a VAS receice window which is used to configure RxFIFO
+	 * for NX.
+	 */
+	rxwin = vas_rx_win_open(vasid, coproc->ct, &rxattr);
+	if (IS_ERR(rxwin)) {
+		ret = PTR_ERR(rxwin);
+		pr_err("setting RxFIFO with VAS failed: %d\n",
+			ret);
+		goto err_out;
+	}
+
+	coproc->vas.rxwin = rxwin;
+	coproc->vas.id = vasid;
+	nx_add_coprocs_list(coproc, chip_id);
+
+	/*
+	 * (lpid, pid, tid) combination has to be unique for each
+	 * coprocessor instance in the system. So to make it
+	 * unique, skiboot uses coprocessor type such as 842 or
+	 * GZIP for pid and provides this value to kernel in pid
+	 * device-tree property.
+	 */
+	*ct = pid;
+
+	return 0;
+
+err_out:
+	kfree(coproc);
+	return ret;
+}
+
+static int __init nx_coproc_init(int chip_id, int ct_842, int ct_gzip)
+{
+	int ret = 0;
+
+	if (opal_check_token(OPAL_NX_COPROC_INIT)) {
+		ret = opal_nx_coproc_init(chip_id, ct_842);
+
+		if (!ret)
+			ret = opal_nx_coproc_init(chip_id, ct_gzip);
+
+		if (ret) {
+			ret = opal_error_code(ret);
+			pr_err("Failed to initialize NX for chip(%d): %d\n",
+				chip_id, ret);
+		}
+	} else
+		pr_warn("Firmware doesn't support NX initialization\n");
+
+	return ret;
+}
+
+static int __init find_nx_device_tree(struct device_node *dn, int chip_id,
+					int vasid, int type, char *devname,
+					int *ct)
+{
+	int ret = 0;
+
+	if (of_device_is_compatible(dn, devname)) {
+		ret  = vas_cfg_coproc_info(dn, chip_id, vasid, type, ct);
+		if (ret)
+			of_node_put(dn);
+	}
+
+	return ret;
+}
+
+static int __init nx_powernv_probe_vas(struct device_node *pn)
+{
+	int chip_id, vasid, ret = 0;
+	int ct_842 = 0, ct_gzip = 0;
+	struct device_node *dn;
+
+	chip_id = of_get_ibm_chip_id(pn);
+	if (chip_id < 0) {
+		pr_err("ibm,chip-id missing\n");
+		return -EINVAL;
+	}
+
+	vasid = chip_to_vas_id(chip_id);
+	if (vasid < 0) {
+		pr_err("Unable to map chip_id %d to vasid\n", chip_id);
+		return -EINVAL;
+	}
+
+	for_each_child_of_node(pn, dn) {
+		ret = find_nx_device_tree(dn, chip_id, vasid, NX_CT_842,
+					"ibm,p9-nx-842", &ct_842);
+
+		if (!ret)
+			ret = find_nx_device_tree(dn, chip_id, vasid,
+				NX_CT_GZIP, "ibm,p9-nx-gzip", &ct_gzip);
+
+		if (ret) {
+			of_node_put(dn);
+			return ret;
+		}
+	}
+
+	if (!ct_842 || !ct_gzip) {
+		pr_err("NX FIFO nodes are missing\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Initialize NX instance for both high and normal priority FIFOs.
+	 */
+	ret = nx_coproc_init(chip_id, ct_842, ct_gzip);
+
+	return ret;
+}
+
+static int __init nx842_powernv_probe(struct device_node *dn)
+{
+	struct nx_coproc *coproc;
+	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;
+	}
+
+	if (of_property_read_u32(dn, "ibm,842-coprocessor-type", &ct)) {
+		pr_err("ibm,842-coprocessor-type missing\n");
+		return -EINVAL;
+	}
+
+	if (of_property_read_u32(dn, "ibm,842-coprocessor-instance", &ci)) {
+		pr_err("ibm,842-coprocessor-instance missing\n");
+		return -EINVAL;
+	}
+
+	coproc = kzalloc(sizeof(*coproc), GFP_KERNEL);
+	if (!coproc)
+		return -ENOMEM;
+
+	coproc->ct = ct;
+	coproc->ci = ci;
+	nx_add_coprocs_list(coproc, chip_id);
+
+	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 void nx_delete_coprocs(void)
+{
+	struct nx_coproc *coproc, *n;
+	struct vas_window *txwin;
+	int i;
+
+	/*
+	 * close percpu txwins that are opened for the corresponding coproc.
+	 */
+	for_each_possible_cpu(i) {
+		txwin = per_cpu(cpu_txwin, i);
+		if (txwin)
+			vas_win_close(txwin);
+
+		per_cpu(cpu_txwin, i) = NULL;
+	}
+
+	list_for_each_entry_safe(coproc, n, &nx_coprocs, list) {
+		if (coproc->vas.rxwin)
+			vas_win_close(coproc->vas.rxwin);
+
+		list_del(&coproc->list);
+		kfree(coproc);
+	}
+}
+
+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 = {
+	.name =		KBUILD_MODNAME,
+	.owner =	THIS_MODULE,
+	.workmem_size =	sizeof(struct nx842_workmem),
+	.constraints =	&nx842_powernv_constraints,
+	.compress =	nx842_powernv_compress,
+	.decompress =	nx842_powernv_decompress,
+};
+
+static int nx842_powernv_crypto_init(struct crypto_tfm *tfm)
+{
+	return nx842_crypto_init(tfm, &nx842_powernv_driver);
+}
+
+static struct crypto_alg nx842_powernv_alg = {
+	.cra_name		= "842",
+	.cra_driver_name	= "842-nx",
+	.cra_priority		= 300,
+	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
+	.cra_ctxsize		= sizeof(struct nx842_crypto_ctx),
+	.cra_module		= THIS_MODULE,
+	.cra_init		= nx842_powernv_crypto_init,
+	.cra_exit		= nx842_crypto_exit,
+	.cra_u			= { .compress = {
+	.coa_compress		= nx842_crypto_compress,
+	.coa_decompress		= nx842_crypto_decompress } }
+};
+
+static __init int nx_compress_powernv_init(void)
+{
+	struct device_node *dn;
+	int ret;
+
+	/* verify workmem size/align restrictions */
+	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);
+
+	for_each_compatible_node(dn, NULL, "ibm,power9-nx") {
+		ret = nx_powernv_probe_vas(dn);
+		if (ret) {
+			nx_delete_coprocs();
+			of_node_put(dn);
+			return ret;
+		}
+	}
+
+	if (list_empty(&nx_coprocs)) {
+		for_each_compatible_node(dn, NULL, "ibm,power-nx")
+			nx842_powernv_probe(dn);
+
+		if (!nx842_ct)
+			return -ENODEV;
+
+		nx842_powernv_exec = nx842_exec_icswx;
+	} else {
+		/*
+		 * Register VAS user space API for NX GZIP so
+		 * that user space can use GZIP engine.
+		 * Using high FIFO priority for kernel requests and
+		 * normal FIFO priority is assigned for userspace.
+		 * 842 compression is supported only in kernel.
+		 */
+		ret = vas_register_api_powernv(THIS_MODULE, VAS_COP_TYPE_GZIP,
+					       "nx-gzip");
+
+		/*
+		 * GZIP is not supported in kernel right now.
+		 * So open tx windows only for 842.
+		 */
+		if (!ret)
+			ret = nx_open_percpu_txwins();
+
+		if (ret) {
+			nx_delete_coprocs();
+			return ret;
+		}
+
+		nx842_powernv_exec = nx842_exec_vas;
+	}
+
+	ret = crypto_register_alg(&nx842_powernv_alg);
+	if (ret) {
+		nx_delete_coprocs();
+		return ret;
+	}
+
+	return 0;
+}
+module_init(nx_compress_powernv_init);
+
+static void __exit nx_compress_powernv_exit(void)
+{
+	/*
+	 * GZIP engine is supported only in power9 or later and nx842_ct
+	 * is used on power8 (icswx).
+	 * VAS API for NX GZIP is registered during init for user space
+	 * use. So delete this API use for GZIP engine.
+	 */
+	if (!nx842_ct)
+		vas_unregister_api_powernv();
+
+	crypto_unregister_alg(&nx842_powernv_alg);
+
+	nx_delete_coprocs();
+}
+module_exit(nx_compress_powernv_exit);