crypto: ccp - Register the CCP as a DMA resource

The CCP has the ability to provide DMA services to the
kernel using pass-through mode of the device. Register
these services as general purpose DMA channels.

Changes since v2:
- Add a Signed-off-by

Changes since v1:
- Allocate memory for a string in ccp_dmaengine_register
- Ensure register/unregister calls are properly ordered
- Verified all changed files are listed in the diffstat
- Undo some superfluous changes
- Added a cc:

Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccp/Kconfig

@@ -3,6 +3,7 @@ config CRYPTO_DEV_CCP_DD
 	depends on CRYPTO_DEV_CCP
 	default m
 	select HW_RANDOM
+	select DMA_ENGINE
 	select CRYPTO_SHA1
 	select CRYPTO_SHA256
 	help

drivers/crypto/ccp/Makefile

@@ -1,5 +1,9 @@
 obj-$(CONFIG_CRYPTO_DEV_CCP_DD) += ccp.o
-ccp-objs := ccp-dev.o ccp-ops.o ccp-dev-v3.o ccp-platform.o
+ccp-objs := ccp-dev.o \
+	    ccp-ops.o \
+	    ccp-dev-v3.o \
+	    ccp-platform.o \
+	    ccp-dmaengine.o
 ccp-$(CONFIG_PCI) += ccp-pci.o
 
 obj-$(CONFIG_CRYPTO_DEV_CCP_CRYPTO) += ccp-crypto.o

drivers/crypto/ccp/ccp-dev-v3.c

@@ -406,6 +406,11 @@ static int ccp_init(struct ccp_device *ccp)
 		goto e_kthread;
 	}
 
+	/* Register the DMA engine support */
+	ret = ccp_dmaengine_register(ccp);
+	if (ret)
+		goto e_hwrng;
+
 	ccp_add_device(ccp);
 
 	/* Enable interrupts */
@@ -413,6 +418,9 @@ static int ccp_init(struct ccp_device *ccp)
 
 	return 0;
 
+e_hwrng:
+	hwrng_unregister(&ccp->hwrng);
+
 e_kthread:
 	for (i = 0; i < ccp->cmd_q_count; i++)
 		if (ccp->cmd_q[i].kthread)
@@ -436,6 +444,9 @@ static void ccp_destroy(struct ccp_device *ccp)
 	/* Remove this device from the list of available units first */
 	ccp_del_device(ccp);
 
+	/* Unregister the DMA engine */
+	ccp_dmaengine_unregister(ccp);
+
 	/* Unregister the RNG */
 	hwrng_unregister(&ccp->hwrng);
 

drivers/crypto/ccp/ccp-dev.h

@@ -22,6 +22,9 @@
 #include <linux/dmapool.h>
 #include <linux/hw_random.h>
 #include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
+#include <linux/dmaengine.h>
 
 #define MAX_CCP_NAME_LEN		16
 #define MAX_DMAPOOL_NAME_LEN		32
@@ -167,6 +170,39 @@ extern struct ccp_vdata ccpv3;
 struct ccp_device;
 struct ccp_cmd;
 
+struct ccp_dma_cmd {
+	struct list_head entry;
+
+	struct ccp_cmd ccp_cmd;
+};
+
+struct ccp_dma_desc {
+	struct list_head entry;
+
+	struct ccp_device *ccp;
+
+	struct list_head pending;
+	struct list_head active;
+
+	enum dma_status status;
+	struct dma_async_tx_descriptor tx_desc;
+	size_t len;
+};
+
+struct ccp_dma_chan {
+	struct ccp_device *ccp;
+
+	spinlock_t lock;
+	struct list_head pending;
+	struct list_head active;
+	struct list_head complete;
+
+	struct tasklet_struct cleanup_tasklet;
+
+	enum dma_status status;
+	struct dma_chan dma_chan;
+};
+
 struct ccp_cmd_queue {
 	struct ccp_device *ccp;
 
@@ -260,6 +296,14 @@ struct ccp_device {
 	struct hwrng hwrng;
 	unsigned int hwrng_retries;
 
+	/*
+	 * Support for the CCP DMA capabilities
+	 */
+	struct dma_device dma_dev;
+	struct ccp_dma_chan *ccp_dma_chan;
+	struct kmem_cache *dma_cmd_cache;
+	struct kmem_cache *dma_desc_cache;
+
 	/*
 	 * A counter used to generate job-ids for cmds submitted to the CCP
 	 */
@@ -418,4 +462,7 @@ int ccp_cmd_queue_thread(void *data);
 
 int ccp_run_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd);
 
+int ccp_dmaengine_register(struct ccp_device *ccp);
+void ccp_dmaengine_unregister(struct ccp_device *ccp);
+
 #endif

drivers/crypto/ccp/ccp-ops.c

@@ -1427,6 +1427,70 @@ e_mask:
 	return ret;
 }
 
+static int ccp_run_passthru_nomap_cmd(struct ccp_cmd_queue *cmd_q,
+				      struct ccp_cmd *cmd)
+{
+	struct ccp_passthru_nomap_engine *pt = &cmd->u.passthru_nomap;
+	struct ccp_dm_workarea mask;
+	struct ccp_op op;
+	int ret;
+
+	if (!pt->final && (pt->src_len & (CCP_PASSTHRU_BLOCKSIZE - 1)))
+		return -EINVAL;
+
+	if (!pt->src_dma || !pt->dst_dma)
+		return -EINVAL;
+
+	if (pt->bit_mod != CCP_PASSTHRU_BITWISE_NOOP) {
+		if (pt->mask_len != CCP_PASSTHRU_MASKSIZE)
+			return -EINVAL;
+		if (!pt->mask)
+			return -EINVAL;
+	}
+
+	BUILD_BUG_ON(CCP_PASSTHRU_KSB_COUNT != 1);
+
+	memset(&op, 0, sizeof(op));
+	op.cmd_q = cmd_q;
+	op.jobid = ccp_gen_jobid(cmd_q->ccp);
+
+	if (pt->bit_mod != CCP_PASSTHRU_BITWISE_NOOP) {
+		/* Load the mask */
+		op.ksb_key = cmd_q->ksb_key;
+
+		mask.length = pt->mask_len;
+		mask.dma.address = pt->mask;
+		mask.dma.length = pt->mask_len;
+
+		ret = ccp_copy_to_ksb(cmd_q, &mask, op.jobid, op.ksb_key,
+				     CCP_PASSTHRU_BYTESWAP_NOOP);
+		if (ret) {
+			cmd->engine_error = cmd_q->cmd_error;
+			return ret;
+		}
+	}
+
+	/* Send data to the CCP Passthru engine */
+	op.eom = 1;
+	op.soc = 1;
+
+	op.src.type = CCP_MEMTYPE_SYSTEM;
+	op.src.u.dma.address = pt->src_dma;
+	op.src.u.dma.offset = 0;
+	op.src.u.dma.length = pt->src_len;
+
+	op.dst.type = CCP_MEMTYPE_SYSTEM;
+	op.dst.u.dma.address = pt->dst_dma;
+	op.dst.u.dma.offset = 0;
+	op.dst.u.dma.length = pt->src_len;
+
+	ret = cmd_q->ccp->vdata->perform->perform_passthru(&op);
+	if (ret)
+		cmd->engine_error = cmd_q->cmd_error;
+
+	return ret;
+}
+
 static int ccp_run_ecc_mm_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
 {
 	struct ccp_ecc_engine *ecc = &cmd->u.ecc;
@@ -1762,7 +1826,10 @@ int ccp_run_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
 		ret = ccp_run_rsa_cmd(cmd_q, cmd);
 		break;
 	case CCP_ENGINE_PASSTHRU:
-		ret = ccp_run_passthru_cmd(cmd_q, cmd);
+		if (cmd->flags & CCP_CMD_PASSTHRU_NO_DMA_MAP)
+			ret = ccp_run_passthru_nomap_cmd(cmd_q, cmd);
+		else
+			ret = ccp_run_passthru_cmd(cmd_q, cmd);
 		break;
 	case CCP_ENGINE_ECC:
 		ret = ccp_run_ecc_cmd(cmd_q, cmd);

include/linux/ccp.h

@@ -1,9 +1,10 @@
 /*
  * AMD Cryptographic Coprocessor (CCP) driver
  *
- * Copyright (C) 2013 Advanced Micro Devices, Inc.
+ * Copyright (C) 2013,2016 Advanced Micro Devices, Inc.
  *
  * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ * Author: Gary R Hook <gary.hook@amd.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -381,6 +382,35 @@ struct ccp_passthru_engine {
 	u32 final;
 };
 
+/**
+ * struct ccp_passthru_nomap_engine - CCP pass-through operation
+ *   without performing DMA mapping
+ * @bit_mod: bitwise operation to perform
+ * @byte_swap: byteswap operation to perform
+ * @mask: mask to be applied to data
+ * @mask_len: length in bytes of mask
+ * @src: data to be used for this operation
+ * @dst: data produced by this operation
+ * @src_len: length in bytes of data used for this operation
+ * @final: indicate final pass-through operation
+ *
+ * Variables required to be set when calling ccp_enqueue_cmd():
+ *   - bit_mod, byte_swap, src, dst, src_len
+ *   - mask, mask_len if bit_mod is not CCP_PASSTHRU_BITWISE_NOOP
+ */
+struct ccp_passthru_nomap_engine {
+	enum ccp_passthru_bitwise bit_mod;
+	enum ccp_passthru_byteswap byte_swap;
+
+	dma_addr_t mask;
+	u32 mask_len;		/* In bytes */
+
+	dma_addr_t src_dma, dst_dma;
+	u64 src_len;		/* In bytes */
+
+	u32 final;
+};
+
 /***** ECC engine *****/
 #define CCP_ECC_MODULUS_BYTES	48	/* 384-bits */
 #define CCP_ECC_MAX_OPERANDS	6
@@ -522,7 +552,8 @@ enum ccp_engine {
 };
 
 /* Flag values for flags member of ccp_cmd */
-#define CCP_CMD_MAY_BACKLOG	0x00000001
+#define CCP_CMD_MAY_BACKLOG		0x00000001
+#define CCP_CMD_PASSTHRU_NO_DMA_MAP	0x00000002
 
 /**
  * struct ccp_cmd - CPP operation request
@@ -562,6 +593,7 @@ struct ccp_cmd {
 		struct ccp_sha_engine sha;
 		struct ccp_rsa_engine rsa;
 		struct ccp_passthru_engine passthru;
+		struct ccp_passthru_nomap_engine passthru_nomap;
 		struct ccp_ecc_engine ecc;
 	} u;