crypto: ccp: Add Platform Security Processor (PSP) device support

The Platform Security Processor (PSP) is part of the AMD Secure
Processor (AMD-SP) functionality. The PSP is a dedicated processor
that provides support for key management commands in Secure Encrypted
Virtualization (SEV) mode, along with software-based Trusted Execution
Environment (TEE) to enable third-party trusted applications.

Note that the key management functionality provided by the SEV firmware
can be used outside of the kvm-amd driver hence it doesn't need to
depend on CONFIG_KVM_AMD.

Cc: Paolo Bonzini <[e-mail]>
Cc: "Radim Krčmář" <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Herbert Xu <[e-mail]>
Cc: Gary Hook <[e-mail]>
Cc: Tom Lendacky <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Improvements-by: Borislav Petkov <[e-mail]>
Signed-off-by: Brijesh Singh <[e-mail]>
Reviewed-by: Borislav Petkov <[e-mail]>

drivers/crypto/ccp/Kconfig

···
 	  Support for using the cryptographic API with the AMD Cryptographic
 	  Coprocessor. This module supports offload of SHA and AES algorithms.
 	  If you choose 'M' here, this module will be called ccp_crypto.
+
+config CRYPTO_DEV_SP_PSP
+	bool "Platform Security Processor (PSP) device"
+	default y
+	depends on CRYPTO_DEV_CCP_DD && X86_64
+	help
+	 Provide support for the AMD Platform Security Processor (PSP).
+	 The PSP is a dedicated processor that provides support for key
+	 management commands in Secure Encrypted Virtualization (SEV) mode,
+	 along with software-based Trusted Execution Environment (TEE) to
+	 enable third-party trusted applications.

drivers/crypto/ccp/Makefile

···
 	    ccp-dmaengine.o \
 	    ccp-debugfs.o
 ccp-$(CONFIG_PCI) += sp-pci.o
+ccp-$(CONFIG_CRYPTO_DEV_SP_PSP) += psp-dev.o
 
 obj-$(CONFIG_CRYPTO_DEV_CCP_CRYPTO) += ccp-crypto.o
 ccp-crypto-objs := ccp-crypto-main.o \

drivers/crypto/ccp/psp-dev.c

···
+/*
+ * AMD Platform Security Processor (PSP) interface
+ *
+ * Copyright (C) 2016-2017 Advanced Micro Devices, Inc.
+ *
+ * Author: Brijesh Singh <[e-mail]>
+ *
+ * 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
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/spinlock_types.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/hw_random.h>
+#include <linux/ccp.h>
+
+#include "sp-dev.h"
+#include "psp-dev.h"
+
+static struct psp_device *psp_alloc_struct(struct sp_device *sp)
+{
+	struct device *dev = sp->dev;
+	struct psp_device *psp;
+
+	psp = devm_kzalloc(dev, sizeof(*psp), GFP_KERNEL);
+	if (!psp)
+		return NULL;
+
+	psp->dev = dev;
+	psp->sp = sp;
+
+	snprintf(psp->name, sizeof(psp->name), "psp-%u", sp->ord);
+
+	return psp;
+}
+
+static irqreturn_t psp_irq_handler(int irq, void *data)
+{
+	return IRQ_HANDLED;
+}
+
+int psp_dev_init(struct sp_device *sp)
+{
+	struct device *dev = sp->dev;
+	struct psp_device *psp;
+	int ret;
+
+	ret = -ENOMEM;
+	psp = psp_alloc_struct(sp);
+	if (!psp)
+		goto e_err;
+
+	sp->psp_data = psp;
+
+	psp->vdata = (struct psp_vdata *)sp->dev_vdata->psp_vdata;
+	if (!psp->vdata) {
+		ret = -ENODEV;
+		dev_err(dev, "missing driver data\n");
+		goto e_err;
+	}
+
+	psp->io_regs = sp->io_map + psp->vdata->offset;
+
+	/* Disable and clear interrupts until ready */
+	iowrite32(0, psp->io_regs + PSP_P2CMSG_INTEN);
+	iowrite32(-1, psp->io_regs + PSP_P2CMSG_INTSTS);
+
+	/* Request an irq */
+	ret = sp_request_psp_irq(psp->sp, psp_irq_handler, psp->name, psp);
+	if (ret) {
+		dev_err(dev, "psp: unable to allocate an IRQ\n");
+		goto e_err;
+	}
+
+	if (sp->set_psp_master_device)
+		sp->set_psp_master_device(sp);
+
+	/* Enable interrupt */
+	iowrite32(-1, psp->io_regs + PSP_P2CMSG_INTEN);
+
+	return 0;
+
+e_err:
+	sp->psp_data = NULL;
+
+	dev_notice(dev, "psp initialization failed\n");
+
+	return ret;
+}
+
+void psp_dev_destroy(struct sp_device *sp)
+{
+	struct psp_device *psp = sp->psp_data;
+
+	sp_free_psp_irq(sp, psp);
+}

drivers/crypto/ccp/psp-dev.h

···
+/*
+ * AMD Platform Security Processor (PSP) interface driver
+ *
+ * Copyright (C) 2017 Advanced Micro Devices, Inc.
+ *
+ * Author: Brijesh Singh <[e-mail]>
+ *
+ * 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
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __PSP_DEV_H__
+#define __PSP_DEV_H__
+
+#include <linux/device.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+#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>
+
+#include "sp-dev.h"
+
+#define PSP_P2CMSG_INTEN		0x0110
+#define PSP_P2CMSG_INTSTS		0x0114
+
+#define PSP_C2PMSG_ATTR_0		0x0118
+#define PSP_C2PMSG_ATTR_1		0x011c
+#define PSP_C2PMSG_ATTR_2		0x0120
+#define PSP_C2PMSG_ATTR_3		0x0124
+#define PSP_P2CMSG_ATTR_0		0x0128
+
+#define PSP_CMDRESP_CMD_SHIFT		16
+#define PSP_CMDRESP_IOC			BIT(0)
+#define PSP_CMDRESP_RESP		BIT(31)
+#define PSP_CMDRESP_ERR_MASK		0xffff
+
+#define MAX_PSP_NAME_LEN		16
+
+struct psp_device {
+	struct list_head entry;
+
+	struct psp_vdata *vdata;
+	char name[MAX_PSP_NAME_LEN];
+
+	struct device *dev;
+	struct sp_device *sp;
+
+	void __iomem *io_regs;
+};
+
+#endif /* __PSP_DEV_H */

drivers/crypto/ccp/sp-dev.c

···
 	if (sp->dev_vdata->ccp_vdata)
 		ccp_dev_init(sp);
 
+	if (sp->dev_vdata->psp_vdata)
+		psp_dev_init(sp);
 	return 0;
 }
 
···
 {
 	if (sp->dev_vdata->ccp_vdata)
 		ccp_dev_destroy(sp);
+
+	if (sp->dev_vdata->psp_vdata)
+		psp_dev_destroy(sp);
 
 	sp_del_device(sp);
 }
···
 	return 0;
 }
 #endif
+
+struct sp_device *sp_get_psp_master_device(void)
+{
+	struct sp_device *i, *ret = NULL;
+	unsigned long flags;
+
+	write_lock_irqsave(&sp_unit_lock, flags);
+	if (list_empty(&sp_units))
+		goto unlock;
+
+	list_for_each_entry(i, &sp_units, entry) {
+		if (i->psp_data)
+			break;
+	}
+
+	if (i->get_psp_master_device)
+		ret = i->get_psp_master_device();
+unlock:
+	write_unlock_irqrestore(&sp_unit_lock, flags);
+	return ret;
+}
 
 static int __init sp_mod_init(void)
 {

drivers/crypto/ccp/sp-dev.h

···
 	const unsigned int offset;
 	const unsigned int rsamax;
 };
+
+struct psp_vdata {
+	const unsigned int offset;
+};
+
 /* Structure to hold SP device data */
 struct sp_dev_vdata {
 	const unsigned int bar;
 
 	const struct ccp_vdata *ccp_vdata;
-	void *psp_vdata;
+	const struct psp_vdata *psp_vdata;
 };
 
 struct sp_device {
···
 
 	/* DMA caching attribute support */
 	unsigned int axcache;
+
+	/* get and set master device */
+	struct sp_device*(*get_psp_master_device)(void);
+	void (*set_psp_master_device)(struct sp_device *);
 
 	bool irq_registered;
 	bool use_tasklet;
···
 int sp_request_psp_irq(struct sp_device *sp, irq_handler_t handler,
 		       const char *name, void *data);
 void sp_free_psp_irq(struct sp_device *sp, void *data);
+struct sp_device *sp_get_psp_master_device(void);
 
 #ifdef CONFIG_CRYPTO_DEV_SP_CCP
 
···
 	return 0;
 }
 #endif	/* CONFIG_CRYPTO_DEV_SP_CCP */
+
+#ifdef CONFIG_CRYPTO_DEV_SP_PSP
+
+int psp_dev_init(struct sp_device *sp);
+void psp_dev_destroy(struct sp_device *sp);
+
+#else /* !CONFIG_CRYPTO_DEV_SP_PSP */
+
+static inline int psp_dev_init(struct sp_device *sp) { return 0; }
+static inline void psp_dev_destroy(struct sp_device *sp) { }
+
+#endif /* CONFIG_CRYPTO_DEV_SP_PSP */
 
 #endif

drivers/crypto/ccp/sp-pci.c

···
 #include <linux/ccp.h>
 
 #include "ccp-dev.h"
+#include "psp-dev.h"
 
 #define MSIX_VECTORS			2
 
···
 	int msix_count;
 	struct msix_entry msix_entry[MSIX_VECTORS];
 };
+static struct sp_device *sp_dev_master;
 
 static int sp_get_msix_irqs(struct sp_device *sp)
 {
···
 	sp->psp_irq = 0;
 }
 
+static bool sp_pci_is_master(struct sp_device *sp)
+{
+	struct device *dev_cur, *dev_new;
+	struct pci_dev *pdev_cur, *pdev_new;
+
+	dev_new = sp->dev;
+	dev_cur = sp_dev_master->dev;
+
+	pdev_new = to_pci_dev(dev_new);
+	pdev_cur = to_pci_dev(dev_cur);
+
+	if (pdev_new->bus->number < pdev_cur->bus->number)
+		return true;
+
+	if (PCI_SLOT(pdev_new->devfn) < PCI_SLOT(pdev_cur->devfn))
+		return true;
+
+	if (PCI_FUNC(pdev_new->devfn) < PCI_FUNC(pdev_cur->devfn))
+		return true;
+
+	return false;
+}
+
+static void psp_set_master(struct sp_device *sp)
+{
+	if (!sp_dev_master) {
+		sp_dev_master = sp;
+		return;
+	}
+
+	if (sp_pci_is_master(sp))
+		sp_dev_master = sp;
+}
+
+static struct sp_device *psp_get_master(void)
+{
+	return sp_dev_master;
+}
+
 static int sp_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct sp_device *sp;
···
 		goto e_err;
 
 	pci_set_master(pdev);
+	sp->set_psp_master_device = psp_set_master;
+	sp->get_psp_master_device = psp_get_master;
 
 	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48));
 	if (ret) {
···
 }
 #endif
 
+#ifdef CONFIG_CRYPTO_DEV_SP_PSP
+static const struct psp_vdata psp_entry = {
+	.offset = 0x10500,
+};
+#endif
+
 static const struct sp_dev_vdata dev_vdata[] = {
 	{
 		.bar = 2,
···
 		.bar = 2,
 #ifdef CONFIG_CRYPTO_DEV_SP_CCP
 		.ccp_vdata = &ccpv5a,
+#endif
+#ifdef CONFIG_CRYPTO_DEV_SP_PSP
+		.psp_vdata = &psp_entry
 #endif
 	},
 	{