soc/amd/common: Add initial support for AMD PSP

Add files for supporting the BIOS->PSP communication not
covered by AGESA. The first command implemented notifies the
PSP that DRAM is ready.

This patch also introduces the amd/common/block directory
structure similar to intel/common/block.

Change-Id: I34b2744b071aa3dfb1071b2aabde32ddb662ab87
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/19753
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

6 files changed, 325 insertions, 0 deletions

diff --git a/src/soc/amd/common/block/Kconfig b/src/soc/amd/common/block/Kconfig
new file mode 100644
index 0000000000..86150ed870
--- /dev/null
+++ b/src/soc/amd/common/block/Kconfig
@@ -0,0 +1,11 @@
+config SOC_AMD_COMMON_BLOCK
+	bool
+	help
+	  SoC driver for AMD common IP code
+
+if SOC_AMD_COMMON_BLOCK
+
+comment "AMD SoC Common IP Code"
+source "src/soc/amd/common/block/*/Kconfig"
+
+endif
diff --git a/src/soc/amd/common/block/Makefile.inc b/src/soc/amd/common/block/Makefile.inc
new file mode 100644
index 0000000000..33c8822fd6
--- /dev/null
+++ b/src/soc/amd/common/block/Makefile.inc
@@ -0,0 +1,7 @@
+ifeq ($(CONFIG_SOC_AMD_COMMON_BLOCK),y)
+
+subdirs-y += ./*
+
+CPPFLAGS_common += -I$(src)/soc/amd/common/block/include/
+
+endif
diff --git a/src/soc/amd/common/block/include/amdblocks/psp.h b/src/soc/amd/common/block/include/amdblocks/psp.h
new file mode 100644
index 0000000000..2d40aed04d
--- /dev/null
+++ b/src/soc/amd/common/block/include/amdblocks/psp.h
@@ -0,0 +1,96 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2017 Advanced Micro Devices, Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#ifndef AMD_PSP_H
+#define AMD_PSP_H
+
+#include <stdint.h>
+#include <Porting.h>
+#include <Proc/Psp/PspBaseLib/PspBaseLib.h>
+
+/* x86 to PSP commands */
+#define MBOX_BIOS_CMD_DRAM_INFO    0x01
+#define MBOX_BIOS_CMD_SMM_INFO     0x02
+#define MBOX_BIOS_CMD_SX_INFO      0x03
+#define MBOX_BIOS_CMD_RSM_INFO     0x04
+#define MBOX_BIOS_CMD_PSP_QUERY    0x05
+#define MBOX_BIOS_CMD_BOOT_DONE    0x06
+#define MBOX_BIOS_CMD_CLEAR_S3_STS 0x07
+#define MBOX_BIOS_CMD_C3_DATA_INFO 0x08
+#define MBOX_BIOS_CMD_NOP          0x09
+#define MBOX_BIOS_CMD_ABORT        0xfe
+
+/* generic PSP interface status */
+#define STATUS_INITIALIZED         0x1
+#define STATUS_ERROR               0x2
+#define STATUS_TERMINATED          0x4
+#define STATUS_HALT                0x8
+#define STATUS_RECOVERY            0x10
+
+/* psp_mbox consists of hardware registers beginning at PSPx000070
+ *   mbox_command: BIOS->PSP command, cleared by PSP when complete
+ *   mbox_status:  BIOS->PSP interface status
+ *   cmd_response: pointer to command/response buffer
+ */
+struct psp_mbox {
+	u32 mbox_command;
+	u32 mbox_status;
+	u64 cmd_response; /* definition conflicts w/BKDG but matches agesa */
+} __attribute__ ((packed));
+
+/* command/response format, BIOS builds this in memory
+ *   mbox_buffer_header: generic header
+ *   mbox_buffer:        command-specific buffer format
+ *
+ * AMD reference code aligns and pads all buffers to 32 bytes.
+ */
+struct mbox_buffer_header {
+	u32 size;	/* total size of buffer */
+	u32 status;	/* command status, filled by PSP if applicable */
+} __attribute__ ((packed));
+
+/* command-specific buffer definitions:  see NDA document #54267
+ *   todo: create new definitions here for additional c2p_mbox_command commands
+ */
+
+struct mbox_default_buffer {	/* command-response buffer unused by command */
+	struct mbox_buffer_header header;
+} __attribute__ ((packed,aligned(32)));
+
+/* send_psp_command() error codes */
+#define PSPSTS_SUCCESS      0
+#define PSPSTS_NOBASE       1
+#define PSPSTS_HALTED       2
+#define PSPSTS_RECOVERY     3
+#define PSPSTS_SEND_ERROR   4
+#define PSPSTS_INIT_TIMEOUT 5
+#define PSPSTS_CMD_TIMEOUT  6
+
+#if !defined(__SIMPLE_DEVICE__)
+#include <device/device.h>
+#include <device/pci_def.h>
+#define PSP_DEV dev_find_slot(0, PCI_DEVFN(PSP_PCI_DEV, PSP_PCI_FN))
+#else
+#include <arch/io.h>
+#define PSP_DEV PCI_DEV(0, PSP_PCI_DEV, PSP_PCI_FN)
+#endif
+
+#define PSP_INIT_TIMEOUT 10000 /* 10 seconds */
+#define PSP_CMD_TIMEOUT 1000 /* 1 second */
+
+/* BIOS-to-PSP functions return 0 if successful, else negative value */
+int psp_notify_dram(void);
+
+#endif /* AMD_PSP_H */
diff --git a/src/soc/amd/common/block/psp/Kconfig b/src/soc/amd/common/block/psp/Kconfig
new file mode 100644
index 0000000000..69958f21aa
--- /dev/null
+++ b/src/soc/amd/common/block/psp/Kconfig
@@ -0,0 +1,6 @@
+config SOC_AMD_COMMON_BLOCK_PSP
+	bool
+	default n
+	help
+	  This option builds in the Platform Security Processor initialization
+	  functions.
diff --git a/src/soc/amd/common/block/psp/Makefile.inc b/src/soc/amd/common/block/psp/Makefile.inc
new file mode 100644
index 0000000000..eebba16e6a
--- /dev/null
+++ b/src/soc/amd/common/block/psp/Makefile.inc
@@ -0,0 +1,2 @@
+romstage-$(CONFIG_SOC_AMD_COMMON_BLOCK_PSP) += psp.c
+ramstage-$(CONFIG_SOC_AMD_COMMON_BLOCK_PSP) += psp.c
diff --git a/src/soc/amd/common/block/psp/psp.c b/src/soc/amd/common/block/psp/psp.c
new file mode 100644
index 0000000000..d61a9147dc
--- /dev/null
+++ b/src/soc/amd/common/block/psp/psp.c
@@ -0,0 +1,203 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2017 Advanced Micro Devices, Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#include <arch/io.h>
+#include <delay.h>
+#include <cbmem.h>
+#include <timer.h>
+#include <device/pci_def.h>
+#include <console/console.h>
+#include <amdblocks/psp.h>
+
+static const char *psp_status_nobase = "error: PSP BAR3 not assigned";
+static const char *psp_status_halted = "error: PSP in halted state";
+static const char *psp_status_recovery = "error: PSP recovery required";
+static const char *psp_status_errcmd = "error sending command";
+static const char *psp_status_init_timeout = "error: PSP init timeout";
+static const char *psp_status_cmd_timeout = "error: PSP command timeout";
+static const char *psp_status_noerror = "";
+
+static const char *status_to_string(int err)
+{
+	switch (err) {
+	case -PSPSTS_NOBASE:
+		return psp_status_nobase;
+	case -PSPSTS_HALTED:
+		return psp_status_halted;
+	case -PSPSTS_RECOVERY:
+		return psp_status_recovery;
+	case -PSPSTS_SEND_ERROR:
+		return psp_status_errcmd;
+	case -PSPSTS_INIT_TIMEOUT:
+		return psp_status_init_timeout;
+	case -PSPSTS_CMD_TIMEOUT:
+		return psp_status_cmd_timeout;
+	default:
+		return psp_status_noerror;
+	}
+}
+
+static struct psp_mbox *get_mbox_address(void)
+{
+	UINT32 base; /* UINT32 for compatibility with PspBaseLib */
+	BOOLEAN bar3_status;
+	uintptr_t baseptr;
+
+	bar3_status = GetPspBar3Addr(&base);
+	if (!bar3_status) {
+		PspBarInitEarly();
+		bar3_status = GetPspBar3Addr(&base);
+	}
+	if (!bar3_status)
+		return NULL;
+
+	baseptr = base;
+	return (struct psp_mbox *)(baseptr + PSP_MAILBOX_BASE);
+}
+
+static u32 rd_mbox_sts(struct psp_mbox *mbox)
+{
+	return read32(&mbox->mbox_status);
+}
+
+static void wr_mbox_cmd(struct psp_mbox *mbox, u32 cmd)
+{
+	write32(&mbox->mbox_command, cmd);
+}
+
+static u32 rd_mbox_cmd(struct psp_mbox *mbox)
+{
+	return read32(&mbox->mbox_command);
+}
+
+static void wr_mbox_cmd_resp(struct psp_mbox *mbox, void *buffer)
+{
+	write64(&mbox->cmd_response, (uintptr_t)buffer);
+}
+
+static u32 rd_resp_sts(struct mbox_default_buffer *buffer)
+{
+	return read32(&buffer->header.status);
+}
+
+static int wait_initialized(struct psp_mbox *mbox)
+{
+	struct stopwatch sw;
+
+	stopwatch_init_msecs_expire(&sw, PSP_INIT_TIMEOUT);
+
+	do {
+		if (rd_mbox_sts(mbox) & STATUS_INITIALIZED)
+			return 0;
+	} while (!stopwatch_expired(&sw));
+
+	return -PSPSTS_INIT_TIMEOUT;
+}
+
+static int wait_command(struct psp_mbox *mbox)
+{
+	struct stopwatch sw;
+
+	stopwatch_init_msecs_expire(&sw, PSP_CMD_TIMEOUT);
+
+	do {
+		if (!rd_mbox_cmd(mbox))
+			return 0;
+	} while (!stopwatch_expired(&sw));
+
+	return -PSPSTS_CMD_TIMEOUT;
+}
+
+static int send_psp_command(u32 command, void *buffer)
+{
+	u32 command_reg;
+	int status = 0;
+
+	struct psp_mbox *mbox = get_mbox_address();
+	if (!mbox)
+		return -PSPSTS_NOBASE;
+
+	command_reg = pci_read_config32(PSP_DEV, PCI_COMMAND);
+	pci_write_config32(PSP_DEV, PCI_COMMAND, command_reg |
+				PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
+
+	/* check for PSP error conditions */
+	if (rd_mbox_sts(mbox) & STATUS_HALT) {
+		status = -PSPSTS_HALTED;
+		goto exit;
+	}
+	if (rd_mbox_sts(mbox) & STATUS_RECOVERY) {
+		status = -PSPSTS_RECOVERY;
+		goto exit;
+	}
+
+	/* PSP must be finished with init and ready to accept a command */
+	if (wait_initialized(mbox)) {
+		status = -PSPSTS_INIT_TIMEOUT;
+		goto exit;
+	}
+	if (wait_command(mbox)) {
+		status = -PSPSTS_CMD_TIMEOUT;
+		goto exit;
+	}
+
+	/* set address of command-response buffer and write command register */
+	wr_mbox_cmd_resp(mbox, buffer);
+	wr_mbox_cmd(mbox, command);
+
+	/* PSP clears command register when complete */
+	if (wait_command(mbox)) {
+		status = -PSPSTS_CMD_TIMEOUT;
+		goto exit;
+	}
+
+	/* check delivery status */
+	if (rd_mbox_sts(mbox) & (STATUS_ERROR | STATUS_TERMINATED)) {
+		status = -PSPSTS_SEND_ERROR;
+		goto exit;
+	}
+exit:
+	/* restore command register to original value */
+	pci_write_config32(PSP_DEV, PCI_COMMAND, command_reg);
+	return status;
+}
+
+/*
+ * Notify the PSP that DRAM is present.  Upon receiving this command, the PSP
+ * will load its OS into fenced DRAM that is not accessible to the x86 cores.
+ */
+int psp_notify_dram(void)
+{
+	struct mbox_default_buffer buffer;
+	int cmd_status;
+
+	printk(BIOS_DEBUG, "PSP: Notify that DRAM is available... ");
+
+	buffer.header.size = sizeof(struct mbox_default_buffer);
+	buffer.header.status = 0; /* PSP does not report status for this cmd */
+
+	cmd_status = send_psp_command(MBOX_BIOS_CMD_DRAM_INFO, &buffer);
+
+	/* buffer's status shouldn't change but report it if it does */
+	if (rd_resp_sts(&buffer))
+		printk(BIOS_DEBUG, "buffer status=0x%x ",
+				rd_resp_sts(&buffer));
+	if (cmd_status)
+		printk(BIOS_DEBUG, "%s\n", status_to_string(cmd_status));
+	else
+		printk(BIOS_DEBUG, "OK\n");
+
+	return cmd_status;
+}