diff mbox

[v2,1/6] firmware: Amlogic: Add secure monitor driver

Message ID 1467203656-14381-2-git-send-email-carlo@caione.org (mailing list archive)
State New, archived
Headers show

Commit Message

Carlo Caione June 29, 2016, 12:34 p.m. UTC
From: Carlo Caione <carlo@endlessm.com>

Introduce a driver to provide calls into secure monitor mode.

In the Amlogic SoCs these calls are used for multiple reasons: access to
NVMEM, set USB boot, enable JTAG, etc...

Signed-off-by: Carlo Caione <carlo@endlessm.com>
---
 drivers/firmware/Kconfig                |   1 +
 drivers/firmware/Makefile               |   1 +
 drivers/firmware/meson/Kconfig          |   9 ++
 drivers/firmware/meson/Makefile         |   1 +
 drivers/firmware/meson/meson_sm.c       | 247 ++++++++++++++++++++++++++++++++
 include/linux/firmware/meson/meson_sm.h |  31 ++++
 6 files changed, 290 insertions(+)
 create mode 100644 drivers/firmware/meson/Kconfig
 create mode 100644 drivers/firmware/meson/Makefile
 create mode 100644 drivers/firmware/meson/meson_sm.c
 create mode 100644 include/linux/firmware/meson/meson_sm.h

Comments

Carlo Caione July 9, 2016, 8:32 a.m. UTC | #1
On 29/06/16 14:34, Carlo Caione wrote:
> From: Carlo Caione <carlo@endlessm.com>
> 
> Introduce a driver to provide calls into secure monitor mode.
> 
> In the Amlogic SoCs these calls are used for multiple reasons: access to
> NVMEM, set USB boot, enable JTAG, etc...
> 
> Signed-off-by: Carlo Caione <carlo@endlessm.com>

(gentle ping)

Mark,
any comment on this?

thanks,
Mark Rutland July 26, 2016, 10:20 a.m. UTC | #2
Hi,

Sorry for the delay.

I don't have any major comments, there are jsut a couple of minor
details.

> +config MESON_SM
> +	bool
> +	default ARCH_MESON
> +	depends on ARM64_4K_PAGES

It would be good to have a commentin the code as to why we depend on
ARM64_4K_PAGES.

That way it's possible for others to figure out without having to go
digging through mail archives and/or git logs.

[...]

> +struct meson_sm_chip gxbb_chip = {
> +	.shmem_size		= 0x1000,

If you include <linux/sizes.h>, you can use SZ_4K here.

Immediately above this is probably the best place for the comment
regarding the 4K page restriction imposed by the FW interface.

Other than that this looks fine, so FWIW:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.
diff mbox

Patch

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 6664f11..686e395 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -199,5 +199,6 @@  config HAVE_ARM_SMCCC
 source "drivers/firmware/broadcom/Kconfig"
 source "drivers/firmware/google/Kconfig"
 source "drivers/firmware/efi/Kconfig"
+source "drivers/firmware/meson/Kconfig"
 
 endmenu
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 474bada..fc4bb09 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -21,6 +21,7 @@  obj-$(CONFIG_QCOM_SCM_32)	+= qcom_scm-32.o
 CFLAGS_qcom_scm-32.o :=$(call as-instr,.arch armv7-a\n.arch_extension sec,-DREQUIRES_SEC=1) -march=armv7-a
 
 obj-y				+= broadcom/
+obj-y				+= meson/
 obj-$(CONFIG_GOOGLE_FIRMWARE)	+= google/
 obj-$(CONFIG_EFI)		+= efi/
 obj-$(CONFIG_UEFI_CPER)		+= efi/
diff --git a/drivers/firmware/meson/Kconfig b/drivers/firmware/meson/Kconfig
new file mode 100644
index 0000000..170d7e8
--- /dev/null
+++ b/drivers/firmware/meson/Kconfig
@@ -0,0 +1,9 @@ 
+#
+# Amlogic Secure Monitor driver
+#
+config MESON_SM
+	bool
+	default ARCH_MESON
+	depends on ARM64_4K_PAGES
+	help
+	  Say y here to enable the Amlogic secure monitor driver
diff --git a/drivers/firmware/meson/Makefile b/drivers/firmware/meson/Makefile
new file mode 100644
index 0000000..9ab3884
--- /dev/null
+++ b/drivers/firmware/meson/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_MESON_SM) +=	meson_sm.o
diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
new file mode 100644
index 0000000..bba594e
--- /dev/null
+++ b/drivers/firmware/meson/meson_sm.c
@@ -0,0 +1,247 @@ 
+/*
+ * Amlogic Secure Monitor driver
+ *
+ * Copyright (C) 2016 Endless Mobile, Inc.
+ * Author: Carlo Caione <carlo@endlessm.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 published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define pr_fmt(fmt) "meson-sm: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/bug.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+
+#include <linux/firmware/meson/meson_sm.h>
+
+struct meson_sm_cmd {
+	unsigned int index;
+	u32 smc_id;
+};
+#define CMD(d, s) { .index = (d), .smc_id = (s), }
+
+struct meson_sm_chip {
+	unsigned int shmem_size;
+	u32 cmd_shmem_in_base;
+	u32 cmd_shmem_out_base;
+	struct meson_sm_cmd cmd[];
+};
+
+struct meson_sm_chip gxbb_chip = {
+	.shmem_size		= 0x1000,
+	.cmd_shmem_in_base	= 0x82000020,
+	.cmd_shmem_out_base	= 0x82000021,
+	.cmd = {
+		CMD(SM_EFUSE_READ,	0x82000030),
+		CMD(SM_EFUSE_WRITE,	0x82000031),
+		CMD(SM_EFUSE_USER_MAX,	0x82000033),
+		{ /* sentinel */ },
+	},
+};
+
+struct meson_sm_firmware {
+	const struct meson_sm_chip *chip;
+	void __iomem *sm_shmem_in_base;
+	void __iomem *sm_shmem_out_base;
+};
+
+static struct meson_sm_firmware fw;
+
+static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip,
+			    unsigned int cmd_index)
+{
+	const struct meson_sm_cmd *cmd = chip->cmd;
+
+	while (cmd->smc_id && cmd->index != cmd_index)
+		cmd++;
+
+	return cmd->smc_id;
+}
+
+static u32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2,
+			   u32 arg3, u32 arg4)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res);
+	return res.a0;
+}
+
+static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size)
+{
+	u32 sm_phy_base;
+
+	sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0);
+	if (!sm_phy_base)
+		return 0;
+
+	return ioremap_cache(sm_phy_base, size);
+}
+
+/**
+ * meson_sm_call - generic SMC32 call to the secure-monitor
+ *
+ * @cmd_index:	Index of the SMC32 function ID
+ * @ret:	Returned value
+ * @arg0:	SMC32 Argument 0
+ * @arg1:	SMC32 Argument 1
+ * @arg2:	SMC32 Argument 2
+ * @arg3:	SMC32 Argument 3
+ * @arg4:	SMC32 Argument 4
+ *
+ * Return:	0 on success, a negative value on error
+ */
+int meson_sm_call(unsigned int cmd_index, u32 *ret, u32 arg0,
+		  u32 arg1, u32 arg2, u32 arg3, u32 arg4)
+{
+	u32 cmd, lret;
+
+	if (!fw.chip)
+		return -ENOENT;
+
+	cmd = meson_sm_get_cmd(fw.chip, cmd_index);
+	if (!cmd)
+		return -EINVAL;
+
+	lret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);
+
+	if (ret)
+		*ret = lret;
+
+	return 0;
+}
+EXPORT_SYMBOL(meson_sm_call);
+
+/**
+ * meson_sm_call_read - retrieve data from secure-monitor
+ *
+ * @buffer:	Buffer to store the retrieved data
+ * @cmd_index:	Index of the SMC32 function ID
+ * @arg0:	SMC32 Argument 0
+ * @arg1:	SMC32 Argument 1
+ * @arg2:	SMC32 Argument 2
+ * @arg3:	SMC32 Argument 3
+ * @arg4:	SMC32 Argument 4
+ *
+ * Return:	size of read data on success, a negative value on error
+ */
+int meson_sm_call_read(void *buffer, unsigned int cmd_index, u32 arg0,
+		       u32 arg1, u32 arg2, u32 arg3, u32 arg4)
+{
+	u32 size;
+
+	if (!fw.chip)
+		return -ENOENT;
+
+	if (!fw.chip->cmd_shmem_out_base)
+		return -EINVAL;
+
+	if (meson_sm_call(cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
+		return -EINVAL;
+
+	if (!size || size > fw.chip->shmem_size)
+		return -EINVAL;
+
+	if (buffer)
+		memcpy(buffer, fw.sm_shmem_out_base, size);
+
+	return size;
+}
+EXPORT_SYMBOL(meson_sm_call_read);
+
+/**
+ * meson_sm_call_write - send data to secure-monitor
+ *
+ * @buffer:	Buffer containing data to send
+ * @size:	Size of the data to send
+ * @cmd_index:	Index of the SMC32 function ID
+ * @arg0:	SMC32 Argument 0
+ * @arg1:	SMC32 Argument 1
+ * @arg2:	SMC32 Argument 2
+ * @arg3:	SMC32 Argument 3
+ * @arg4:	SMC32 Argument 4
+ *
+ * Return:	size of sent data on success, a negative value on error
+ */
+int meson_sm_call_write(void *buffer, unsigned int size, unsigned int cmd_index,
+			u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
+{
+	u32 written;
+
+	if (!fw.chip)
+		return -ENOENT;
+
+	if (size > fw.chip->shmem_size)
+		return -EINVAL;
+
+	if (!fw.chip->cmd_shmem_in_base)
+		return -EINVAL;
+
+	memcpy(fw.sm_shmem_in_base, buffer, size);
+
+	if (meson_sm_call(cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0)
+		return -EINVAL;
+
+	if (!written)
+		return -EINVAL;
+
+	return written;
+}
+EXPORT_SYMBOL(meson_sm_call_write);
+
+static const struct of_device_id meson_sm_ids[] = {
+	{ .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },
+	{ /* sentinel */ },
+};
+
+int __init meson_sm_init(void)
+{
+	const struct meson_sm_chip *chip;
+	const struct of_device_id *matched_np;
+	struct device_node *np;
+
+	np = of_find_matching_node_and_match(NULL, meson_sm_ids, &matched_np);
+	if (!np)
+		return -ENODEV;
+
+	chip = matched_np->data;
+	if (!chip) {
+		pr_err("unable to setup secure-monitor data\n");
+		goto out;
+	}
+
+	if (chip->cmd_shmem_in_base) {
+		fw.sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base,
+							 chip->shmem_size);
+		if (WARN_ON(!fw.sm_shmem_in_base))
+			goto out;
+	}
+
+	if (chip->cmd_shmem_out_base) {
+		fw.sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base,
+							  chip->shmem_size);
+		if (WARN_ON(!fw.sm_shmem_out_base))
+			goto out_in_base;
+	}
+
+	fw.chip = chip;
+	pr_info("secure-monitor enabled\n");
+
+	return 0;
+
+out_in_base:
+	iounmap(fw.sm_shmem_in_base);
+out:
+	return -EINVAL;
+}
+device_initcall(meson_sm_init);
diff --git a/include/linux/firmware/meson/meson_sm.h b/include/linux/firmware/meson/meson_sm.h
new file mode 100644
index 0000000..8e953c6
--- /dev/null
+++ b/include/linux/firmware/meson/meson_sm.h
@@ -0,0 +1,31 @@ 
+/*
+ * Copyright (C) 2016 Endless Mobile, Inc.
+ * Author: Carlo Caione <carlo@endlessm.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 published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _MESON_SM_FW_H_
+#define _MESON_SM_FW_H_
+
+enum {
+	SM_EFUSE_READ,
+	SM_EFUSE_WRITE,
+	SM_EFUSE_USER_MAX,
+};
+
+struct meson_sm_firmware;
+
+int meson_sm_call(unsigned int cmd_index, u32 *ret, u32 arg0, u32 arg1,
+		  u32 arg2, u32 arg3, u32 arg4);
+int meson_sm_call_write(void *buffer, unsigned int b_size, unsigned int cmd_index,
+			u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
+int meson_sm_call_read(void *buffer, unsigned int cmd_index, u32 arg0, u32 arg1,
+		       u32 arg2, u32 arg3, u32 arg4);
+
+#endif /* _MESON_SM_FW_H_ */