On Wed, 25 Sep 2019 02:09:11 +0000 Peng Fan <peng.fan@xxxxxxx> wrote: Hi, > From: Peng Fan <peng.fan@xxxxxxx> > > This mailbox driver implements a mailbox which signals transmitted data > via an ARM smc (secure monitor call) instruction. The mailbox receiver > is implemented in firmware and can synchronously return data when it > returns execution to the non-secure world again. > An asynchronous receive path is not implemented. > This allows the usage of a mailbox to trigger firmware actions on SoCs > which either don't have a separate management processor or on which such > a core is not available. A user of this mailbox could be the SCP > interface. > > Modified from Andre Przywara's v2 patch > https://lore.kernel.org/patchwork/patch/812999/ > > Cc: Andre Przywara <andre.przywara@xxxxxxx> > Signed-off-by: Peng Fan <peng.fan@xxxxxxx> Many thanks for the changes, that looks good to me now! One tiny thing below, but anyway: Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx> > --- > drivers/mailbox/Kconfig | 7 ++ > drivers/mailbox/Makefile | 2 + > drivers/mailbox/arm-smc-mailbox.c | 167 +++++++++++++++++++++++++++++++++ > include/linux/mailbox/arm-smccc-mbox.h | 20 ++++ > 4 files changed, 196 insertions(+) > create mode 100644 drivers/mailbox/arm-smc-mailbox.c > create mode 100644 include/linux/mailbox/arm-smccc-mbox.h > > diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig > index ab4eb750bbdd..7707ee26251a 100644 > --- a/drivers/mailbox/Kconfig > +++ b/drivers/mailbox/Kconfig > @@ -16,6 +16,13 @@ config ARM_MHU > The controller has 3 mailbox channels, the last of which can be > used in Secure mode only. > > +config ARM_SMC_MBOX > + tristate "Generic ARM smc mailbox" > + depends on OF && HAVE_ARM_SMCCC > + help > + Generic mailbox driver which uses ARM smc calls to call into > + firmware for triggering mailboxes. > + > config IMX_MBOX > tristate "i.MX Mailbox" > depends on ARCH_MXC || COMPILE_TEST > diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile > index c22fad6f696b..93918a84c91b 100644 > --- a/drivers/mailbox/Makefile > +++ b/drivers/mailbox/Makefile > @@ -7,6 +7,8 @@ obj-$(CONFIG_MAILBOX_TEST) += mailbox-test.o > > obj-$(CONFIG_ARM_MHU) += arm_mhu.o > > +obj-$(CONFIG_ARM_SMC_MBOX) += arm-smc-mailbox.o > + > obj-$(CONFIG_IMX_MBOX) += imx-mailbox.o > > obj-$(CONFIG_ARMADA_37XX_RWTM_MBOX) += armada-37xx-rwtm-mailbox.o > diff --git a/drivers/mailbox/arm-smc-mailbox.c b/drivers/mailbox/arm-smc-mailbox.c > new file mode 100644 > index 000000000000..6f0b5fd6ad1b > --- /dev/null > +++ b/drivers/mailbox/arm-smc-mailbox.c > @@ -0,0 +1,167 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2016,2017 ARM Ltd. > + * Copyright 2019 NXP > + */ > + > +#include <linux/arm-smccc.h> > +#include <linux/device.h> > +#include <linux/kernel.h> > +#include <linux/interrupt.h> We don't need this include anymore. Cheers, Andre. > +#include <linux/mailbox_controller.h> > +#include <linux/mailbox/arm-smccc-mbox.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > + > +typedef unsigned long (smc_mbox_fn)(unsigned int, unsigned long, > + unsigned long, unsigned long, > + unsigned long, unsigned long, > + unsigned long); > + > +struct arm_smc_chan_data { > + unsigned int function_id; > + smc_mbox_fn *invoke_smc_mbox_fn; > +}; > + > +static int arm_smc_send_data(struct mbox_chan *link, void *data) > +{ > + struct arm_smc_chan_data *chan_data = link->con_priv; > + struct arm_smccc_mbox_cmd *cmd = data; > + unsigned long ret; > + > + if (ARM_SMCCC_IS_64(chan_data->function_id)) { > + ret = chan_data->invoke_smc_mbox_fn(chan_data->function_id, > + cmd->args_smccc64[0], > + cmd->args_smccc64[1], > + cmd->args_smccc64[2], > + cmd->args_smccc64[3], > + cmd->args_smccc64[4], > + cmd->args_smccc64[5]); > + } else { > + ret = chan_data->invoke_smc_mbox_fn(chan_data->function_id, > + cmd->args_smccc32[0], > + cmd->args_smccc32[1], > + cmd->args_smccc32[2], > + cmd->args_smccc32[3], > + cmd->args_smccc32[4], > + cmd->args_smccc32[5]); > + } > + > + mbox_chan_received_data(link, (void *)ret); > + > + return 0; > +} > + > +static unsigned long __invoke_fn_hvc(unsigned int function_id, > + unsigned long arg0, unsigned long arg1, > + unsigned long arg2, unsigned long arg3, > + unsigned long arg4, unsigned long arg5) > +{ > + struct arm_smccc_res res; > + > + arm_smccc_hvc(function_id, arg0, arg1, arg2, arg3, arg4, > + arg5, 0, &res); > + return res.a0; > +} > + > +static unsigned long __invoke_fn_smc(unsigned int function_id, > + unsigned long arg0, unsigned long arg1, > + unsigned long arg2, unsigned long arg3, > + unsigned long arg4, unsigned long arg5) > +{ > + struct arm_smccc_res res; > + > + arm_smccc_smc(function_id, arg0, arg1, arg2, arg3, arg4, > + arg5, 0, &res); > + return res.a0; > +} > + > +static const struct mbox_chan_ops arm_smc_mbox_chan_ops = { > + .send_data = arm_smc_send_data, > +}; > + > +static struct mbox_chan * > +arm_smc_mbox_of_xlate(struct mbox_controller *mbox, > + const struct of_phandle_args *sp) > +{ > + return mbox->chans; > +} > + > +static int arm_smc_mbox_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct mbox_controller *mbox; > + struct arm_smc_chan_data *chan_data; > + int ret; > + > + mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL); > + if (!mbox) > + return -ENOMEM; > + > + mbox->of_xlate = arm_smc_mbox_of_xlate; > + mbox->num_chans = 1; > + mbox->chans = devm_kzalloc(dev, sizeof(*mbox->chans), GFP_KERNEL); > + if (!mbox->chans) > + return -ENOMEM; > + > + chan_data = devm_kzalloc(dev, sizeof(*chan_data), GFP_KERNEL); > + if (!chan_data) > + return -ENOMEM; > + > + ret = of_property_read_u32(dev->of_node, "arm,func-id", > + &chan_data->function_id); > + if (ret) > + return ret; > + > + if (of_device_is_compatible(dev->of_node, "arm,smc-mbox")) > + chan_data->invoke_smc_mbox_fn = __invoke_fn_smc; > + else > + chan_data->invoke_smc_mbox_fn = __invoke_fn_hvc; > + > + > + mbox->chans->con_priv = chan_data; > + > + mbox->txdone_poll = false; > + mbox->txdone_irq = false; > + mbox->ops = &arm_smc_mbox_chan_ops; > + mbox->dev = dev; > + > + platform_set_drvdata(pdev, mbox); > + > + ret = devm_mbox_controller_register(dev, mbox); > + if (ret) > + return ret; > + > + dev_info(dev, "ARM SMC mailbox enabled.\n"); > + > + return ret; > +} > + > +static int arm_smc_mbox_remove(struct platform_device *pdev) > +{ > + struct mbox_controller *mbox = platform_get_drvdata(pdev); > + > + mbox_controller_unregister(mbox); > + return 0; > +} > + > +static const struct of_device_id arm_smc_mbox_of_match[] = { > + { .compatible = "arm,smc-mbox", }, > + { .compatible = "arm,hvc-mbox", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, arm_smc_mbox_of_match); > + > +static struct platform_driver arm_smc_mbox_driver = { > + .driver = { > + .name = "arm-smc-mbox", > + .of_match_table = arm_smc_mbox_of_match, > + }, > + .probe = arm_smc_mbox_probe, > + .remove = arm_smc_mbox_remove, > +}; > +module_platform_driver(arm_smc_mbox_driver); > + > +MODULE_AUTHOR("Peng Fan <peng.fan@xxxxxxx>"); > +MODULE_DESCRIPTION("Generic ARM smc mailbox driver"); > +MODULE_LICENSE("GPL v2"); > diff --git a/include/linux/mailbox/arm-smccc-mbox.h b/include/linux/mailbox/arm-smccc-mbox.h > new file mode 100644 > index 000000000000..d35fb89a77f5 > --- /dev/null > +++ b/include/linux/mailbox/arm-smccc-mbox.h > @@ -0,0 +1,20 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#ifndef _LINUX_ARM_SMCCC_MBOX_H_ > +#define _LINUX_ARM_SMCCC_MBOX_H_ > + > +#include <linux/types.h> > + > +/** > + * struct arm_smccc_mbox_cmd - ARM SMCCC message structure > + * @args_smccc32/64: actual usage of registers is up to the protocol > + * (within the SMCCC limits) > + */ > +struct arm_smccc_mbox_cmd { > + union { > + u32 args_smccc32[6]; > + u64 args_smccc64[6]; > + }; > +}; > + > +#endif /* _LINUX_ARM_SMCCC_MBOX_H_ */
