On Tue, Jun 21, 2011 at 10:18:28AM +0300, Ohad Ben-Cohen wrote:
> From: Guzman Lugo, Fernando <fernando.l...@ti.com>
>
> Add remoteproc implementation for OMAP4, so we can load the M3 and DSP
> remote processors.
>
> Based on code by Hari Kanigeri <h-kanige...@ti.com>
>
> While this code is functional, and works on OMAP4 & its M3's,
> it is still preliminary and going to substantially change:
>
> 1. Splitting physically contiguous regions to pages should happen
> inside the IOMMU API framework, and not here (so omap_rproc_map_unmap
> should go away).
> 2. IOMMU programming in general should go away too; it should be handled by
> generic code (preferably using the DMA mapping API), and not by an OMAP
> specific component.
>
> This patch depends on OMAP's IOMMU API migration, as posted here:
> https://lkml.org/lkml/2011/6/2/369
>
> [o...@wizery.com: commit log, generic iommu api migration, refactoring,
> cleanups]
>
> Signed-off-by: Guzman Lugo, Fernando <fernando.l...@ti.com>
> Signed-off-by: Ohad Ben-Cohen <o...@wizery.com>
> ---
> arch/arm/plat-omap/include/plat/remoteproc.h | 41 +++++
> drivers/remoteproc/Kconfig | 21 +++
> drivers/remoteproc/Makefile | 1 +
> drivers/remoteproc/omap_remoteproc.c | 243
> ++++++++++++++++++++++++++
> 4 files changed, 306 insertions(+), 0 deletions(-)
> create mode 100644 arch/arm/plat-omap/include/plat/remoteproc.h
> create mode 100644 drivers/remoteproc/omap_remoteproc.c
>
> diff --git a/arch/arm/plat-omap/include/plat/remoteproc.h
> b/arch/arm/plat-omap/include/plat/remoteproc.h
> new file mode 100644
> index 0000000..6494570
> --- /dev/null
> +++ b/arch/arm/plat-omap/include/plat/remoteproc.h
> @@ -0,0 +1,41 @@
> +/*
> + * Remote Processor - omap-specific bits
> + *
> + * Copyright (C) 2011 Texas Instruments, Inc.
> + *
> + * 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.
> + *
> + * 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 _PLAT_REMOTEPROC_H
> +#define _PLAT_REMOTEPROC_H
> +
> +#include <linux/remoteproc.h>
> +
> +/*
> + * struct omap_rproc_pdata - omap remoteproc's platform data
> + * @name: the remoteproc's name, cannot exceed RPROC_MAX_NAME bytes
> + * @iommu_name: iommu device we're behind of
> + * @oh_name: omap hwmod device
> + * @oh_name_opt: optional, secondary omap hwmod device
> + * @firmware: name of firmware file to load
> + * @ops: start/stop rproc handlers
> + * @memory_maps: table of da-to-pa iommu memory maps
> + */
> +struct omap_rproc_pdata {
> + const char *name;
> + const char *iommu_name;
> + const char *oh_name;
> + const char *oh_name_opt;
> + const char *firmware;
> + const struct rproc_ops *ops;
> + const struct rproc_mem_entry *memory_maps;
> +};
> +
> +#endif /* _PLAT_REMOTEPROC_H */
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index a60bb12..88421bd 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -5,3 +5,24 @@
> # REMOTE_PROC gets selected by whoever wants it
> config REMOTE_PROC
> tristate
> +
> +# for tristate, either expose omap_device_* or pass it via pdata
> +config OMAP_REMOTE_PROC
> + bool "OMAP remoteproc support"
> + depends on ARCH_OMAP4
> + select OMAP_IOMMU
> + select REMOTE_PROC
> + select OMAP_MBOX_FWK
> + default y
> + help
> + Say y here to support OMAP's remote processors (dual M3
> + and DSP on OMAP4) via the remote processor framework.
> +
> + Currently only supported on OMAP4.
> +
> + Usually you want to say y here, in order to enable multimedia
> + use-cases to run on your platform (multimedia codecs are
> + offloaded to remote DSP processors using this framework).
> +
> + It's safe to say n here if you're not interested in multimedia
> + offloading or just want a bare minimum kernel.
> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> index d0f60c7..0198b1d 100644
> --- a/drivers/remoteproc/Makefile
> +++ b/drivers/remoteproc/Makefile
> @@ -3,3 +3,4 @@
> #
>
> obj-$(CONFIG_REMOTE_PROC) += remoteproc.o
> +obj-$(CONFIG_OMAP_REMOTE_PROC) += omap_remoteproc.o
> diff --git a/drivers/remoteproc/omap_remoteproc.c
> b/drivers/remoteproc/omap_remoteproc.c
> new file mode 100644
> index 0000000..91f7f11
> --- /dev/null
> +++ b/drivers/remoteproc/omap_remoteproc.c
> @@ -0,0 +1,243 @@
> +/*
> + * Remote processor machine-specific module for OMAP4
> + *
> + * Copyright (C) 2011 Texas Instruments, Inc.
> + *
> + * 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.
> + *
> + * 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.
> + */
> +
> +#define pr_fmt(fmt) "%s: " fmt, __func__
> +
> +#include <linux/kernel.h>
> +#include <linux/err.h>
> +#include <linux/platform_device.h>
> +#include <linux/iommu.h>
> +#include <linux/slab.h>
> +#include <linux/remoteproc.h>
> +
> +#include <plat/iommu.h>
> +#include <plat/omap_device.h>
> +#include <plat/remoteproc.h>
> +
> +struct omap_rproc_priv {
> + struct iommu_domain *domain;
> + struct device *iommu;
> +};
> +
> +/*
> + * Map a physically contiguous memory region using biggest pages possible.
> + * TODO: this code should go away; it belongs in the generic IOMMU layer
> + */
> +static int omap_rproc_map_unmap(struct iommu_domain *domain,
> + const struct rproc_mem_entry *me, bool map)
> +{
> + u32 all_bits;
> + /* these are the page sizes supported by OMAP's IOMMU */
> + u32 pg_size[] = {SZ_16M, SZ_1M, SZ_64K, SZ_4K};
> + int i, ret, size = me->size;
> + u32 da = me->da;
> + u32 pa = me->pa;
> + int order;
> + int flags;
> +
> + /* must be aligned at least with the smallest supported iommu page */
> + if (!IS_ALIGNED(size, SZ_4K) || !IS_ALIGNED(da | pa, SZ_4K)) {
> + pr_err("misaligned: size %x da 0x%x pa 0x%x\n", size, da, pa);
> + return -EINVAL;
> + }
> +
> + while (size) {
> + /* find the max page size with which both pa, da are aligned */
> + all_bits = pa | da;
> + for (i = 0; i < ARRAY_SIZE(pg_size); i++) {
> + if ((size >= pg_size[i]) &&
> + ((all_bits & (pg_size[i] - 1)) == 0)) {
> + break;
> + }
> + }
> +
> + order = get_order(pg_size[i]);
> +
> + /* OMAP4's M3 is little endian, so no need for conversions */
> + flags = MMU_RAM_ENDIAN_LITTLE | MMU_RAM_ELSZ_NONE;
> +
> + if (map)
> + ret = iommu_map(domain, da, pa, order, flags);
> + else
> + ret = iommu_unmap(domain, da, order);
> +
> + if (ret)
> + return ret;
> +
> + size -= pg_size[i];
> + da += pg_size[i];
> + pa += pg_size[i];
> + }
> +
> + return 0;
> +}
> +
> +/* bootaddr isn't needed for the dual M3's */
> +static inline int omap_rproc_start(struct rproc *rproc, u64 bootaddr)
> +{
> + struct device *dev = rproc->dev;
> + struct platform_device *pdev = to_platform_device(dev);
> + struct omap_rproc_pdata *pdata = dev->platform_data;
> + struct iommu_domain *domain;
> + struct device *iommu;
> + struct omap_rproc_priv *priv;
> + int ret, i;
> +
> + if (!iommu_found()) {
> + dev_err(&pdev->dev, "iommu not found\n");
> + return -ENODEV;
> + }
> +
> + priv = kmalloc(sizeof(*priv), GFP_KERNEL);
> + if (!priv) {
> + dev_err(&pdev->dev, "kzalloc failed\n");
> + return -ENOMEM;
> + }
> +
> + /*
> + * Use the specified iommu name to find our iommu device.
> + * TODO: solve this generically so other platforms can use it, too
> + */
> + iommu = omap_find_iommu_device(pdata->iommu_name);
> + if (!iommu) {
> + dev_err(dev, "omap_find_iommu_device failed\n");
> + ret = -ENODEV;
> + goto free_mem;
> + }
> +
> + domain = iommu_domain_alloc();
> + if (!domain) {
> + dev_err(&pdev->dev, "can't alloc iommu domain\n");
> + ret = -ENODEV;
> + goto free_mem;
> + }
> +
> + priv->iommu = iommu;
> + priv->domain = domain;
> + rproc->priv = priv;
> +
> + ret = iommu_attach_device(domain, iommu);
> + if (ret) {
> + dev_err(&pdev->dev, "can't attach iommu device: %d\n", ret);
> + goto free_domain;
> + }
> +
> + for (i = 0; rproc->memory_maps[i].size; i++) {
> + const struct rproc_mem_entry *me = &rproc->memory_maps[i];
> +
> + ret = omap_rproc_map_unmap(domain, me, true);
> + if (ret) {
> + dev_err(&pdev->dev, "iommu_map failed: %d\n", ret);
> + goto unmap_regions;
> + }
> + }
> +
> + /* power on the remote processor itself */
> + ret = omap_device_enable(pdev);
> + if (ret)
> + goto unmap_regions;
> +
> + return 0;
> +
> +unmap_regions:
> + for (--i; i >= 0 && rproc->memory_maps[i].size; i--) {
> + const struct rproc_mem_entry *me = &rproc->memory_maps[i];
> + omap_rproc_map_unmap(domain, me, false);
> + }
> +free_domain:
> + iommu_domain_free(domain);
> +free_mem:
> + kfree(priv);
> + return ret;
> +}
> +
> +static inline int omap_rproc_stop(struct rproc *rproc)
> +{
> + struct device *dev = rproc->dev;
> + struct platform_device *pdev = to_platform_device(dev);
> + struct omap_rproc_priv *priv = rproc->priv;
> + struct iommu_domain *domain = priv->domain;
> + struct device *iommu = priv->iommu;
> + int ret, i;
> +
> + /* power off the remote processor itself */
> + ret = omap_device_shutdown(pdev);
> + if (ret) {
> + dev_err(dev, "failed to shutdown: %d\n", ret);
> + goto out;
> + }
> +
> + for (i = 0; rproc->memory_maps[i].size; i++) {
> + const struct rproc_mem_entry *me = &rproc->memory_maps[i];
> +
> + ret = omap_rproc_map_unmap(domain, me, false);
> + if (ret) {
> + dev_err(&pdev->dev, "iommu_unmap failed: %d\n", ret);
> + goto out;
> + }
> + }
> +
> + iommu_detach_device(domain, iommu);
> + iommu_domain_free(domain);
> +
> +out:
> + return ret;
> +}
> +
> +static struct rproc_ops omap_rproc_ops = {
> + .start = omap_rproc_start,
> + .stop = omap_rproc_stop,
> +};
> +
> +static int omap_rproc_probe(struct platform_device *pdev)
> +{
> + struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
> +
> + return rproc_register(&pdev->dev, pdata->name, &omap_rproc_ops,
> + pdata->firmware, pdata->memory_maps,
> + THIS_MODULE);
Very little for me to comment on here. However, something I just
noticed. Why is it necessary to pass in THIS_MODULE to the
rproc_register function? Having a reference to the pdev gives you the
pointer to the driver, which has the THIS_MODULE value in it. That
should be sufficient.
/me also isn't sure if incrementing the refcount on the module is the
best way to prevent the rproc from going away, but I haven't dug into
the details in the driver code to find out. Drivers can get unbound
from devices without the driver being unloaded, so I imagine there is
an in-use count on the device itself that would prevent driver
unbinding.
> +}
> +
> +static int __devexit omap_rproc_remove(struct platform_device *pdev)
> +{
> + struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
> +
> + return rproc_unregister(pdata->name);
> +}
> +
> +static struct platform_driver omap_rproc_driver = {
> + .probe = omap_rproc_probe,
> + .remove = __devexit_p(omap_rproc_remove),
> + .driver = {
> + .name = "omap-rproc",
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +static int __init omap_rproc_init(void)
> +{
> + return platform_driver_register(&omap_rproc_driver);
> +}
> +/* must be ready in time for device_initcall users */
> +subsys_initcall(omap_rproc_init);
> +
> +static void __exit omap_rproc_exit(void)
> +{
> + platform_driver_unregister(&omap_rproc_driver);
> +}
> +module_exit(omap_rproc_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("OMAP Remote Processor control driver");
> --
> 1.7.1
>
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