Messages in this thread Patch in this message |  | | Date | Tue, 2 Oct 2018 15:18:59 -0700 | Subject | [PATCH 11/15] platform: goldfish: pipe: Split the driver to v2 specific and the rest | From | rkir@google ... |
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From: Roman Kiryanov <rkir@google.com>
Move probe/remove and other driver stuff to a separate file to plug v1 there later.
Signed-off-by: Roman Kiryanov <rkir@google.com> --- drivers/platform/goldfish/Makefile | 3 +- drivers/platform/goldfish/goldfish_pipe.c | 124 +++++++++++++++++++ drivers/platform/goldfish/goldfish_pipe.h | 10 ++ drivers/platform/goldfish/goldfish_pipe_v2.c | 112 +++-------------- drivers/platform/goldfish/goldfish_pipe_v2.h | 10 ++ 5 files changed, 161 insertions(+), 98 deletions(-) create mode 100644 drivers/platform/goldfish/goldfish_pipe.c create mode 100644 drivers/platform/goldfish/goldfish_pipe.h create mode 100644 drivers/platform/goldfish/goldfish_pipe_v2.h
diff --git a/drivers/platform/goldfish/Makefile b/drivers/platform/goldfish/Makefile index 81f899a987a2..016769e003d8 100644 --- a/drivers/platform/goldfish/Makefile +++ b/drivers/platform/goldfish/Makefile @@ -1,4 +1,5 @@ # # Makefile for Goldfish platform specific drivers # -obj-$(CONFIG_GOLDFISH_PIPE) += goldfish_pipe_v2.o +obj-$(CONFIG_GOLDFISH_PIPE) += goldfish_pipe_all.o +goldfish_pipe_all-objs := goldfish_pipe.o goldfish_pipe_v2.o diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c new file mode 100644 index 000000000000..792b20bdf76c --- /dev/null +++ b/drivers/platform/goldfish/goldfish_pipe.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* This source file contains the implementation of a special device driver + * that intends to provide a *very* fast communication channel between the + * guest system and the QEMU emulator. + * + * Usage from the guest is simply the following (error handling simplified): + * + * int fd = open("/dev/qemu_pipe",O_RDWR); + * .... write() or read() through the pipe. + * + * This driver doesn't deal with the exact protocol used during the session. + * It is intended to be as simple as something like: + * + * // do this _just_ after opening the fd to connect to a specific + * // emulator service. + * const char* msg = "<pipename>"; + * if (write(fd, msg, strlen(msg)+1) < 0) { + * ... could not connect to <pipename> service + * close(fd); + * } + * + * // after this, simply read() and write() to communicate with the + * // service. Exact protocol details left as an exercise to the reader. + * + * This driver is very fast because it doesn't copy any data through + * intermediate buffers, since the emulator is capable of translating + * guest user addresses into host ones. + * + * Note that we must however ensure that each user page involved in the + * exchange is properly mapped during a transfer. + */ + +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/acpi.h> +#include "goldfish_pipe_qemu.h" +#include "goldfish_pipe.h" +#include "goldfish_pipe_v2.h" + +/* + * Update this when something changes in the driver's behavior so the host + * can benefit from knowing it + */ +enum { + PIPE_DRIVER_VERSION = 2, + PIPE_CURRENT_DEVICE_VERSION = 2 +}; + +static int goldfish_pipe_probe(struct platform_device *pdev) +{ + struct resource *r; + char __iomem *base; + int irq; + int version; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!r || resource_size(r) < PAGE_SIZE) { + dev_err(&pdev->dev, "can't allocate i/o page\n"); + return -EINVAL; + } + base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE); + if (!base) { + dev_err(&pdev->dev, "ioremap failed\n"); + return -EINVAL; + } + + r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!r) + return -EINVAL; + + irq = r->start; + + /* + * Exchange the versions with the host device + * + * Note: v1 driver used to not report its version, so we write it before + * reading device version back: this allows the host implementation to + * detect the old driver (if there was no version write before read). + */ + writel(PIPE_DRIVER_VERSION, base + PIPE_REG_VERSION); + version = readl(base + PIPE_REG_VERSION); + + if (WARN_ON(version < PIPE_CURRENT_DEVICE_VERSION)) + return -EINVAL; + + return goldfish_pipe_device_init(pdev, base, irq); +} + +static int goldfish_pipe_remove(struct platform_device *pdev) +{ + struct goldfish_pipe_dev_base *dev = platform_get_drvdata(pdev); + + return dev->deinit(dev, pdev); +} + +static const struct acpi_device_id goldfish_pipe_acpi_match[] = { + { "GFSH0003", 0 }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, goldfish_pipe_acpi_match); + +static const struct of_device_id goldfish_pipe_of_match[] = { + { .compatible = "google,android-pipe", }, + {}, +}; +MODULE_DEVICE_TABLE(of, goldfish_pipe_of_match); + +static struct platform_driver goldfish_pipe_driver = { + .probe = goldfish_pipe_probe, + .remove = goldfish_pipe_remove, + .driver = { + .name = "goldfish_pipe", + .of_match_table = goldfish_pipe_of_match, + .acpi_match_table = ACPI_PTR(goldfish_pipe_acpi_match), + } +}; + +module_platform_driver(goldfish_pipe_driver); +MODULE_AUTHOR("David Turner <digit@google.com>"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/platform/goldfish/goldfish_pipe.h b/drivers/platform/goldfish/goldfish_pipe.h new file mode 100644 index 000000000000..ee0b54bcb165 --- /dev/null +++ b/drivers/platform/goldfish/goldfish_pipe.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef GOLDFISH_PIPE_H +#define GOLDFISH_PIPE_H + +struct goldfish_pipe_dev_base { + /* the destructor, the pointer is set in init */ + int (*deinit)(void *pipe_dev, struct platform_device *pdev); +}; + +#endif /* GOLDFISH_PIPE_H */ diff --git a/drivers/platform/goldfish/goldfish_pipe_v2.c b/drivers/platform/goldfish/goldfish_pipe_v2.c index ff5d88e7959a..641dfdcc3ffd 100644 --- a/drivers/platform/goldfish/goldfish_pipe_v2.c +++ b/drivers/platform/goldfish/goldfish_pipe_v2.c @@ -30,8 +30,6 @@ * exchange is properly mapped during a transfer. */ -#include <linux/module.h> -#include <linux/mod_devicetable.h> #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/spinlock.h> @@ -44,18 +42,9 @@ #include <linux/io.h> #include <linux/dma-mapping.h> #include <linux/mm.h> -#include <linux/acpi.h> #include <linux/bug.h> #include "goldfish_pipe_qemu.h" - -/* - * Update this when something changes in the driver's behavior so the host - * can benefit from knowing it - */ -enum { - PIPE_DRIVER_VERSION = 2, - PIPE_CURRENT_DEVICE_VERSION = 2 -}; +#include "goldfish_pipe.h" enum { MAX_BUFFERS_PER_COMMAND = 336, @@ -65,6 +54,9 @@ enum { struct goldfish_pipe_dev; +static int goldfish_pipe_device_deinit(void *raw_dev, + struct platform_device *pdev); + /* A per-pipe command structure, shared with the host */ struct goldfish_pipe_command { s32 cmd; /* PipeCmdCode, guest -> host */ @@ -152,8 +144,8 @@ struct goldfish_pipe { * waiting to be awoken. */ struct goldfish_pipe_dev { - /* A magic number to check if this is an instance of this struct */ - void *magic; + /* Needed for 'remove' */ + struct goldfish_pipe_dev_base super; /* * Global device spinlock. Protects the following members: @@ -593,9 +585,6 @@ static void goldfish_interrupt_task(unsigned long dev_addr) } } -static void goldfish_pipe_device_deinit(struct platform_device *pdev, - struct goldfish_pipe_dev *dev); - /* * The general idea of the interrupt handling: * @@ -616,7 +605,7 @@ static irqreturn_t goldfish_pipe_interrupt(int irq, void *dev_id) unsigned long flags; struct goldfish_pipe_dev *dev = dev_id; - if (dev->magic != &goldfish_pipe_device_deinit) + if (dev->super.deinit != &goldfish_pipe_device_deinit) return IRQ_NONE; /* Request the signalled pipes from the device */ @@ -798,9 +787,9 @@ static void write_pa_addr(void *addr, void __iomem *portl, void __iomem *porth) writel(lower_32_bits(paddr), portl); } -static int goldfish_pipe_device_init(struct platform_device *pdev, - char __iomem *base, - int irq) +int goldfish_pipe_device_init(struct platform_device *pdev, + char __iomem *base, + int irq) { struct goldfish_pipe_dev *dev; int err; @@ -809,7 +798,7 @@ static int goldfish_pipe_device_init(struct platform_device *pdev, if (!dev) return -ENOMEM; - dev->magic = &goldfish_pipe_device_deinit; + dev->super.deinit = &goldfish_pipe_device_deinit; spin_lock_init(&dev->lock); tasklet_init(&dev->irq_tasklet, &goldfish_interrupt_task, @@ -872,9 +861,11 @@ static int goldfish_pipe_device_init(struct platform_device *pdev, return 0; } -static int goldfish_pipe_device_deinit(struct platform_device *pdev, - struct goldfish_pipe_dev *dev) +static int goldfish_pipe_device_deinit(void *raw_dev, + struct platform_device *pdev) { + struct goldfish_pipe_dev *dev = raw_dev; + misc_deregister(&dev->miscdev); tasklet_kill(&dev->irq_tasklet); kfree(dev->pipes); @@ -882,76 +873,3 @@ static int goldfish_pipe_device_deinit(struct platform_device *pdev, return 0; } - -static int goldfish_pipe_probe(struct platform_device *pdev) -{ - struct resource *r; - char __iomem *base; - int irq; - int version; - - r = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!r || resource_size(r) < PAGE_SIZE) { - dev_err(&pdev->dev, "can't allocate i/o page\n"); - return -EINVAL; - } - - base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE); - if (!base) { - dev_err(&pdev->dev, "ioremap failed\n"); - return -EINVAL; - } - - r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); - if (!r) - return -EINVAL; - - irq = r->start; - - /* - * Exchange the versions with the host device - * - * Note: v1 driver used to not report its version, so we write it before - * reading device version back: this allows the host implementation to - * detect the old driver (if there was no version write before read). - */ - writel(PIPE_DRIVER_VERSION, base + PIPE_REG_VERSION); - version = readl(base + PIPE_REG_VERSION); - if (WARN_ON(version < PIPE_CURRENT_DEVICE_VERSION)) - return -EINVAL; - - return goldfish_pipe_device_init(pdev, base, irq); -} - -static int goldfish_pipe_remove(struct platform_device *pdev) -{ - struct goldfish_pipe_dev *dev = platform_get_drvdata(pdev); - - return goldfish_pipe_device_deinit(pdev, dev); -} - -static const struct acpi_device_id goldfish_pipe_acpi_match[] = { - { "GFSH0003", 0 }, - { }, -}; -MODULE_DEVICE_TABLE(acpi, goldfish_pipe_acpi_match); - -static const struct of_device_id goldfish_pipe_of_match[] = { - { .compatible = "google,android-pipe", }, - {}, -}; -MODULE_DEVICE_TABLE(of, goldfish_pipe_of_match); - -static struct platform_driver goldfish_pipe_driver = { - .probe = goldfish_pipe_probe, - .remove = goldfish_pipe_remove, - .driver = { - .name = "goldfish_pipe", - .of_match_table = goldfish_pipe_of_match, - .acpi_match_table = ACPI_PTR(goldfish_pipe_acpi_match), - } -}; - -module_platform_driver(goldfish_pipe_driver); -MODULE_AUTHOR("David Turner <digit@google.com>"); -MODULE_LICENSE("GPL v2"); diff --git a/drivers/platform/goldfish/goldfish_pipe_v2.h b/drivers/platform/goldfish/goldfish_pipe_v2.h new file mode 100644 index 000000000000..03b476fb9978 --- /dev/null +++ b/drivers/platform/goldfish/goldfish_pipe_v2.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef GOLDFISH_PIPE_V2_H +#define GOLDFISH_PIPE_V2_H + +/* The entry point to the pipe v2 driver */ +int goldfish_pipe_device_init(struct platform_device *pdev, + char __iomem *base, + int irq); + +#endif /* #define GOLDFISH_PIPE_V2_H */ -- 2.19.0.605.g01d371f741-goog
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