[4/9] soc: apple: Add SART driver

Message ID	20220321165049.35985-5-sven@svenpeter.dev (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org> From: Sven Peter <sven@svenpeter.dev> To: Cc: Sven Peter <sven@svenpeter.dev>, Hector Martin <marcan@marcan.st>, Alyssa Rosenzweig <alyssa@rosenzweig.io>, Rob Herring <robh+dt@kernel.org>, Arnd Bergmann <arnd@arndb.de>, Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@fb.com>, Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>, Marc Zyngier <maz@kernel.org>, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org Subject: [PATCH 4/9] soc: apple: Add SART driver Date: Mon, 21 Mar 2022 17:50:44 +0100 Message-Id: <20220321165049.35985-5-sven@svenpeter.dev> In-Reply-To: <20220321165049.35985-1-sven@svenpeter.dev> References: <20220321165049.35985-1-sven@svenpeter.dev> MIME-Version: 1.0 Precedence: list Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org
Series	Apple M1 (Pro/Max) NVMe driver \| expand [0/9] Apple M1 (Pro/Max) NVMe driver [1/9] dt-bindings: soc: apple: Add Apple SART [2/9] dt-bindings: soc: apple: Add ANS NVMe [3/9] soc: apple: Always include Makefile [4/9] soc: apple: Add SART driver [5/9] soc: apple: Add RTKit IPC library [6/9] nvme-apple: Add initial Apple SoC NVMe driver [7/9] nvme-apple: Serialize command issue [8/9] nvme-apple: Add support for multiple power domains [9/9] nvme-apple: Add support for suspend/resume

diff --git a/MAINTAINERS b/MAINTAINERS index 027c3b4ad61c..3d37fe7a0408 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1787,6 +1787,7 @@ F: drivers/watchdog/apple_wdt.c F: include/dt-bindings/interrupt-controller/apple-aic.h F: include/dt-bindings/pinctrl/apple.h F: include/linux/apple-mailbox.h +F: include/linux/soc/apple/* ARM/ARTPEC MACHINE SUPPORT M: Jesper Nilsson <jesper.nilsson@axis.com> diff --git a/drivers/soc/apple/Kconfig b/drivers/soc/apple/Kconfig index 9b8de31d6a8f..8c37ffd53fbd 100644 --- a/drivers/soc/apple/Kconfig +++ b/drivers/soc/apple/Kconfig @@ -17,6 +17,17 @@ config APPLE_PMGR_PWRSTATE controls for SoC devices. This driver manages them through the generic power domain framework, and also provides reset support. +config APPLE_SART + tristate "Apple SART DMA address filter" + depends on ARCH_APPLE || COMPILE_TEST + default ARCH_APPLE + help + Apple SART is a simple DMA address filter used on Apple SoCs such + as the M1. It is usually required for the NVMe coprocessor which does + not use a proper IOMMU. + + Say 'y' here if you have an Apple SoC. + endmenu endif diff --git a/drivers/soc/apple/Makefile b/drivers/soc/apple/Makefile index c114e84667e4..c83c66317098 100644 --- a/drivers/soc/apple/Makefile +++ b/drivers/soc/apple/Makefile @@ -1,2 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_APPLE_PMGR_PWRSTATE) += apple-pmgr-pwrstate.o + +obj-$(CONFIG_APPLE_SART) += apple-sart.o +apple-sart-y = sart.o diff --git a/drivers/soc/apple/sart.c b/drivers/soc/apple/sart.c new file mode 100644 index 000000000000..836ea68db2fc --- /dev/null +++ b/drivers/soc/apple/sart.c @@ -0,0 +1,318 @@ +// SPDX-License-Identifier: GPL-2.0-only OR MIT +/* + * Apple SART device driver + * Copyright (C) The Asahi Linux Contributors + * + * Apple SART is a simple address filter for some DMA transactions. + * Regions of physical memory must be added to the SART's allow + * list before any DMA can target these. Unlike a proper + * IOMMU no remapping can be done and special support in the + * consumer driver is required since not all DMA transactions of + * a single device are subject to SART filtering. + */ + +#include <linux/soc/apple/sart.h> +#include <linux/atomic.h> +#include <linux/bits.h> +#include <linux/bitfield.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/types.h> + +#define APPLE_SART_MAX_ENTRIES 16 + +/* This is probably a bitfield but the exact meaning of each bit is unknown. */ +#define APPLE_SART_FLAGS_ALLOW 0xff + +/* SARTv2 registers */ +#define APPLE_SART2_CONFIG(idx) (0x00 + 4 * (idx)) +#define APPLE_SART2_CONFIG_FLAGS GENMASK(31, 24) +#define APPLE_SART2_CONFIG_SIZE GENMASK(23, 0) +#define APPLE_SART2_CONFIG_SIZE_SHIFT 12 +#define APPLE_SART2_CONFIG_SIZE_MAX GENMASK(23, 0) + +#define APPLE_SART2_PADDR(idx) (0x40 + 4 * (idx)) +#define APPLE_SART2_PADDR_SHIFT 12 + +/* SARTv3 registers */ +#define APPLE_SART3_CONFIG(idx) (0x00 + 4 * (idx)) + +#define APPLE_SART3_PADDR(idx) (0x40 + 4 * (idx)) +#define APPLE_SART3_PADDR_SHIFT 12 + +#define APPLE_SART3_SIZE(idx) (0x80 + 4 * (idx)) +#define APPLE_SART3_SIZE_SHIFT 12 +#define APPLE_SART3_SIZE_MAX GENMASK(29, 0) + +struct apple_sart_ops { + void (*get_entry)(struct apple_sart *sart, int index, u8 *flags, + phys_addr_t *paddr, size_t *size); + int (*set_entry)(struct apple_sart *sart, int index, u8 flags, + phys_addr_t paddr, size_t size); +}; + +struct apple_sart { + struct device *dev; + void __iomem *regs; + + const struct apple_sart_ops *ops; + + unsigned long protected_entries; + unsigned long used_entries; +}; + +static void sart2_get_entry(struct apple_sart *sart, int index, u8 *flags, + phys_addr_t *paddr, size_t *size) +{ + u32 cfg = readl_relaxed(sart->regs + APPLE_SART2_CONFIG(index)); + u32 paddr_ = readl_relaxed(sart->regs + APPLE_SART2_PADDR(index)); + u32 size_ = FIELD_GET(APPLE_SART2_CONFIG_SIZE, cfg); + + *flags = FIELD_GET(APPLE_SART2_CONFIG_FLAGS, cfg); + *size = (size_t)size_ << APPLE_SART2_CONFIG_SIZE_SHIFT; + *paddr = (phys_addr_t)paddr_ << APPLE_SART2_PADDR_SHIFT; +} + +static int sart2_set_entry(struct apple_sart *sart, int index, u8 flags, + phys_addr_t paddr, size_t size) +{ + u32 cfg; + + if (size & ((1 << APPLE_SART2_CONFIG_SIZE_SHIFT) - 1)) + return -EINVAL; + if (paddr & ((1 << APPLE_SART2_PADDR_SHIFT) - 1)) + return -EINVAL; + + size >>= APPLE_SART2_CONFIG_SIZE_SHIFT; + paddr >>= APPLE_SART2_PADDR_SHIFT; + + if (size > APPLE_SART2_CONFIG_SIZE_MAX) + return -EINVAL; + + cfg = FIELD_PREP(APPLE_SART2_CONFIG_FLAGS, flags); + cfg |= FIELD_PREP(APPLE_SART2_CONFIG_SIZE, size); + + writel_relaxed(paddr, sart->regs + APPLE_SART2_PADDR(index)); + writel_relaxed(cfg, sart->regs + APPLE_SART2_CONFIG(index)); + + return 0; +} + +static struct apple_sart_ops sart_ops_v2 = { + .get_entry = sart2_get_entry, + .set_entry = sart2_set_entry, +}; + +static void sart3_get_entry(struct apple_sart *sart, int index, u8 *flags, + phys_addr_t *paddr, size_t *size) +{ + u32 paddr_ = readl_relaxed(sart->regs + APPLE_SART3_PADDR(index)); + u32 size_ = readl_relaxed(sart->regs + APPLE_SART3_SIZE(index)); + + *flags = readl_relaxed(sart->regs + APPLE_SART3_CONFIG(index)); + *size = (size_t)size_ << APPLE_SART3_SIZE_SHIFT; + *paddr = (phys_addr_t)paddr_ << APPLE_SART3_PADDR_SHIFT; +} + +static int sart3_set_entry(struct apple_sart *sart, int index, u8 flags, + phys_addr_t paddr, size_t size) +{ + if (size & ((1 << APPLE_SART3_SIZE_SHIFT) - 1)) + return -EINVAL; + if (paddr & ((1 << APPLE_SART3_PADDR_SHIFT) - 1)) + return -EINVAL; + + paddr >>= APPLE_SART3_PADDR_SHIFT; + size >>= APPLE_SART3_SIZE_SHIFT; + + if (size > APPLE_SART3_SIZE_MAX) + return -EINVAL; + + writel_relaxed(paddr, sart->regs + APPLE_SART3_PADDR(index)); + writel_relaxed(size, sart->regs + APPLE_SART3_SIZE(index)); + writel_relaxed(flags, sart->regs + APPLE_SART3_CONFIG(index)); + + return 0; +} + +static struct apple_sart_ops sart_ops_v3 = { + .get_entry = sart3_get_entry, + .set_entry = sart3_set_entry, +}; + +static int apple_sart_probe(struct platform_device *pdev) +{ + int i; + struct apple_sart *sart; + struct device *dev = &pdev->dev; + + sart = devm_kzalloc(dev, sizeof(*sart), GFP_KERNEL); + if (!sart) + return -ENOMEM; + + sart->dev = dev; + sart->ops = of_device_get_match_data(dev); + + sart->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(sart->regs)) + return PTR_ERR(sart->regs); + + for (i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) { + u8 flags; + size_t size; + phys_addr_t paddr; + + sart->ops->get_entry(sart, i, &flags, &paddr, &size); + + if (!flags) + continue; + + dev_dbg(sart->dev, + "SART bootloader entry: index %02d; flags: 0x%02x; paddr: %pa; size: 0x%zx\n", + i, flags, &paddr, size); + set_bit(i, &sart->protected_entries); + } + + platform_set_drvdata(pdev, sart); + return 0; +} + +struct apple_sart *apple_sart_get(struct device *dev) +{ + struct device_node *sart_node; + struct platform_device *sart_pdev; + struct apple_sart *sart; + + sart_node = of_parse_phandle(dev->of_node, "apple,sart", 0); + if (!sart_node) + return ERR_PTR(ENODEV); + + sart_pdev = of_find_device_by_node(sart_node); + of_node_put(sart_node); + + if (!sart_pdev) + return ERR_PTR(ENODEV); + + sart = dev_get_drvdata(&sart_pdev->dev); + if (!sart) + return ERR_PTR(EPROBE_DEFER); + + device_link_add(dev, &sart_pdev->dev, + DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER); + + return sart; +} +EXPORT_SYMBOL(apple_sart_get); + +int apple_sart_add_allowed_region(struct apple_sart *sart, phys_addr_t paddr, + size_t size) +{ + int i, ret; + + for (i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) { + if (test_bit(i, &sart->protected_entries)) + continue; + if (test_and_set_bit(i, &sart->used_entries)) + continue; + + ret = sart->ops->set_entry(sart, i, APPLE_SART_FLAGS_ALLOW, + paddr, size); + if (ret) { + dev_dbg(sart->dev, + "unable to set entry %d to [%pa, 0x%zx]\n", + i, &paddr, size); + clear_bit(i, &sart->used_entries); + return ret; + } + + dev_dbg(sart->dev, "wrote [%pa, 0x%zx] to %d\n", &paddr, size, + i); + return 0; + } + + dev_warn(sart->dev, + "no free entries left to add [paddr: 0x%llx, size: 0x%zx]\n", + paddr, size); + + return -EBUSY; +} +EXPORT_SYMBOL(apple_sart_add_allowed_region); + +int apple_sart_remove_allowed_region(struct apple_sart *sart, phys_addr_t paddr, + size_t size) +{ + int i; + + dev_dbg(sart->dev, + "will remove [paddr: %pa, size: 0x%zx] from allowed regions\n", + &paddr, size); + + for (i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) { + u8 eflags; + size_t esize; + phys_addr_t epaddr; + + if (test_bit(i, &sart->protected_entries)) + continue; + + sart->ops->get_entry(sart, i, &eflags, &epaddr, &esize); + + if (epaddr != paddr || esize != size) + continue; + + sart->ops->set_entry(sart, i, 0, 0, 0); + + clear_bit(i, &sart->used_entries); + dev_dbg(sart->dev, "cleared entry %d\n", i); + return 0; + } + + dev_warn(sart->dev, "entry [paddr: 0x%llx, size: 0x%zx] not found\n", + paddr, size); + + return -EINVAL; +} +EXPORT_SYMBOL(apple_sart_remove_allowed_region); + +static void apple_sart_shutdown(struct platform_device *pdev) +{ + struct apple_sart *sart = dev_get_drvdata(&pdev->dev); + int i; + + for (i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) { + if (test_bit(i, &sart->protected_entries)) + continue; + + sart->ops->set_entry(sart, i, 0, 0, 0); + } +} + +static const struct of_device_id apple_sart_of_match[] = { + { + .compatible = "apple,t6000-sart", + .data = &sart_ops_v3, + }, + { + .compatible = "apple,t8103-sart", + .data = &sart_ops_v2, + }, + {} +}; +MODULE_DEVICE_TABLE(of, apple_sart_of_match); + +static struct platform_driver apple_sart_driver = { + .driver = { + .name = "apple-sart", + .of_match_table = apple_sart_of_match, + }, + .probe = apple_sart_probe, + .shutdown = apple_sart_shutdown, +}; +module_platform_driver(apple_sart_driver); + +MODULE_LICENSE("Dual MIT/GPL"); +MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>"); +MODULE_DESCRIPTION("Apple SART driver"); diff --git a/include/linux/soc/apple/sart.h b/include/linux/soc/apple/sart.h new file mode 100644 index 000000000000..4e3d4960be5a --- /dev/null +++ b/include/linux/soc/apple/sart.h @@ -0,0 +1,77 @@ +/* SPDX-License-Identifier: GPL-2.0-only OR MIT */ +/* + * Apple SART device driver + * Copyright (C) The Asahi Linux Contributors + * + * Apple SART is a simple address filter for DMA transactions. + * Regions of physical memory must be added to the SART's allow + * list before any DMA can target these. Unlike a proper + * IOMMU no remapping can be done. + */ + +#ifndef _LINUX_SOC_APPLE_SART_H_ +#define _LINUX_SOC_APPLE_SART_H_ + +#include <linux/device.h> +#include <linux/err.h> +#include <linux/types.h> + +struct apple_sart; + +#if IS_ENABLED(CONFIG_APPLE_SART) + +/* + * Get a reference to the SART attached to dev. + * + * Looks for the phandle reference in apple,sart and returns a pointer + * to the corresponding apple_sart struct to be used with + * apple_sart_add_allowed_region and apple_sart_remove_allowed_region. + */ +struct apple_sart *apple_sart_get(struct device *dev); + +/* + * Adds the region [paddr, paddr+size] to the DMA allow list. + * + * @sart: SART reference + * @paddr: Start address of the region to be used for DMA + * @size: Size of the region to be used for DMA. + */ +int apple_sart_add_allowed_region(struct apple_sart *sart, phys_addr_t paddr, + size_t size); + +/* + * Removes the region [paddr, paddr+size] from the DMA allow list. + * + * Note that exact same paddr and size used for apple_sart_add_allowed_region + * have to be passed. + * + * @sart: SART reference + * @paddr: Start address of the region no longer used for DMA + * @size: Size of the region no longer used for DMA. + */ +int apple_sart_remove_allowed_region(struct apple_sart *sart, phys_addr_t paddr, + size_t size); + +#else + +static inline struct apple_sart *apple_sart_get(struct device *dev) +{ + return ERR_PTR(-ENODEV); +} + +static inline int apple_sart_add_allowed_region(struct apple_sart *sart, + phys_addr_t paddr, size_t size) +{ + return -ENODEV; +} + +static inline int apple_sart_remove_allowed_region(struct apple_sart *sart, + phys_addr_t paddr, + size_t size) +{ + return -ENODEV; +} + +#endif /* IS_ENABLED(CONFIG_APPLE_SART) */ + +#endif /* _LINUX_SOC_APPLE_SART_H_ */

[4/9] soc: apple: Add SART driver

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