From 1d277bc8c275fae8e8cd400344bdacbdce3a6b46 Mon Sep 17 00:00:00 2001
From: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
Date: Tue, 13 Dec 2022 19:47:49 +0000
Subject: [PATCH 27/43] drivers/nvmxip: introduce NVM XIP block storage
 emulation

add block storage emulation for NVM XIP flash devices

Some paltforms such as Corstone-1000 need to see NVM XIP raw flash
as a block storage device with read only capability.

Here NVM flash devices are devices with addressable
memory (e.g: QSPI NOR flash).

The implementation is generic and can be used by different platforms.

Two drivers are provided as follows.

  nvmxip-blk :

    a generic block driver allowing to read from the XIP flash

  nvmxip_qspi :

    The driver probed with the DT and parent of the nvmxip-blk device.
    nvmxip_qspi can be reused by other platforms. If the platform
    has custom settings to apply before using the flash, then the platform
    can provide its own parent driver belonging to UCLASS_NVMXIP and reuse
    nvmxip-blk. The custom driver can be implmented like nvmxip_qspi in
    addition to the platform custom settings.

Platforms can use multiple NVM XIP devices at the same time by defining a
DT node for each one of them.

For more details please refer to doc/develop/driver-model/nvmxip.rst

Upstream-Status: Submitted
Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
---
 MAINTAINERS                                |   7 ++
 doc/develop/driver-model/index.rst         |   1 +
 doc/develop/driver-model/nvmxip.rst        |  70 ++++++++++++
 doc/device-tree-bindings/nvmxip/nvmxip.txt |  56 +++++++++
 drivers/Kconfig                            |   2 +
 drivers/Makefile                           |   1 +
 drivers/block/blk-uclass.c                 |   1 +
 drivers/nvmxip/Kconfig                     |  17 +++
 drivers/nvmxip/Makefile                    |   7 ++
 drivers/nvmxip/nvmxip-uclass.c             |  13 +++
 drivers/nvmxip/nvmxip.c                    | 127 +++++++++++++++++++++
 drivers/nvmxip/nvmxip.h                    |  46 ++++++++
 drivers/nvmxip/nvmxip_qspi.c               |  65 +++++++++++
 include/dm/uclass-id.h                     |   1 +
 14 files changed, 414 insertions(+)
 create mode 100644 doc/develop/driver-model/nvmxip.rst
 create mode 100644 doc/device-tree-bindings/nvmxip/nvmxip.txt
 create mode 100644 drivers/nvmxip/Kconfig
 create mode 100644 drivers/nvmxip/Makefile
 create mode 100644 drivers/nvmxip/nvmxip-uclass.c
 create mode 100644 drivers/nvmxip/nvmxip.c
 create mode 100644 drivers/nvmxip/nvmxip.h
 create mode 100644 drivers/nvmxip/nvmxip_qspi.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 9feaf0502f5b..ba15dd02d58d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1204,6 +1204,13 @@ F:	cmd/nvme.c
 F:	include/nvme.h
 F:	doc/develop/driver-model/nvme.rst
 
+NVMXIP
+M:	Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+S:	Maintained
+F:	doc/develop/driver-model/nvmxip.rst
+F:	doc/device-tree-bindings/nvmxip/nvmxip.txt
+F:	drivers/nvmxip/
+
 NVMEM
 M:	Sean Anderson <seanga2@gmail.com>
 S:	Maintained
diff --git a/doc/develop/driver-model/index.rst b/doc/develop/driver-model/index.rst
index 7366ef818c5a..8e12bbd9366a 100644
--- a/doc/develop/driver-model/index.rst
+++ b/doc/develop/driver-model/index.rst
@@ -20,6 +20,7 @@ subsystems
    livetree
    migration
    nvme
+   nvmxip
    of-plat
    pci-info
    pmic-framework
diff --git a/doc/develop/driver-model/nvmxip.rst b/doc/develop/driver-model/nvmxip.rst
new file mode 100644
index 000000000000..91b24e4e50d2
--- /dev/null
+++ b/doc/develop/driver-model/nvmxip.rst
@@ -0,0 +1,70 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+NVM XIP Block Storage Emulation Driver
+=======================================
+
+Summary
+-------
+
+Non-Volatile Memory devices with addressable memory (e.g: QSPI NOR flash) could
+be used for block storage needs (e.g: parsing a GPT layout in a raw QSPI NOR flash).
+
+The NVMXIP class provides this functionality and can be used for any 64-bit platform.
+
+The NVMXIP class provides the following drivers:
+
+      nvmxip-blk :
+
+        A generic block driver allowing to read from the XIP flash.
+	The driver belongs to UCLASS_BLK.
+	The driver implemented by drivers/nvmxip/nvmxip.c
+
+      nvmxip_qspi :
+
+        The driver probed with the DT and parent of the nvmxip-blk device.
+        nvmxip_qspi can be reused by other platforms. If the platform
+        has custom settings to apply before using the flash, then the platform
+        can provide its own parent driver belonging to UCLASS_NVMXIP and reuse
+        nvmxip-blk. The custom driver can be implmented like nvmxip_qspi in
+        addition to the platform custom settings.
+	The nvmxip_qspi driver belongs to UCLASS_NVMXIP.
+	The driver implemented by drivers/nvmxip/nvmxip_qspi.c
+
+    The implementation is generic and can be used by different platforms.
+
+Supported hardware
+--------------------------------
+
+Any 64-bit plaform.
+
+Configuration
+----------------------
+
+config NVMXIP
+	  This option allows the emulation of a block storage device
+	  on top of a direct access non volatile memory XIP flash devices.
+	  This support provides the read operation.
+	  This option provides the block storage driver nvmxip-blk which
+	  handles the read operation. This driver is HW agnostic and can support
+	  multiple flash devices at the same time.
+
+config NVMXIP_QSPI
+	  This option allows the emulation of a block storage device on top of a QSPI XIP flash.
+	  Any platform that needs to emulate one or multiple XIP flash devices can turn this
+	  option on to enable the functionality. NVMXIP config is selected automatically.
+	  Platforms that need to add custom treatments before accessing to the flash, can
+	  write their own driver (same as nvmxip_qspi in addition to the custom settings).
+
+Device Tree nodes
+--------------------
+
+Multiple XIP flash devices can be used at the same time by describing them through DT
+nodes.
+
+Please refer to the documentation of the DT binding at:
+
+doc/device-tree-bindings/nvmxip/nvmxip.txt
+
+Contributors
+------------
+   * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
diff --git a/doc/device-tree-bindings/nvmxip/nvmxip.txt b/doc/device-tree-bindings/nvmxip/nvmxip.txt
new file mode 100644
index 000000000000..7c4b03f66b57
--- /dev/null
+++ b/doc/device-tree-bindings/nvmxip/nvmxip.txt
@@ -0,0 +1,56 @@
+Specifying NVMXIP information for devices
+======================================
+
+NVM XIP flash device nodes
+---------------------------
+
+Each flash device should have its own node.
+
+Each node must specify the following fields:
+
+1)
+		compatible = "nvmxip,qspi";
+
+This allows to bind the flash device with the nvmxip_qspi driver
+If a platform has its own driver, please provide your own compatible
+string.
+
+2)
+		reg = <0x0 0x08000000 0x0 0x00200000>;
+
+The start address and size of the flash device. The values give here are an
+example (when the cell size is 2).
+
+When cell size is 1, the reg field looks like this:
+
+		reg = <0x08000000 0x00200000>;
+
+3)
+
+		lba_shift = <9>;
+
+The number of bit shifts used to calculate the size in bytes of one block.
+In this example the block size is 1 << 9 = 2 ^ 9 = 512 bytes
+
+4)
+
+		lba = <4096>;
+
+The number of blocks.
+
+Example of multiple flash devices
+----------------------------------------------------
+
+	nvmxip-qspi1@08000000 {
+		compatible = "nvmxip,qspi";
+		reg = <0x0 0x08000000 0x0 0x00200000>;
+		lba_shift = <9>;
+		lba = <4096>;
+	};
+
+	nvmxip-qspi2@08200000 {
+		compatible = "nvmxip,qspi";
+		reg = <0x0 0x08200000 0x0 0x00100000>;
+		lba_shift = <9>;
+		lba = <2048>;
+	};
diff --git a/drivers/Kconfig b/drivers/Kconfig
index e51f0547c3da..d425ff1e76c7 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -78,6 +78,8 @@ source "drivers/net/Kconfig"
 
 source "drivers/nvme/Kconfig"
 
+source "drivers/nvmxip/Kconfig"
+
 source "drivers/pci/Kconfig"
 
 source "drivers/pci_endpoint/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index f0a7530295c5..fb1b62cbd6ff 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -89,6 +89,7 @@ obj-$(CONFIG_FWU_MDATA) += fwu-mdata/
 obj-y += misc/
 obj-$(CONFIG_MMC) += mmc/
 obj-$(CONFIG_NVME) += nvme/
+obj-$(CONFIG_NVMXIP) += nvmxip/
 obj-$(CONFIG_PCI_ENDPOINT) += pci_endpoint/
 obj-y += dfu/
 obj-$(CONFIG_PCH) += pch/
diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index c69fc4d51829..e8ab576c3253 100644
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -28,6 +28,7 @@ static struct {
 	{ UCLASS_AHCI, "sata" },
 	{ UCLASS_HOST, "host" },
 	{ UCLASS_NVME, "nvme" },
+	{ UCLASS_NVMXIP, "nvmxip" },
 	{ UCLASS_EFI_MEDIA, "efi" },
 	{ UCLASS_EFI_LOADER, "efiloader" },
 	{ UCLASS_VIRTIO, "virtio" },
diff --git a/drivers/nvmxip/Kconfig b/drivers/nvmxip/Kconfig
new file mode 100644
index 000000000000..6a23acaf1895
--- /dev/null
+++ b/drivers/nvmxip/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2022, Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+
+config NVMXIP
+	bool "NVM XIP devices support"
+	select BLK
+	help
+	  This option allows the emulation of a block storage device
+	  on top of a direct access non volatile memory XIP flash devices.
+	  This support provides the read operation.
+
+config NVMXIP_QSPI
+	bool "QSPI XIP  support"
+	select NVMXIP
+	help
+	  This option allows the emulation of a block storage device on top of a QSPI XIP flash
diff --git a/drivers/nvmxip/Makefile b/drivers/nvmxip/Makefile
new file mode 100644
index 000000000000..d8ad2a160b47
--- /dev/null
+++ b/drivers/nvmxip/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# (C) Copyright 2022
+# Abdellatif El Khlifi, Arm Limited, abdellatif.elkhlifi@arm.com.
+
+obj-y += nvmxip-uclass.o nvmxip.o
+obj-$(CONFIG_NVMXIP_QSPI) += nvmxip_qspi.o
diff --git a/drivers/nvmxip/nvmxip-uclass.c b/drivers/nvmxip/nvmxip-uclass.c
new file mode 100644
index 000000000000..0f7e47b8af86
--- /dev/null
+++ b/drivers/nvmxip/nvmxip-uclass.c
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2022 ARM Limited
+ * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+
+UCLASS_DRIVER(nvmxip) = {
+	.name	= "nvmxip",
+	.id	= UCLASS_NVMXIP,
+};
diff --git a/drivers/nvmxip/nvmxip.c b/drivers/nvmxip/nvmxip.c
new file mode 100644
index 000000000000..6ba48183c575
--- /dev/null
+++ b/drivers/nvmxip/nvmxip.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2022 ARM Limited
+ * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include "nvmxip.h"
+
+static u32 nvmxip_bdev_max_devs;
+
+static int nvmxip_mmio_rawread(const phys_addr_t address, u64 *value)
+{
+	*value = readq(address);
+	return 0;
+}
+
+static ulong nvmxip_blk_read(struct udevice *udev, lbaint_t blknr, lbaint_t blkcnt, void *buffer)
+{
+	struct nvmxip_blk_priv *bpriv_data = dev_get_priv(udev);
+	struct blk_desc *desc = dev_get_uclass_plat(udev);
+
+	/* size of 1 block */
+	/* number of the u64 words to read */
+	u32 qwords = (blkcnt * desc->blksz) / sizeof(u64);
+	/* physical address of the first block to read */
+	phys_addr_t blkaddr = bpriv_data->pplat_data->phys_base + blknr * desc->blksz;
+	u64 *virt_blkaddr;
+	u64 *pdst = buffer;
+	u32 qdata_idx;
+
+	if (!pdst)
+		return -EINVAL;
+
+	pr_debug("[%s]: reading from blknr: %lu , blkcnt: %lu\n", udev->name, blknr, blkcnt);
+
+	virt_blkaddr = map_sysmem(blkaddr, 0);
+
+	/* assumption: the data is virtually contiguous */
+
+	for (qdata_idx = 0 ; qdata_idx < qwords ; qdata_idx++)
+		nvmxip_mmio_rawread((phys_addr_t)(virt_blkaddr + qdata_idx), pdst++);
+
+	pr_debug("[%s]:     src[0]: 0x%llx , dst[0]: 0x%llx , src[-1]: 0x%llx , dst[-1]: 0x%llx\n",
+		 udev->name,
+		 *virt_blkaddr,
+		 *(u64 *)buffer,
+		 *(u64 *)((u8 *)virt_blkaddr + desc->blksz * blkcnt - sizeof(u64)),
+		 *(u64 *)((u8 *)buffer + desc->blksz * blkcnt - sizeof(u64)));
+
+	unmap_sysmem(virt_blkaddr);
+
+	return blkcnt;
+}
+
+static int nvmxip_blk_probe(struct udevice *udev)
+{
+	struct nvmxip_priv *ppriv_data = dev_get_priv(udev->parent);
+	struct blk_desc *desc = dev_get_uclass_plat(udev);
+	struct nvmxip_blk_priv *bpriv_data = dev_get_priv(udev);
+
+	bpriv_data->bdev = udev;
+	bpriv_data->pplat_data = ppriv_data->plat_data;
+	desc->lba = bpriv_data->pplat_data->lba;
+	desc->log2blksz = bpriv_data->pplat_data->lba_shift;
+	desc->blksz = 1 << bpriv_data->pplat_data->lba_shift;
+	desc->bdev = bpriv_data->bdev;
+
+	pr_debug("[%s]: block storage layout\n    lbas: %lu , log2blksz: %d, blksz: %lu\n",
+		 udev->name, desc->lba, desc->log2blksz, desc->blksz);
+
+	return 0;
+}
+
+int nvmxip_init(struct udevice *udev)
+{
+	struct nvmxip_plat *plat_data = dev_get_plat(udev);
+	struct nvmxip_priv *priv_data = dev_get_priv(udev);
+	int ret;
+	struct udevice *bdev = NULL;
+	char bdev_name[NVMXIP_BLKDEV_NAME_SZ + 1] = {0};
+
+	priv_data->udev = udev;
+	priv_data->plat_data = plat_data;
+
+	nvmxip_bdev_max_devs++;
+
+	snprintf(bdev_name, NVMXIP_BLKDEV_NAME_SZ, "nvmxip-blk#%d", nvmxip_bdev_max_devs);
+
+	ret = blk_create_devicef(udev, NVMXIP_BLKDRV_NAME, bdev_name, UCLASS_NVMXIP,
+				 nvmxip_bdev_max_devs, NVMXIP_DEFAULT_LBA_SZ,
+				 NVMXIP_DEFAULT_LBA_COUNT, &bdev);
+	if (ret) {
+		pr_err("[%s]: failure during creation of the block device %s, error %d\n",
+		       udev->name, bdev_name, ret);
+		goto blkdev_setup_error;
+	}
+
+	ret = blk_probe_or_unbind(bdev);
+	if (ret) {
+		pr_err("[%s]: failure during probing the block device %s, error %d\n",
+		       udev->name, bdev_name, ret);
+		goto blkdev_setup_error;
+	}
+
+	pr_info("[%s]: the block device %s ready for use\n", udev->name, bdev_name);
+
+	return 0;
+
+blkdev_setup_error:
+	nvmxip_bdev_max_devs--;
+	return ret;
+}
+
+static const struct blk_ops nvmxip_blk_ops = {
+	.read	= nvmxip_blk_read,
+};
+
+U_BOOT_DRIVER(nvmxip_blk) = {
+	.name	= NVMXIP_BLKDRV_NAME,
+	.id	= UCLASS_BLK,
+	.probe	= nvmxip_blk_probe,
+	.ops	= &nvmxip_blk_ops,
+	.priv_auto	= sizeof(struct nvmxip_blk_priv),
+};
diff --git a/drivers/nvmxip/nvmxip.h b/drivers/nvmxip/nvmxip.h
new file mode 100644
index 000000000000..393172cc2f86
--- /dev/null
+++ b/drivers/nvmxip/nvmxip.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2022 ARM Limited
+ * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+ */
+
+#ifndef __DRIVER_NVMXIP_H__
+#define __DRIVER_NVMXIP_H__
+
+#include <asm/io.h>
+#include <blk.h>
+#include <linux/bitops.h>
+#include <linux/compat.h>
+#include <mapmem.h>
+
+#define NVMXIP_BLKDRV_NAME    "nvmxip-blk"
+
+#define NVMXIP_BLKDEV_NAME_SZ 20
+
+#define NVMXIP_DEFAULT_LBA_SHIFT 10 /* 1024 bytes per block */
+#define NVMXIP_DEFAULT_LBA_COUNT 1024 /* block count */
+
+#define NVMXIP_DEFAULT_LBA_SZ BIT(NVMXIP_DEFAULT_LBA_SHIFT)
+
+/* NVM XIP device platform data */
+struct nvmxip_plat {
+	phys_addr_t phys_base; /* NVM XIP device base address */
+	u32 lba_shift; /* block size shift count (read from device tree) */
+	lbaint_t lba; /* number of blocks (read from device tree) */
+};
+
+/* NVM XIP device private data */
+struct nvmxip_priv {
+	struct udevice *udev;
+	struct nvmxip_plat *plat_data;
+};
+
+/* Private data of the block device associated with the NVM XIP device (the parent) */
+struct nvmxip_blk_priv {
+	struct udevice *bdev;
+	struct nvmxip_plat *pplat_data; /* parent device platform data */
+};
+
+int nvmxip_init(struct udevice *udev);
+
+#endif /* __DRIVER_NVMXIP_H__ */
diff --git a/drivers/nvmxip/nvmxip_qspi.c b/drivers/nvmxip/nvmxip_qspi.c
new file mode 100644
index 000000000000..749625134acd
--- /dev/null
+++ b/drivers/nvmxip/nvmxip_qspi.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2022 ARM Limited
+ * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <fdt_support.h>
+#include "nvmxip.h"
+
+#include <asm/global_data.h>
+DECLARE_GLOBAL_DATA_PTR;
+
+#define NVMXIP_QSPI_DRV_NAME "nvmxip_qspi"
+
+static int nvmxip_qspi_probe(struct udevice *dev)
+{
+	pr_debug("[%s][%s]\n", __func__, dev->name);
+	return nvmxip_init(dev);
+}
+
+static int nvmxip_qspi_of_to_plat(struct udevice *dev)
+{
+	struct nvmxip_plat *plat_data = dev_get_plat(dev);
+	int ret;
+
+	plat_data->phys_base = (phys_addr_t)dev_read_addr(dev);
+	if (plat_data->phys_base == FDT_ADDR_T_NONE) {
+		pr_err("[%s]: can not get base address from device tree\n", dev->name);
+		return -EINVAL;
+	}
+
+	ret = dev_read_u32(dev, "lba_shift", &plat_data->lba_shift);
+	if (ret) {
+		pr_err("[%s]: can not get lba_shift from device tree\n", dev->name);
+		return -EINVAL;
+	}
+
+	ret = dev_read_u32(dev, "lba", (u32 *)&plat_data->lba);
+	if (ret) {
+		pr_err("[%s]: can not get lba from device tree\n", dev->name);
+		return -EINVAL;
+	}
+
+	pr_debug("[%s]: XIP device base addr: 0x%llx , lba_shift: %d , lbas: %lu\n",
+		 dev->name, plat_data->phys_base, plat_data->lba_shift, plat_data->lba);
+
+	return 0;
+}
+
+static const struct udevice_id nvmxip_qspi_ids[] = {
+	{ .compatible = "nvmxip,qspi" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(nvmxip_qspi) = {
+	.name = NVMXIP_QSPI_DRV_NAME,
+	.id = UCLASS_NVMXIP,
+	.of_match = nvmxip_qspi_ids,
+	.of_to_plat = nvmxip_qspi_of_to_plat,
+	.priv_auto = sizeof(struct nvmxip_priv),
+	.plat_auto = sizeof(struct nvmxip_plat),
+	.probe = nvmxip_qspi_probe,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index fa08a66ac8e0..f3564a49d912 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -92,6 +92,7 @@ enum uclass_id {
 	UCLASS_NOP,		/* No-op devices */
 	UCLASS_NORTHBRIDGE,	/* Intel Northbridge / SDRAM controller */
 	UCLASS_NVME,		/* NVM Express device */
+	UCLASS_NVMXIP,		/* NVM XIP devices */
 	UCLASS_P2SB,		/* (x86) Primary-to-Sideband Bus */
 	UCLASS_PANEL,		/* Display panel, such as an LCD */
 	UCLASS_PANEL_BACKLIGHT,	/* Backlight controller for panel */
-- 
2.39.2