[PATCH 3/3 v4] powerpc/powernv: Add opal-prd channel
Jeremy Kerr
jk at ozlabs.org
Thu Jun 4 23:51:47 AEST 2015
This change adds a char device to access the "PRD" (processor runtime
diagnostics) channel to OPAL firmware.
Includes contributions from Vaidyanathan Srinivasan, Neelesh Gupta &
Vishal Kulkarni.
Signed-off-by: Neelesh Gupta <neelegup at linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk at ozlabs.org>
Acked-by: Stewart Smith <stewart at linux.vnet.ibm.com>
---
v4:
- Address reviews from mpe:
- GPLv2+ -> GPLv2, fix copyrights, remove authors
- fix pgprot manipulations
- formatting & space fixes
- constify opal_prd_fops
v3:
- Add versioning description and reserved fields in opal_prd_info
for future expansion
- Fix node leak in opal_prd_range_is_valid
- Explain open() & probe() semantics
- Fix miscdev_register error path
---
arch/powerpc/include/asm/opal-api.h | 21
arch/powerpc/include/asm/opal.h | 1
arch/powerpc/include/uapi/asm/opal-prd.h | 58 ++
arch/powerpc/platforms/powernv/Kconfig | 7
arch/powerpc/platforms/powernv/Makefile | 1
arch/powerpc/platforms/powernv/opal-prd.c | 445 +++++++++++++++++
arch/powerpc/platforms/powernv/opal-wrappers.S | 1
arch/powerpc/platforms/powernv/opal.c | 4
8 files changed, 536 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 0321a90..2407f12 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -153,7 +153,8 @@
#define OPAL_FLASH_READ 110
#define OPAL_FLASH_WRITE 111
#define OPAL_FLASH_ERASE 112
-#define OPAL_LAST 112
+#define OPAL_PRD_MSG 113
+#define OPAL_LAST 113
/* Device tree flags */
@@ -352,6 +353,7 @@ enum opal_msg_type {
OPAL_MSG_SHUTDOWN, /* params[0] = 1 reboot, 0 shutdown */
OPAL_MSG_HMI_EVT,
OPAL_MSG_DPO,
+ OPAL_MSG_PRD,
OPAL_MSG_TYPE_MAX,
};
@@ -674,6 +676,23 @@ typedef struct oppanel_line {
__be64 line_len;
} oppanel_line_t;
+enum opal_prd_msg_type {
+ OPAL_PRD_MSG_TYPE_INIT = 0, /* HBRT --> OPAL */
+ OPAL_PRD_MSG_TYPE_FINI, /* HBRT/kernel --> OPAL */
+ OPAL_PRD_MSG_TYPE_ATTN, /* HBRT <-- OPAL */
+ OPAL_PRD_MSG_TYPE_ATTN_ACK, /* HBRT --> OPAL */
+ OPAL_PRD_MSG_TYPE_OCC_ERROR, /* HBRT <-- OPAL */
+ OPAL_PRD_MSG_TYPE_OCC_RESET, /* HBRT <-- OPAL */
+};
+
+struct opal_prd_msg_header {
+ uint8_t type;
+ uint8_t pad[1];
+ __be16 size;
+};
+
+struct opal_prd_msg;
+
/*
* SG entries
*
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 042af1a..93704af 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -193,6 +193,7 @@ int64_t opal_ipmi_recv(uint64_t interface, struct opal_ipmi_msg *msg,
uint64_t *msg_len);
int64_t opal_i2c_request(uint64_t async_token, uint32_t bus_id,
struct opal_i2c_request *oreq);
+int64_t opal_prd_msg(struct opal_prd_msg *msg);
int64_t opal_flash_read(uint64_t id, uint64_t offset, uint64_t buf,
uint64_t size, uint64_t token);
diff --git a/arch/powerpc/include/uapi/asm/opal-prd.h b/arch/powerpc/include/uapi/asm/opal-prd.h
new file mode 100644
index 0000000..319ff4a
--- /dev/null
+++ b/arch/powerpc/include/uapi/asm/opal-prd.h
@@ -0,0 +1,58 @@
+/*
+ * OPAL Runtime Diagnostics interface driver
+ * Supported on POWERNV platform
+ *
+ * (C) Copyright IBM 2015
+ *
+ * Author: Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>
+ * Author: Jeremy Kerr <jk at ozlabs.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * 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 _UAPI_ASM_POWERPC_OPAL_PRD_H_
+#define _UAPI_ASM_POWERPC_OPAL_PRD_H_
+
+#include <linux/types.h>
+
+/**
+ * The version of the kernel interface of the PRD system. This describes the
+ * interface available for the /dev/opal-prd device. The actual PRD message
+ * layout and content is private to the firmware <--> userspace interface, so
+ * is not covered by this versioning.
+ *
+ * Future interface versions are backwards-compatible; if a later kernel
+ * version is encountered, functionality provided in earlier versions
+ * will work.
+ */
+#define OPAL_PRD_KERNEL_VERSION 1
+
+#define OPAL_PRD_GET_INFO _IOR('o', 0x01, struct opal_prd_info)
+#define OPAL_PRD_SCOM_READ _IOR('o', 0x02, struct opal_prd_scom)
+#define OPAL_PRD_SCOM_WRITE _IOW('o', 0x03, struct opal_prd_scom)
+
+#ifndef __ASSEMBLY__
+
+struct opal_prd_info {
+ __u64 version;
+ __u64 reserved[3];
+};
+
+struct opal_prd_scom {
+ __u64 chip;
+ __u64 addr;
+ __u64 data;
+ __s64 rc;
+};
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _UAPI_ASM_POWERPC_OPAL_PRD_H */
diff --git a/arch/powerpc/platforms/powernv/Kconfig b/arch/powerpc/platforms/powernv/Kconfig
index 4b044d8..604190c 100644
--- a/arch/powerpc/platforms/powernv/Kconfig
+++ b/arch/powerpc/platforms/powernv/Kconfig
@@ -19,3 +19,10 @@ config PPC_POWERNV
select CPU_FREQ_GOV_CONSERVATIVE
select PPC_DOORBELL
default y
+
+config OPAL_PRD
+ tristate 'OPAL PRD driver'
+ depends on PPC_POWERNV
+ help
+ This enables the opal-prd driver, a facility to run processor
+ recovery diagnostics on OpenPower machines
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index 33e44f3..eab1513 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_EEH) += eeh-powernv.o
obj-$(CONFIG_PPC_SCOM) += opal-xscom.o
obj-$(CONFIG_MEMORY_FAILURE) += opal-memory-errors.o
obj-$(CONFIG_TRACEPOINTS) += opal-tracepoints.o
+obj-$(CONFIG_OPAL_PRD) += opal-prd.o
diff --git a/arch/powerpc/platforms/powernv/opal-prd.c b/arch/powerpc/platforms/powernv/opal-prd.c
new file mode 100644
index 0000000..64694dd
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-prd.c
@@ -0,0 +1,445 @@
+/*
+ * OPAL Runtime Diagnostics interface driver
+ * Supported on POWERNV platform
+ *
+ * Copyright IBM Corporation 2015
+ *
+ * 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) "opal-prd: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/poll.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <asm/opal-prd.h>
+#include <asm/opal.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+
+struct opal_prd_msg_queue_item {
+ struct opal_prd_msg_header msg;
+ struct list_head list;
+};
+
+static struct device_node *prd_node;
+static LIST_HEAD(opal_prd_msg_queue);
+static DEFINE_SPINLOCK(opal_prd_msg_queue_lock);
+static DECLARE_WAIT_QUEUE_HEAD(opal_prd_msg_wait);
+static atomic_t prd_usage;
+
+static bool opal_prd_range_is_valid(uint64_t addr, uint64_t size)
+{
+ struct device_node *parent, *node;
+ bool found;
+
+ if (addr + size < addr)
+ return false;
+
+ parent = of_find_node_by_path("/reserved-memory");
+ if (!parent)
+ return false;
+
+ found = false;
+
+ for_each_child_of_node(parent, node) {
+ uint64_t range_addr, range_size, range_end;
+ const __be32 *addrp;
+ const char *label;
+
+ addrp = of_get_address(node, 0, &range_size, NULL);
+
+ range_addr = of_read_number(addrp, 2);
+ range_end = range_addr + range_size;
+
+ label = of_get_property(node, "ibm,prd-label", NULL);
+
+ /* PRD ranges need a label */
+ if (!label)
+ continue;
+
+ if (range_end <= range_addr)
+ continue;
+
+ if (addr >= range_addr && addr + size <= range_end) {
+ found = true;
+ of_node_put(node);
+ break;
+ }
+ }
+
+ of_node_put(parent);
+ return found;
+}
+
+static int opal_prd_open(struct inode *inode, struct file *file)
+{
+ /*
+ * Prevent multiple (separate) processes from concurrent interactions
+ * with the FW PRD channel
+ */
+ if (atomic_xchg(&prd_usage, 1) == 1)
+ return -EBUSY;
+
+ return 0;
+}
+
+/*
+ * opal_prd_mmap - maps firmware-provided ranges into userspace
+ * @file: file structure for the device
+ * @vma: VMA to map the registers into
+ */
+
+static int opal_prd_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ size_t addr, size;
+ int rc;
+
+ pr_devel("opal_prd_mmap(0x%016lx, 0x%016lx, 0x%lx, 0x%lx)\n",
+ vma->vm_start, vma->vm_end, vma->vm_pgoff,
+ vma->vm_flags);
+
+ addr = vma->vm_pgoff << PAGE_SHIFT;
+ size = vma->vm_end - vma->vm_start;
+
+ /* ensure we're mapping within one of the allowable ranges */
+ if (!opal_prd_range_is_valid(addr, size))
+ return -EINVAL;
+
+ vma->vm_page_prot = __pgprot(pgprot_val(phys_mem_access_prot(file,
+ vma->vm_pgoff,
+ size, vma->vm_page_prot))
+ | _PAGE_SPECIAL);
+
+ rc = remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, size,
+ vma->vm_page_prot);
+
+ return rc;
+}
+
+static bool opal_msg_queue_empty(void)
+{
+ unsigned long flags;
+ bool ret;
+
+ spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
+ ret = list_empty(&opal_prd_msg_queue);
+ spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
+
+ return ret;
+}
+
+static unsigned int opal_prd_poll(struct file *file,
+ struct poll_table_struct *wait)
+{
+ poll_wait(file, &opal_prd_msg_wait, wait);
+
+ if (!opal_msg_queue_empty())
+ return POLLIN | POLLRDNORM;
+
+ return 0;
+}
+
+static ssize_t opal_prd_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct opal_prd_msg_queue_item *item;
+ unsigned long flags;
+ ssize_t size, err;
+ int rc;
+
+ /* we need at least a header's worth of data */
+ if (count < sizeof(item->msg))
+ return -EINVAL;
+
+ if (*ppos)
+ return -ESPIPE;
+
+ item = NULL;
+
+ for (;;) {
+
+ spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
+ if (!list_empty(&opal_prd_msg_queue)) {
+ item = list_first_entry(&opal_prd_msg_queue,
+ struct opal_prd_msg_queue_item, list);
+ list_del(&item->list);
+ }
+ spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
+
+ if (item)
+ break;
+
+ if (file->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+
+ rc = wait_event_interruptible(opal_prd_msg_wait,
+ !opal_msg_queue_empty());
+ if (rc)
+ return -EINTR;
+ }
+
+ size = be16_to_cpu(item->msg.size);
+ if (size > count) {
+ err = -EINVAL;
+ goto err_requeue;
+ }
+
+ rc = copy_to_user(buf, &item->msg, size);
+ if (rc) {
+ err = -EFAULT;
+ goto err_requeue;
+ }
+
+ kfree(item);
+
+ return size;
+
+err_requeue:
+ /* eep! re-queue at the head of the list */
+ spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
+ list_add(&item->list, &opal_prd_msg_queue);
+ spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
+ return err;
+}
+
+static ssize_t opal_prd_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct opal_prd_msg_header hdr;
+ ssize_t size;
+ void *msg;
+ int rc;
+
+ size = sizeof(hdr);
+
+ if (count < size)
+ return -EINVAL;
+
+ /* grab the header */
+ rc = copy_from_user(&hdr, buf, sizeof(hdr));
+ if (rc)
+ return -EFAULT;
+
+ size = be16_to_cpu(hdr.size);
+
+ msg = kmalloc(size, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ rc = copy_from_user(msg, buf, size);
+ if (rc) {
+ size = -EFAULT;
+ goto out_free;
+ }
+
+ rc = opal_prd_msg(msg);
+ if (rc) {
+ pr_warn("write: opal_prd_msg returned %d\n", rc);
+ size = -EIO;
+ }
+
+out_free:
+ kfree(msg);
+
+ return size;
+}
+
+static int opal_prd_release(struct inode *inode, struct file *file)
+{
+ struct opal_prd_msg_header msg;
+
+ msg.size = cpu_to_be16(sizeof(msg));
+ msg.type = OPAL_PRD_MSG_TYPE_FINI;
+
+ opal_prd_msg((struct opal_prd_msg *)&msg);
+
+ atomic_xchg(&prd_usage, 0);
+
+ return 0;
+}
+
+static long opal_prd_ioctl(struct file *file, unsigned int cmd,
+ unsigned long param)
+{
+ struct opal_prd_info info;
+ struct opal_prd_scom scom;
+ int rc = 0;
+
+ switch (cmd) {
+ case OPAL_PRD_GET_INFO:
+ memset(&info, 0, sizeof(info));
+ info.version = OPAL_PRD_KERNEL_VERSION;
+ rc = copy_to_user((void __user *)param, &info, sizeof(info));
+ if (rc)
+ return -EFAULT;
+ break;
+
+ case OPAL_PRD_SCOM_READ:
+ rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
+ if (rc)
+ return -EFAULT;
+
+ scom.rc = opal_xscom_read(scom.chip, scom.addr,
+ (__be64 *)&scom.data);
+ scom.data = be64_to_cpu(scom.data);
+ pr_devel("ioctl SCOM_READ: chip %llx addr %016llx data %016llx rc %lld\n",
+ scom.chip, scom.addr, scom.data, scom.rc);
+
+ rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
+ if (rc)
+ return -EFAULT;
+ break;
+
+ case OPAL_PRD_SCOM_WRITE:
+ rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
+ if (rc)
+ return -EFAULT;
+
+ scom.rc = opal_xscom_write(scom.chip, scom.addr, scom.data);
+ pr_devel("ioctl SCOM_WRITE: chip %llx addr %016llx data %016llx rc %lld\n",
+ scom.chip, scom.addr, scom.data, scom.rc);
+
+ rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
+ if (rc)
+ return -EFAULT;
+ break;
+
+ default:
+ rc = -EINVAL;
+ }
+
+ return rc;
+}
+
+static const struct file_operations opal_prd_fops = {
+ .open = opal_prd_open,
+ .mmap = opal_prd_mmap,
+ .poll = opal_prd_poll,
+ .read = opal_prd_read,
+ .write = opal_prd_write,
+ .unlocked_ioctl = opal_prd_ioctl,
+ .release = opal_prd_release,
+ .owner = THIS_MODULE,
+};
+
+static struct miscdevice opal_prd_dev = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "opal-prd",
+ .fops = &opal_prd_fops,
+};
+
+/* opal interface */
+static int opal_prd_msg_notifier(struct notifier_block *nb,
+ unsigned long msg_type, void *_msg)
+{
+ struct opal_prd_msg_queue_item *item;
+ struct opal_prd_msg_header *hdr;
+ struct opal_msg *msg = _msg;
+ unsigned long flags;
+ int size;
+
+ if (msg_type != OPAL_MSG_PRD)
+ return 0;
+
+ /* Calculate total size of the item we need to store. The 'size' field
+ * in the header includes the header itself. */
+ hdr = (void *)msg->params;
+ size = (sizeof(*item) - sizeof(item->msg)) + be16_to_cpu(hdr->size);
+
+ item = kzalloc(size, GFP_ATOMIC);
+ if (!item)
+ return -ENOMEM;
+
+ memcpy(&item->msg, msg->params, size);
+
+ spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
+ list_add_tail(&item->list, &opal_prd_msg_queue);
+ spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
+
+ wake_up_interruptible(&opal_prd_msg_wait);
+
+ return 0;
+}
+
+static struct notifier_block opal_prd_event_nb = {
+ .notifier_call = opal_prd_msg_notifier,
+ .next = NULL,
+ .priority = 0,
+};
+
+static int opal_prd_probe(struct platform_device *pdev)
+{
+ int rc;
+
+ if (!pdev || !pdev->dev.of_node)
+ return -ENODEV;
+
+ /* We should only have one prd driver instance per machine; ensure
+ * that we only get a valid probe on a single OF node.
+ */
+ if (prd_node)
+ return -EBUSY;
+
+ prd_node = pdev->dev.of_node;
+
+ rc = opal_message_notifier_register(OPAL_MSG_PRD, &opal_prd_event_nb);
+ if (rc) {
+ pr_err("Couldn't register event notifier\n");
+ return rc;
+ }
+
+ rc = misc_register(&opal_prd_dev);
+ if (rc) {
+ pr_err("failed to register miscdev\n");
+ opal_message_notifier_unregister(OPAL_MSG_PRD,
+ &opal_prd_event_nb);
+ return rc;
+ }
+
+ return 0;
+}
+
+static int opal_prd_remove(struct platform_device *pdev)
+{
+ misc_deregister(&opal_prd_dev);
+ opal_message_notifier_unregister(OPAL_MSG_PRD, &opal_prd_event_nb);
+ return 0;
+}
+
+static const struct of_device_id opal_prd_match[] = {
+ { .compatible = "ibm,opal-prd" },
+ { },
+};
+
+static struct platform_driver opal_prd_driver = {
+ .driver = {
+ .name = "opal-prd",
+ .owner = THIS_MODULE,
+ .of_match_table = opal_prd_match,
+ },
+ .probe = opal_prd_probe,
+ .remove = opal_prd_remove,
+};
+
+module_platform_driver(opal_prd_driver);
+
+MODULE_DEVICE_TABLE(of, opal_prd_match);
+MODULE_DESCRIPTION("PowerNV OPAL runtime diagnostic driver");
+MODULE_LICENSE("GPL");
+
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index a7ade94..77644fa 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -295,3 +295,4 @@ OPAL_CALL(opal_i2c_request, OPAL_I2C_REQUEST);
OPAL_CALL(opal_flash_read, OPAL_FLASH_READ);
OPAL_CALL(opal_flash_write, OPAL_FLASH_WRITE);
OPAL_CALL(opal_flash_erase, OPAL_FLASH_ERASE);
+OPAL_CALL(opal_prd_msg, OPAL_PRD_MSG);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index b40624d..400fe45 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -829,9 +829,10 @@ static int __init opal_init(void)
opal_msglog_init();
}
- /* Initialize platform devices: IPMI backend & flash interface */
+ /* Initialize platform devices: IPMI backend, PRD & flash interface */
opal_pdev_init(opal_node, "ibm,opal-ipmi");
opal_pdev_init(opal_node, "ibm,opal-flash");
+ opal_pdev_init(opal_node, "ibm,opal-prd");
return 0;
}
@@ -876,6 +877,7 @@ EXPORT_SYMBOL_GPL(opal_ipmi_recv);
EXPORT_SYMBOL_GPL(opal_flash_read);
EXPORT_SYMBOL_GPL(opal_flash_write);
EXPORT_SYMBOL_GPL(opal_flash_erase);
+EXPORT_SYMBOL_GPL(opal_prd_msg);
/* Convert a region of vmalloc memory to an opal sg list */
struct opal_sg_list *opal_vmalloc_to_sg_list(void *vmalloc_addr,
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