[RFC] powerpc/pseries: delete scanlog

* [RFC] powerpc/pseries: delete scanlog
@ 2021-05-03 17:18 Nathan Lynch
  2021-05-03 20:38 ` Tyrel Datwyler
  0 siblings, 1 reply; 2+ messages in thread
From: Nathan Lynch @ 2021-05-03 17:18 UTC (permalink / raw)
  To: linuxppc-dev

A commit from 2008 says this driver was relevant only for "older
systems", and currently supported hardware doesn't have this
facility. Get rid of it.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
---
 arch/powerpc/configs/ppc64_defconfig     |   1 -
 arch/powerpc/configs/pseries_defconfig   |   1 -
 arch/powerpc/platforms/pseries/Kconfig   |   4 -
 arch/powerpc/platforms/pseries/Makefile  |   1 -
 arch/powerpc/platforms/pseries/scanlog.c | 195 -----------------------
 5 files changed, 202 deletions(-)
 delete mode 100644 arch/powerpc/platforms/pseries/scanlog.c

diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig
index 701811c91a6f..acf13b4917c4 100644
--- a/arch/powerpc/configs/ppc64_defconfig
+++ b/arch/powerpc/configs/ppc64_defconfig
@@ -26,7 +26,6 @@ CONFIG_PPC64=y
 CONFIG_NR_CPUS=2048
 CONFIG_PPC_SPLPAR=y
 CONFIG_DTL=y
-CONFIG_SCANLOG=m
 CONFIG_PPC_SMLPAR=y
 CONFIG_IBMEBUS=y
 CONFIG_PPC_SVM=y
diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig
index 50168dde4ea5..d120321e4eea 100644
--- a/arch/powerpc/configs/pseries_defconfig
+++ b/arch/powerpc/configs/pseries_defconfig
@@ -38,7 +38,6 @@ CONFIG_MODULE_SRCVERSION_ALL=y
 CONFIG_PARTITION_ADVANCED=y
 CONFIG_PPC_SPLPAR=y
 CONFIG_DTL=y
-CONFIG_SCANLOG=m
 CONFIG_PPC_SMLPAR=y
 CONFIG_IBMEBUS=y
 CONFIG_PAPR_SCM=m
diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index 5e037df2a3a1..bf9b612a929b 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -61,10 +61,6 @@ config PSERIES_ENERGY
 	  Provides: /sys/devices/system/cpu/pseries_(de)activation_hint_list
 	  and /sys/devices/system/cpu/cpuN/pseries_(de)activation_hint
 
-config SCANLOG
-	tristate "Scanlog dump interface"
-	depends on RTAS_PROC && PPC_PSERIES
-
 config IO_EVENT_IRQ
 	bool "IO Event Interrupt support"
 	depends on PPC_PSERIES
diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
index c8a2b0b05ac0..754d1102de08 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -8,7 +8,6 @@ obj-y			:= lpar.o hvCall.o nvram.o reconfig.o \
 			   firmware.o power.o dlpar.o mobility.o rng.o \
 			   pci.o pci_dlpar.o eeh_pseries.o msi.o
 obj-$(CONFIG_SMP)	+= smp.o
-obj-$(CONFIG_SCANLOG)	+= scanlog.o
 obj-$(CONFIG_KEXEC_CORE)	+= kexec.o
 obj-$(CONFIG_PSERIES_ENERGY)	+= pseries_energy.o
 
diff --git a/arch/powerpc/platforms/pseries/scanlog.c b/arch/powerpc/platforms/pseries/scanlog.c
deleted file mode 100644
index 2879c4f0ceb7..000000000000
--- a/arch/powerpc/platforms/pseries/scanlog.c
+++ /dev/null
@@ -1,195 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- *  c 2001 PPC 64 Team, IBM Corp
- *
- * scan-log-data driver for PPC64  Todd Inglett <tinglett@vnet.ibm.com>
- *
- * When ppc64 hardware fails the service processor dumps internal state
- * of the system.  After a reboot the operating system can access a dump
- * of this data using this driver.  A dump exists if the device-tree
- * /chosen/ibm,scan-log-data property exists.
- *
- * This driver exports /proc/powerpc/scan-log-dump which can be read.
- * The driver supports only sequential reads.
- *
- * The driver looks at a write to the driver for the single word "reset".
- * If given, the driver will reset the scanlog so the platform can free it.
- */
-
-#include <linux/module.h>
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/proc_fs.h>
-#include <linux/init.h>
-#include <linux/delay.h>
-#include <linux/slab.h>
-#include <linux/uaccess.h>
-#include <asm/rtas.h>
-#include <asm/prom.h>
-
-#define MODULE_VERS "1.0"
-#define MODULE_NAME "scanlog"
-
-/* Status returns from ibm,scan-log-dump */
-#define SCANLOG_COMPLETE 0
-#define SCANLOG_HWERROR -1
-#define SCANLOG_CONTINUE 1
-
-
-static unsigned int ibm_scan_log_dump;			/* RTAS token */
-static unsigned int *scanlog_buffer;			/* The data buffer */
-
-static ssize_t scanlog_read(struct file *file, char __user *buf,
-			    size_t count, loff_t *ppos)
-{
-	unsigned int *data = scanlog_buffer;
-	int status;
-	unsigned long len, off;
-	unsigned int wait_time;
-
-	if (count > RTAS_DATA_BUF_SIZE)
-		count = RTAS_DATA_BUF_SIZE;
-
-	if (count < 1024) {
-		/* This is the min supported by this RTAS call.  Rather
-		 * than do all the buffering we insist the user code handle
-		 * larger reads.  As long as cp works... :)
-		 */
-		printk(KERN_ERR "scanlog: cannot perform a small read (%ld)\n", count);
-		return -EINVAL;
-	}
-
-	if (!access_ok(buf, count))
-		return -EFAULT;
-
-	for (;;) {
-		wait_time = 500;	/* default wait if no data */
-		spin_lock(&rtas_data_buf_lock);
-		memcpy(rtas_data_buf, data, RTAS_DATA_BUF_SIZE);
-		status = rtas_call(ibm_scan_log_dump, 2, 1, NULL,
-				   (u32) __pa(rtas_data_buf), (u32) count);
-		memcpy(data, rtas_data_buf, RTAS_DATA_BUF_SIZE);
-		spin_unlock(&rtas_data_buf_lock);
-
-		pr_debug("scanlog: status=%d, data[0]=%x, data[1]=%x, " \
-			 "data[2]=%x\n", status, data[0], data[1], data[2]);
-		switch (status) {
-		    case SCANLOG_COMPLETE:
-			pr_debug("scanlog: hit eof\n");
-			return 0;
-		    case SCANLOG_HWERROR:
-			pr_debug("scanlog: hardware error reading data\n");
-			return -EIO;
-		    case SCANLOG_CONTINUE:
-			/* We may or may not have data yet */
-			len = data[1];
-			off = data[2];
-			if (len > 0) {
-				if (copy_to_user(buf, ((char *)data)+off, len))
-					return -EFAULT;
-				return len;
-			}
-			/* Break to sleep default time */
-			break;
-		    default:
-			/* Assume extended busy */
-			wait_time = rtas_busy_delay_time(status);
-			if (!wait_time) {
-				printk(KERN_ERR "scanlog: unknown error " \
-				       "from rtas: %d\n", status);
-				return -EIO;
-			}
-		}
-		/* Apparently no data yet.  Wait and try again. */
-		msleep_interruptible(wait_time);
-	}
-	/*NOTREACHED*/
-}
-
-static ssize_t scanlog_write(struct file * file, const char __user * buf,
-			     size_t count, loff_t *ppos)
-{
-	char stkbuf[20];
-	int status;
-
-	if (count > 19) count = 19;
-	if (copy_from_user (stkbuf, buf, count)) {
-		return -EFAULT;
-	}
-	stkbuf[count] = 0;
-
-	if (buf) {
-		if (strncmp(stkbuf, "reset", 5) == 0) {
-			pr_debug("scanlog: reset scanlog\n");
-			status = rtas_call(ibm_scan_log_dump, 2, 1, NULL, 0, 0);
-			pr_debug("scanlog: rtas returns %d\n", status);
-		}
-	}
-	return count;
-}
-
-static int scanlog_open(struct inode * inode, struct file * file)
-{
-	unsigned int *data = scanlog_buffer;
-
-	if (data[0] != 0) {
-		/* This imperfect test stops a second copy of the
-		 * data (or a reset while data is being copied)
-		 */
-		return -EBUSY;
-	}
-
-	data[0] = 0;	/* re-init so we restart the scan */
-
-	return 0;
-}
-
-static int scanlog_release(struct inode * inode, struct file * file)
-{
-	unsigned int *data = scanlog_buffer;
-
-	data[0] = 0;
-	return 0;
-}
-
-static const struct proc_ops scanlog_proc_ops = {
-	.proc_read	= scanlog_read,
-	.proc_write	= scanlog_write,
-	.proc_open	= scanlog_open,
-	.proc_release	= scanlog_release,
-	.proc_lseek	= noop_llseek,
-};
-
-static int __init scanlog_init(void)
-{
-	struct proc_dir_entry *ent;
-	int err = -ENOMEM;
-
-	ibm_scan_log_dump = rtas_token("ibm,scan-log-dump");
-	if (ibm_scan_log_dump == RTAS_UNKNOWN_SERVICE)
-		return -ENODEV;
-
-	/* Ideally we could allocate a buffer < 4G */
-	scanlog_buffer = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
-	if (!scanlog_buffer)
-		goto err;
-
-	ent = proc_create("powerpc/rtas/scan-log-dump", 0400, NULL,
-			  &scanlog_proc_ops);
-	if (!ent)
-		goto err;
-	return 0;
-err:
-	kfree(scanlog_buffer);
-	return err;
-}
-
-static void __exit scanlog_cleanup(void)
-{
-	remove_proc_entry("powerpc/rtas/scan-log-dump", NULL);
-	kfree(scanlog_buffer);
-}
-
-module_init(scanlog_init);
-module_exit(scanlog_cleanup);
-MODULE_LICENSE("GPL");
-- 
2.30.2


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