On 5/3/21 10:18 AM, Nathan Lynch wrote: > 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.
The only references I could find to scan log dump support are several Power 4+ systems, in particular the IntelliStation POWER 9114 and pSeries 615, which were released in 2003 at the same time this code was originally introduced. Historical Linux commit form February 2003: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=f92e361842d5251e50562b09664082dcbd0548bb IntelliStation and pSeries docs: http://ps-2.retropc.se/basil.holloway/ALL%20PDF/380635.pdf http://ps-2.kev009.com/rs6000/manuals/p/p615-6C3-6E3/6C3_and_6E3_Users_Guide_SA38-0629.pdf Current firmware RTAS implementations have no reference to ibm,scan-log-dump, and a long standing developer for that code has no recollection of its existence. This appears to be a straggler from RPA and Power 4 days. Based on my understanding that we dropped support Power 4 in mainline this looks pretty orphaned to me and a solid candidate for removal barring and insight from someone else that knows better. +1 Feel free to add my RB tag to any non-RFC followup. Reviewed-by: Tyrel Datwyler <tyr...@linux.ibm.com> > > Signed-off-by: Nathan Lynch <nath...@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 <tingl...@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"); >
