Commit 5027a34a authored by Eddie James's avatar Eddie James Committed by Joel Stanley
Browse files

hwmon: (occ) Provide the SBEFIFO FFDC in binary sysfs 



Save any FFDC provided by the OCC driver, and provide it to userspace
through a binary sysfs entry. Notify userspace pollers when there is an
error too.

Signed-off-by: default avatarEddie James <eajames@linux.ibm.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20211019205307.36946-5-eajames@linux.ibm.com


Signed-off-by: default avatarJoel Stanley <joel@jms.id.au>
parent 4cf400e1

drivers/hwmon/occ/p9_sbe.c

+85 −1
Original line number Diff line number Diff line
@@ -4,18 +4,79 @@ 
#include <linux/device.h>

#include <linux/errno.h>

#include <linux/fsi-occ.h>

#include <linux/mm.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/platform_device.h>

#include <linux/string.h>

#include <linux/sysfs.h>



#include "common.h"



struct p9_sbe_occ {

	struct occ occ;

	bool sbe_error;

	void *ffdc;

	size_t ffdc_len;

	size_t ffdc_size;

	struct mutex sbe_error_lock;	/* lock access to ffdc data */

	struct device *sbe;

};



#define to_p9_sbe_occ(x)	container_of((x), struct p9_sbe_occ, occ)



static ssize_t ffdc_read(struct file *filp, struct kobject *kobj,

			 struct bin_attribute *battr, char *buf, loff_t pos,

			 size_t count)

{

	ssize_t rc = 0;

	struct occ *occ = dev_get_drvdata(kobj_to_dev(kobj));

	struct p9_sbe_occ *ctx = to_p9_sbe_occ(occ);



	mutex_lock(&ctx->sbe_error_lock);

	if (ctx->sbe_error) {

		rc = memory_read_from_buffer(buf, count, &pos, ctx->ffdc,

					     ctx->ffdc_len);

		if (pos >= ctx->ffdc_len)

			ctx->sbe_error = false;

	}

	mutex_unlock(&ctx->sbe_error_lock);



	return rc;

}

static BIN_ATTR_RO(ffdc, OCC_MAX_RESP_WORDS * 4);



static bool p9_sbe_occ_save_ffdc(struct p9_sbe_occ *ctx, const void *resp,

				 size_t resp_len)

{

	bool notify = false;



	mutex_lock(&ctx->sbe_error_lock);

	if (!ctx->sbe_error) {

		if (resp_len > ctx->ffdc_size) {

			if (ctx->ffdc)

				kvfree(ctx->ffdc);

			ctx->ffdc = kvmalloc(resp_len, GFP_KERNEL);

			if (!ctx->ffdc) {

				ctx->ffdc_len = 0;

				ctx->ffdc_size = 0;

				goto done;

			}



			ctx->ffdc_size = resp_len;

		}



		notify = true;

		ctx->sbe_error = true;

		ctx->ffdc_len = resp_len;

		memcpy(ctx->ffdc, resp, resp_len);

	}



done:

	mutex_unlock(&ctx->sbe_error_lock);

	return notify;

}



static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd, size_t len)

{

	struct occ_response *resp = &occ->resp;
@@ -24,8 +85,15 @@ static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd, size_t len) 
	int rc;



	rc = fsi_occ_submit(ctx->sbe, cmd, len, resp, &resp_len);

	if (rc < 0)

	if (rc < 0) {

		if (resp_len) {

			if (p9_sbe_occ_save_ffdc(ctx, resp, resp_len))

				sysfs_notify(&occ->bus_dev->kobj, NULL,

					     bin_attr_ffdc.attr.name);

		}



		return rc;

	}



	switch (resp->return_status) {

	case OCC_RESP_CMD_IN_PRG:
@@ -65,6 +133,8 @@ static int p9_sbe_occ_probe(struct platform_device *pdev) 
	if (!ctx)

		return -ENOMEM;



	mutex_init(&ctx->sbe_error_lock);



	ctx->sbe = pdev->dev.parent;

	occ = &ctx->occ;

	occ->bus_dev = &pdev->dev;
@@ -78,6 +148,15 @@ static int p9_sbe_occ_probe(struct platform_device *pdev) 
	if (rc == -ESHUTDOWN)

		rc = -ENODEV;	/* Host is shutdown, don't spew errors */



	if (!rc) {

		rc = device_create_bin_file(occ->bus_dev, &bin_attr_ffdc);

		if (rc) {

			dev_warn(occ->bus_dev,

				 "failed to create SBE error ffdc file\n");

			rc = 0;

		}

	}



	return rc;

}
@@ -86,9 +165,14 @@ static int p9_sbe_occ_remove(struct platform_device *pdev) 
	struct occ *occ = platform_get_drvdata(pdev);

	struct p9_sbe_occ *ctx = to_p9_sbe_occ(occ);



	device_remove_bin_file(occ->bus_dev, &bin_attr_ffdc);



	ctx->sbe = NULL;

	occ_shutdown(occ);



	if (ctx->ffdc)

		kvfree(ctx->ffdc);



	return 0;

}