[PATCH v2 3/5] powerpc/powernv: Get rid of old scom_controller abstraction
Andrew Donnellan
ajd at linux.ibm.com
Thu May 9 15:11:17 AEST 2019
Once upon a time, the SCOM access code was used by the WSP platform as well
as powernv. Thus it made sense to have a generic SCOM access interface to
abstract between different platforms.
Now that it's just powernv, with no other platforms currently on the
horizon, let's rip out scom_controller and make everything much simpler and
more direct.
While we're here, fix up the comment block at the top and add a SPDX
header.
Signed-off-by: Andrew Donnellan <ajd at linux.ibm.com>
---
v1->v2:
- new patch
---
arch/powerpc/platforms/powernv/Makefile | 2 +-
arch/powerpc/platforms/powernv/opal-xscom.c | 215 +++++++++++++-------
arch/powerpc/platforms/powernv/scom.c | 170 ----------------
arch/powerpc/platforms/powernv/scom.h | 133 ------------
4 files changed, 143 insertions(+), 377 deletions(-)
delete mode 100644 arch/powerpc/platforms/powernv/scom.c
delete mode 100644 arch/powerpc/platforms/powernv/scom.h
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index 4b1644150135..69a3aefa905b 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -4,7 +4,6 @@ obj-y += idle.o opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
obj-y += rng.o opal-elog.o opal-dump.o opal-sysparam.o opal-sensor.o
obj-y += opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
obj-y += opal-kmsg.o opal-powercap.o opal-psr.o opal-sensor-groups.o
-obj-y += opal-xscom.o scom.o
obj-$(CONFIG_SMP) += smp.o subcore.o subcore-asm.o
obj-$(CONFIG_PCI) += pci.o pci-ioda.o npu-dma.o pci-ioda-tce.o
@@ -16,3 +15,4 @@ obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
obj-$(CONFIG_PPC_MEMTRACE) += memtrace.o
obj-$(CONFIG_PPC_VAS) += vas.o vas-window.o vas-debug.o
obj-$(CONFIG_OCXL_BASE) += ocxl.o
+obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
diff --git a/arch/powerpc/platforms/powernv/opal-xscom.c b/arch/powerpc/platforms/powernv/opal-xscom.c
index 66337d92cb63..e16b0e346d7e 100644
--- a/arch/powerpc/platforms/powernv/opal-xscom.c
+++ b/arch/powerpc/platforms/powernv/opal-xscom.c
@@ -1,6 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0+
/*
- * PowerNV LPC bus handling.
+ * PowerNV SCOM bus debugfs interface
*
+ * Copyright 2010 Benjamin Herrenschmidt, IBM Corp
+ * <benh at kernel.crashing.org>
+ * and David Gibson, IBM Corporation.
* Copyright 2013 IBM Corp.
*
* This program is free software; you can redistribute it and/or
@@ -14,63 +18,13 @@
#include <linux/bug.h>
#include <linux/gfp.h>
#include <linux/slab.h>
+#include <linux/uaccess.h>
#include <asm/machdep.h>
#include <asm/firmware.h>
#include <asm/opal.h>
-
-#include "scom.h"
-
-/*
- * We could probably fit that inside the scom_map_t
- * which is a void* after all but it's really too ugly
- * so let's kmalloc it for now
- */
-struct opal_scom_map {
- uint32_t chip;
- uint64_t addr;
-};
-
-static scom_map_t opal_scom_map(struct device_node *dev, u64 reg, u64 count)
-{
- struct opal_scom_map *m;
- const __be32 *gcid;
-
- if (!of_get_property(dev, "scom-controller", NULL)) {
- pr_err("%s: device %pOF is not a SCOM controller\n",
- __func__, dev);
- return SCOM_MAP_INVALID;
- }
- gcid = of_get_property(dev, "ibm,chip-id", NULL);
- if (!gcid) {
- pr_err("%s: device %pOF has no ibm,chip-id\n",
- __func__, dev);
- return SCOM_MAP_INVALID;
- }
- m = kmalloc(sizeof(*m), GFP_KERNEL);
- if (!m)
- return NULL;
- m->chip = be32_to_cpup(gcid);
- m->addr = reg;
-
- return (scom_map_t)m;
-}
-
-static void opal_scom_unmap(scom_map_t map)
-{
- kfree(map);
-}
-
-static int opal_xscom_err_xlate(int64_t rc)
-{
- switch(rc) {
- case 0:
- return 0;
- /* Add more translations if necessary */
- default:
- return -EIO;
- }
-}
+#include <asm/debugfs.h>
+#include <asm/prom.h>
static u64 opal_scom_unmangle(u64 addr)
{
@@ -103,39 +57,154 @@ static u64 opal_scom_unmangle(u64 addr)
return addr;
}
-static int opal_scom_read(scom_map_t map, u64 reg, u64 *value)
+static int opal_scom_read(uint32_t chip, uint64_t addr, u64 reg, u64 *value)
{
- struct opal_scom_map *m = map;
int64_t rc;
__be64 v;
- reg = opal_scom_unmangle(m->addr + reg);
- rc = opal_xscom_read(m->chip, reg, (__be64 *)__pa(&v));
+ reg = opal_scom_unmangle(addr + reg);
+ rc = opal_xscom_read(chip, reg, (__be64 *)__pa(&v));
+ if (rc) {
+ *value = 0xfffffffffffffffful;
+ return -EIO;
+ }
*value = be64_to_cpu(v);
- return opal_xscom_err_xlate(rc);
+ return 0;
}
-static int opal_scom_write(scom_map_t map, u64 reg, u64 value)
+static int opal_scom_write(uint32_t chip, uint64_t addr, u64 reg, u64 value)
{
- struct opal_scom_map *m = map;
int64_t rc;
- reg = opal_scom_unmangle(m->addr + reg);
- rc = opal_xscom_write(m->chip, reg, value);
- return opal_xscom_err_xlate(rc);
+ reg = opal_scom_unmangle(addr + reg);
+ rc = opal_xscom_write(chip, reg, value);
+ if (rc)
+ return -EIO;
+ return 0;
+}
+
+struct scom_debug_entry {
+ u32 chip;
+ struct debugfs_blob_wrapper path;
+ char name[16];
+};
+
+static ssize_t scom_debug_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ struct scom_debug_entry *ent = filp->private_data;
+ u64 __user *ubuf64 = (u64 __user *)ubuf;
+ loff_t off = *ppos;
+ ssize_t done = 0;
+ u64 reg, reg_base, reg_cnt, val;
+ int rc;
+
+ if (off < 0 || (off & 7) || (count & 7))
+ return -EINVAL;
+ reg_base = off >> 3;
+ reg_cnt = count >> 3;
+
+ for (reg = 0; reg < reg_cnt; reg++) {
+ rc = opal_scom_read(ent->chip, reg_base, reg, &val);
+ if (!rc)
+ rc = put_user(val, ubuf64);
+ if (rc) {
+ if (!done)
+ done = rc;
+ break;
+ }
+ ubuf64++;
+ *ppos += 8;
+ done += 8;
+ }
+ return done;
+}
+
+static ssize_t scom_debug_write(struct file* filp, const char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ struct scom_debug_entry *ent = filp->private_data;
+ u64 __user *ubuf64 = (u64 __user *)ubuf;
+ loff_t off = *ppos;
+ ssize_t done = 0;
+ u64 reg, reg_base, reg_cnt, val;
+ int rc;
+
+ if (off < 0 || (off & 7) || (count & 7))
+ return -EINVAL;
+ reg_base = off >> 3;
+ reg_cnt = count >> 3;
+
+ for (reg = 0; reg < reg_cnt; reg++) {
+ rc = get_user(val, ubuf64);
+ if (!rc)
+ rc = opal_scom_write(ent->chip, reg_base, reg, val);
+ if (rc) {
+ if (!done)
+ done = rc;
+ break;
+ }
+ ubuf64++;
+ done += 8;
+ }
+ return done;
}
-static const struct scom_controller opal_scom_controller = {
- .map = opal_scom_map,
- .unmap = opal_scom_unmap,
- .read = opal_scom_read,
- .write = opal_scom_write
+static const struct file_operations scom_debug_fops = {
+ .read = scom_debug_read,
+ .write = scom_debug_write,
+ .open = simple_open,
+ .llseek = default_llseek,
};
-static int opal_xscom_init(void)
+static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
+ int chip)
{
- if (firmware_has_feature(FW_FEATURE_OPAL))
- scom_init(&opal_scom_controller);
+ struct scom_debug_entry *ent;
+ struct dentry *dir;
+
+ ent = kzalloc(sizeof(*ent), GFP_KERNEL);
+ if (!ent)
+ return -ENOMEM;
+
+ ent->chip = chip;
+ snprintf(ent->name, 16, "%08x", chip);
+ ent->path.data = (void*)kasprintf(GFP_KERNEL, "%pOF", dn);
+ ent->path.size = strlen((char *)ent->path.data);
+
+ dir = debugfs_create_dir(ent->name, root);
+ if (!dir) {
+ kfree(ent->path.data);
+ kfree(ent);
+ return -1;
+ }
+
+ debugfs_create_blob("devspec", 0400, dir, &ent->path);
+ debugfs_create_file("access", 0600, dir, ent, &scom_debug_fops);
+
return 0;
}
-machine_arch_initcall(powernv, opal_xscom_init);
+
+static int scom_debug_init(void)
+{
+ struct device_node *dn;
+ struct dentry *root;
+ int chip, rc;
+
+ if (!firmware_has_feature(FW_FEATURE_OPAL))
+ return 0;
+
+ root = debugfs_create_dir("scom", powerpc_debugfs_root);
+ if (!root)
+ return -1;
+
+ rc = 0;
+ for_each_node_with_property(dn, "scom-controller") {
+ chip = of_get_ibm_chip_id(dn);
+ WARN_ON(chip == -1);
+ rc |= scom_debug_init_one(root, dn, chip);
+ }
+
+ return rc;
+}
+device_initcall(scom_debug_init);
diff --git a/arch/powerpc/platforms/powernv/scom.c b/arch/powerpc/platforms/powernv/scom.c
deleted file mode 100644
index 288580e5fdfe..000000000000
--- a/arch/powerpc/platforms/powernv/scom.c
+++ /dev/null
@@ -1,170 +0,0 @@
-/*
- * Copyright 2010 Benjamin Herrenschmidt, IBM Corp
- * <benh at kernel.crashing.org>
- * and David Gibson, IBM Corporation.
- *
- * 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 of the License, 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <linux/export.h>
-#include <asm/debugfs.h>
-#include <asm/prom.h>
-#include <linux/uaccess.h>
-
-#include "scom.h"
-
-const struct scom_controller *scom_controller;
-
-#ifdef CONFIG_SCOM_DEBUGFS
-struct scom_debug_entry {
- struct device_node *dn;
- struct debugfs_blob_wrapper path;
- char name[16];
-};
-
-static ssize_t scom_debug_read(struct file *filp, char __user *ubuf,
- size_t count, loff_t *ppos)
-{
- struct scom_debug_entry *ent = filp->private_data;
- u64 __user *ubuf64 = (u64 __user *)ubuf;
- loff_t off = *ppos;
- ssize_t done = 0;
- u64 reg, reg_cnt, val;
- scom_map_t map;
- int rc;
-
- if (off < 0 || (off & 7) || (count & 7))
- return -EINVAL;
- reg = off >> 3;
- reg_cnt = count >> 3;
-
- map = scom_map(ent->dn, reg, reg_cnt);
- if (!scom_map_ok(map))
- return -ENXIO;
-
- for (reg = 0; reg < reg_cnt; reg++) {
- rc = scom_read(map, reg, &val);
- if (!rc)
- rc = put_user(val, ubuf64);
- if (rc) {
- if (!done)
- done = rc;
- break;
- }
- ubuf64++;
- *ppos += 8;
- done += 8;
- }
- scom_unmap(map);
- return done;
-}
-
-static ssize_t scom_debug_write(struct file* filp, const char __user *ubuf,
- size_t count, loff_t *ppos)
-{
- struct scom_debug_entry *ent = filp->private_data;
- u64 __user *ubuf64 = (u64 __user *)ubuf;
- loff_t off = *ppos;
- ssize_t done = 0;
- u64 reg, reg_cnt, val;
- scom_map_t map;
- int rc;
-
- if (off < 0 || (off & 7) || (count & 7))
- return -EINVAL;
- reg = off >> 3;
- reg_cnt = count >> 3;
-
- map = scom_map(ent->dn, reg, reg_cnt);
- if (!scom_map_ok(map))
- return -ENXIO;
-
- for (reg = 0; reg < reg_cnt; reg++) {
- rc = get_user(val, ubuf64);
- if (!rc)
- rc = scom_write(map, reg, val);
- if (rc) {
- if (!done)
- done = rc;
- break;
- }
- ubuf64++;
- done += 8;
- }
- scom_unmap(map);
- return done;
-}
-
-static const struct file_operations scom_debug_fops = {
- .read = scom_debug_read,
- .write = scom_debug_write,
- .open = simple_open,
- .llseek = default_llseek,
-};
-
-static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
- int i)
-{
- struct scom_debug_entry *ent;
- struct dentry *dir;
-
- ent = kzalloc(sizeof(*ent), GFP_KERNEL);
- if (!ent)
- return -ENOMEM;
-
- ent->dn = of_node_get(dn);
- snprintf(ent->name, 16, "%08x", i);
- ent->path.data = (void*)kasprintf(GFP_KERNEL, "%pOF", dn);
- ent->path.size = strlen((char *)ent->path.data);
-
- dir = debugfs_create_dir(ent->name, root);
- if (!dir) {
- of_node_put(dn);
- kfree(ent->path.data);
- kfree(ent);
- return -1;
- }
-
- debugfs_create_blob("devspec", 0400, dir, &ent->path);
- debugfs_create_file("access", 0600, dir, ent, &scom_debug_fops);
-
- return 0;
-}
-
-static int scom_debug_init(void)
-{
- struct device_node *dn;
- struct dentry *root;
- int i, rc;
-
- root = debugfs_create_dir("scom", powerpc_debugfs_root);
- if (!root)
- return -1;
-
- i = rc = 0;
- for_each_node_with_property(dn, "scom-controller") {
- int id = of_get_ibm_chip_id(dn);
- if (id == -1)
- id = i;
- rc |= scom_debug_init_one(root, dn, id);
- i++;
- }
-
- return rc;
-}
-device_initcall(scom_debug_init);
-#endif /* CONFIG_SCOM_DEBUGFS */
diff --git a/arch/powerpc/platforms/powernv/scom.h b/arch/powerpc/platforms/powernv/scom.h
deleted file mode 100644
index 2c72f7fc8726..000000000000
--- a/arch/powerpc/platforms/powernv/scom.h
+++ /dev/null
@@ -1,133 +0,0 @@
-/*
- * Copyright 2010 Benjamin Herrenschmidt, IBM Corp
- * <benh at kernel.crashing.org>
- * and David Gibson, IBM Corporation.
- *
- * 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 of the License, 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#ifndef _SCOM_H
-#define _SCOM_H
-
-/*
- * The SCOM bus is a sideband bus used for accessing various internal
- * registers of the processor or the chipset. The implementation details
- * differ between processors and platforms, and the access method as
- * well.
- *
- * This API allows to "map" ranges of SCOM register numbers associated
- * with a given SCOM controller. The later must be represented by a
- * device node, though some implementations might support NULL if there
- * is no possible ambiguity
- *
- * Then, scom_read/scom_write can be used to accesses registers inside
- * that range. The argument passed is a register number relative to
- * the beginning of the range mapped.
- */
-
-typedef void *scom_map_t;
-
-/* Value for an invalid SCOM map */
-#define SCOM_MAP_INVALID (NULL)
-
-/* The scom_controller data structure is what the platform passes
- * to the core code in scom_init, it provides the actual implementation
- * of all the SCOM functions
- */
-struct scom_controller {
- scom_map_t (*map)(struct device_node *ctrl_dev, u64 reg, u64 count);
- void (*unmap)(scom_map_t map);
-
- int (*read)(scom_map_t map, u64 reg, u64 *value);
- int (*write)(scom_map_t map, u64 reg, u64 value);
-};
-
-extern const struct scom_controller *scom_controller;
-
-/**
- * scom_init - Initialize the SCOM backend, called by the platform
- * @controller: The platform SCOM controller
- */
-static inline void scom_init(const struct scom_controller *controller)
-{
- scom_controller = controller;
-}
-
-/**
- * scom_map_ok - Test is a SCOM mapping is successful
- * @map: The result of scom_map to test
- */
-static inline int scom_map_ok(scom_map_t map)
-{
- return map != SCOM_MAP_INVALID;
-}
-
-/**
- * scom_map - Map a block of SCOM registers
- * @ctrl_dev: Device node of the SCOM controller
- * some implementations allow NULL here
- * @reg: first SCOM register to map
- * @count: Number of SCOM registers to map
- */
-
-static inline scom_map_t scom_map(struct device_node *ctrl_dev,
- u64 reg, u64 count)
-{
- return scom_controller->map(ctrl_dev, reg, count);
-}
-
-/**
- * scom_unmap - Unmap a block of SCOM registers
- * @map: Result of scom_map is to be unmapped
- */
-static inline void scom_unmap(scom_map_t map)
-{
- if (scom_map_ok(map))
- scom_controller->unmap(map);
-}
-
-/**
- * scom_read - Read a SCOM register
- * @map: Result of scom_map
- * @reg: Register index within that map
- * @value: Updated with the value read
- *
- * Returns 0 (success) or a negative error code
- */
-static inline int scom_read(scom_map_t map, u64 reg, u64 *value)
-{
- int rc;
-
- rc = scom_controller->read(map, reg, value);
- if (rc)
- *value = 0xfffffffffffffffful;
- return rc;
-}
-
-/**
- * scom_write - Write to a SCOM register
- * @map: Result of scom_map
- * @reg: Register index within that map
- * @value: Value to write
- *
- * Returns 0 (success) or a negative error code
- */
-static inline int scom_write(scom_map_t map, u64 reg, u64 value)
-{
- return scom_controller->write(map, reg, value);
-}
-
-
-#endif /* _SCOM_H */
--
2.20.1
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