diff options
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-xscom.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-xscom.c | 213 |
1 files changed, 141 insertions, 72 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-xscom.c b/arch/powerpc/platforms/powernv/opal-xscom.c index 66430eebe869..fd510d961b8c 100644 --- a/arch/powerpc/platforms/powernv/opal-xscom.c +++ b/arch/powerpc/platforms/powernv/opal-xscom.c @@ -1,7 +1,10 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* - * PowerNV LPC bus handling. + * PowerNV SCOM bus debugfs interface * + * Copyright 2010 Benjamin Herrenschmidt, IBM Corp + * <benh@kernel.crashing.org> + * and David Gibson, IBM Corporation. * Copyright 2013 IBM Corp. */ @@ -10,62 +13,13 @@ #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 <asm/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) { @@ -98,39 +52,154 @@ 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); |