From: Andrew Donnellan Date: Thu, 9 May 2019 05:11:17 +0000 (+1000) Subject: powerpc/powernv: Get rid of old scom_controller abstraction X-Git-Tag: v5.15~5474^2~240 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bfd2f0d49aef8abfe6bf58f12719f39912993cc6;p=platform%2Fkernel%2Flinux-starfive.git powerpc/powernv: Get rid of old scom_controller abstraction 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. Signed-off-by: Andrew Donnellan Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190509051119.7694-3-ajd@linux.ibm.com --- diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile index 4b16441..69a3aef 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 3f48ee6..cb172af 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 + * + * and David Gibson, IBM Corporation. * Copyright 2013 IBM Corp. */ @@ -10,63 +13,13 @@ #include #include #include +#include #include #include #include - -#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 +#include static u64 opal_scom_unmangle(u64 addr) { @@ -99,39 +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); diff --git a/arch/powerpc/platforms/powernv/scom.c b/arch/powerpc/platforms/powernv/scom.c deleted file mode 100644 index acd6968..0000000 --- a/arch/powerpc/platforms/powernv/scom.c +++ /dev/null @@ -1,157 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright 2010 Benjamin Herrenschmidt, IBM Corp - * - * and David Gibson, IBM Corporation. - */ - -#include -#include -#include -#include -#include -#include - -#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 9827a66..0000000 --- a/arch/powerpc/platforms/powernv/scom.h +++ /dev/null @@ -1,120 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * Copyright 2010 Benjamin Herrenschmidt, IBM Corp - * - * and David Gibson, IBM Corporation. - */ - -#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 */