--- /dev/null
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ */
+#include <linux/debugfs.h>
+#include <linux/dma-mapping.h>
+#include <linux/uaccess.h>
+
+#include <soc/tegra/bpmp.h>
+#include <soc/tegra/bpmp-abi.h>
+
+struct seqbuf {
+ char *buf;
+ size_t pos;
+ size_t size;
+};
+
+static void seqbuf_init(struct seqbuf *seqbuf, void *buf, size_t size)
+{
+ seqbuf->buf = buf;
+ seqbuf->size = size;
+ seqbuf->pos = 0;
+}
+
+static size_t seqbuf_avail(struct seqbuf *seqbuf)
+{
+ return seqbuf->pos < seqbuf->size ? seqbuf->size - seqbuf->pos : 0;
+}
+
+static size_t seqbuf_status(struct seqbuf *seqbuf)
+{
+ return seqbuf->pos <= seqbuf->size ? 0 : -EOVERFLOW;
+}
+
+static int seqbuf_eof(struct seqbuf *seqbuf)
+{
+ return seqbuf->pos >= seqbuf->size;
+}
+
+static int seqbuf_read(struct seqbuf *seqbuf, void *buf, size_t nbyte)
+{
+ nbyte = min(nbyte, seqbuf_avail(seqbuf));
+ memcpy(buf, seqbuf->buf + seqbuf->pos, nbyte);
+ seqbuf->pos += nbyte;
+ return seqbuf_status(seqbuf);
+}
+
+static int seqbuf_read_u32(struct seqbuf *seqbuf, uint32_t *v)
+{
+ int err;
+
+ err = seqbuf_read(seqbuf, v, 4);
+ *v = le32_to_cpu(*v);
+ return err;
+}
+
+static int seqbuf_read_str(struct seqbuf *seqbuf, const char **str)
+{
+ *str = seqbuf->buf + seqbuf->pos;
+ seqbuf->pos += strnlen(*str, seqbuf_avail(seqbuf));
+ seqbuf->pos++;
+ return seqbuf_status(seqbuf);
+}
+
+static void seqbuf_seek(struct seqbuf *seqbuf, ssize_t offset)
+{
+ seqbuf->pos += offset;
+}
+
+/* map filename in Linux debugfs to corresponding entry in BPMP */
+static const char *get_filename(struct tegra_bpmp *bpmp,
+ const struct file *file, char *buf, int size)
+{
+ char root_path_buf[512];
+ const char *root_path;
+ const char *filename;
+ size_t root_len;
+
+ root_path = dentry_path(bpmp->debugfs_mirror, root_path_buf,
+ sizeof(root_path_buf));
+ if (IS_ERR(root_path))
+ return NULL;
+
+ root_len = strlen(root_path);
+
+ filename = dentry_path(file->f_path.dentry, buf, size);
+ if (IS_ERR(filename))
+ return NULL;
+
+ if (strlen(filename) < root_len ||
+ strncmp(filename, root_path, root_len))
+ return NULL;
+
+ filename += root_len;
+
+ return filename;
+}
+
+static int mrq_debugfs_read(struct tegra_bpmp *bpmp,
+ dma_addr_t name, size_t sz_name,
+ dma_addr_t data, size_t sz_data,
+ size_t *nbytes)
+{
+ struct mrq_debugfs_request req = {
+ .cmd = cpu_to_le32(CMD_DEBUGFS_READ),
+ .fop = {
+ .fnameaddr = cpu_to_le32((uint32_t)name),
+ .fnamelen = cpu_to_le32((uint32_t)sz_name),
+ .dataaddr = cpu_to_le32((uint32_t)data),
+ .datalen = cpu_to_le32((uint32_t)sz_data),
+ },
+ };
+ struct mrq_debugfs_response resp;
+ struct tegra_bpmp_message msg = {
+ .mrq = MRQ_DEBUGFS,
+ .tx = {
+ .data = &req,
+ .size = sizeof(req),
+ },
+ .rx = {
+ .data = &resp,
+ .size = sizeof(resp),
+ },
+ };
+ int err;
+
+ err = tegra_bpmp_transfer(bpmp, &msg);
+ if (err < 0)
+ return err;
+
+ *nbytes = (size_t)resp.fop.nbytes;
+
+ return 0;
+}
+
+static int mrq_debugfs_write(struct tegra_bpmp *bpmp,
+ dma_addr_t name, size_t sz_name,
+ dma_addr_t data, size_t sz_data)
+{
+ const struct mrq_debugfs_request req = {
+ .cmd = cpu_to_le32(CMD_DEBUGFS_WRITE),
+ .fop = {
+ .fnameaddr = cpu_to_le32((uint32_t)name),
+ .fnamelen = cpu_to_le32((uint32_t)sz_name),
+ .dataaddr = cpu_to_le32((uint32_t)data),
+ .datalen = cpu_to_le32((uint32_t)sz_data),
+ },
+ };
+ struct tegra_bpmp_message msg = {
+ .mrq = MRQ_DEBUGFS,
+ .tx = {
+ .data = &req,
+ .size = sizeof(req),
+ },
+ };
+
+ return tegra_bpmp_transfer(bpmp, &msg);
+}
+
+static int mrq_debugfs_dumpdir(struct tegra_bpmp *bpmp, dma_addr_t addr,
+ size_t size, size_t *nbytes)
+{
+ const struct mrq_debugfs_request req = {
+ .cmd = cpu_to_le32(CMD_DEBUGFS_DUMPDIR),
+ .dumpdir = {
+ .dataaddr = cpu_to_le32((uint32_t)addr),
+ .datalen = cpu_to_le32((uint32_t)size),
+ },
+ };
+ struct mrq_debugfs_response resp;
+ struct tegra_bpmp_message msg = {
+ .mrq = MRQ_DEBUGFS,
+ .tx = {
+ .data = &req,
+ .size = sizeof(req),
+ },
+ .rx = {
+ .data = &resp,
+ .size = sizeof(resp),
+ },
+ };
+ int err;
+
+ err = tegra_bpmp_transfer(bpmp, &msg);
+ if (err < 0)
+ return err;
+
+ *nbytes = (size_t)resp.dumpdir.nbytes;
+
+ return 0;
+}
+
+static int debugfs_show(struct seq_file *m, void *p)
+{
+ struct file *file = m->private;
+ struct inode *inode = file_inode(file);
+ struct tegra_bpmp *bpmp = inode->i_private;
+ const size_t datasize = m->size;
+ const size_t namesize = SZ_256;
+ void *datavirt, *namevirt;
+ dma_addr_t dataphys, namephys;
+ char buf[256];
+ const char *filename;
+ size_t len, nbytes;
+ int ret;
+
+ filename = get_filename(bpmp, file, buf, sizeof(buf));
+ if (!filename)
+ return -ENOENT;
+
+ namevirt = dma_alloc_coherent(bpmp->dev, namesize, &namephys,
+ GFP_KERNEL | GFP_DMA32);
+ if (!namevirt)
+ return -ENOMEM;
+
+ datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
+ GFP_KERNEL | GFP_DMA32);
+ if (!datavirt) {
+ ret = -ENOMEM;
+ goto free_namebuf;
+ }
+
+ len = strlen(filename);
+ strncpy(namevirt, filename, namesize);
+
+ ret = mrq_debugfs_read(bpmp, namephys, len, dataphys, datasize,
+ &nbytes);
+
+ if (!ret)
+ seq_write(m, datavirt, nbytes);
+
+ dma_free_coherent(bpmp->dev, datasize, datavirt, dataphys);
+free_namebuf:
+ dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
+
+ return ret;
+}
+
+static int debugfs_open(struct inode *inode, struct file *file)
+{
+ return single_open_size(file, debugfs_show, file, SZ_128K);
+}
+
+static ssize_t debugfs_store(struct file *file, const char __user *buf,
+ size_t count, loff_t *f_pos)
+{
+ struct inode *inode = file_inode(file);
+ struct tegra_bpmp *bpmp = inode->i_private;
+ const size_t datasize = count;
+ const size_t namesize = SZ_256;
+ void *datavirt, *namevirt;
+ dma_addr_t dataphys, namephys;
+ char fnamebuf[256];
+ const char *filename;
+ size_t len;
+ int ret;
+
+ filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
+ if (!filename)
+ return -ENOENT;
+
+ namevirt = dma_alloc_coherent(bpmp->dev, namesize, &namephys,
+ GFP_KERNEL | GFP_DMA32);
+ if (!namevirt)
+ return -ENOMEM;
+
+ datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
+ GFP_KERNEL | GFP_DMA32);
+ if (!datavirt) {
+ ret = -ENOMEM;
+ goto free_namebuf;
+ }
+
+ len = strlen(filename);
+ strncpy(namevirt, filename, namesize);
+
+ if (copy_from_user(datavirt, buf, count)) {
+ ret = -EFAULT;
+ goto free_databuf;
+ }
+
+ ret = mrq_debugfs_write(bpmp, namephys, len, dataphys,
+ count);
+
+free_databuf:
+ dma_free_coherent(bpmp->dev, datasize, datavirt, dataphys);
+free_namebuf:
+ dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
+
+ return ret ?: count;
+}
+
+static const struct file_operations debugfs_fops = {
+ .open = debugfs_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .write = debugfs_store,
+ .release = single_release,
+};
+
+static int bpmp_populate_dir(struct tegra_bpmp *bpmp, struct seqbuf *seqbuf,
+ struct dentry *parent, uint32_t depth)
+{
+ int err;
+ uint32_t d, t;
+ const char *name;
+ struct dentry *dentry;
+
+ while (!seqbuf_eof(seqbuf)) {
+ err = seqbuf_read_u32(seqbuf, &d);
+ if (err < 0)
+ return err;
+
+ if (d < depth) {
+ seqbuf_seek(seqbuf, -4);
+ /* go up a level */
+ return 0;
+ } else if (d != depth) {
+ /* malformed data received from BPMP */
+ return -EIO;
+ }
+
+ err = seqbuf_read_u32(seqbuf, &t);
+ if (err < 0)
+ return err;
+ err = seqbuf_read_str(seqbuf, &name);
+ if (err < 0)
+ return err;
+
+ if (t & DEBUGFS_S_ISDIR) {
+ dentry = debugfs_create_dir(name, parent);
+ if (!dentry)
+ return -ENOMEM;
+ err = bpmp_populate_dir(bpmp, seqbuf, dentry, depth+1);
+ if (err < 0)
+ return err;
+ } else {
+ umode_t mode;
+
+ mode = t & DEBUGFS_S_IRUSR ? S_IRUSR : 0;
+ mode |= t & DEBUGFS_S_IWUSR ? S_IWUSR : 0;
+ dentry = debugfs_create_file(name, mode,
+ parent, bpmp,
+ &debugfs_fops);
+ if (!dentry)
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+static int create_debugfs_mirror(struct tegra_bpmp *bpmp, void *buf,
+ size_t bufsize, struct dentry *root)
+{
+ struct seqbuf seqbuf;
+ int err;
+
+ bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
+ if (!bpmp->debugfs_mirror)
+ return -ENOMEM;
+
+ seqbuf_init(&seqbuf, buf, bufsize);
+ err = bpmp_populate_dir(bpmp, &seqbuf, bpmp->debugfs_mirror, 0);
+ if (err < 0) {
+ debugfs_remove_recursive(bpmp->debugfs_mirror);
+ bpmp->debugfs_mirror = NULL;
+ }
+
+ return err;
+}
+
+static int mrq_is_supported(struct tegra_bpmp *bpmp, unsigned int mrq)
+{
+ struct mrq_query_abi_request req = { .mrq = cpu_to_le32(mrq) };
+ struct mrq_query_abi_response resp;
+ struct tegra_bpmp_message msg = {
+ .mrq = MRQ_QUERY_ABI,
+ .tx = {
+ .data = &req,
+ .size = sizeof(req),
+ },
+ .rx = {
+ .data = &resp,
+ .size = sizeof(resp),
+ },
+ };
+ int ret;
+
+ ret = tegra_bpmp_transfer(bpmp, &msg);
+ if (ret < 0) {
+ /* something went wrong; assume not supported */
+ dev_warn(bpmp->dev, "tegra_bpmp_transfer failed (%d)\n", ret);
+ return 0;
+ }
+
+ return resp.status ? 0 : 1;
+}
+
+int tegra_bpmp_init_debugfs(struct tegra_bpmp *bpmp)
+{
+ dma_addr_t phys;
+ void *virt;
+ const size_t sz = SZ_256K;
+ size_t nbytes;
+ int ret;
+ struct dentry *root;
+
+ if (!mrq_is_supported(bpmp, MRQ_DEBUGFS))
+ return 0;
+
+ root = debugfs_create_dir("bpmp", NULL);
+ if (!root)
+ return -ENOMEM;
+
+ virt = dma_alloc_coherent(bpmp->dev, sz, &phys,
+ GFP_KERNEL | GFP_DMA32);
+ if (!virt) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = mrq_debugfs_dumpdir(bpmp, phys, sz, &nbytes);
+ if (ret < 0)
+ goto free;
+
+ ret = create_debugfs_mirror(bpmp, virt, nbytes, root);
+free:
+ dma_free_coherent(bpmp->dev, sz, virt, phys);
+out:
+ if (ret < 0)
+ debugfs_remove(root);
+
+ return ret;
+}