Add support for retrieving BPMP debug information via in-band messaging
as opposed to using shared-memory which older BPMP firmware used. Note
that it is possible to detect at runtime whether the BPMP firmware being
used supports the in-band messaging for retrieving the debug
informaation. Therefore, if the BPMP firmware supports the in-band
messaging for debug use this and otherwise fall-back to using shared
memory.
Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
---
drivers/firmware/tegra/bpmp-debugfs.c | 377 +++++++++++++++++++++++++-
include/soc/tegra/bpmp-abi.h | 189 ++++++++++++-
2 files changed, 557 insertions(+), 9 deletions(-)
diff --git a/drivers/firmware/tegra/bpmp-debugfs.c b/drivers/firmware/tegra/bpmp-debugfs.c
index a1a1a3b9e667..fb269f940a35 100644
--- a/drivers/firmware/tegra/bpmp-debugfs.c
+++ b/drivers/firmware/tegra/bpmp-debugfs.c
@@ -4,11 +4,14 @@
*/
#include <linux/debugfs.h>
#include <linux/dma-mapping.h>
+#include <linux/slab.h>
#include <linux/uaccess.h>
#include <soc/tegra/bpmp.h>
#include <soc/tegra/bpmp-abi.h>
+static DEFINE_MUTEX(bpmp_debug_lock);
+
struct seqbuf {
char *buf;
size_t pos;
@@ -96,6 +99,354 @@ static const char *get_filename(struct tegra_bpmp *bpmp,
return filename;
}
+static int mrq_debug_open(struct tegra_bpmp *bpmp, const char *name,
+ uint32_t *fd, uint32_t *len, bool write)
+{
+ struct mrq_debug_request req = {
+ .cmd = cpu_to_le32(write ? CMD_DEBUG_OPEN_WO : \
+ CMD_DEBUG_OPEN_RO),
+ };
+ struct mrq_debug_response resp;
+ struct tegra_bpmp_message msg = {
+ .mrq = MRQ_DEBUG,
+ .tx = {
+ .data = &req,
+ .size = sizeof(req),
+ },
+ .rx = {
+ .data = &resp,
+ .size = sizeof(resp),
+ },
+ };
+ ssize_t sz_name;
+ int err = 0;
+
+ sz_name = strscpy(req.fop.name, name, sizeof(req.fop.name));
+ if (sz_name < 0) {
+ pr_err("File name too large: %s\n", name);
+ return -EINVAL;
+ }
+
+ err = tegra_bpmp_transfer(bpmp, &msg);
+ if (err < 0)
+ return err;
+ else if (msg.rx.ret < 0)
+ return -EINVAL;
+
+ *len = resp.fop.datalen;
+ *fd = resp.fop.fd;
+
+ return 0;
+}
+
+static int mrq_debug_close(struct tegra_bpmp *bpmp, uint32_t fd)
+{
+ struct mrq_debug_request req = {
+ .cmd = cpu_to_le32(CMD_DEBUG_CLOSE),
+ .frd = {
+ .fd = fd,
+ },
+ };
+ struct mrq_debug_response resp;
+ struct tegra_bpmp_message msg = {
+ .mrq = MRQ_DEBUG,
+ .tx = {
+ .data = &req,
+ .size = sizeof(req),
+ },
+ .rx = {
+ .data = &resp,
+ .size = sizeof(resp),
+ },
+ };
+ int err = 0;
+
+ err = tegra_bpmp_transfer(bpmp, &msg);
+ if (err < 0)
+ return err;
+ else if (msg.rx.ret < 0)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int mrq_debug_read(struct tegra_bpmp *bpmp, const char *name,
+ char *data, size_t sz_data, uint32_t *nbytes)
+{
+ struct mrq_debug_request req = {
+ .cmd = cpu_to_le32(CMD_DEBUG_READ),
+ };
+ struct mrq_debug_response resp;
+ struct tegra_bpmp_message msg = {
+ .mrq = MRQ_DEBUG,
+ .tx = {
+ .data = &req,
+ .size = sizeof(req),
+ },
+ .rx = {
+ .data = &resp,
+ .size = sizeof(resp),
+ },
+ };
+ uint32_t fd = 0, len = 0;
+ int remaining, err;
+
+ mutex_lock(&bpmp_debug_lock);
+ err = mrq_debug_open(bpmp, name, &fd, &len, 0);
+ if (err)
+ goto out;
+
+ if (len > sz_data) {
+ err = -EFBIG;
+ goto close;
+ }
+
+ req.frd.fd = fd;
+ remaining = len;
+
+ while (remaining > 0) {
+ err = tegra_bpmp_transfer(bpmp, &msg);
+ if (err < 0) {
+ goto close;
+ } else if (msg.rx.ret < 0) {
+ err = -EINVAL;
+ goto close;
+ }
+
+ if (resp.frd.readlen > remaining) {
+ pr_err("%s: read data length invalid\n", __func__);
+ err = -EINVAL;
+ goto close;
+ }
+
+ memcpy(data, resp.frd.data, resp.frd.readlen);
+ data += resp.frd.readlen;
+ remaining -= resp.frd.readlen;
+ }
+
+ *nbytes = len;
+
+close:
+ err = mrq_debug_close(bpmp, fd);
+out:
+ mutex_unlock(&bpmp_debug_lock);
+ return err;
+}
+
+static int mrq_debug_write(struct tegra_bpmp *bpmp, const char *name,
+ uint8_t *data, size_t sz_data)
+{
+ struct mrq_debug_request req = {
+ .cmd = cpu_to_le32(CMD_DEBUG_WRITE)
+ };
+ struct mrq_debug_response resp;
+ struct tegra_bpmp_message msg = {
+ .mrq = MRQ_DEBUG,
+ .tx = {
+ .data = &req,
+ .size = sizeof(req),
+ },
+ .rx = {
+ .data = &resp,
+ .size = sizeof(resp),
+ },
+ };
+ uint32_t fd = 0, len = 0;
+ int remaining, err;
+
+ mutex_lock(&bpmp_debug_lock);
+ err = mrq_debug_open(bpmp, name, &fd, &len, 1);
+ if (err)
+ goto out;
+
+ if (sz_data > len) {
+ err = -EINVAL;
+ goto close;
+ }
+
+ req.fwr.fd = fd;
+ remaining = sz_data;
+
+ while (remaining > 0) {
+ len = min(remaining, (int)sizeof(req.fwr.data));
+ memcpy(req.fwr.data, data, len);
+ req.fwr.datalen = len;
+
+ err = tegra_bpmp_transfer(bpmp, &msg);
+ if (err < 0) {
+ goto close;
+ } else if (msg.rx.ret < 0) {
+ err = -EINVAL;
+ goto close;
+ }
+
+ data += req.fwr.datalen;
+ remaining -= req.fwr.datalen;
+ }
+
+close:
+ err = mrq_debug_close(bpmp, fd);
+out:
+ mutex_unlock(&bpmp_debug_lock);
+ return err;
+}
+
+static int bpmp_debug_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;
+ char *databuf = NULL;
+ char fnamebuf[256];
+ const char *filename;
+ uint32_t nbytes = 0;
+ size_t len;
+ int err;
+
+ len = seq_get_buf(m, &databuf);
+ if (!databuf)
+ return -ENOMEM;
+
+ filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
+ if (!filename)
+ return -ENOENT;
+
+ err = mrq_debug_read(bpmp, filename, databuf, len, &nbytes);
+ if (!err)
+ seq_commit(m, nbytes);
+
+ return err;
+}
+
+static ssize_t bpmp_debug_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;
+ char *databuf = NULL;
+ char fnamebuf[256];
+ const char *filename;
+ ssize_t err;
+
+ filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
+ if (!filename)
+ return -ENOENT;
+
+ databuf = kmalloc(count, GFP_KERNEL);
+ if (!databuf)
+ return -ENOMEM;
+
+ if (copy_from_user(databuf, buf, count)) {
+ err = -EFAULT;
+ goto free_ret;
+ }
+
+ err = mrq_debug_write(bpmp, filename, databuf, count);
+
+free_ret:
+ kfree(databuf);
+
+ return err ?: count;
+}
+
+static int bpmp_debug_open(struct inode *inode, struct file *file)
+{
+ return single_open_size(file, bpmp_debug_show, file, SZ_256K);
+}
+
+static const struct file_operations bpmp_debug_fops = {
+ .open = bpmp_debug_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .write = bpmp_debug_store,
+ .release = single_release,
+};
+
+static int bpmp_populate_debugfs_inband(struct tegra_bpmp *bpmp,
+ struct dentry *parent,
+ char *ppath)
+{
+ const size_t pathlen = SZ_256;
+ const size_t bufsize = SZ_16K;
+ uint32_t dsize, attrs = 0;
+ struct dentry *dentry;
+ struct seqbuf seqbuf;
+ char *buf, *pathbuf;
+ const char *name;
+ int err = 0;
+
+ if (!bpmp || !parent || !ppath)
+ return -EINVAL;
+
+ buf = kmalloc(bufsize, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ pathbuf = kzalloc(pathlen, GFP_KERNEL);
+ if (!pathbuf) {
+ kfree(buf);
+ return -ENOMEM;
+ }
+
+ err = mrq_debug_read(bpmp, ppath, buf, bufsize, &dsize);
+ if (err)
+ goto out;
+
+ seqbuf_init(&seqbuf, buf, dsize);
+
+ while (!seqbuf_eof(&seqbuf)) {
+ err = seqbuf_read_u32(&seqbuf, &attrs);
+ if (err)
+ goto out;
+
+ err = seqbuf_read_str(&seqbuf, &name);
+ if (err < 0)
+ goto out;
+
+ if (attrs & DEBUGFS_S_ISDIR) {
+ size_t len;
+
+ dentry = debugfs_create_dir(name, parent);
+ if (IS_ERR(dentry)) {
+ err = PTR_ERR(dentry);
+ goto out;
+ }
+
+ len = strlen(ppath) + strlen(name) + 1;
+ if (len >= pathlen) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ strncpy(pathbuf, ppath, pathlen);
+ strncat(pathbuf, name, strlen(name));
+ strcat(pathbuf, "/");
+
+ err = bpmp_populate_debugfs_inband(bpmp, dentry,
+ pathbuf);
+ if (err < 0)
+ goto out;
+ } else {
+ umode_t mode;
+
+ mode = attrs & DEBUGFS_S_IRUSR ? S_IRUSR : 0;
+ mode |= attrs & DEBUGFS_S_IWUSR ? S_IWUSR : 0;
+ dentry = debugfs_create_file(name, mode, parent, bpmp,
+ &bpmp_debug_fops);
+ if (!dentry) {
+ err = -ENOMEM;
+ goto out;
+ }
+ }
+ }
+
+out:
+ kfree(pathbuf);
+ kfree(buf);
+
+ return err;
+}
+
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,
@@ -354,8 +705,7 @@ static int bpmp_populate_dir(struct tegra_bpmp *bpmp, struct seqbuf *seqbuf,
return 0;
}
-static int bpmp_populate_debugfs_shmem(struct tegra_bpmp *bpmp,
- struct dentry *root)
+static int bpmp_populate_debugfs_shmem(struct tegra_bpmp *bpmp)
{
struct seqbuf seqbuf;
const size_t sz = SZ_512K;
@@ -364,10 +714,6 @@ static int bpmp_populate_debugfs_shmem(struct tegra_bpmp *bpmp,
void *virt;
int err;
- bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
- if (!bpmp->debugfs_mirror)
- return -ENOMEM;
-
virt = dma_alloc_coherent(bpmp->dev, sz, &phys,
GFP_KERNEL | GFP_DMA32);
if (!virt)
@@ -392,16 +738,31 @@ static int bpmp_populate_debugfs_shmem(struct tegra_bpmp *bpmp,
int tegra_bpmp_init_debugfs(struct tegra_bpmp *bpmp)
{
struct dentry *root;
+ bool inband;
int err;
- if (!tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUGFS))
+ inband = tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUG);
+
+ if (!inband && !tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUGFS))
return 0;
root = debugfs_create_dir("bpmp", NULL);
if (!root)
return -ENOMEM;
- err = bpmp_populate_debugfs_shmem(bpmp, root);
+ bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
+ if (!bpmp->debugfs_mirror) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ if (inband)
+ err = bpmp_populate_debugfs_inband(bpmp, bpmp->debugfs_mirror,
+ "/");
+ else
+ err = bpmp_populate_debugfs_shmem(bpmp);
+
+out:
if (err < 0)
debugfs_remove_recursive(root);
diff --git a/include/soc/tegra/bpmp-abi.h b/include/soc/tegra/bpmp-abi.h
index 8f8e73e5cd45..4896227eef1a 100644
--- a/include/soc/tegra/bpmp-abi.h
+++ b/include/soc/tegra/bpmp-abi.h
@@ -148,6 +148,7 @@ struct mrq_response {
#define MRQ_FMON 72
#define MRQ_EC 73
#define MRQ_FBVOLT_STATUS 74
+#define MRQ_DEBUG 75
/** @} */
@@ -156,7 +157,7 @@ struct mrq_response {
* @brief Maximum MRQ code to be sent by CPU software to
* BPMP. Subject to change in future
*/
-#define MAX_CPU_MRQ_ID 74
+#define MAX_CPU_MRQ_ID 75
/**
* @addtogroup MRQ_Payloads
@@ -532,6 +533,8 @@ struct mrq_module_mail_response {
* @def MRQ_DEBUGFS
* @brief Interact with BPMP's debugfs file nodes
*
+ * @deprecated use MRQ_DEBUG instead.
+ *
* * Platforms: T186, T194
* * Initiators: Any
* * Targets: BPMP
@@ -671,6 +674,190 @@ struct mrq_debugfs_response {
#define DEBUGFS_S_IWUSR (1 << 7)
/** @} */
+/**
+ * @ingroup MRQ_Codes
+ * @def MRQ_DEBUG
+ * @brief Interact with BPMP's debugfs file nodes. Use message payload
+ * for exchanging data. This is functionally equivalent to
+ * @ref MRQ_DEBUGFS. But the way in which data is exchanged is different.
+ * When software running on CPU tries to read a debugfs file,
+ * the file path and read data will be stored in message payload.
+ * Since the message payload size is limited, a debugfs file
+ * transaction might require multiple frames of data exchanged
+ * between BPMP and CPU until the transaction completes.
+ *
+ * * Platforms: T194
+ * * Initiators: Any
+ * * Targets: BPMP
+ * * Request Payload: @ref mrq_debug_request
+ * * Response Payload: @ref mrq_debug_response
+ */
+
+/** @ingroup Debugfs */
+enum mrq_debug_commands {
+ /** @brief Open required file for read operation */
+ CMD_DEBUG_OPEN_RO = 0,
+ /** @brief Open required file for write operation */
+ CMD_DEBUG_OPEN_WO = 1,
+ /** @brief Perform read */
+ CMD_DEBUG_READ = 2,
+ /** @brief Perform write */
+ CMD_DEBUG_WRITE = 3,
+ /** @brief Close file */
+ CMD_DEBUG_CLOSE = 4,
+ /** @brief Not a command */
+ CMD_DEBUG_MAX
+};
+
+/**
+ * @ingroup Debugfs
+ * @brief Maximum number of files that can be open at a given time
+ */
+#define DEBUG_MAX_OPEN_FILES 1
+
+/**
+ * @ingroup Debugfs
+ * @brief Maximum size of null-terminated file name string in bytes.
+ * Value is derived from memory available in message payload while
+ * using @ref cmd_debug_fopen_request
+ * Value 4 corresponds to size of @ref mrq_debug_commands
+ * in @ref mrq_debug_request.
+ * 120 - 4 dbg_cmd(32bit) = 116
+ */
+#define DEBUG_FNAME_MAX_SZ (MSG_DATA_MIN_SZ - 4)
+
+/**
+ * @ingroup Debugfs
+ * @brief Parameters for CMD_DEBUG_OPEN command
+ */
+struct cmd_debug_fopen_request {
+ /** @brief File name - Null-terminated string with maximum
+ * length @ref DEBUG_FNAME_MAX_SZ
+ */
+ char name[DEBUG_FNAME_MAX_SZ];
+} __ABI_PACKED;
+
+/**
+ * @ingroup Debugfs
+ * @brief Response data for CMD_DEBUG_OPEN_RO/WO command
+ */
+struct cmd_debug_fopen_response {
+ /** @brief Identifier for file access */
+ uint32_t fd;
+ /** @brief Data length. File data size for READ command.
+ * Maximum allowed length for WRITE command
+ */
+ uint32_t datalen;
+} __ABI_PACKED;
+
+/**
+ * @ingroup Debugfs
+ * @brief Parameters for CMD_DEBUG_READ command
+ */
+struct cmd_debug_fread_request {
+ /** @brief File access identifier received in response
+ * to CMD_DEBUG_OPEN_RO request
+ */
+ uint32_t fd;
+} __ABI_PACKED;
+
+/**
+ * @ingroup Debugfs
+ * @brief Maximum size of read data in bytes.
+ * Value is derived from memory available in message payload while
+ * using @ref cmd_debug_fread_response.
+ */
+#define DEBUG_READ_MAX_SZ (MSG_DATA_MIN_SZ - 4)
+
+/**
+ * @ingroup Debugfs
+ * @brief Response data for CMD_DEBUG_READ command
+ */
+struct cmd_debug_fread_response {
+ /** @brief Size of data provided in this response in bytes */
+ uint32_t readlen;
+ /** @brief File data from seek position */
+ char data[DEBUG_READ_MAX_SZ];
+} __ABI_PACKED;
+
+/**
+ * @ingroup Debugfs
+ * @brief Maximum size of write data in bytes.
+ * Value is derived from memory available in message payload while
+ * using @ref cmd_debug_fwrite_request.
+ */
+#define DEBUG_WRITE_MAX_SZ (MSG_DATA_MIN_SZ - 12)
+
+/**
+ * @ingroup Debugfs
+ * @brief Parameters for CMD_DEBUG_WRITE command
+ */
+struct cmd_debug_fwrite_request {
+ /** @brief File access identifier received in response
+ * to CMD_DEBUG_OPEN_RO request
+ */
+ uint32_t fd;
+ /** @brief Size of write data in bytes */
+ uint32_t datalen;
+ /** @brief Data to be written */
+ char data[DEBUG_WRITE_MAX_SZ];
+} __ABI_PACKED;
+
+/**
+ * @ingroup Debugfs
+ * @brief Parameters for CMD_DEBUG_CLOSE command
+ */
+struct cmd_debug_fclose_request {
+ /** @brief File access identifier received in response
+ * to CMD_DEBUG_OPEN_RO request
+ */
+ uint32_t fd;
+} __ABI_PACKED;
+
+/**
+ * @ingroup Debugfs
+ * @brief Request with #MRQ_DEBUG.
+ *
+ * The sender of an MRQ_DEBUG message uses #cmd to specify a debugfs
+ * command to execute. Legal commands are the values of @ref
+ * mrq_debug_commands. Each command requires a specific additional
+ * payload of data.
+ *
+ * |command |payload|
+ * |-------------------|-------|
+ * |CMD_DEBUG_OPEN_RO |fop |
+ * |CMD_DEBUG_OPEN_WO |fop |
+ * |CMD_DEBUG_READ |frd |
+ * |CMD_DEBUG_WRITE |fwr |
+ * |CMD_DEBUG_CLOSE |fcl |
+ */
+struct mrq_debug_request {
+ /** @brief Sub-command (@ref mrq_debug_commands) */
+ uint32_t cmd;
+ union {
+ /** @brief Request payload for CMD_DEBUG_OPEN_RO/WO command */
+ struct cmd_debug_fopen_request fop;
+ /** @brief Request payload for CMD_DEBUG_READ command */
+ struct cmd_debug_fread_request frd;
+ /** @brief Request payload for CMD_DEBUG_WRITE command */
+ struct cmd_debug_fwrite_request fwr;
+ /** @brief Request payload for CMD_DEBUG_CLOSE command */
+ struct cmd_debug_fclose_request fcl;
+ } __UNION_ANON;
+} __ABI_PACKED;
+
+/**
+ * @ingroup Debugfs
+ */
+struct mrq_debug_response {
+ union {
+ /** @brief Response data for CMD_DEBUG_OPEN_RO/WO command */
+ struct cmd_debug_fopen_response fop;
+ /** @brief Response data for CMD_DEBUG_READ command */
+ struct cmd_debug_fread_response frd;
+ } __UNION_ANON;
+} __ABI_PACKED;
+
/**
* @ingroup MRQ_Codes
* @def MRQ_RESET
--
2.17.1
