#include "nvdebug_linux.h"
#include <linux/seq_file.h> // For seq_* functions and types
#include <linux/uaccess.h> // For copy_to_user()
// Generic register printing function, used for PTOP_*_NUM registers (+more)
// @param f File being read from. `data` field is register offset to read.
// @param buf User buffer for result
// @param size Length of user buffer
// @param off Requested offset. Updated by number of characters written.
// @return -errno on error, otherwise number of bytes written to *buf
// Note: Parent `data` field MUST be the GPU index
static ssize_t nvdebug_reg32_read(struct file *f, char __user *buf, size_t size, loff_t *off) {
char out[16];
int chars_written;
uint32_t read;
struct nvdebug_state *g = &g_nvdebug_state[file2parentgpuidx(f)];
if (size < 16 || *off != 0)
return 0;
if ((read = nvdebug_readl(g, (uintptr_t)pde_data(file_inode(f)))) == -1)
return -EOPNOTSUPP;
// 32 bit register will always take less than 16 characters to print
chars_written = scnprintf(out, 16, "%#0x\n", nvdebug_readl(g, read));
if (copy_to_user(buf, out, chars_written))
printk(KERN_WARNING "[nvdebug] %s: Unable to copy all data for %s\n", __func__, file_dentry(f)->d_name.name);
*off += chars_written;
return chars_written;
}
struct file_operations nvdebug_read_reg32_file_ops = {
.read = nvdebug_reg32_read,
.llseek = default_llseek,
};
static ssize_t nvdebug_reg_range_read(struct file *f, char __user *buf, size_t size, loff_t *off) {
char out[12];
int chars_written;
uint32_t read, mask;
struct nvdebug_state *g = &g_nvdebug_state[file2parentgpuidx(f)];
// See comment in nvdebug_entry.c to understand `union reg_range`
union reg_range range;
range.raw = (uintptr_t)pde_data(file_inode(f));
// "0x" + up to 32-bit register as hex + "\n\0" is at most 12 characters
if (size < 12 || *off != 0)
return 0;
// Print bits `start_bit` to `stop_bit` from 32 bits at address `offset`
if ((read = nvdebug_readl(g, range.offset)) == -1)
return -EOPNOTSUPP;
// Setup `mask` used to throw out unused upper bits
mask = -1u >> (32 - range.stop_bit + range.start_bit);
// Throw out unused lower bits via a shift, apply the mask, and print
chars_written = scnprintf(out, 12, "%#0x\n", (read >> range.start_bit) & mask);
if (copy_to_user(buf, out, chars_written))
printk(KERN_WARNING "Unable to copy all data for %s\n", file_dentry(f)->d_name.name);
*off += chars_written;
return chars_written;
}
// Generic mechanism used for printing a subset of bits from a register
// Please store a `union reg_range` rather than a `uintptr_t` in the pde_data
struct file_operations nvdebug_read_reg_range_file_ops = {
.read = nvdebug_reg_range_read,
.llseek = default_llseek,
};
static ssize_t local_memory_read(struct file *f, char __user *buf, size_t size, loff_t *off) {
struct nvdebug_state *g = &g_nvdebug_state[file2parentgpuidx(f)];
char out[30];
int chars_written;
memory_range_t mem_range;
if (size < 30 || *off != 0)
return 0;
mem_range.raw = nvdebug_readl(g, NV_FB_MMU_LOCAL_MEMORY_RANGE);
if (mem_range.raw == -1)
return -EIO;
// 64-bit size has at most 19 characters + 8 for text and termination
chars_written = scnprintf(out, 30, "%lld bytes\n", memory_range_to_bytes(mem_range));
if (copy_to_user(buf, out, chars_written))
printk(KERN_WARNING "Unable to copy all data for %s\n", file_dentry(f)->d_name.name);
*off += chars_written;
return chars_written;
}
// Read out size of on-device VRAM
struct file_operations local_memory_file_ops = {
.read = local_memory_read,
.llseek = default_llseek,
};
typedef struct {
int idx; // Current index in the device_info table
int length; // Length of device_info table (including unpopulated entries)
int type_of_next_entry; // Only used on Ampere+ GPUs
bool has_next_entry; // Only used on Ampere+ GPUs for show() idempotence
} device_info_iter;
//// ==v== PTOP_DEVICE_INFO ==v== ////
// Called to start or resume a sequence. Prior to 4.19, *pos is unreliable.
// Initializes iterator `iter` state and returns it. Ends sequence on NULL.
static void* device_info_file_seq_start(struct seq_file *s, loff_t *pos) {
static device_info_iter iter;
// If freshly starting a sequence, reset the iterator
if (*pos == 0) {
struct nvdebug_state *g = &g_nvdebug_state[seq2gpuidx(s)];
iter.idx = 0;
iter.type_of_next_entry = 0;
iter.has_next_entry = 0;
// On Ampere+, the device_info table length can vary
if (g->chip_id >= NV_CHIP_ID_AMPERE)
iter.length = NV_PTOP_DEVICE_INFO__SIZE_1_GA100(g);
else
iter.length = NV_PTOP_DEVICE_INFO__SIZE_1_GK104;
}
// Number of possible info entries is fixed, and list is sparse, so stop
// iterating only when all entries have been checked, rather than on the first
// empty entry.
if (iter.idx >= iter.length)
return NULL;
return &iter;
}
// Steps to next record. Returns `&iter` (address should not change)
// Calls show() on non-NULL return
static void* device_info_file_seq_next(struct seq_file *s, void *iter_raw,
loff_t *pos) {
device_info_iter *iter = (device_info_iter*)iter_raw;
(*pos)++; // Required by seq interface
// Number of possible info entries is fixed, and list is sparse, so stop
// iterating only when all entries have been checked, rather than on the first
// empty entry.
if (++iter->idx >= iter->length)
return NULL;
// The info_type field is not available in the Ampere device_info data, so
// it must be inferred. NOP for older devices (cheaper than another branch).
// This has to be here (rather than in the show function) to support the
// idempotence requirements of show() in the seq_file interface.
iter->type_of_next_entry = iter->has_next_entry ? iter->type_of_next_entry + 1 : 0;
return iter;
}
// Print info at iter->idx for Kepler--Turing GPUs. Returns non-zero on error.
// Implementation of this function must be idempotent
static int device_info_file_seq_show_gk104(struct seq_file *s, void *iter_raw) {
device_info_iter *iter = (device_info_iter*)iter_raw;
ptop_device_info_gk104_t curr_info;
struct nvdebug_state *g = &g_nvdebug_state[seq2gpuidx(s)];
curr_info.raw = nvdebug_readl(g, NV_PTOP_DEVICE_INFO_GK104(iter->idx));
// Check for read errors
if (curr_info.raw == -1)
return -EIO;
// Parse and print the data
switch(curr_info.info_type) {
case INFO_TYPE_DATA:
// As of early 2022, only the ENUM2 format of this entry exists
if (curr_info.is_not_enum2)
break;
seq_printf(s, "| BAR0 Base %#.8x\n"
"| instance %d\n",
curr_info.pri_base << 12, curr_info.inst_id);
if (curr_info.fault_id_is_valid)
seq_printf(s, "| Fault ID: %3d\n", curr_info.fault_id);
break;
case INFO_TYPE_ENUM:
if (curr_info.engine_is_valid)
seq_printf(s, "| Host's Engine ID: %2d\n", curr_info.engine_enum);
if (curr_info.runlist_is_valid)
seq_printf(s, "| Runlist ID: %2d\n", curr_info.runlist_enum);
if (curr_info.intr_is_valid)
seq_printf(s, "| Interrupt ID: %2d\n", curr_info.intr_enum);
if (curr_info.reset_is_valid)
seq_printf(s, "| Reset ID: %2d\n", curr_info.reset_enum);
break;
case INFO_TYPE_ENGINE_TYPE:
seq_printf(s, "| Engine Type: %2d (", curr_info.engine_type);
if (curr_info.engine_type < ENGINE_TYPES_LEN)
seq_printf(s, "%s)\n", ENGINE_TYPES_NAMES[curr_info.engine_type]);
else
seq_printf(s, "Unknown Historical)\n");
break;
case INFO_TYPE_NOT_VALID:
default:
// Device info records are sparse, so skip unset or unknown ones
return 0;
}
// Draw a line between each device entry
if (!curr_info.has_next_entry)
seq_printf(s, "+---------------------+\n");
return 0;
}
// Print info at iter->idx for Ampere+ GPUs. Returns non-zero on error.
// Implementation of this function must be idempotent
static int device_info_file_seq_show_ga100(struct seq_file *s, void *iter_raw) {
device_info_iter *iter = (device_info_iter*)iter_raw;
ptop_device_info_ga100_t curr_info;
struct nvdebug_state *g = &g_nvdebug_state[seq2gpuidx(s)];
curr_info.raw = nvdebug_readl(g, NV_PTOP_DEVICE_INFO_GA100(iter->idx));
// Check for read errors
if (curr_info.raw == -1)
return -EIO;
// Update tracking data only used by next(); allows preserving idempotence
iter->has_next_entry = curr_info.has_next_entry;
// Silently skip empty entries
if (curr_info.raw == 0)
return 0;
// In nvdebug, an entry is considered invalid if it does not consist of at
// least two rows. So, if this is the first row of an entry, but another row
// is not indicated, this entry is invalid and should be skipped.
if (iter->type_of_next_entry == 0 && !curr_info.has_next_entry) {
printk(KERN_WARNING "[nvdebug] Skipping seemingly-invalid device_info entry (idx: %d, raw: %#0x)\n", iter->idx, curr_info.raw);
return 0;
}
// Parse and print the data
// Note: The goal of this interface is to present useful information to
// a human user, NOT to provide a stable format for scripts to parse.
// Because of this, we favor accurately printing the data in each entry,
// rather than providing stable (if imperfectly correct) field names
switch(iter->type_of_next_entry) {
case 0:
seq_printf(s, "| Engine Type: %3d (", curr_info.engine_type);
if (curr_info.engine_type < ENGINE_TYPES_LEN)
seq_printf(s, "%s)\n", ENGINE_TYPES_NAMES[curr_info.engine_type]);
else
seq_printf(s, "Unknown, introduced post-Lovelace)\n");
seq_printf(s, "| instance %d\n", curr_info.inst_id);
seq_printf(s, "| Fault ID: %4d\n", curr_info.fault_id);
break;
case 1:
seq_printf(s, "| BAR0 Base %#.8x\n", curr_info.pri_base << 8);
seq_printf(s, "| Reset ID: %3d\n", curr_info.reset_id);
seq_printf(s, "| Is Engine: %1d\n", curr_info.is_engine);
break;
case 2:
seq_printf(s, "| Runlist Eng. ID: %1d\n", curr_info.rleng_id);
// Theoretically, we could extract an ID from the runlist RAM
seq_printf(s, "| RL Base: %#.8x\n", curr_info.runlist_pri_base << 10);
break;
default:
printk(KERN_WARNING "[nvdebug] Skipping unexpected continuation of device_info entry (idx: %d, raw: %#0x)\n", iter->idx, curr_info.raw);
}
// Draw a line between each device entry
if (!curr_info.has_next_entry)
seq_printf(s, "+---------------------+\n");
return 0;
}
static void device_info_file_seq_stop(struct seq_file *s, void *idx) {
// No cleanup needed
}
static struct seq_operations device_info_file_seq_ops = {
.start = device_info_file_seq_start,
.next = device_info_file_seq_next,
.stop = device_info_file_seq_stop,
};
static int device_info_file_open(struct inode *inode, struct file *f) {
if (g_nvdebug_state[file2parentgpuidx(f)].chip_id >= NV_CHIP_ID_AMPERE)
device_info_file_seq_ops.show = device_info_file_seq_show_ga100;
else
device_info_file_seq_ops.show = device_info_file_seq_show_gk104;
return seq_open(f, &device_info_file_seq_ops);
}
struct file_operations device_info_file_ops = {
.open = device_info_file_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
