1 files changed, 143 insertions, 0 deletions

diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c
index d20961011039..a5afd805e66f 100644
--- a/drivers/firmware/dmi-sysfs.c
+++ b/drivers/firmware/dmi-sysfs.c
@@ -312,6 +312,140 @@ static struct kobj_type dmi_system_event_log_ktype = {
         .default_attrs = dmi_sysfs_sel_attrs,
 };
 
+typedef u8 (*sel_io_reader)(const struct dmi_system_event_log *sel,
+                            loff_t offset);
+
+static DEFINE_MUTEX(io_port_lock);
+
+static u8 read_sel_8bit_indexed_io(const struct dmi_system_event_log *sel,
+                                   loff_t offset)
+{
+        u8 ret;
+
+        mutex_lock(&io_port_lock);
+        outb((u8)offset, sel->io.index_addr);
+        ret = inb(sel->io.data_addr);
+        mutex_unlock(&io_port_lock);
+        return ret;
+}
+
+static u8 read_sel_2x8bit_indexed_io(const struct dmi_system_event_log *sel,
+                                     loff_t offset)
+{
+        u8 ret;
+
+        mutex_lock(&io_port_lock);
+        outb((u8)offset, sel->io.index_addr);
+        outb((u8)(offset >> 8), sel->io.index_addr + 1);
+        ret = inb(sel->io.data_addr);
+        mutex_unlock(&io_port_lock);
+        return ret;
+}
+
+static u8 read_sel_16bit_indexed_io(const struct dmi_system_event_log *sel,
+                                    loff_t offset)
+{
+        u8 ret;
+
+        mutex_lock(&io_port_lock);
+        outw((u16)offset, sel->io.index_addr);
+        ret = inb(sel->io.data_addr);
+        mutex_unlock(&io_port_lock);
+        return ret;
+}
+
+static sel_io_reader sel_io_readers[] = {
+        [DMI_SEL_ACCESS_METHOD_IO8]     = read_sel_8bit_indexed_io,
+        [DMI_SEL_ACCESS_METHOD_IO2x8]   = read_sel_2x8bit_indexed_io,
+        [DMI_SEL_ACCESS_METHOD_IO16]    = read_sel_16bit_indexed_io,
+};
+
+static ssize_t dmi_sel_raw_read_io(struct dmi_sysfs_entry *entry,
+                                   const struct dmi_system_event_log *sel,
+                                   char *buf, loff_t pos, size_t count)
+{
+        ssize_t wrote = 0;
+
+        sel_io_reader io_reader = sel_io_readers[sel->access_method];
+
+        while (count && pos < sel->area_length) {
+                count--;
+                *(buf++) = io_reader(sel, pos++);
+                wrote++;
+        }
+
+        return wrote;
+}
+
+static ssize_t dmi_sel_raw_read_phys32(struct dmi_sysfs_entry *entry,
+                                       const struct dmi_system_event_log *sel,
+                                       char *buf, loff_t pos, size_t count)
+{
+        u8 __iomem *mapped;
+        ssize_t wrote = 0;
+
+        mapped = ioremap(sel->access_method_address, sel->area_length);
+        if (!mapped)
+                return -EIO;
+
+        while (count && pos < sel->area_length) {
+                count--;
+                *(buf++) = readb(mapped + pos++);
+                wrote++;
+        }
+
+        iounmap(mapped);
+        return wrote;
+}
+
+static ssize_t dmi_sel_raw_read_helper(struct dmi_sysfs_entry *entry,
+                                       const struct dmi_header *dh,
+                                       void *_state)
+{
+        struct dmi_read_state *state = _state;
+        const struct dmi_system_event_log *sel = to_sel(dh);
+
+        if (sizeof(*sel) > dmi_entry_length(dh))
+                return -EIO;
+
+        switch (sel->access_method) {
+        case DMI_SEL_ACCESS_METHOD_IO8:
+        case DMI_SEL_ACCESS_METHOD_IO2x8:
+        case DMI_SEL_ACCESS_METHOD_IO16:
+                return dmi_sel_raw_read_io(entry, sel, state->buf,
+                                           state->pos, state->count);
+        case DMI_SEL_ACCESS_METHOD_PHYS32:
+                return dmi_sel_raw_read_phys32(entry, sel, state->buf,
+                                               state->pos, state->count);
+        case DMI_SEL_ACCESS_METHOD_GPNV:
+                pr_info("dmi-sysfs: GPNV support missing.\n");
+                return -EIO;
+        default:
+                pr_info("dmi-sysfs: Unknown access method %02x\n",
+                        sel->access_method);
+                return -EIO;
+        }
+}
+
+static ssize_t dmi_sel_raw_read(struct file *filp, struct kobject *kobj,
+                                struct bin_attribute *bin_attr,
+                                char *buf, loff_t pos, size_t count)
+{
+        struct dmi_sysfs_entry *entry = to_entry(kobj->parent);
+        struct dmi_read_state state = {
+                .buf = buf,
+                .pos = pos,
+                .count = count,
+        };
+
+        return find_dmi_entry(entry, dmi_sel_raw_read_helper, &state);
+}
+
+static struct bin_attribute dmi_sel_raw_attr = {
+        .attr = {.name = "raw_event_log", .mode = 0400},
+        .read = dmi_sel_raw_read,
+};
+
 static int dmi_system_event_log(struct dmi_sysfs_entry *entry)
 {
         int ret;
@@ -325,6 +459,15 @@ static int dmi_system_event_log(struct dmi_sysfs_entry *entry)
                                    "system_event_log");
         if (ret)
                 goto out_free;
+
+        ret = sysfs_create_bin_file(entry->child, &dmi_sel_raw_attr);
+        if (ret)
+                goto out_del;
+
+        return 0;
+
+out_del:
+        kobject_del(entry->child);
 out_free:
         kfree(entry->child);
         return ret;