Changeset c4cfe4c in mainline for kernel/genarch/src/drivers

Timestamp:

2025-04-17T16:01:16Z (9 months ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

master

Children:

888c06e

Parents:

1db4e2ae (diff), 250a435 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2025-04-17 15:51:11)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2025-04-17 16:01:16)

Message:

Convert kernel console writing to byte arrays

More buffer per buffer (the original char32_t buffer takes up four
times as much space for the same amount of backlog, which is wasteful).
It is also faster, possibly thanks to bigger chunks being processed in bulk.
Gonna try to figure out if the locking can be improved further.

Also changed to use a syscall for reading KIO buffer from uspace,
to allow better synchronization.

Location:

kernel/genarch/src/drivers

Files:

• ega/ega.c (modified) (3 diffs)
• ns16550/ns16550.c (modified) (1 diff)
• pl011/pl011.c (modified) (2 diffs)

kernel/genarch/src/drivers/ega/ega.c

@@ -69 +69 @@
         uint8_t *backbuf;
         ioport8_t *base;
+        mbstate_t mbstate;
 } ega_instance_t;
 
-static void ega_putuchar(outdev_t *, char32_t);
+static void ega_write(outdev_t *, const char *, size_t);
 static void ega_redraw(outdev_t *);
 
 static outdev_operations_t egadev_ops = {
-        .write = ega_putuchar,
+        .write = ega_write,
         .redraw = ega_redraw,
         .scroll_up = NULL,
@@ -538 +539 @@
 }
 
-static void ega_putuchar(outdev_t *dev, char32_t ch)
-{
-        ega_instance_t *instance = (ega_instance_t *) dev->data;
-
-        irq_spinlock_lock(&instance->lock, true);
-
+static void _putuchar(ega_instance_t *instance, char32_t ch)
+{
         switch (ch) {
         case '\n':
@@ -564 +561 @@
         ega_check_cursor(instance);
         ega_move_cursor(instance);
+}
+
+static void ega_write(outdev_t *dev, const char *s, size_t n)
+{
+        ega_instance_t *instance = (ega_instance_t *) dev->data;
+
+        irq_spinlock_lock(&instance->lock, true);
+
+        size_t offset = 0;
+        char32_t ch;
+
+        while ((ch = str_decode_r(s, &offset, n, U_SPECIAL, &instance->mbstate)))
+                _putuchar(instance, ch);
 
         irq_spinlock_unlock(&instance->lock, true);

kernel/genarch/src/drivers/ns16550/ns16550.c

@@ -112 +112 @@
 }
 
-static void ns16550_putuchar(outdev_t *dev, char32_t ch)
+static void ns16550_write(outdev_t *dev, const char *s, size_t n)
 {
         ns16550_instance_t *instance = (ns16550_instance_t *) dev->data;
 
-        if ((!instance->parea.mapped) || (console_override)) {
-                if (ch == '\n')
+        if (instance->parea.mapped && !console_override)
+                return;
+
+        const char *top = s + n;
+        assert(top >= s);
+
+        for (; s < top; s++) {
+                if (*s == '\n')
                         ns16550_sendb(instance, '\r');
 
-                if (ascii_check(ch))
-                        ns16550_sendb(instance, (uint8_t) ch);
-                else
-                        ns16550_sendb(instance, U_SPECIAL);
+                ns16550_sendb(instance, (uint8_t) *s);
         }
 }
 
 static outdev_operations_t ns16550_ops = {
-        .write = ns16550_putuchar,
+        .write = ns16550_write,
         .redraw = NULL
 };

kernel/genarch/src/drivers/pl011/pl011.c

@@ -56 +56 @@
 }
 
-static void pl011_uart_putuchar(outdev_t *dev, char32_t ch)
+static void pl011_uart_write(outdev_t *dev, const char *s, size_t n)
 {
         pl011_uart_t *uart = dev->data;
@@ -64 +64 @@
                 return;
 
-        if (!ascii_check(ch))
-                pl011_uart_sendb(uart, U_SPECIAL);
-        else {
-                if (ch == '\n')
-                        pl011_uart_sendb(uart, (uint8_t) '\r');
-                pl011_uart_sendb(uart, (uint8_t) ch);
+        const char *top = s + n;
+        assert(top >= s);
+
+        for (; s < top; s++) {
+                if (*s == '\n')
+                        pl011_uart_sendb(uart, '\r');
+
+                pl011_uart_sendb(uart, (uint8_t) *s);
         }
 }
 
 static outdev_operations_t pl011_uart_ops = {
-        .write = pl011_uart_putuchar,
+        .write = pl011_uart_write,
         .redraw = NULL,
         .scroll_up = NULL,