From 47db243233cdf9cafc5148e2026aa55b119a59ec Mon Sep 17 00:00:00 2001 From: =?utf8?q?Volker=20R=C3=BCmelin?= Date: Tue, 10 Aug 2021 15:32:56 +0200 Subject: [PATCH] ps2: use the whole ps2 buffer but keep queue size MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Extend the used ps2 buffer size to the available buffer size but keep the maximum ps2 queue size. The next patch needs a few bytes of the larger buffer size. Signed-off-by: Volker Rümelin Message-Id: <20210810133258.8231-1-vr_qemu@t-online.de> Signed-off-by: Gerd Hoffmann --- hw/input/ps2.c | 69 +++++++++++++++++----------------------------------------- 1 file changed, 20 insertions(+), 49 deletions(-) diff --git a/hw/input/ps2.c b/hw/input/ps2.c index 8dd482c1f6..23e7befee5 100644 --- a/hw/input/ps2.c +++ b/hw/input/ps2.c @@ -74,7 +74,12 @@ #define MOUSE_STATUS_ENABLED 0x20 #define MOUSE_STATUS_SCALE21 0x10 -#define PS2_QUEUE_SIZE 16 /* Buffer size required by PS/2 protocol */ +/* + * PS/2 buffer size. Keep 256 bytes for compatibility with + * older QEMU versions. + */ +#define PS2_BUFFER_SIZE 256 +#define PS2_QUEUE_SIZE 16 /* Queue size required by PS/2 protocol */ /* Bits for 'modifiers' field in PS2KbdState */ #define MOD_CTRL_L (1 << 0) @@ -85,9 +90,7 @@ #define MOD_ALT_R (1 << 5) typedef struct { - /* Keep the data array 256 bytes long, which compatibility - with older qemu versions. */ - uint8_t data[256]; + uint8_t data[PS2_BUFFER_SIZE]; int rptr, wptr, count; } PS2Queue; @@ -200,8 +203,9 @@ void ps2_queue_noirq(PS2State *s, int b) } q->data[q->wptr] = b; - if (++q->wptr == PS2_QUEUE_SIZE) + if (++q->wptr == PS2_BUFFER_SIZE) { q->wptr = 0; + } q->count++; } @@ -509,13 +513,15 @@ uint32_t ps2_read_data(PS2State *s) (needed for EMM386) */ /* XXX: need a timer to do things correctly */ index = q->rptr - 1; - if (index < 0) - index = PS2_QUEUE_SIZE - 1; + if (index < 0) { + index = PS2_BUFFER_SIZE - 1; + } val = q->data[index]; } else { val = q->data[q->rptr]; - if (++q->rptr == PS2_QUEUE_SIZE) + if (++q->rptr == PS2_BUFFER_SIZE) { q->rptr = 0; + } q->count--; /* reading deasserts IRQ */ s->update_irq(s->update_arg, 0); @@ -926,30 +932,17 @@ static void ps2_common_reset(PS2State *s) static void ps2_common_post_load(PS2State *s) { PS2Queue *q = &s->queue; - uint8_t i, size; - uint8_t tmp_data[PS2_QUEUE_SIZE]; - /* set the useful data buffer queue size, < PS2_QUEUE_SIZE */ - size = q->count; + /* set the useful data buffer queue size <= PS2_QUEUE_SIZE */ if (q->count < 0) { - size = 0; + q->count = 0; } else if (q->count > PS2_QUEUE_SIZE) { - size = PS2_QUEUE_SIZE; - } - - /* move the queue elements to the start of data array */ - for (i = 0; i < size; i++) { - if (q->rptr < 0 || q->rptr >= sizeof(q->data)) { - q->rptr = 0; - } - tmp_data[i] = q->data[q->rptr++]; + q->count = PS2_QUEUE_SIZE; } - memcpy(q->data, tmp_data, size); - /* reset rptr/wptr/count */ - q->rptr = 0; - q->wptr = (size == PS2_QUEUE_SIZE) ? 0 : size; - q->count = size; + /* sanitize rptr and recalculate wptr */ + q->rptr = q->rptr & (PS2_BUFFER_SIZE - 1); + q->wptr = (q->rptr + q->count) & (PS2_BUFFER_SIZE - 1); } static void ps2_kbd_reset(void *opaque) @@ -1053,22 +1046,11 @@ static int ps2_kbd_post_load(void* opaque, int version_id) return 0; } -static int ps2_kbd_pre_save(void *opaque) -{ - PS2KbdState *s = (PS2KbdState *)opaque; - PS2State *ps2 = &s->common; - - ps2_common_post_load(ps2); - - return 0; -} - static const VMStateDescription vmstate_ps2_keyboard = { .name = "ps2kbd", .version_id = 3, .minimum_version_id = 2, .post_load = ps2_kbd_post_load, - .pre_save = ps2_kbd_pre_save, .fields = (VMStateField[]) { VMSTATE_STRUCT(common, PS2KbdState, 0, vmstate_ps2_common, PS2State), VMSTATE_INT32(scan_enabled, PS2KbdState), @@ -1093,22 +1075,11 @@ static int ps2_mouse_post_load(void *opaque, int version_id) return 0; } -static int ps2_mouse_pre_save(void *opaque) -{ - PS2MouseState *s = (PS2MouseState *)opaque; - PS2State *ps2 = &s->common; - - ps2_common_post_load(ps2); - - return 0; -} - static const VMStateDescription vmstate_ps2_mouse = { .name = "ps2mouse", .version_id = 2, .minimum_version_id = 2, .post_load = ps2_mouse_post_load, - .pre_save = ps2_mouse_pre_save, .fields = (VMStateField[]) { VMSTATE_STRUCT(common, PS2MouseState, 0, vmstate_ps2_common, PS2State), VMSTATE_UINT8(mouse_status, PS2MouseState), -- 2.11.0