On Thu, 11 Feb 2021 16:55:43 +0000
Alexandru Elisei [off-list ref] wrote:

Hi,

On 12/10/20 2:28 PM, Andre Przywara wrote:

quoted

The i8042 is clearly an 8-bit era device, so there is little room for
32-bit registers.
Clean up the data types used.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 hw/i8042.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/hw/i8042.c b/hw/i8042.c
index 37a99a2d..36ee183f 100644
--- a/hw/i8042.c
+++ b/hw/i8042.c

@@ -64,11 +64,11 @@
 struct kbd_state {
 	struct kvm		*kvm;
 
-	char			kq[QUEUE_SIZE];	/* Keyboard queue */
+	u8			kq[QUEUE_SIZE];	/* Keyboard queue */
 	int			kread, kwrite;	/* Indexes into the queue */
 	int			kcount;		/* number of elements in queue */
 
-	char			mq[QUEUE_SIZE];
+	u8			mq[QUEUE_SIZE];
 	int			mread, mwrite;
 	int			mcount;  

I think the write_cmd field further down should also be u8 because it stores the
first byte of a command (and it's set only to an 8 bit value in kbd_write_command()).

Yes, looks like it, will change it on the way. I guess I wanted to
suppress my rewrite-everything complex ;-)

If you allow, I will also fix the confusing indentation bug in the big
switch statement on the way.
 

Otherwise, it looks ok to me. osdev wiki seems to confirm that the device is
indeed 8 bit only, and all the registers are 8 bit now:

Reviewed-by: Alexandru Elisei <redacted>

Thanks!
Andre

quoted

@@ -173,9 +173,9 @@ static void kbd_write_command(struct kvm *kvm, u8 val)
 /*
  * Called when the OS reads from port 0x60 (PS/2 data)
  */
-static u32 kbd_read_data(void)
+static u8 kbd_read_data(void)
 {
-	u32 ret;
+	u8 ret;
 	int i;
 
 	if (state.kcount != 0) {

@@ -202,9 +202,9 @@ static u32 kbd_read_data(void)
 /*
  * Called when the OS read from port 0x64, the command port
  */
-static u32 kbd_read_status(void)
+static u8 kbd_read_status(void)
 {
-	return (u32)state.status;
+	return state.status;
 }
 
 /*

@@ -212,7 +212,7 @@ static u32 kbd_read_status(void)
  * Things written here are generally arguments to commands previously
  * written to port 0x64 and stored in state.write_cmd
  */
-static void kbd_write_data(u32 val)
+static void kbd_write_data(u8 val)
 {
 	switch (state.write_cmd) {
 	case I8042_CMD_CTL_WCTR:

@@ -304,8 +304,8 @@ static bool kbd_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *
 		break;
 	}
 	case I8042_DATA_REG: {
-		u32 value = kbd_read_data();
-		ioport__write32(data, value);
+		u8 value = kbd_read_data();
+		ioport__write8(data, value);
 		break;
 	}
 	case I8042_PORT_B_REG: {

@@ -328,7 +328,7 @@ static bool kbd_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void
 		break;
 	}
 	case I8042_DATA_REG: {
-		u32 value = ioport__read32(data);
+		u8 value = ioport__read8(data);
 		kbd_write_data(value);
 		break;
 	}  

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