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hp-wmi: allow setting input and output buffer sizes separately
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Split buffersize parameter of hp_wmi_perform_query to insize and
outsize. Existing callers are changed to use the same value for insize
and outsize to avoid any regressions, with the exception of
hp_wmi_set_block where the output buffer is unused and therefore outsize
is set to 0 (this change is not seen by BIOS code).

The maximum input buffer size is kept at 4 bytes as per struct
bios_args. Some commands exist that take longer buffers, but they
haven't been implemented. The data portion of bios_args can be trivially
made dynamically allocated later when such larger buffers become needed.

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
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Anssi Hannula authored and Matthew Garrett committed Mar 28, 2011
1 parent 25bb067 commit c3021ea
Showing 1 changed file with 39 additions and 24 deletions.
63 changes: 39 additions & 24 deletions drivers/platform/x86/hp-wmi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -86,7 +86,6 @@ struct bios_args {
struct bios_return {
u32 sigpass;
u32 return_code;
u32 value;
};

enum hp_return_value {
Expand Down Expand Up @@ -136,7 +135,8 @@ static struct platform_driver hp_wmi_driver = {
* query: The commandtype -> What should be queried
* write: The command -> 0 read, 1 write, 3 ODM specific
* buffer: Buffer used as input and/or output
* buffersize: Size of buffer
* insize: Size of input buffer
* outsize: Size of output buffer
*
* returns zero on success
* an HP WMI query specific error code (which is positive)
Expand All @@ -147,23 +147,28 @@ static struct platform_driver hp_wmi_driver = {
* size. E.g. Battery info query (0x7) is defined to have 1 byte input
* and 128 byte output. The caller would do:
* buffer = kzalloc(128, GFP_KERNEL);
* ret = hp_wmi_perform_query(0x7, 0, buffer, 128)
* ret = hp_wmi_perform_query(0x7, 0, buffer, 1, 128)
*/
static int hp_wmi_perform_query(int query, int write, u32 *buffer,
int buffersize)
static int hp_wmi_perform_query(int query, int write, void *buffer,
int insize, int outsize)
{
struct bios_return bios_return;
struct bios_return *bios_return;
int actual_outsize;
union acpi_object *obj;
struct bios_args args = {
.signature = 0x55434553,
.command = write ? 0x2 : 0x1,
.commandtype = query,
.datasize = buffersize,
.data = *buffer,
.datasize = insize,
.data = 0,
};
struct acpi_buffer input = { sizeof(struct bios_args), &args };
struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };

if (WARN_ON(insize > sizeof(args.data)))
return -EINVAL;
memcpy(&args.data, buffer, insize);

wmi_evaluate_method(HPWMI_BIOS_GUID, 0, 0x3, &input, &output);

obj = output.pointer;
Expand All @@ -175,19 +180,26 @@ static int hp_wmi_perform_query(int query, int write, u32 *buffer,
return -EINVAL;
}

bios_return = *((struct bios_return *)obj->buffer.pointer);
bios_return = (struct bios_return *)obj->buffer.pointer;

if (bios_return.return_code) {
if (bios_return.return_code != HPWMI_RET_UNKNOWN_CMDTYPE)
if (bios_return->return_code) {
if (bios_return->return_code != HPWMI_RET_UNKNOWN_CMDTYPE)
printk(KERN_WARNING PREFIX "query 0x%x returned "
"error 0x%x\n",
query, bios_return.return_code);
query, bios_return->return_code);
kfree(obj);
return bios_return.return_code;
return bios_return->return_code;
}

memcpy(buffer, &bios_return.value, sizeof(bios_return.value));
if (!outsize) {
/* ignore output data */
kfree(obj);
return 0;
}

actual_outsize = min(outsize, (int)(obj->buffer.length - sizeof(*bios_return)));
memcpy(buffer, obj->buffer.pointer + sizeof(*bios_return), actual_outsize);
memset(buffer + actual_outsize, 0, outsize - actual_outsize);
kfree(obj);
return 0;
}
Expand All @@ -196,7 +208,7 @@ static int hp_wmi_display_state(void)
{
int state = 0;
int ret = hp_wmi_perform_query(HPWMI_DISPLAY_QUERY, 0, &state,
sizeof(state));
sizeof(state), sizeof(state));
if (ret)
return -EINVAL;
return state;
Expand All @@ -206,7 +218,7 @@ static int hp_wmi_hddtemp_state(void)
{
int state = 0;
int ret = hp_wmi_perform_query(HPWMI_HDDTEMP_QUERY, 0, &state,
sizeof(state));
sizeof(state), sizeof(state));
if (ret)
return -EINVAL;
return state;
Expand All @@ -216,7 +228,7 @@ static int hp_wmi_als_state(void)
{
int state = 0;
int ret = hp_wmi_perform_query(HPWMI_ALS_QUERY, 0, &state,
sizeof(state));
sizeof(state), sizeof(state));
if (ret)
return -EINVAL;
return state;
Expand All @@ -226,7 +238,7 @@ static int hp_wmi_dock_state(void)
{
int state = 0;
int ret = hp_wmi_perform_query(HPWMI_HARDWARE_QUERY, 0, &state,
sizeof(state));
sizeof(state), sizeof(state));

if (ret)
return -EINVAL;
Expand All @@ -238,7 +250,7 @@ static int hp_wmi_tablet_state(void)
{
int state = 0;
int ret = hp_wmi_perform_query(HPWMI_HARDWARE_QUERY, 0, &state,
sizeof(state));
sizeof(state), sizeof(state));
if (ret)
return ret;

Expand All @@ -252,7 +264,7 @@ static int hp_wmi_set_block(void *data, bool blocked)
int ret;

ret = hp_wmi_perform_query(HPWMI_WIRELESS_QUERY, 1,
&query, sizeof(query));
&query, sizeof(query), 0);
if (ret)
return -EINVAL;
return 0;
Expand All @@ -267,7 +279,8 @@ static bool hp_wmi_get_sw_state(enum hp_wmi_radio r)
int wireless = 0;
int mask;
hp_wmi_perform_query(HPWMI_WIRELESS_QUERY, 0,
&wireless, sizeof(wireless));
&wireless, sizeof(wireless),
sizeof(wireless));
/* TBD: Pass error */

mask = 0x200 << (r * 8);
Expand All @@ -283,7 +296,8 @@ static bool hp_wmi_get_hw_state(enum hp_wmi_radio r)
int wireless = 0;
int mask;
hp_wmi_perform_query(HPWMI_WIRELESS_QUERY, 0,
&wireless, sizeof(wireless));
&wireless, sizeof(wireless),
sizeof(wireless));
/* TBD: Pass error */

mask = 0x800 << (r * 8);
Expand Down Expand Up @@ -344,7 +358,7 @@ static ssize_t set_als(struct device *dev, struct device_attribute *attr,
{
u32 tmp = simple_strtoul(buf, NULL, 10);
int ret = hp_wmi_perform_query(HPWMI_ALS_QUERY, 1, &tmp,
sizeof(tmp));
sizeof(tmp), sizeof(tmp));
if (ret)
return -EINVAL;

Expand Down Expand Up @@ -417,6 +431,7 @@ static void hp_wmi_notify(u32 value, void *context)
case HPWMI_BEZEL_BUTTON:
ret = hp_wmi_perform_query(HPWMI_HOTKEY_QUERY, 0,
&key_code,
sizeof(key_code),
sizeof(key_code));
if (ret)
break;
Expand Down Expand Up @@ -523,7 +538,7 @@ static int __devinit hp_wmi_bios_setup(struct platform_device *device)
int wireless = 0;

err = hp_wmi_perform_query(HPWMI_WIRELESS_QUERY, 0, &wireless,
sizeof(wireless));
sizeof(wireless), sizeof(wireless));
if (err)
return err;

Expand Down

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