drm/radeon: gcc fixes for radeon_atombios.c

Newer versions of gcc seem to wander off into the
weeds when dealing with variable sizes arrays in
structs.  Rather than indexing the arrays, use
pointer arithmetic.

See bugs:
https://bugs.freedesktop.org/show_bug.cgi?id=66932
https://bugs.freedesktop.org/show_bug.cgi?id=66972
https://bugs.freedesktop.org/show_bug.cgi?id=66945

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index ad91354..404e25d 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -163,8 +163,8 @@ static struct radeon_i2c_bus_rec radeon_lookup_i2c_gpio(struct radeon_device *rd
                num_indices = (size - sizeof(ATOM_COMMON_TABLE_HEADER)) /
                        sizeof(ATOM_GPIO_I2C_ASSIGMENT);
 
+               gpio = &i2c_info->asGPIO_Info[0];
                for (i = 0; i < num_indices; i++) {
-                       gpio = &i2c_info->asGPIO_Info[i];
 
                        radeon_lookup_i2c_gpio_quirks(rdev, gpio, i);
 
@@ -172,6 +172,8 @@ static struct radeon_i2c_bus_rec radeon_lookup_i2c_gpio(struct radeon_device *rd
                                i2c = radeon_get_bus_rec_for_i2c_gpio(gpio);
                                break;
                        }
+                       gpio = (ATOM_GPIO_I2C_ASSIGMENT *)
+                               ((u8 *)gpio + sizeof(ATOM_GPIO_I2C_ASSIGMENT));
                }
        }
 
@@ -195,9 +197,8 @@ void radeon_atombios_i2c_init(struct radeon_device *rdev)
                num_indices = (size - sizeof(ATOM_COMMON_TABLE_HEADER)) /
                        sizeof(ATOM_GPIO_I2C_ASSIGMENT);
 
+               gpio = &i2c_info->asGPIO_Info[0];
                for (i = 0; i < num_indices; i++) {
-                       gpio = &i2c_info->asGPIO_Info[i];
-
                        radeon_lookup_i2c_gpio_quirks(rdev, gpio, i);
 
                        i2c = radeon_get_bus_rec_for_i2c_gpio(gpio);
@@ -206,6 +207,8 @@ void radeon_atombios_i2c_init(struct radeon_device *rdev)
                                sprintf(stmp, "0x%x", i2c.i2c_id);
                                rdev->i2c_bus[i] = radeon_i2c_create(rdev->ddev, &i2c, stmp);
                        }
+                       gpio = (ATOM_GPIO_I2C_ASSIGMENT *)
+                               ((u8 *)gpio + sizeof(ATOM_GPIO_I2C_ASSIGMENT));
                }
        }
 }
@@ -230,8 +233,8 @@ static struct radeon_gpio_rec radeon_lookup_gpio(struct radeon_device *rdev,
                num_indices = (size - sizeof(ATOM_COMMON_TABLE_HEADER)) /
                        sizeof(ATOM_GPIO_PIN_ASSIGNMENT);
 
+               pin = gpio_info->asGPIO_Pin;
                for (i = 0; i < num_indices; i++) {
-                       pin = &gpio_info->asGPIO_Pin[i];
                        if (id == pin->ucGPIO_ID) {
                                gpio.id = pin->ucGPIO_ID;
                                gpio.reg = le16_to_cpu(pin->usGpioPin_AIndex) * 4;
@@ -239,6 +242,8 @@ static struct radeon_gpio_rec radeon_lookup_gpio(struct radeon_device *rdev,
                                gpio.valid = true;
                                break;
                        }
+                       pin = (ATOM_GPIO_PIN_ASSIGNMENT *)
+                               ((u8 *)pin + sizeof(ATOM_GPIO_PIN_ASSIGNMENT));
                }
        }
 
@@ -3413,10 +3418,11 @@ int radeon_atom_get_max_voltage(struct radeon_device *rdev,
                                ATOM_VOLTAGE_FORMULA_V2 *formula =
                                        &voltage_object->v2.asFormula;
                                if (formula->ucNumOfVoltageEntries) {
+                                       VOLTAGE_LUT_ENTRY *lut = (VOLTAGE_LUT_ENTRY *)
+                                               ((u8 *)&formula->asVIDAdjustEntries[0] +
+                                                (sizeof(VOLTAGE_LUT_ENTRY) * (formula->ucNumOfVoltageEntries - 1)));
                                        *max_voltage =
-                                               le16_to_cpu(formula->asVIDAdjustEntries[
-                                                                   formula->ucNumOfVoltageEntries - 1
-                                                                   ].usVoltageValue);
+                                               le16_to_cpu(lut->usVoltageValue);
                                        return 0;
                                }
                        }
@@ -3576,11 +3582,13 @@ int radeon_atom_get_voltage_table(struct radeon_device *rdev,
                                if (voltage_object) {
                                        ATOM_VOLTAGE_FORMULA_V2 *formula =
                                                &voltage_object->v2.asFormula;
+                                       VOLTAGE_LUT_ENTRY *lut;
                                        if (formula->ucNumOfVoltageEntries > MAX_VOLTAGE_ENTRIES)
                                                return -EINVAL;
+                                       lut = &formula->asVIDAdjustEntries[0];
                                        for (i = 0; i < formula->ucNumOfVoltageEntries; i++) {
                                                voltage_table->entries[i].value =
-                                                       le16_to_cpu(formula->asVIDAdjustEntries[i].usVoltageValue);
+                                                       le16_to_cpu(lut->usVoltageValue);
                                                ret = radeon_atom_get_voltage_gpio_settings(rdev,
                                                                                            voltage_table->entries[i].value,
                                                                                            voltage_type,
@@ -3588,6 +3596,8 @@ int radeon_atom_get_voltage_table(struct radeon_device *rdev,
                                                                                            &voltage_table->mask_low);
                                                if (ret)
                                                        return ret;
+                                               lut = (VOLTAGE_LUT_ENTRY *)
+                                                       ((u8 *)lut + sizeof(VOLTAGE_LUT_ENTRY));
                                        }
                                        voltage_table->count = formula->ucNumOfVoltageEntries;
                                        return 0;
@@ -3607,13 +3617,17 @@ int radeon_atom_get_voltage_table(struct radeon_device *rdev,
                                if (voltage_object) {
                                        ATOM_GPIO_VOLTAGE_OBJECT_V3 *gpio =
                                                &voltage_object->v3.asGpioVoltageObj;
+                                       VOLTAGE_LUT_ENTRY_V2 *lut;
                                        if (gpio->ucGpioEntryNum > MAX_VOLTAGE_ENTRIES)
                                                return -EINVAL;
+                                       lut = &gpio->asVolGpioLut[0];
                                        for (i = 0; i < gpio->ucGpioEntryNum; i++) {
                                                voltage_table->entries[i].value =
-                                                       le16_to_cpu(gpio->asVolGpioLut[i].usVoltageValue);
+                                                       le16_to_cpu(lut->usVoltageValue);
                                                voltage_table->entries[i].smio_low =
-                                                       le32_to_cpu(gpio->asVolGpioLut[i].ulVoltageId);
+                                                       le32_to_cpu(lut->ulVoltageId);
+                                               lut = (VOLTAGE_LUT_ENTRY_V2 *)
+                                                       ((u8 *)lut + sizeof(VOLTAGE_LUT_ENTRY_V2));
                                        }
                                        voltage_table->mask_low = le32_to_cpu(gpio->ulGpioMaskVal);
                                        voltage_table->count = gpio->ucGpioEntryNum;
@@ -3739,7 +3753,6 @@ int radeon_atom_get_mclk_range_table(struct radeon_device *rdev,
        union vram_info *vram_info;
        u32 mem_timing_size = gddr5 ?
                sizeof(ATOM_MEMORY_TIMING_FORMAT_V2) : sizeof(ATOM_MEMORY_TIMING_FORMAT);
-       u8 *p;
 
        memset(mclk_range_table, 0, sizeof(struct atom_memory_clock_range_table));
 
@@ -3758,6 +3771,7 @@ int radeon_atom_get_mclk_range_table(struct radeon_device *rdev,
                                if (module_index < vram_info->v1_4.ucNumOfVRAMModule) {
                                        ATOM_VRAM_MODULE_V4 *vram_module =
                                                (ATOM_VRAM_MODULE_V4 *)vram_info->v1_4.aVramInfo;
+                                       ATOM_MEMORY_TIMING_FORMAT *format;
 
                                        for (i = 0; i < module_index; i++) {
                                                if (le16_to_cpu(vram_module->usModuleSize) == 0)
@@ -3768,11 +3782,11 @@ int radeon_atom_get_mclk_range_table(struct radeon_device *rdev,
                                        mclk_range_table->num_entries = (u8)
                                                ((le16_to_cpu(vram_module->usModuleSize) - offsetof(ATOM_VRAM_MODULE_V4, asMemTiming)) /
                                                 mem_timing_size);
-                                       p = (u8 *)&vram_module->asMemTiming[0];
+                                       format = &vram_module->asMemTiming[0];
                                        for (i = 0; i < mclk_range_table->num_entries; i++) {
-                                               ATOM_MEMORY_TIMING_FORMAT *format = (ATOM_MEMORY_TIMING_FORMAT *)p;
                                                mclk_range_table->mclk[i] = le32_to_cpu(format->ulClkRange);
-                                               p += mem_timing_size;
+                                               format = (ATOM_MEMORY_TIMING_FORMAT *)
+                                                       ((u8 *)format + mem_timing_size);
                                        }
                                } else
                                        return -EINVAL;