示例#1
0
文件: hwregs.c 项目: AngleFork/linux
static u8
acpi_hw_get_access_bit_width(struct acpi_generic_address *reg, u8 max_bit_width)
{
	u64 address;

	if (!reg->access_width) {
		/*
		 * Detect old register descriptors where only the bit_width field
		 * makes senses. The target address is copied to handle possible
		 * alignment issues.
		 */
		ACPI_MOVE_64_TO_64(&address, &reg->address);
		if (!reg->bit_offset && reg->bit_width &&
		    ACPI_IS_POWER_OF_TWO(reg->bit_width) &&
		    ACPI_IS_ALIGNED(reg->bit_width, 8) &&
		    ACPI_IS_ALIGNED(address, reg->bit_width)) {
			return (reg->bit_width);
		} else {
			if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
				return (32);
			} else {
				return (max_bit_width);
			}
		}
	} else {
		return (1 << (reg->access_width + 2));
	}
}
示例#2
0
static u8
acpi_hw_get_access_bit_width(u64 address,
			     struct acpi_generic_address *reg, u8 max_bit_width)
{
	u8 access_bit_width;

	/*
	 * GAS format "register", used by FADT:
	 *  1. Detected if bit_offset is 0 and bit_width is 8/16/32/64;
	 *  2. access_size field is ignored and bit_width field is used for
	 *     determining the boundary of the IO accesses.
	 * GAS format "region", used by APEI registers:
	 *  1. Detected if bit_offset is not 0 or bit_width is not 8/16/32/64;
	 *  2. access_size field is used for determining the boundary of the
	 *     IO accesses;
	 *  3. bit_offset/bit_width fields are used to describe the "region".
	 *
	 * Note: This algorithm assumes that the "Address" fields should always
	 *       contain aligned values.
	 */
	if (!reg->bit_offset && reg->bit_width &&
	    ACPI_IS_POWER_OF_TWO(reg->bit_width) &&
	    ACPI_IS_ALIGNED(reg->bit_width, 8)) {
		access_bit_width = reg->bit_width;
	} else if (reg->access_width) {
		access_bit_width = ACPI_ACCESS_BIT_WIDTH(reg->access_width);
	} else {
		access_bit_width =
		    ACPI_ROUND_UP_POWER_OF_TWO_8(reg->bit_offset +
						 reg->bit_width);
		if (access_bit_width <= 8) {
			access_bit_width = 8;
		} else {
			while (!ACPI_IS_ALIGNED(address, access_bit_width >> 3)) {
				access_bit_width >>= 1;
			}
		}
	}

	/* Maximum IO port access bit width is 32 */

	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
		max_bit_width = 32;
	}

	/*
	 * Return access width according to the requested maximum access bit width,
	 * as the caller should know the format of the register and may enforce
	 * a 32-bit accesses.
	 */
	if (access_bit_width < max_bit_width) {
		return (access_bit_width);
	}
	return (max_bit_width);
}
示例#3
0
static u8
acpi_hw_get_access_bit_width(struct acpi_generic_address *reg, u8 max_bit_width)
{
	if (!reg->access_width) {
		if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
			max_bit_width = 32;
		}

		/*
		 * Detect old register descriptors where only the bit_width field
		 * makes senses.
		 */
		if (reg->bit_width < max_bit_width &&
		    !reg->bit_offset && reg->bit_width &&
		    ACPI_IS_POWER_OF_TWO(reg->bit_width) &&
		    ACPI_IS_ALIGNED(reg->bit_width, 8)) {
			return (reg->bit_width);
		}
		return (max_bit_width);
	} else {
		return (1 << (reg->access_width + 2));
	}
}
示例#4
0
static UINT8
AcpiHwGetAccessBitWidth (
    UINT64                  Address,
    ACPI_GENERIC_ADDRESS    *Reg,
    UINT8                   MaxBitWidth)
{
    UINT8                   AccessBitWidth;


    /*
     * GAS format "register", used by FADT:
     *  1. Detected if BitOffset is 0 and BitWidth is 8/16/32/64;
     *  2. AccessSize field is ignored and BitWidth field is used for
     *     determining the boundary of the IO accesses.
     * GAS format "region", used by APEI registers:
     *  1. Detected if BitOffset is not 0 or BitWidth is not 8/16/32/64;
     *  2. AccessSize field is used for determining the boundary of the
     *     IO accesses;
     *  3. BitOffset/BitWidth fields are used to describe the "region".
     *
     * Note: This algorithm assumes that the "Address" fields should always
     *       contain aligned values.
     */
    if (!Reg->BitOffset && Reg->BitWidth &&
        ACPI_IS_POWER_OF_TWO (Reg->BitWidth) &&
        ACPI_IS_ALIGNED (Reg->BitWidth, 8))
    {
        AccessBitWidth = Reg->BitWidth;
    }
    else if (Reg->AccessWidth)
    {
        AccessBitWidth = ACPI_ACCESS_BIT_WIDTH (Reg->AccessWidth);
    }
    else
    {
        AccessBitWidth = ACPI_ROUND_UP_POWER_OF_TWO_8 (
            Reg->BitOffset + Reg->BitWidth);
        if (AccessBitWidth <= 8)
        {
            AccessBitWidth = 8;
        }
        else
        {
            while (!ACPI_IS_ALIGNED (Address, AccessBitWidth >> 3))
            {
                AccessBitWidth >>= 1;
            }
        }
    }

    /* Maximum IO port access bit width is 32 */

    if (Reg->SpaceId == ACPI_ADR_SPACE_SYSTEM_IO)
    {
        MaxBitWidth = 32;
    }

    /*
     * Return access width according to the requested maximum access bit width,
     * as the caller should know the format of the register and may enforce
     * a 32-bit accesses.
     */
    if (AccessBitWidth < MaxBitWidth)
    {
        return (AccessBitWidth);
    }
    return (MaxBitWidth);
}