1 /*******************************************************************************
3 * Module Name: hwregs - Read/write access functions for the various ACPI
4 * control and status registers.
6 ******************************************************************************/
9 * Copyright (C) 2000 - 2017, Intel Corp.
10 * All rights reserved.
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13 * modification, are permitted provided that the following conditions
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21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
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24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
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49 #define _COMPONENT ACPI_HARDWARE
50 ACPI_MODULE_NAME ("hwregs")
53 #if (!ACPI_REDUCED_HARDWARE)
55 /* Local Prototypes */
58 AcpiHwGetAccessBitWidth (
60 ACPI_GENERIC_ADDRESS
*Reg
,
66 ACPI_GENERIC_ADDRESS
*RegisterA
,
67 ACPI_GENERIC_ADDRESS
*RegisterB
);
72 ACPI_GENERIC_ADDRESS
*RegisterA
,
73 ACPI_GENERIC_ADDRESS
*RegisterB
);
75 #endif /* !ACPI_REDUCED_HARDWARE */
78 /******************************************************************************
80 * FUNCTION: AcpiHwGetAccessBitWidth
82 * PARAMETERS: Address - GAS register address
83 * Reg - GAS register structure
84 * MaxBitWidth - Max BitWidth supported (32 or 64)
88 * DESCRIPTION: Obtain optimal access bit width
90 ******************************************************************************/
93 AcpiHwGetAccessBitWidth (
95 ACPI_GENERIC_ADDRESS
*Reg
,
102 * GAS format "register", used by FADT:
103 * 1. Detected if BitOffset is 0 and BitWidth is 8/16/32/64;
104 * 2. AccessSize field is ignored and BitWidth field is used for
105 * determining the boundary of the IO accesses.
106 * GAS format "region", used by APEI registers:
107 * 1. Detected if BitOffset is not 0 or BitWidth is not 8/16/32/64;
108 * 2. AccessSize field is used for determining the boundary of the
110 * 3. BitOffset/BitWidth fields are used to describe the "region".
112 * Note: This algorithm assumes that the "Address" fields should always
113 * contain aligned values.
115 if (!Reg
->BitOffset
&& Reg
->BitWidth
&&
116 ACPI_IS_POWER_OF_TWO (Reg
->BitWidth
) &&
117 ACPI_IS_ALIGNED (Reg
->BitWidth
, 8))
119 AccessBitWidth
= Reg
->BitWidth
;
121 else if (Reg
->AccessWidth
)
123 AccessBitWidth
= (1 << (Reg
->AccessWidth
+ 2));
127 AccessBitWidth
= ACPI_ROUND_UP_POWER_OF_TWO_8 (
128 Reg
->BitOffset
+ Reg
->BitWidth
);
129 if (AccessBitWidth
<= 8)
135 while (!ACPI_IS_ALIGNED (Address
, AccessBitWidth
>> 3))
137 AccessBitWidth
>>= 1;
142 /* Maximum IO port access bit width is 32 */
144 if (Reg
->SpaceId
== ACPI_ADR_SPACE_SYSTEM_IO
)
150 * Return access width according to the requested maximum access bit width,
151 * as the caller should know the format of the register and may enforce
154 if (AccessBitWidth
< MaxBitWidth
)
156 return (AccessBitWidth
);
158 return (MaxBitWidth
);
162 /******************************************************************************
164 * FUNCTION: AcpiHwValidateRegister
166 * PARAMETERS: Reg - GAS register structure
167 * MaxBitWidth - Max BitWidth supported (32 or 64)
168 * Address - Pointer to where the gas->address
173 * DESCRIPTION: Validate the contents of a GAS register. Checks the GAS
174 * pointer, Address, SpaceId, BitWidth, and BitOffset.
176 ******************************************************************************/
179 AcpiHwValidateRegister (
180 ACPI_GENERIC_ADDRESS
*Reg
,
188 /* Must have a valid pointer to a GAS structure */
192 return (AE_BAD_PARAMETER
);
196 * Copy the target address. This handles possible alignment issues.
197 * Address must not be null. A null address also indicates an optional
198 * ACPI register that is not supported, so no error message.
200 ACPI_MOVE_64_TO_64 (Address
, &Reg
->Address
);
203 return (AE_BAD_ADDRESS
);
206 /* Validate the SpaceID */
208 if ((Reg
->SpaceId
!= ACPI_ADR_SPACE_SYSTEM_MEMORY
) &&
209 (Reg
->SpaceId
!= ACPI_ADR_SPACE_SYSTEM_IO
))
211 ACPI_ERROR ((AE_INFO
,
212 "Unsupported address space: 0x%X", Reg
->SpaceId
));
216 /* Validate the AccessWidth */
218 if (Reg
->AccessWidth
> 4)
220 ACPI_ERROR ((AE_INFO
,
221 "Unsupported register access width: 0x%X", Reg
->AccessWidth
));
225 /* Validate the BitWidth, convert AccessWidth into number of bits */
227 AccessWidth
= AcpiHwGetAccessBitWidth (*Address
, Reg
, MaxBitWidth
);
228 BitWidth
= ACPI_ROUND_UP (Reg
->BitOffset
+ Reg
->BitWidth
, AccessWidth
);
229 if (MaxBitWidth
< BitWidth
)
231 ACPI_WARNING ((AE_INFO
,
232 "Requested bit width 0x%X is smaller than register bit width 0x%X",
233 MaxBitWidth
, BitWidth
));
241 /******************************************************************************
243 * FUNCTION: AcpiHwRead
245 * PARAMETERS: Value - Where the value is returned
246 * Reg - GAS register structure
250 * DESCRIPTION: Read from either memory or IO space. This is a 32-bit max
251 * version of AcpiRead, used internally since the overhead of
252 * 64-bit values is not needed.
254 * LIMITATIONS: <These limitations also apply to AcpiHwWrite>
255 * SpaceID must be SystemMemory or SystemIO.
257 ******************************************************************************/
262 ACPI_GENERIC_ADDRESS
*Reg
)
274 ACPI_FUNCTION_NAME (HwRead
);
277 /* Validate contents of the GAS register */
279 Status
= AcpiHwValidateRegister (Reg
, 32, &Address
);
280 if (ACPI_FAILURE (Status
))
286 * Initialize entire 32-bit return value to zero, convert AccessWidth
287 * into number of bits based
290 AccessWidth
= AcpiHwGetAccessBitWidth (Address
, Reg
, 32);
291 BitWidth
= Reg
->BitOffset
+ Reg
->BitWidth
;
292 BitOffset
= Reg
->BitOffset
;
295 * Two address spaces supported: Memory or IO. PCI_Config is
296 * not supported here because the GAS structure is insufficient
301 if (BitOffset
>= AccessWidth
)
304 BitOffset
-= AccessWidth
;
308 if (Reg
->SpaceId
== ACPI_ADR_SPACE_SYSTEM_MEMORY
)
310 Status
= AcpiOsReadMemory ((ACPI_PHYSICAL_ADDRESS
)
311 Address
+ Index
* ACPI_DIV_8 (AccessWidth
),
312 &Value64
, AccessWidth
);
313 Value32
= (UINT32
) Value64
;
315 else /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
317 Status
= AcpiHwReadPort ((ACPI_IO_ADDRESS
)
318 Address
+ Index
* ACPI_DIV_8 (AccessWidth
),
319 &Value32
, AccessWidth
);
324 * Use offset style bit writes because "Index * AccessWidth" is
325 * ensured to be less than 32-bits by AcpiHwValidateRegister().
327 ACPI_SET_BITS (Value
, Index
* AccessWidth
,
328 ACPI_MASK_BITS_ABOVE_32 (AccessWidth
), Value32
);
330 BitWidth
-= BitWidth
> AccessWidth
? AccessWidth
: BitWidth
;
334 ACPI_DEBUG_PRINT ((ACPI_DB_IO
,
335 "Read: %8.8X width %2d from %8.8X%8.8X (%s)\n",
336 *Value
, AccessWidth
, ACPI_FORMAT_UINT64 (Address
),
337 AcpiUtGetRegionName (Reg
->SpaceId
)));
343 /******************************************************************************
345 * FUNCTION: AcpiHwWrite
347 * PARAMETERS: Value - Value to be written
348 * Reg - GAS register structure
352 * DESCRIPTION: Write to either memory or IO space. This is a 32-bit max
353 * version of AcpiWrite, used internally since the overhead of
354 * 64-bit values is not needed.
356 ******************************************************************************/
361 ACPI_GENERIC_ADDRESS
*Reg
)
373 ACPI_FUNCTION_NAME (HwWrite
);
376 /* Validate contents of the GAS register */
378 Status
= AcpiHwValidateRegister (Reg
, 32, &Address
);
379 if (ACPI_FAILURE (Status
))
384 /* Convert AccessWidth into number of bits based */
386 AccessWidth
= AcpiHwGetAccessBitWidth (Address
, Reg
, 32);
387 BitWidth
= Reg
->BitOffset
+ Reg
->BitWidth
;
388 BitOffset
= Reg
->BitOffset
;
391 * Two address spaces supported: Memory or IO. PCI_Config is
392 * not supported here because the GAS structure is insufficient
398 * Use offset style bit reads because "Index * AccessWidth" is
399 * ensured to be less than 32-bits by AcpiHwValidateRegister().
401 Value32
= ACPI_GET_BITS (&Value
, Index
* AccessWidth
,
402 ACPI_MASK_BITS_ABOVE_32 (AccessWidth
));
404 if (BitOffset
>= AccessWidth
)
406 BitOffset
-= AccessWidth
;
410 if (Reg
->SpaceId
== ACPI_ADR_SPACE_SYSTEM_MEMORY
)
412 Value64
= (UINT64
) Value32
;
413 Status
= AcpiOsWriteMemory ((ACPI_PHYSICAL_ADDRESS
)
414 Address
+ Index
* ACPI_DIV_8 (AccessWidth
),
415 Value64
, AccessWidth
);
417 else /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
419 Status
= AcpiHwWritePort ((ACPI_IO_ADDRESS
)
420 Address
+ Index
* ACPI_DIV_8 (AccessWidth
),
421 Value32
, AccessWidth
);
426 * Index * AccessWidth is ensured to be less than 32-bits by
427 * AcpiHwValidateRegister().
429 BitWidth
-= BitWidth
> AccessWidth
? AccessWidth
: BitWidth
;
433 ACPI_DEBUG_PRINT ((ACPI_DB_IO
,
434 "Wrote: %8.8X width %2d to %8.8X%8.8X (%s)\n",
435 Value
, AccessWidth
, ACPI_FORMAT_UINT64 (Address
),
436 AcpiUtGetRegionName (Reg
->SpaceId
)));
442 #if (!ACPI_REDUCED_HARDWARE)
443 /*******************************************************************************
445 * FUNCTION: AcpiHwClearAcpiStatus
451 * DESCRIPTION: Clears all fixed and general purpose status bits
453 ******************************************************************************/
456 AcpiHwClearAcpiStatus (
460 ACPI_CPU_FLAGS LockFlags
= 0;
463 ACPI_FUNCTION_TRACE (HwClearAcpiStatus
);
466 ACPI_DEBUG_PRINT ((ACPI_DB_IO
, "About to write %04X to %8.8X%8.8X\n",
467 ACPI_BITMASK_ALL_FIXED_STATUS
,
468 ACPI_FORMAT_UINT64 (AcpiGbl_XPm1aStatus
.Address
)));
470 LockFlags
= AcpiOsAcquireLock (AcpiGbl_HardwareLock
);
472 /* Clear the fixed events in PM1 A/B */
474 Status
= AcpiHwRegisterWrite (ACPI_REGISTER_PM1_STATUS
,
475 ACPI_BITMASK_ALL_FIXED_STATUS
);
477 AcpiOsReleaseLock (AcpiGbl_HardwareLock
, LockFlags
);
479 if (ACPI_FAILURE (Status
))
484 /* Clear the GPE Bits in all GPE registers in all GPE blocks */
486 Status
= AcpiEvWalkGpeList (AcpiHwClearGpeBlock
, NULL
);
489 return_ACPI_STATUS (Status
);
493 /*******************************************************************************
495 * FUNCTION: AcpiHwGetBitRegisterInfo
497 * PARAMETERS: RegisterId - Index of ACPI Register to access
499 * RETURN: The bitmask to be used when accessing the register
501 * DESCRIPTION: Map RegisterId into a register bitmask.
503 ******************************************************************************/
505 ACPI_BIT_REGISTER_INFO
*
506 AcpiHwGetBitRegisterInfo (
509 ACPI_FUNCTION_ENTRY ();
512 if (RegisterId
> ACPI_BITREG_MAX
)
514 ACPI_ERROR ((AE_INFO
, "Invalid BitRegister ID: 0x%X", RegisterId
));
518 return (&AcpiGbl_BitRegisterInfo
[RegisterId
]);
522 /******************************************************************************
524 * FUNCTION: AcpiHwWritePm1Control
526 * PARAMETERS: Pm1aControl - Value to be written to PM1A control
527 * Pm1bControl - Value to be written to PM1B control
531 * DESCRIPTION: Write the PM1 A/B control registers. These registers are
532 * different than than the PM1 A/B status and enable registers
533 * in that different values can be written to the A/B registers.
534 * Most notably, the SLP_TYP bits can be different, as per the
535 * values returned from the _Sx predefined methods.
537 ******************************************************************************/
540 AcpiHwWritePm1Control (
547 ACPI_FUNCTION_TRACE (HwWritePm1Control
);
550 Status
= AcpiHwWrite (Pm1aControl
, &AcpiGbl_FADT
.XPm1aControlBlock
);
551 if (ACPI_FAILURE (Status
))
553 return_ACPI_STATUS (Status
);
556 if (AcpiGbl_FADT
.XPm1bControlBlock
.Address
)
558 Status
= AcpiHwWrite (Pm1bControl
, &AcpiGbl_FADT
.XPm1bControlBlock
);
560 return_ACPI_STATUS (Status
);
564 /******************************************************************************
566 * FUNCTION: AcpiHwRegisterRead
568 * PARAMETERS: RegisterId - ACPI Register ID
569 * ReturnValue - Where the register value is returned
571 * RETURN: Status and the value read.
573 * DESCRIPTION: Read from the specified ACPI register
575 ******************************************************************************/
586 ACPI_FUNCTION_TRACE (HwRegisterRead
);
591 case ACPI_REGISTER_PM1_STATUS
: /* PM1 A/B: 16-bit access each */
593 Status
= AcpiHwReadMultiple (&Value
,
594 &AcpiGbl_XPm1aStatus
,
595 &AcpiGbl_XPm1bStatus
);
598 case ACPI_REGISTER_PM1_ENABLE
: /* PM1 A/B: 16-bit access each */
600 Status
= AcpiHwReadMultiple (&Value
,
601 &AcpiGbl_XPm1aEnable
,
602 &AcpiGbl_XPm1bEnable
);
605 case ACPI_REGISTER_PM1_CONTROL
: /* PM1 A/B: 16-bit access each */
607 Status
= AcpiHwReadMultiple (&Value
,
608 &AcpiGbl_FADT
.XPm1aControlBlock
,
609 &AcpiGbl_FADT
.XPm1bControlBlock
);
612 * Zero the write-only bits. From the ACPI specification, "Hardware
613 * Write-Only Bits": "Upon reads to registers with write-only bits,
614 * software masks out all write-only bits."
616 Value
&= ~ACPI_PM1_CONTROL_WRITEONLY_BITS
;
619 case ACPI_REGISTER_PM2_CONTROL
: /* 8-bit access */
621 Status
= AcpiHwRead (&Value
, &AcpiGbl_FADT
.XPm2ControlBlock
);
624 case ACPI_REGISTER_PM_TIMER
: /* 32-bit access */
626 Status
= AcpiHwRead (&Value
, &AcpiGbl_FADT
.XPmTimerBlock
);
629 case ACPI_REGISTER_SMI_COMMAND_BLOCK
: /* 8-bit access */
631 Status
= AcpiHwReadPort (AcpiGbl_FADT
.SmiCommand
, &Value
, 8);
636 ACPI_ERROR ((AE_INFO
, "Unknown Register ID: 0x%X",
638 Status
= AE_BAD_PARAMETER
;
642 if (ACPI_SUCCESS (Status
))
644 *ReturnValue
= Value
;
647 return_ACPI_STATUS (Status
);
651 /******************************************************************************
653 * FUNCTION: AcpiHwRegisterWrite
655 * PARAMETERS: RegisterId - ACPI Register ID
656 * Value - The value to write
660 * DESCRIPTION: Write to the specified ACPI register
662 * NOTE: In accordance with the ACPI specification, this function automatically
663 * preserves the value of the following bits, meaning that these bits cannot be
664 * changed via this interface:
666 * PM1_CONTROL[0] = SCI_EN
671 * 1) Hardware Ignored Bits: When software writes to a register with ignored
672 * bit fields, it preserves the ignored bit fields
673 * 2) SCI_EN: OSPM always preserves this bit position
675 ******************************************************************************/
678 AcpiHwRegisterWrite (
686 ACPI_FUNCTION_TRACE (HwRegisterWrite
);
691 case ACPI_REGISTER_PM1_STATUS
: /* PM1 A/B: 16-bit access each */
693 * Handle the "ignored" bit in PM1 Status. According to the ACPI
694 * specification, ignored bits are to be preserved when writing.
695 * Normally, this would mean a read/modify/write sequence. However,
696 * preserving a bit in the status register is different. Writing a
697 * one clears the status, and writing a zero preserves the status.
698 * Therefore, we must always write zero to the ignored bit.
700 * This behavior is clarified in the ACPI 4.0 specification.
702 Value
&= ~ACPI_PM1_STATUS_PRESERVED_BITS
;
704 Status
= AcpiHwWriteMultiple (Value
,
705 &AcpiGbl_XPm1aStatus
,
706 &AcpiGbl_XPm1bStatus
);
709 case ACPI_REGISTER_PM1_ENABLE
: /* PM1 A/B: 16-bit access each */
711 Status
= AcpiHwWriteMultiple (Value
,
712 &AcpiGbl_XPm1aEnable
,
713 &AcpiGbl_XPm1bEnable
);
716 case ACPI_REGISTER_PM1_CONTROL
: /* PM1 A/B: 16-bit access each */
718 * Perform a read first to preserve certain bits (per ACPI spec)
719 * Note: This includes SCI_EN, we never want to change this bit
721 Status
= AcpiHwReadMultiple (&ReadValue
,
722 &AcpiGbl_FADT
.XPm1aControlBlock
,
723 &AcpiGbl_FADT
.XPm1bControlBlock
);
724 if (ACPI_FAILURE (Status
))
729 /* Insert the bits to be preserved */
731 ACPI_INSERT_BITS (Value
, ACPI_PM1_CONTROL_PRESERVED_BITS
, ReadValue
);
733 /* Now we can write the data */
735 Status
= AcpiHwWriteMultiple (Value
,
736 &AcpiGbl_FADT
.XPm1aControlBlock
,
737 &AcpiGbl_FADT
.XPm1bControlBlock
);
740 case ACPI_REGISTER_PM2_CONTROL
: /* 8-bit access */
742 * For control registers, all reserved bits must be preserved,
743 * as per the ACPI spec.
745 Status
= AcpiHwRead (&ReadValue
, &AcpiGbl_FADT
.XPm2ControlBlock
);
746 if (ACPI_FAILURE (Status
))
751 /* Insert the bits to be preserved */
753 ACPI_INSERT_BITS (Value
, ACPI_PM2_CONTROL_PRESERVED_BITS
, ReadValue
);
755 Status
= AcpiHwWrite (Value
, &AcpiGbl_FADT
.XPm2ControlBlock
);
758 case ACPI_REGISTER_PM_TIMER
: /* 32-bit access */
760 Status
= AcpiHwWrite (Value
, &AcpiGbl_FADT
.XPmTimerBlock
);
763 case ACPI_REGISTER_SMI_COMMAND_BLOCK
: /* 8-bit access */
765 /* SMI_CMD is currently always in IO space */
767 Status
= AcpiHwWritePort (AcpiGbl_FADT
.SmiCommand
, Value
, 8);
772 ACPI_ERROR ((AE_INFO
, "Unknown Register ID: 0x%X",
774 Status
= AE_BAD_PARAMETER
;
779 return_ACPI_STATUS (Status
);
783 /******************************************************************************
785 * FUNCTION: AcpiHwReadMultiple
787 * PARAMETERS: Value - Where the register value is returned
788 * RegisterA - First ACPI register (required)
789 * RegisterB - Second ACPI register (optional)
793 * DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B)
795 ******************************************************************************/
800 ACPI_GENERIC_ADDRESS
*RegisterA
,
801 ACPI_GENERIC_ADDRESS
*RegisterB
)
808 /* The first register is always required */
810 Status
= AcpiHwRead (&ValueA
, RegisterA
);
811 if (ACPI_FAILURE (Status
))
816 /* Second register is optional */
818 if (RegisterB
->Address
)
820 Status
= AcpiHwRead (&ValueB
, RegisterB
);
821 if (ACPI_FAILURE (Status
))
828 * OR the two return values together. No shifting or masking is necessary,
829 * because of how the PM1 registers are defined in the ACPI specification:
831 * "Although the bits can be split between the two register blocks (each
832 * register block has a unique pointer within the FADT), the bit positions
833 * are maintained. The register block with unimplemented bits (that is,
834 * those implemented in the other register block) always returns zeros,
835 * and writes have no side effects"
837 *Value
= (ValueA
| ValueB
);
842 /******************************************************************************
844 * FUNCTION: AcpiHwWriteMultiple
846 * PARAMETERS: Value - The value to write
847 * RegisterA - First ACPI register (required)
848 * RegisterB - Second ACPI register (optional)
852 * DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B)
854 ******************************************************************************/
857 AcpiHwWriteMultiple (
859 ACPI_GENERIC_ADDRESS
*RegisterA
,
860 ACPI_GENERIC_ADDRESS
*RegisterB
)
865 /* The first register is always required */
867 Status
= AcpiHwWrite (Value
, RegisterA
);
868 if (ACPI_FAILURE (Status
))
874 * Second register is optional
876 * No bit shifting or clearing is necessary, because of how the PM1
877 * registers are defined in the ACPI specification:
879 * "Although the bits can be split between the two register blocks (each
880 * register block has a unique pointer within the FADT), the bit positions
881 * are maintained. The register block with unimplemented bits (that is,
882 * those implemented in the other register block) always returns zeros,
883 * and writes have no side effects"
885 if (RegisterB
->Address
)
887 Status
= AcpiHwWrite (Value
, RegisterB
);
893 #endif /* !ACPI_REDUCED_HARDWARE */