diff options
Diffstat (limited to 'libacpica/hwregs.c')
| -rw-r--r-- | libacpica/hwregs.c | 800 |
1 files changed, 800 insertions, 0 deletions
diff --git a/libacpica/hwregs.c b/libacpica/hwregs.c new file mode 100644 index 00000000..7454a6b2 --- /dev/null +++ b/libacpica/hwregs.c @@ -0,0 +1,800 @@ +// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 +/******************************************************************************* + * + * Module Name: hwregs - Read/write access functions for the various ACPI + * control and status registers. + * + ******************************************************************************/ + +#include <acpi/acpi.h> +#include "accommon.h" +#include "acevents.h" + +#define _COMPONENT ACPI_HARDWARE +ACPI_MODULE_NAME("hwregs") +#if (!ACPI_REDUCED_HARDWARE) +/* Local Prototypes */ +static u8 +acpi_hw_get_access_bit_width(u64 address, + struct acpi_generic_address *reg, + u8 max_bit_width); + +static acpi_status +acpi_hw_read_multiple(u32 *value, + struct acpi_generic_address *register_a, + struct acpi_generic_address *register_b); + +static acpi_status +acpi_hw_write_multiple(u32 value, + struct acpi_generic_address *register_a, + struct acpi_generic_address *register_b); + +#endif /* !ACPI_REDUCED_HARDWARE */ + +/****************************************************************************** + * + * FUNCTION: acpi_hw_get_access_bit_width + * + * PARAMETERS: address - GAS register address + * reg - GAS register structure + * max_bit_width - Max bit_width supported (32 or 64) + * + * RETURN: Status + * + * DESCRIPTION: Obtain optimal access bit width + * + ******************************************************************************/ + +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); +} + +/****************************************************************************** + * + * FUNCTION: acpi_hw_validate_register + * + * PARAMETERS: reg - GAS register structure + * max_bit_width - Max bit_width supported (32 or 64) + * address - Pointer to where the gas->address + * is returned + * + * RETURN: Status + * + * DESCRIPTION: Validate the contents of a GAS register. Checks the GAS + * pointer, Address, space_id, bit_width, and bit_offset. + * + ******************************************************************************/ + +acpi_status +acpi_hw_validate_register(struct acpi_generic_address *reg, + u8 max_bit_width, u64 *address) +{ + u8 bit_width; + u8 access_width; + + /* Must have a valid pointer to a GAS structure */ + + if (!reg) { + return (AE_BAD_PARAMETER); + } + + /* + * Copy the target address. This handles possible alignment issues. + * Address must not be null. A null address also indicates an optional + * ACPI register that is not supported, so no error message. + */ + ACPI_MOVE_64_TO_64(address, ®->address); + if (!(*address)) { + return (AE_BAD_ADDRESS); + } + + /* Validate the space_ID */ + + if ((reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) && + (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) { + ACPI_ERROR((AE_INFO, + "Unsupported address space: 0x%X", reg->space_id)); + return (AE_SUPPORT); + } + + /* Validate the access_width */ + + if (reg->access_width > 4) { + ACPI_ERROR((AE_INFO, + "Unsupported register access width: 0x%X", + reg->access_width)); + return (AE_SUPPORT); + } + + /* Validate the bit_width, convert access_width into number of bits */ + + access_width = + acpi_hw_get_access_bit_width(*address, reg, max_bit_width); + bit_width = + ACPI_ROUND_UP(reg->bit_offset + reg->bit_width, access_width); + if (max_bit_width < bit_width) { + ACPI_WARNING((AE_INFO, + "Requested bit width 0x%X is smaller than register bit width 0x%X", + max_bit_width, bit_width)); + return (AE_SUPPORT); + } + + return (AE_OK); +} + +/****************************************************************************** + * + * FUNCTION: acpi_hw_read + * + * PARAMETERS: value - Where the value is returned + * reg - GAS register structure + * + * RETURN: Status + * + * DESCRIPTION: Read from either memory or IO space. This is a 64-bit max + * version of acpi_read. + * + * LIMITATIONS: <These limitations also apply to acpi_hw_write> + * space_ID must be system_memory or system_IO. + * + ******************************************************************************/ + +acpi_status acpi_hw_read(u64 *value, struct acpi_generic_address *reg) +{ + u64 address; + u8 access_width; + u32 bit_width; + u8 bit_offset; + u64 value64; + u32 value32; + u8 index; + acpi_status status; + + ACPI_FUNCTION_NAME(hw_read); + + /* Validate contents of the GAS register */ + + status = acpi_hw_validate_register(reg, 64, &address); + if (ACPI_FAILURE(status)) { + return (status); + } + + /* + * Initialize entire 64-bit return value to zero, convert access_width + * into number of bits based + */ + *value = 0; + access_width = acpi_hw_get_access_bit_width(address, reg, 64); + bit_width = reg->bit_offset + reg->bit_width; + bit_offset = reg->bit_offset; + + /* + * Two address spaces supported: Memory or IO. PCI_Config is + * not supported here because the GAS structure is insufficient + */ + index = 0; + while (bit_width) { + if (bit_offset >= access_width) { + value64 = 0; + bit_offset -= access_width; + } else { + if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { + status = + acpi_os_read_memory((acpi_physical_address) + address + + index * + ACPI_DIV_8 + (access_width), + &value64, access_width); + } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */ + status = acpi_hw_read_port((acpi_io_address) + address + + index * + ACPI_DIV_8 + (access_width), + &value32, + access_width); + value64 = (u64)value32; + } + } + + /* + * Use offset style bit writes because "Index * AccessWidth" is + * ensured to be less than 64-bits by acpi_hw_validate_register(). + */ + ACPI_SET_BITS(value, index * access_width, + ACPI_MASK_BITS_ABOVE_64(access_width), value64); + + bit_width -= + bit_width > access_width ? access_width : bit_width; + index++; + } + + ACPI_DEBUG_PRINT((ACPI_DB_IO, + "Read: %8.8X%8.8X width %2d from %8.8X%8.8X (%s)\n", + ACPI_FORMAT_UINT64(*value), access_width, + ACPI_FORMAT_UINT64(address), + acpi_ut_get_region_name(reg->space_id))); + + return (status); +} + +/****************************************************************************** + * + * FUNCTION: acpi_hw_write + * + * PARAMETERS: value - Value to be written + * reg - GAS register structure + * + * RETURN: Status + * + * DESCRIPTION: Write to either memory or IO space. This is a 64-bit max + * version of acpi_write. + * + ******************************************************************************/ + +acpi_status acpi_hw_write(u64 value, struct acpi_generic_address *reg) +{ + u64 address; + u8 access_width; + u32 bit_width; + u8 bit_offset; + u64 value64; + u8 index; + acpi_status status; + + ACPI_FUNCTION_NAME(hw_write); + + /* Validate contents of the GAS register */ + + status = acpi_hw_validate_register(reg, 64, &address); + if (ACPI_FAILURE(status)) { + return (status); + } + + /* Convert access_width into number of bits based */ + + access_width = acpi_hw_get_access_bit_width(address, reg, 64); + bit_width = reg->bit_offset + reg->bit_width; + bit_offset = reg->bit_offset; + + /* + * Two address spaces supported: Memory or IO. PCI_Config is + * not supported here because the GAS structure is insufficient + */ + index = 0; + while (bit_width) { + /* + * Use offset style bit reads because "Index * AccessWidth" is + * ensured to be less than 64-bits by acpi_hw_validate_register(). + */ + value64 = ACPI_GET_BITS(&value, index * access_width, + ACPI_MASK_BITS_ABOVE_64(access_width)); + + if (bit_offset >= access_width) { + bit_offset -= access_width; + } else { + if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { + status = + acpi_os_write_memory((acpi_physical_address) + address + + index * + ACPI_DIV_8 + (access_width), + value64, access_width); + } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */ + status = acpi_hw_write_port((acpi_io_address) + address + + index * + ACPI_DIV_8 + (access_width), + (u32)value64, + access_width); + } + } + + /* + * Index * access_width is ensured to be less than 32-bits by + * acpi_hw_validate_register(). + */ + bit_width -= + bit_width > access_width ? access_width : bit_width; + index++; + } + + ACPI_DEBUG_PRINT((ACPI_DB_IO, + "Wrote: %8.8X%8.8X width %2d to %8.8X%8.8X (%s)\n", + ACPI_FORMAT_UINT64(value), access_width, + ACPI_FORMAT_UINT64(address), + acpi_ut_get_region_name(reg->space_id))); + + return (status); +} + +#if (!ACPI_REDUCED_HARDWARE) +/******************************************************************************* + * + * FUNCTION: acpi_hw_clear_acpi_status + * + * PARAMETERS: None + * + * RETURN: Status + * + * DESCRIPTION: Clears all fixed and general purpose status bits + * + ******************************************************************************/ + +acpi_status acpi_hw_clear_acpi_status(void) +{ + acpi_status status; + acpi_cpu_flags lock_flags = 0; + + ACPI_FUNCTION_TRACE(hw_clear_acpi_status); + + ACPI_DEBUG_PRINT((ACPI_DB_IO, "About to write %04X to %8.8X%8.8X\n", + ACPI_BITMASK_ALL_FIXED_STATUS, + ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address))); + + lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock); + + /* Clear the fixed events in PM1 A/B */ + + status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS, + ACPI_BITMASK_ALL_FIXED_STATUS); + + acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags); + + if (ACPI_FAILURE(status)) { + goto exit; + } + + /* Clear the GPE Bits in all GPE registers in all GPE blocks */ + + status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL); + +exit: + return_ACPI_STATUS(status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_hw_get_bit_register_info + * + * PARAMETERS: register_id - Index of ACPI Register to access + * + * RETURN: The bitmask to be used when accessing the register + * + * DESCRIPTION: Map register_id into a register bitmask. + * + ******************************************************************************/ + +struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id) +{ + ACPI_FUNCTION_ENTRY(); + + if (register_id > ACPI_BITREG_MAX) { + ACPI_ERROR((AE_INFO, "Invalid BitRegister ID: 0x%X", + register_id)); + return (NULL); + } + + return (&acpi_gbl_bit_register_info[register_id]); +} + +/****************************************************************************** + * + * FUNCTION: acpi_hw_write_pm1_control + * + * PARAMETERS: pm1a_control - Value to be written to PM1A control + * pm1b_control - Value to be written to PM1B control + * + * RETURN: Status + * + * DESCRIPTION: Write the PM1 A/B control registers. These registers are + * different than than the PM1 A/B status and enable registers + * in that different values can be written to the A/B registers. + * Most notably, the SLP_TYP bits can be different, as per the + * values returned from the _Sx predefined methods. + * + ******************************************************************************/ + +acpi_status acpi_hw_write_pm1_control(u32 pm1a_control, u32 pm1b_control) +{ + acpi_status status; + + ACPI_FUNCTION_TRACE(hw_write_pm1_control); + + status = + acpi_hw_write(pm1a_control, &acpi_gbl_FADT.xpm1a_control_block); + if (ACPI_FAILURE(status)) { + return_ACPI_STATUS(status); + } + + if (acpi_gbl_FADT.xpm1b_control_block.address) { + status = + acpi_hw_write(pm1b_control, + &acpi_gbl_FADT.xpm1b_control_block); + } + return_ACPI_STATUS(status); +} + +/****************************************************************************** + * + * FUNCTION: acpi_hw_register_read + * + * PARAMETERS: register_id - ACPI Register ID + * return_value - Where the register value is returned + * + * RETURN: Status and the value read. + * + * DESCRIPTION: Read from the specified ACPI register + * + ******************************************************************************/ + +acpi_status acpi_hw_register_read(u32 register_id, u32 *return_value) +{ + u32 value = 0; + u64 value64; + acpi_status status; + + ACPI_FUNCTION_TRACE(hw_register_read); + + switch (register_id) { + case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */ + + status = acpi_hw_read_multiple(&value, + &acpi_gbl_xpm1a_status, + &acpi_gbl_xpm1b_status); + break; + + case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */ + + status = acpi_hw_read_multiple(&value, + &acpi_gbl_xpm1a_enable, + &acpi_gbl_xpm1b_enable); + break; + + case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */ + + status = acpi_hw_read_multiple(&value, + &acpi_gbl_FADT. + xpm1a_control_block, + &acpi_gbl_FADT. + xpm1b_control_block); + + /* + * Zero the write-only bits. From the ACPI specification, "Hardware + * Write-Only Bits": "Upon reads to registers with write-only bits, + * software masks out all write-only bits." + */ + value &= ~ACPI_PM1_CONTROL_WRITEONLY_BITS; + break; + + case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */ + + status = + acpi_hw_read(&value64, &acpi_gbl_FADT.xpm2_control_block); + if (ACPI_SUCCESS(status)) { + value = (u32)value64; + } + break; + + case ACPI_REGISTER_PM_TIMER: /* 32-bit access */ + + status = acpi_hw_read(&value64, &acpi_gbl_FADT.xpm_timer_block); + if (ACPI_SUCCESS(status)) { + value = (u32)value64; + } + + break; + + case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */ + + status = + acpi_hw_read_port(acpi_gbl_FADT.smi_command, &value, 8); + break; + + default: + + ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id)); + status = AE_BAD_PARAMETER; + break; + } + + if (ACPI_SUCCESS(status)) { + *return_value = (u32)value; + } + + return_ACPI_STATUS(status); +} + +/****************************************************************************** + * + * FUNCTION: acpi_hw_register_write + * + * PARAMETERS: register_id - ACPI Register ID + * value - The value to write + * + * RETURN: Status + * + * DESCRIPTION: Write to the specified ACPI register + * + * NOTE: In accordance with the ACPI specification, this function automatically + * preserves the value of the following bits, meaning that these bits cannot be + * changed via this interface: + * + * PM1_CONTROL[0] = SCI_EN + * PM1_CONTROL[9] + * PM1_STATUS[11] + * + * ACPI References: + * 1) Hardware Ignored Bits: When software writes to a register with ignored + * bit fields, it preserves the ignored bit fields + * 2) SCI_EN: OSPM always preserves this bit position + * + ******************************************************************************/ + +acpi_status acpi_hw_register_write(u32 register_id, u32 value) +{ + acpi_status status; + u32 read_value; + u64 read_value64; + + ACPI_FUNCTION_TRACE(hw_register_write); + + switch (register_id) { + case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */ + /* + * Handle the "ignored" bit in PM1 Status. According to the ACPI + * specification, ignored bits are to be preserved when writing. + * Normally, this would mean a read/modify/write sequence. However, + * preserving a bit in the status register is different. Writing a + * one clears the status, and writing a zero preserves the status. + * Therefore, we must always write zero to the ignored bit. + * + * This behavior is clarified in the ACPI 4.0 specification. + */ + value &= ~ACPI_PM1_STATUS_PRESERVED_BITS; + + status = acpi_hw_write_multiple(value, + &acpi_gbl_xpm1a_status, + &acpi_gbl_xpm1b_status); + break; + + case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */ + + status = acpi_hw_write_multiple(value, + &acpi_gbl_xpm1a_enable, + &acpi_gbl_xpm1b_enable); + break; + + case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */ + /* + * Perform a read first to preserve certain bits (per ACPI spec) + * Note: This includes SCI_EN, we never want to change this bit + */ + status = acpi_hw_read_multiple(&read_value, + &acpi_gbl_FADT. + xpm1a_control_block, + &acpi_gbl_FADT. + xpm1b_control_block); + if (ACPI_FAILURE(status)) { + goto exit; + } + + /* Insert the bits to be preserved */ + + ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS, + read_value); + + /* Now we can write the data */ + + status = acpi_hw_write_multiple(value, + &acpi_gbl_FADT. + xpm1a_control_block, + &acpi_gbl_FADT. + xpm1b_control_block); + break; + + case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */ + /* + * For control registers, all reserved bits must be preserved, + * as per the ACPI spec. + */ + status = + acpi_hw_read(&read_value64, + &acpi_gbl_FADT.xpm2_control_block); + if (ACPI_FAILURE(status)) { + goto exit; + } + read_value = (u32)read_value64; + + /* Insert the bits to be preserved */ + + ACPI_INSERT_BITS(value, ACPI_PM2_CONTROL_PRESERVED_BITS, + read_value); + + status = + acpi_hw_write(value, &acpi_gbl_FADT.xpm2_control_block); + break; + + case ACPI_REGISTER_PM_TIMER: /* 32-bit access */ + + status = acpi_hw_write(value, &acpi_gbl_FADT.xpm_timer_block); + break; + + case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */ + + /* SMI_CMD is currently always in IO space */ + + status = + acpi_hw_write_port(acpi_gbl_FADT.smi_command, value, 8); + break; + + default: + + ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id)); + status = AE_BAD_PARAMETER; + break; + } + +exit: + return_ACPI_STATUS(status); +} + +/****************************************************************************** + * + * FUNCTION: acpi_hw_read_multiple + * + * PARAMETERS: value - Where the register value is returned + * register_a - First ACPI register (required) + * register_b - Second ACPI register (optional) + * + * RETURN: Status + * + * DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B) + * + ******************************************************************************/ + +static acpi_status +acpi_hw_read_multiple(u32 *value, + struct acpi_generic_address *register_a, + struct acpi_generic_address *register_b) +{ + u32 value_a = 0; + u32 value_b = 0; + u64 value64; + acpi_status status; + + /* The first register is always required */ + + status = acpi_hw_read(&value64, register_a); + if (ACPI_FAILURE(status)) { + return (status); + } + value_a = (u32)value64; + + /* Second register is optional */ + + if (register_b->address) { + status = acpi_hw_read(&value64, register_b); + if (ACPI_FAILURE(status)) { + return (status); + } + value_b = (u32)value64; + } + + /* + * OR the two return values together. No shifting or masking is necessary, + * because of how the PM1 registers are defined in the ACPI specification: + * + * "Although the bits can be split between the two register blocks (each + * register block has a unique pointer within the FADT), the bit positions + * are maintained. The register block with unimplemented bits (that is, + * those implemented in the other register block) always returns zeros, + * and writes have no side effects" + */ + *value = (value_a | value_b); + return (AE_OK); +} + +/****************************************************************************** + * + * FUNCTION: acpi_hw_write_multiple + * + * PARAMETERS: value - The value to write + * register_a - First ACPI register (required) + * register_b - Second ACPI register (optional) + * + * RETURN: Status + * + * DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B) + * + ******************************************************************************/ + +static acpi_status +acpi_hw_write_multiple(u32 value, + struct acpi_generic_address *register_a, + struct acpi_generic_address *register_b) +{ + acpi_status status; + + /* The first register is always required */ + + status = acpi_hw_write(value, register_a); + if (ACPI_FAILURE(status)) { + return (status); + } + + /* + * Second register is optional + * + * No bit shifting or clearing is necessary, because of how the PM1 + * registers are defined in the ACPI specification: + * + * "Although the bits can be split between the two register blocks (each + * register block has a unique pointer within the FADT), the bit positions + * are maintained. The register block with unimplemented bits (that is, + * those implemented in the other register block) always returns zeros, + * and writes have no side effects" + */ + if (register_b->address) { + status = acpi_hw_write(value, register_b); + } + + return (status); +} + +#endif /* !ACPI_REDUCED_HARDWARE */ |