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| author | Lv Zheng <lv.zheng@intel.com> | 2016-05-05 12:58:39 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-05-05 15:22:27 +0200 |
| commit | b314a172ee968d45f72dffea68ab8af38aa80ded (patch) | |
| tree | fde8dae9e9616f7acc4fab60a58463a9d16a49c7 /drivers/acpi | |
| parent | e35d75024b28083b0a84cdb73b826f8450b29d49 (diff) | |
| download | linux-b314a172ee968d45f72dffea68ab8af38aa80ded.tar.bz2 | |
ACPICA: Hardware: Add optimized access bit width support
ACPICA commit c49a751b4dae7baec1790748a2b4b6e8ab599f51
For Access Size = 0, it actually can use user expected access bit width.
This patch implements this.
Besides of the ACPICA upstream commit, this patch also includes a fix fixing
the issue reported by the FreeBSD community.
The old register descriptors are translated in acpi_tb_init_generic_address()
with access_width being filled with 0. This breaks code in
acpi_hw_get_access_bit_width() when the registers are 16-bit IO ports and their
bit_width fields are filled with 16. The rapid fix is meant to make code
written for acpi_hw_get_access_bit_width() regression safer before the issue is
correctly fixed from acpi_tb_init_generic_address(). Reported by
John Baldwin <jhb@freebsd.org>, fixed by Lv Zheng <lv.zheng@intel.com>, tested
by Jung-uk Kim <jkim@freebsd.org>.
Link: https://github.com/acpica/acpica/commit/c49a751b
Reported-by: John Baldwin <jhb@freebsd.org>
Tested-by Jung-uk Kim <jkim@freebsd.org>.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/acpica/hwregs.c | 49 |
1 files changed, 47 insertions, 2 deletions
diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c index 035fb52c3bcd..892e677f524f 100644 --- a/drivers/acpi/acpica/hwregs.c +++ b/drivers/acpi/acpica/hwregs.c @@ -51,6 +51,10 @@ ACPI_MODULE_NAME("hwregs") #if (!ACPI_REDUCED_HARDWARE) /* Local Prototypes */ +static u8 +acpi_hw_get_access_bit_width(struct acpi_generic_address *reg, + u8 max_bit_width); + static acpi_status acpi_hw_read_multiple(u32 *value, struct acpi_generic_address *register_a, @@ -65,6 +69,48 @@ acpi_hw_write_multiple(u32 value, /****************************************************************************** * + * FUNCTION: acpi_hw_get_access_bit_width + * + * PARAMETERS: 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(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, ®->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)); + } +} + +/****************************************************************************** + * * FUNCTION: acpi_hw_validate_register * * PARAMETERS: reg - GAS register structure @@ -122,8 +168,7 @@ acpi_hw_validate_register(struct acpi_generic_address *reg, /* Validate the bit_width, convert access_width into number of bits */ - access_width = reg->access_width ? reg->access_width : 1; - access_width = 1 << (access_width + 2); + access_width = acpi_hw_get_access_bit_width(reg, max_bit_width); bit_width = ACPI_ROUND_UP(reg->bit_offset + reg->bit_width, access_width); if (max_bit_width < bit_width) { |