This patch adds default 64-bit mathematics in aclinux.h using do_div(). As do_div() can be used for all Linux architectures, this can also be used as stub macros for ACPICA 64-bit mathematics.
But this is not a performance friendly way, as ACPICA's architecture specific division OSL only requires a dividing 64-bit number with a 32-bit number implementation, while Linux __div64_32() is not available for all build environments. So currently, if an architecture really wants to support ACPICA, it must implement its own division OSL. This is required by the ACPICA header stub support. ACPICA header stubs are useful to protect CONFIG_ACPI=n Linux kernel builds where ACPICA headers are included. Lv Zheng. Signed-off-by: Lv Zheng <lv.zh...@intel.com> --- include/acpi/platform/aclinuxex.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/include/acpi/platform/aclinuxex.h b/include/acpi/platform/aclinuxex.h index 191e741..568d4b8 100644 --- a/include/acpi/platform/aclinuxex.h +++ b/include/acpi/platform/aclinuxex.h @@ -46,6 +46,28 @@ #ifdef __KERNEL__ +#ifndef ACPI_USE_NATIVE_DIVIDE + +#ifndef ACPI_DIV_64_BY_32 +#define ACPI_DIV_64_BY_32(n_hi, n_lo, d32, q32, r32) \ + do { \ + u64 (__n) = ((u64) n_hi) << 32 | (n_lo); \ + (r32) = do_div ((__n), (d32)); \ + (q32) = (u32) (__n); \ + } while (0) +#endif + +#ifndef ACPI_SHIFT_RIGHT_64 +#define ACPI_SHIFT_RIGHT_64(n_hi, n_lo) \ + do { \ + (n_lo) >>= 1; \ + (n_lo) |= (((n_hi) & 1) << 31); \ + (n_hi) >>= 1; \ + } while (0) +#endif + +#endif + /* * Overrides for in-kernel ACPICA */ -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/