/* * Copyright (C) 2003 Bernardo Innocenti * * Based on former do_div() implementation from asm-parisc/div64.h: * Copyright (C) 1999 Hewlett-Packard Co * Copyright (C) 1999 David Mosberger-Tang * * * Generic C version of 64bit/32bit division and modulo, with * 64bit result and 32bit remainder. * * The fast case for (n>>32 == 0) is handled inline by do_div(). * * Code generated for this function might be very inefficient * for some CPUs. __div64_32() can be overridden by linking arch-specific * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S * or by defining a preprocessor macro in arch/include/asm/div64.h. */ #include #include #include /* Not needed on 64bit architectures */ #if BITS_PER_LONG == 32 #ifndef __div64_32 uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base) { uint64_t rem = *n; uint64_t b = base; uint64_t res, d = 1; uint32_t high = rem >> 32; /* Reduce the thing a bit first */ res = 0; if (high >= base) { high /= base; res = (uint64_t) high << 32; rem -= (uint64_t) (high*base) << 32; } while ((int64_t)b > 0 && b < rem) { b = b+b; d = d+d; } do { if (rem >= b) { rem -= b; res += d; } b >>= 1; d >>= 1; } while (d); *n = res; return rem; } EXPORT_SYMBOL(__div64_32); #endif #ifndef div_s64_rem s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder) { u64 quotient; if (dividend < 0) { quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder); *remainder = -*remainder; if (divisor > 0) quotient = -quotient; } else { quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder); if (divisor < 0) quotient = -quotient; } return quotient; } EXPORT_SYMBOL(div_s64_rem); #endif /** * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder * @dividend: 64bit dividend * @divisor: 64bit divisor * @remainder: 64bit remainder * * This implementation is a comparable to algorithm used by div64_u64. * But this operation, which includes math for calculating the remainder, * is kept distinct to avoid slowing down the div64_u64 operation on 32bit * systems. */ #ifndef div64_u64_rem u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder) { u32 high = divisor >> 32; u64 quot; if (high == 0) { u32 rem32; quot = div_u64_rem(dividend, divisor, &rem32); *remainder = rem32; } else { int n = 1 + fls(high); quot = div_u64(dividend >> n, divisor >> n); if (quot != 0) quot--; *remainder = dividend - quot * divisor; if (*remainder >= divisor) { quot++; *remainder -= divisor; } } return quot; } EXPORT_SYMBOL(div64_u64_rem); #endif /** * div64_u64 - unsigned 64bit divide with 64bit divisor * @dividend: 64bit dividend * @divisor: 64bit divisor * * This implementation is a modified version of the algorithm proposed * by the book 'Hacker's Delight'. The original source and full proof * can be found here and is available for use without restriction. * * 'http://www.hackersdelight.org/hdcodetxt/divDouble.c.txt' */ #ifndef div64_u64 u64 div64_u64(u64 dividend, u64 divisor) { u32 high = divisor >> 32; u64 quot; if (high == 0) { quot = div_u64(dividend, divisor); } else { int n = 1 + fls(high); quot = div_u64(dividend >> n, divisor >> n); if (quot != 0) quot--; if ((dividend - quot * divisor) >= divisor) quot++; } return quot; } EXPORT_SYMBOL(div64_u64); #endif /** * div64_s64 - signed 64bit divide with 64bit divisor * @dividend: 64bit dividend * @divisor: 64bit divisor */ #ifndef div64_s64 s64 div64_s64(s64 dividend, s64 divisor) { s64 quot, t; quot = div64_u64(abs(dividend), abs(divisor)); t = (dividend ^ divisor) >> 63; return (quot ^ t) - t; } EXPORT_SYMBOL(div64_s64); #endif #endif /* BITS_PER_LONG == 32 */ /* * Iterative div/mod for use when dividend is not expected to be much * bigger than divisor. */ u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder) { return __iter_div_u64_rem(dividend, divisor, remainder); } EXPORT_SYMBOL(iter_div_u64_rem); ion>space:mode:
authorDavid S. Miller <davem@davemloft.net>2017-01-30 14:28:22 -0800
committerDavid S. Miller <davem@davemloft.net>2017-01-30 14:28:22 -0800
commit54791b276b4000b307339f269d3bf7db877d536f (patch)
tree1c2616bd373ce5ea28aac2a53e32f5b5834901ce /include/dt-bindings/reset/tegra186-reset.h
parent5d0e7705774dd412a465896d08d59a81a345c1e4 (diff)
parent047487241ff59374fded8c477f21453681f5995c (diff)
Merge branch 'sparc64-non-resumable-user-error-recovery'
Liam R. Howlett says: ==================== sparc64: Recover from userspace non-resumable PIO & MEM errors A non-resumable error from userspace is able to cause a kernel panic or trap loop due to the setup and handling of the queued traps once in the kernel. This patch series addresses both of these issues. The queues are fixed by simply zeroing the memory before use. PIO errors from userspace will result in a SIGBUS being sent to the user process. The MEM errors form userspace will result in a SIGKILL and also cause the offending pages to be claimed so they are no longer used in future tasks. SIGKILL is used to ensure that the process does not try to coredump and result in an attempt to read the memory again from within kernel space. Although there is a HV call to scrub the memory (mem_scrub), there is no easy way to guarantee that the real memory address(es) are not used by other tasks. Clearing the error with mem_scrub would zero the memory and cause the other processes to proceed with bad data. The handling of other non-resumable errors remain unchanged and will cause a panic. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/dt-bindings/reset/tegra186-reset.h')