cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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io.c (1814B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/export.h>
      3#include <linux/types.h>
      4#include <linux/io.h>
      5#include <linux/spinlock.h>
      6
      7static DEFINE_RAW_SPINLOCK(__io_lock);
      8
      9/*
     10 * Generic atomic MMIO modify.
     11 *
     12 * Allows thread-safe access to registers shared by unrelated subsystems.
     13 * The access is protected by a single MMIO-wide lock.
     14 */
     15void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set)
     16{
     17	unsigned long flags;
     18	u32 value;
     19
     20	raw_spin_lock_irqsave(&__io_lock, flags);
     21	value = readl_relaxed(reg) & ~mask;
     22	value |= (set & mask);
     23	writel_relaxed(value, reg);
     24	raw_spin_unlock_irqrestore(&__io_lock, flags);
     25}
     26EXPORT_SYMBOL(atomic_io_modify_relaxed);
     27
     28void atomic_io_modify(void __iomem *reg, u32 mask, u32 set)
     29{
     30	unsigned long flags;
     31	u32 value;
     32
     33	raw_spin_lock_irqsave(&__io_lock, flags);
     34	value = readl_relaxed(reg) & ~mask;
     35	value |= (set & mask);
     36	writel(value, reg);
     37	raw_spin_unlock_irqrestore(&__io_lock, flags);
     38}
     39EXPORT_SYMBOL(atomic_io_modify);
     40
     41/*
     42 * Copy data from IO memory space to "real" memory space.
     43 * This needs to be optimized.
     44 */
     45void _memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
     46{
     47	unsigned char *t = to;
     48	while (count) {
     49		count--;
     50		*t = readb(from);
     51		t++;
     52		from++;
     53	}
     54}
     55EXPORT_SYMBOL(_memcpy_fromio);
     56
     57/*
     58 * Copy data from "real" memory space to IO memory space.
     59 * This needs to be optimized.
     60 */
     61void _memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
     62{
     63	const unsigned char *f = from;
     64	while (count) {
     65		count--;
     66		writeb(*f, to);
     67		f++;
     68		to++;
     69	}
     70}
     71EXPORT_SYMBOL(_memcpy_toio);
     72
     73/*
     74 * "memset" on IO memory space.
     75 * This needs to be optimized.
     76 */
     77void _memset_io(volatile void __iomem *dst, int c, size_t count)
     78{
     79	while (count) {
     80		count--;
     81		writeb(c, dst);
     82		dst++;
     83	}
     84}
     85EXPORT_SYMBOL(_memset_io);