int mtrr_del(int reg, unsigned long base, unsigned long size) { if (mtrr_check(base, size)) return -EINVAL; return mtrr_del_page(reg, base >> PAGE_SHIFT, size >> PAGE_SHIFT); }
/** * mtrr_add - Add a memory type region * @base: Physical base address of region * @size: Physical size of region * @type: Type of MTRR desired * @increment: If this is true do usage counting on the region * * Memory type region registers control the caching on newer Intel and * non Intel processors. This function allows drivers to request an * MTRR is added. The details and hardware specifics of each processor's * implementation are hidden from the caller, but nevertheless the * caller should expect to need to provide a power of two size on an * equivalent power of two boundary. * * If the region cannot be added either because all regions are in use * or the CPU cannot support it a negative value is returned. On success * the register number for this entry is returned, but should be treated * as a cookie only. * * On a multiprocessor machine the changes are made to all processors. * This is required on x86 by the Intel processors. * * The available types are * * %MTRR_TYPE_UNCACHABLE - No caching * * %MTRR_TYPE_WRBACK - Write data back in bursts whenever * * %MTRR_TYPE_WRCOMB - Write data back soon but allow bursts * * %MTRR_TYPE_WRTHROUGH - Cache reads but not writes * * BUGS: Needs a quiet flag for the cases where drivers do not mind * failures and do not wish system log messages to be sent. */ int mtrr_add(unsigned long base, unsigned long size, unsigned int type, bool increment) { if (mtrr_check(base, size)) return -EINVAL; return mtrr_add_page(base >> PAGE_SHIFT, size >> PAGE_SHIFT, type, increment); }