1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun #include <linux/init.h> 3*4882a593Smuzhiyun #include <linux/module.h> 4*4882a593Smuzhiyun #include <linux/sizes.h> 5*4882a593Smuzhiyun #include <asm/page.h> 6*4882a593Smuzhiyun #include <asm/addrspace.h> 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun /* 9*4882a593Smuzhiyun * This is the offset of the uncached section from its cached alias. 10*4882a593Smuzhiyun * 11*4882a593Smuzhiyun * Legacy platforms handle trivial transitions between cached and 12*4882a593Smuzhiyun * uncached segments by making use of the 1:1 mapping relationship in 13*4882a593Smuzhiyun * 512MB lowmem, others via a special uncached mapping. 14*4882a593Smuzhiyun * 15*4882a593Smuzhiyun * Default value only valid in 29 bit mode, in 32bit mode this will be 16*4882a593Smuzhiyun * updated by the early PMB initialization code. 17*4882a593Smuzhiyun */ 18*4882a593Smuzhiyun unsigned long cached_to_uncached = SZ_512M; 19*4882a593Smuzhiyun unsigned long uncached_size = SZ_512M; 20*4882a593Smuzhiyun unsigned long uncached_start, uncached_end; 21*4882a593Smuzhiyun EXPORT_SYMBOL(uncached_start); 22*4882a593Smuzhiyun EXPORT_SYMBOL(uncached_end); 23*4882a593Smuzhiyun virt_addr_uncached(unsigned long kaddr)24*4882a593Smuzhiyunint virt_addr_uncached(unsigned long kaddr) 25*4882a593Smuzhiyun { 26*4882a593Smuzhiyun return (kaddr >= uncached_start) && (kaddr < uncached_end); 27*4882a593Smuzhiyun } 28*4882a593Smuzhiyun EXPORT_SYMBOL(virt_addr_uncached); 29*4882a593Smuzhiyun uncached_init(void)30*4882a593Smuzhiyunvoid __init uncached_init(void) 31*4882a593Smuzhiyun { 32*4882a593Smuzhiyun #if defined(CONFIG_29BIT) || !defined(CONFIG_MMU) 33*4882a593Smuzhiyun uncached_start = P2SEG; 34*4882a593Smuzhiyun #else 35*4882a593Smuzhiyun uncached_start = memory_end; 36*4882a593Smuzhiyun #endif 37*4882a593Smuzhiyun uncached_end = uncached_start + uncached_size; 38*4882a593Smuzhiyun } 39*4882a593Smuzhiyun uncached_resize(unsigned long size)40*4882a593Smuzhiyunvoid __init uncached_resize(unsigned long size) 41*4882a593Smuzhiyun { 42*4882a593Smuzhiyun uncached_size = size; 43*4882a593Smuzhiyun uncached_end = uncached_start + uncached_size; 44*4882a593Smuzhiyun } 45