From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/arm/mm/cache-feroceon-l2.c | 350 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 350 insertions(+) create mode 100644 arch/arm/mm/cache-feroceon-l2.c (limited to 'arch/arm/mm/cache-feroceon-l2.c') diff --git a/arch/arm/mm/cache-feroceon-l2.c b/arch/arm/mm/cache-feroceon-l2.c new file mode 100644 index 00000000..e0b0e7a4 --- /dev/null +++ b/arch/arm/mm/cache-feroceon-l2.c @@ -0,0 +1,350 @@ +/* + * arch/arm/mm/cache-feroceon-l2.c - Feroceon L2 cache controller support + * + * Copyright (C) 2008 Marvell Semiconductor + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + * + * References: + * - Unified Layer 2 Cache for Feroceon CPU Cores, + * Document ID MV-S104858-00, Rev. A, October 23 2007. + */ + +#include +#include +#include +#include + +/* + * Low-level cache maintenance operations. + * + * As well as the regular 'clean/invalidate/flush L2 cache line by + * MVA' instructions, the Feroceon L2 cache controller also features + * 'clean/invalidate L2 range by MVA' operations. + * + * Cache range operations are initiated by writing the start and + * end addresses to successive cp15 registers, and process every + * cache line whose first byte address lies in the inclusive range + * [start:end]. + * + * The cache range operations stall the CPU pipeline until completion. + * + * The range operations require two successive cp15 writes, in + * between which we don't want to be preempted. + */ + +static inline unsigned long l2_get_va(unsigned long paddr) +{ +#ifdef CONFIG_HIGHMEM + /* + * Because range ops can't be done on physical addresses, + * we simply install a virtual mapping for it only for the + * TLB lookup to occur, hence no need to flush the untouched + * memory mapping afterwards (note: a cache flush may happen + * in some circumstances depending on the path taken in kunmap_atomic). + */ + void *vaddr = kmap_atomic_pfn(paddr >> PAGE_SHIFT); + return (unsigned long)vaddr + (paddr & ~PAGE_MASK); +#else + return __phys_to_virt(paddr); +#endif +} + +static inline void l2_put_va(unsigned long vaddr) +{ +#ifdef CONFIG_HIGHMEM + kunmap_atomic((void *)vaddr); +#endif +} + +static inline void l2_clean_pa(unsigned long addr) +{ + __asm__("mcr p15, 1, %0, c15, c9, 3" : : "r" (addr)); +} + +static inline void l2_clean_pa_range(unsigned long start, unsigned long end) +{ + unsigned long va_start, va_end, flags; + + /* + * Make sure 'start' and 'end' reference the same page, as + * L2 is PIPT and range operations only do a TLB lookup on + * the start address. + */ + BUG_ON((start ^ end) >> PAGE_SHIFT); + + va_start = l2_get_va(start); + va_end = va_start + (end - start); + raw_local_irq_save(flags); + __asm__("mcr p15, 1, %0, c15, c9, 4\n\t" + "mcr p15, 1, %1, c15, c9, 5" + : : "r" (va_start), "r" (va_end)); + raw_local_irq_restore(flags); + l2_put_va(va_start); +} + +static inline void l2_clean_inv_pa(unsigned long addr) +{ + __asm__("mcr p15, 1, %0, c15, c10, 3" : : "r" (addr)); +} + +static inline void l2_inv_pa(unsigned long addr) +{ + __asm__("mcr p15, 1, %0, c15, c11, 3" : : "r" (addr)); +} + +static inline void l2_inv_pa_range(unsigned long start, unsigned long end) +{ + unsigned long va_start, va_end, flags; + + /* + * Make sure 'start' and 'end' reference the same page, as + * L2 is PIPT and range operations only do a TLB lookup on + * the start address. + */ + BUG_ON((start ^ end) >> PAGE_SHIFT); + + va_start = l2_get_va(start); + va_end = va_start + (end - start); + raw_local_irq_save(flags); + __asm__("mcr p15, 1, %0, c15, c11, 4\n\t" + "mcr p15, 1, %1, c15, c11, 5" + : : "r" (va_start), "r" (va_end)); + raw_local_irq_restore(flags); + l2_put_va(va_start); +} + +static inline void l2_inv_all(void) +{ + __asm__("mcr p15, 1, %0, c15, c11, 0" : : "r" (0)); +} + +/* + * Linux primitives. + * + * Note that the end addresses passed to Linux primitives are + * noninclusive, while the hardware cache range operations use + * inclusive start and end addresses. + */ +#define CACHE_LINE_SIZE 32 +#define MAX_RANGE_SIZE 1024 + +static int l2_wt_override; + +static unsigned long calc_range_end(unsigned long start, unsigned long end) +{ + unsigned long range_end; + + BUG_ON(start & (CACHE_LINE_SIZE - 1)); + BUG_ON(end & (CACHE_LINE_SIZE - 1)); + + /* + * Try to process all cache lines between 'start' and 'end'. + */ + range_end = end; + + /* + * Limit the number of cache lines processed at once, + * since cache range operations stall the CPU pipeline + * until completion. + */ + if (range_end > start + MAX_RANGE_SIZE) + range_end = start + MAX_RANGE_SIZE; + + /* + * Cache range operations can't straddle a page boundary. + */ + if (range_end > (start | (PAGE_SIZE - 1)) + 1) + range_end = (start | (PAGE_SIZE - 1)) + 1; + + return range_end; +} + +static void feroceon_l2_inv_range(unsigned long start, unsigned long end) +{ + /* + * Clean and invalidate partial first cache line. + */ + if (start & (CACHE_LINE_SIZE - 1)) { + l2_clean_inv_pa(start & ~(CACHE_LINE_SIZE - 1)); + start = (start | (CACHE_LINE_SIZE - 1)) + 1; + } + + /* + * Clean and invalidate partial last cache line. + */ + if (start < end && end & (CACHE_LINE_SIZE - 1)) { + l2_clean_inv_pa(end & ~(CACHE_LINE_SIZE - 1)); + end &= ~(CACHE_LINE_SIZE - 1); + } + + /* + * Invalidate all full cache lines between 'start' and 'end'. + */ + while (start < end) { + unsigned long range_end = calc_range_end(start, end); + l2_inv_pa_range(start, range_end - CACHE_LINE_SIZE); + start = range_end; + } + + dsb(); +} + +static void feroceon_l2_clean_range(unsigned long start, unsigned long end) +{ + /* + * If L2 is forced to WT, the L2 will always be clean and we + * don't need to do anything here. + */ + if (!l2_wt_override) { + start &= ~(CACHE_LINE_SIZE - 1); + end = (end + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1); + while (start != end) { + unsigned long range_end = calc_range_end(start, end); + l2_clean_pa_range(start, range_end - CACHE_LINE_SIZE); + start = range_end; + } + } + + dsb(); +} + +static void feroceon_l2_flush_range(unsigned long start, unsigned long end) +{ + start &= ~(CACHE_LINE_SIZE - 1); + end = (end + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1); + while (start != end) { + unsigned long range_end = calc_range_end(start, end); + if (!l2_wt_override) + l2_clean_pa_range(start, range_end - CACHE_LINE_SIZE); + l2_inv_pa_range(start, range_end - CACHE_LINE_SIZE); + start = range_end; + } + + dsb(); +} + + +/* + * Routines to disable and re-enable the D-cache and I-cache at run + * time. These are necessary because the L2 cache can only be enabled + * or disabled while the L1 Dcache and Icache are both disabled. + */ +static int __init flush_and_disable_dcache(void) +{ + u32 cr; + + cr = get_cr(); + if (cr & CR_C) { + unsigned long flags; + + raw_local_irq_save(flags); + flush_cache_all(); + set_cr(cr & ~CR_C); + raw_local_irq_restore(flags); + return 1; + } + return 0; +} + +static void __init enable_dcache(void) +{ + u32 cr; + + cr = get_cr(); + set_cr(cr | CR_C); +} + +static void __init __invalidate_icache(void) +{ + __asm__("mcr p15, 0, %0, c7, c5, 0" : : "r" (0)); +} + +static int __init invalidate_and_disable_icache(void) +{ + u32 cr; + + cr = get_cr(); + if (cr & CR_I) { + set_cr(cr & ~CR_I); + __invalidate_icache(); + return 1; + } + return 0; +} + +static void __init enable_icache(void) +{ + u32 cr; + + cr = get_cr(); + set_cr(cr | CR_I); +} + +static inline u32 read_extra_features(void) +{ + u32 u; + + __asm__("mrc p15, 1, %0, c15, c1, 0" : "=r" (u)); + + return u; +} + +static inline void write_extra_features(u32 u) +{ + __asm__("mcr p15, 1, %0, c15, c1, 0" : : "r" (u)); +} + +static void __init disable_l2_prefetch(void) +{ + u32 u; + + /* + * Read the CPU Extra Features register and verify that the + * Disable L2 Prefetch bit is set. + */ + u = read_extra_features(); + if (!(u & 0x01000000)) { + printk(KERN_INFO "Feroceon L2: Disabling L2 prefetch.\n"); + write_extra_features(u | 0x01000000); + } +} + +static void __init enable_l2(void) +{ + u32 u; + + u = read_extra_features(); + if (!(u & 0x00400000)) { + int i, d; + + printk(KERN_INFO "Feroceon L2: Enabling L2\n"); + + d = flush_and_disable_dcache(); + i = invalidate_and_disable_icache(); + l2_inv_all(); + write_extra_features(u | 0x00400000); + if (i) + enable_icache(); + if (d) + enable_dcache(); + } +} + +void __init feroceon_l2_init(int __l2_wt_override) +{ + l2_wt_override = __l2_wt_override; + + disable_l2_prefetch(); + + outer_cache.inv_range = feroceon_l2_inv_range; + outer_cache.clean_range = feroceon_l2_clean_range; + outer_cache.flush_range = feroceon_l2_flush_range; + + enable_l2(); + + printk(KERN_INFO "Feroceon L2: Cache support initialised%s.\n", + l2_wt_override ? ", in WT override mode" : ""); +} -- cgit v1.2.3