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author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-07-15 07:44:51 +0200 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-07-15 07:44:51 +0200 |
commit | 43d2548bb2ef7e6d753f91468a746784041e522d (patch) | |
tree | 77d13fcd48fd998393abb825ec36e2b732684a73 /arch/arm/mm/cache-feroceon-l2.c | |
parent | powerpc: Fix pte_update for CONFIG_PTE_64BIT and !PTE_ATOMIC_UPDATES (diff) | |
parent | Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm (diff) | |
download | linux-43d2548bb2ef7e6d753f91468a746784041e522d.tar.xz linux-43d2548bb2ef7e6d753f91468a746784041e522d.zip |
Merge commit '85082fd7cbe3173198aac0eb5e85ab1edcc6352c' into test-build
Manual fixup of:
arch/powerpc/Kconfig
Diffstat (limited to 'arch/arm/mm/cache-feroceon-l2.c')
-rw-r--r-- | arch/arm/mm/cache-feroceon-l2.c | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/arch/arm/mm/cache-feroceon-l2.c b/arch/arm/mm/cache-feroceon-l2.c new file mode 100644 index 000000000000..20eec4ba173f --- /dev/null +++ b/arch/arm/mm/cache-feroceon-l2.c @@ -0,0 +1,318 @@ +/* + * 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 <linux/init.h> +#include <asm/cacheflush.h> +#include <asm/plat-orion/cache-feroceon-l2.h> + + +/* + * 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 void l2_clean_pa(unsigned long addr) +{ + __asm__("mcr p15, 1, %0, c15, c9, 3" : : "r" (addr)); +} + +static inline void l2_clean_mva_range(unsigned long start, unsigned long end) +{ + unsigned long 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_SIZE - 1)); + + raw_local_irq_save(flags); + __asm__("mcr p15, 1, %0, c15, c9, 4" : : "r" (start)); + __asm__("mcr p15, 1, %0, c15, c9, 5" : : "r" (end)); + raw_local_irq_restore(flags); +} + +static inline void l2_clean_pa_range(unsigned long start, unsigned long end) +{ + l2_clean_mva_range(__phys_to_virt(start), __phys_to_virt(end)); +} + +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_mva_range(unsigned long start, unsigned long end) +{ + unsigned long 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_SIZE - 1)); + + raw_local_irq_save(flags); + __asm__("mcr p15, 1, %0, c15, c11, 4" : : "r" (start)); + __asm__("mcr p15, 1, %0, c15, c11, 5" : : "r" (end)); + raw_local_irq_restore(flags); +} + +static inline void l2_inv_pa_range(unsigned long start, unsigned long end) +{ + l2_inv_mva_range(__phys_to_virt(start), __phys_to_virt(end)); +} + + +/* + * 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 (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 void __init invalidate_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); + } +} + +static void __init enable_dcache(void) +{ + u32 cr; + + cr = get_cr(); + if (!(cr & CR_C)) + set_cr(cr | CR_C); +} + +static void __init __invalidate_icache(void) +{ + int dummy; + + __asm__ __volatile__("mcr p15, 0, %0, c7, c5, 0\n" : "=r" (dummy)); +} + +static void __init invalidate_and_disable_icache(void) +{ + u32 cr; + + cr = get_cr(); + if (cr & CR_I) { + set_cr(cr & ~CR_I); + __invalidate_icache(); + } +} + +static void __init enable_icache(void) +{ + u32 cr; + + cr = get_cr(); + if (!(cr & CR_I)) + 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)) { + printk(KERN_INFO "Feroceon L2: Enabling L2\n"); + + invalidate_and_disable_dcache(); + invalidate_and_disable_icache(); + write_extra_features(u | 0x00400000); + enable_icache(); + 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" : ""); +} |