From 3902a15e784e9b1efa8e6ad246489c609e0ef880 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Thu, 18 Sep 2008 22:55:47 -0400 Subject: [PATCH] [ARM] xsc3: add highmem support to L2 cache handling code On xsc3, L2 cache ops are possible only on virtual addresses. The code is rearranged so to have a linear progression requiring the least amount of pte setups in the highmem case. To protect the virtual mapping so created, interrupts must be disabled currently up to a page worth of address range. The interrupt disabling is done in a way to minimize the overhead within the inner loop. The alternative would consist in separate code for the highmem and non highmem compilation which is less preferable. Signed-off-by: Nicolas Pitre --- arch/arm/mm/cache-xsc3l2.c | 107 +++++++++++++++++++++++++++---------- 1 file changed, 80 insertions(+), 27 deletions(-) diff --git a/arch/arm/mm/cache-xsc3l2.c b/arch/arm/mm/cache-xsc3l2.c index 464de893a988..5d180cb0bd94 100644 --- a/arch/arm/mm/cache-xsc3l2.c +++ b/arch/arm/mm/cache-xsc3l2.c @@ -17,12 +17,14 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include -#include -#include - #include #include #include +#include +#include +#include +#include +#include "mm.h" #define CR_L2 (1 << 26) @@ -47,21 +49,11 @@ static inline void xsc3_l2_clean_mva(unsigned long addr) __asm__("mcr p15, 1, %0, c7, c11, 1" : : "r" (addr)); } -static inline void xsc3_l2_clean_pa(unsigned long addr) -{ - xsc3_l2_clean_mva(__phys_to_virt(addr)); -} - static inline void xsc3_l2_inv_mva(unsigned long addr) { __asm__("mcr p15, 1, %0, c7, c7, 1" : : "r" (addr)); } -static inline void xsc3_l2_inv_pa(unsigned long addr) -{ - xsc3_l2_inv_mva(__phys_to_virt(addr)); -} - static inline void xsc3_l2_inv_all(void) { unsigned long l2ctype, set_way; @@ -79,50 +71,103 @@ static inline void xsc3_l2_inv_all(void) dsb(); } +#ifdef CONFIG_HIGHMEM +#define l2_map_save_flags(x) raw_local_save_flags(x) +#define l2_map_restore_flags(x) raw_local_irq_restore(x) +#else +#define l2_map_save_flags(x) ((x) = 0) +#define l2_map_restore_flags(x) ((void)(x)) +#endif + +static inline unsigned long l2_map_va(unsigned long pa, unsigned long prev_va, + unsigned long flags) +{ +#ifdef CONFIG_HIGHMEM + unsigned long va = prev_va & PAGE_MASK; + unsigned long pa_offset = pa << (32 - PAGE_SHIFT); + if (unlikely(pa_offset < (prev_va << (32 - PAGE_SHIFT)))) { + /* + * Switching to a new page. Because cache ops are + * using virtual addresses only, we must put a mapping + * in place for it. We also enable interrupts for a + * short while and disable them again to protect this + * mapping. + */ + unsigned long idx; + raw_local_irq_restore(flags); + idx = KM_L2_CACHE + KM_TYPE_NR * smp_processor_id(); + va = __fix_to_virt(FIX_KMAP_BEGIN + idx); + raw_local_irq_restore(flags | PSR_I_BIT); + set_pte_ext(TOP_PTE(va), pfn_pte(pa >> PAGE_SHIFT, PAGE_KERNEL), 0); + local_flush_tlb_kernel_page(va); + } + return va + (pa_offset >> (32 - PAGE_SHIFT)); +#else + return __phys_to_virt(pa); +#endif +} + static void xsc3_l2_inv_range(unsigned long start, unsigned long end) { + unsigned long vaddr, flags; + if (start == 0 && end == -1ul) { xsc3_l2_inv_all(); return; } + vaddr = -1; /* to force the first mapping */ + l2_map_save_flags(flags); + /* * Clean and invalidate partial first cache line. */ if (start & (CACHE_LINE_SIZE - 1)) { - xsc3_l2_clean_pa(start & ~(CACHE_LINE_SIZE - 1)); - xsc3_l2_inv_pa(start & ~(CACHE_LINE_SIZE - 1)); + vaddr = l2_map_va(start & ~(CACHE_LINE_SIZE - 1), vaddr, flags); + xsc3_l2_clean_mva(vaddr); + xsc3_l2_inv_mva(vaddr); start = (start | (CACHE_LINE_SIZE - 1)) + 1; } /* - * Clean and invalidate partial last cache line. + * Invalidate all full cache lines between 'start' and 'end'. */ - if (start < end && (end & (CACHE_LINE_SIZE - 1))) { - xsc3_l2_clean_pa(end & ~(CACHE_LINE_SIZE - 1)); - xsc3_l2_inv_pa(end & ~(CACHE_LINE_SIZE - 1)); - end &= ~(CACHE_LINE_SIZE - 1); + while (start < (end & ~(CACHE_LINE_SIZE - 1))) { + vaddr = l2_map_va(start, vaddr, flags); + xsc3_l2_inv_mva(vaddr); + start += CACHE_LINE_SIZE; } /* - * Invalidate all full cache lines between 'start' and 'end'. + * Clean and invalidate partial last cache line. */ - while (start < end) { - xsc3_l2_inv_pa(start); - start += CACHE_LINE_SIZE; + if (start < end) { + vaddr = l2_map_va(start, vaddr, flags); + xsc3_l2_clean_mva(vaddr); + xsc3_l2_inv_mva(vaddr); } + l2_map_restore_flags(flags); + dsb(); } static void xsc3_l2_clean_range(unsigned long start, unsigned long end) { + unsigned long vaddr, flags; + + vaddr = -1; /* to force the first mapping */ + l2_map_save_flags(flags); + start &= ~(CACHE_LINE_SIZE - 1); while (start < end) { - xsc3_l2_clean_pa(start); + vaddr = l2_map_va(start, vaddr, flags); + xsc3_l2_clean_mva(vaddr); start += CACHE_LINE_SIZE; } + l2_map_restore_flags(flags); + dsb(); } @@ -148,18 +193,26 @@ static inline void xsc3_l2_flush_all(void) static void xsc3_l2_flush_range(unsigned long start, unsigned long end) { + unsigned long vaddr, flags; + if (start == 0 && end == -1ul) { xsc3_l2_flush_all(); return; } + vaddr = -1; /* to force the first mapping */ + l2_map_save_flags(flags); + start &= ~(CACHE_LINE_SIZE - 1); while (start < end) { - xsc3_l2_clean_pa(start); - xsc3_l2_inv_pa(start); + vaddr = l2_map_va(start, vaddr, flags); + xsc3_l2_clean_mva(vaddr); + xsc3_l2_inv_mva(vaddr); start += CACHE_LINE_SIZE; } + l2_map_restore_flags(flags); + dsb(); } -- GitLab