f1f8926a94
Previously this took an explicit range, update this to use the same behaviour as the rest of the SH parts where we simply flush out a line from the start address. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
1032 lines
35 KiB
C
1032 lines
35 KiB
C
/*
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* arch/sh/mm/cache-sh5.c
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*
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* Original version Copyright (C) 2000, 2001 Paolo Alberelli
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* Second version Copyright (C) benedict.gaster@superh.com 2002
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* Third version Copyright Richard.Curnow@superh.com 2003
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* Hacks to third version Copyright (C) 2003 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/init.h>
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#include <linux/mman.h>
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#include <linux/mm.h>
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#include <linux/threads.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/processor.h>
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#include <asm/cache.h>
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#include <asm/tlb.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/mmu_context.h>
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#include <asm/pgalloc.h> /* for flush_itlb_range */
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#include <linux/proc_fs.h>
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/* This function is in entry.S */
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extern unsigned long switch_and_save_asid(unsigned long new_asid);
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/* Wired TLB entry for the D-cache */
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static unsigned long long dtlb_cache_slot;
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/**
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* sh64_cache_init()
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*
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* This is pretty much just a straightforward clone of the SH
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* detect_cpu_and_cache_system().
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*
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* This function is responsible for setting up all of the cache
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* info dynamically as well as taking care of CPU probing and
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* setting up the relevant subtype data.
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*
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* FIXME: For the time being, we only really support the SH5-101
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* out of the box, and don't support dynamic probing for things
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* like the SH5-103 or even cut2 of the SH5-101. Implement this
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* later!
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*/
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int __init sh64_cache_init(void)
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{
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/*
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* First, setup some sane values for the I-cache.
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*/
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cpu_data->icache.ways = 4;
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cpu_data->icache.sets = 256;
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cpu_data->icache.linesz = L1_CACHE_BYTES;
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/*
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* FIXME: This can probably be cleaned up a bit as well.. for example,
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* do we really need the way shift _and_ the way_step_shift ?? Judging
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* by the existing code, I would guess no.. is there any valid reason
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* why we need to be tracking this around?
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*/
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cpu_data->icache.way_shift = 13;
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cpu_data->icache.entry_shift = 5;
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cpu_data->icache.set_shift = 4;
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cpu_data->icache.way_step_shift = 16;
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cpu_data->icache.asid_shift = 2;
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/*
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* way offset = cache size / associativity, so just don't factor in
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* associativity in the first place..
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*/
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cpu_data->icache.way_ofs = cpu_data->icache.sets *
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cpu_data->icache.linesz;
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cpu_data->icache.asid_mask = 0x3fc;
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cpu_data->icache.idx_mask = 0x1fe0;
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cpu_data->icache.epn_mask = 0xffffe000;
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cpu_data->icache.flags = 0;
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/*
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* Next, setup some sane values for the D-cache.
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*
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* On the SH5, these are pretty consistent with the I-cache settings,
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* so we just copy over the existing definitions.. these can be fixed
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* up later, especially if we add runtime CPU probing.
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*
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* Though in the meantime it saves us from having to duplicate all of
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* the above definitions..
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*/
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cpu_data->dcache = cpu_data->icache;
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/*
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* Setup any cache-related flags here
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*/
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#if defined(CONFIG_DCACHE_WRITE_THROUGH)
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set_bit(SH_CACHE_MODE_WT, &(cpu_data->dcache.flags));
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#elif defined(CONFIG_DCACHE_WRITE_BACK)
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set_bit(SH_CACHE_MODE_WB, &(cpu_data->dcache.flags));
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#endif
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/*
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* We also need to reserve a slot for the D-cache in the DTLB, so we
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* do this now ..
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*/
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dtlb_cache_slot = sh64_get_wired_dtlb_entry();
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return 0;
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}
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#ifdef CONFIG_DCACHE_DISABLED
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#define sh64_dcache_purge_all() do { } while (0)
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#define sh64_dcache_purge_coloured_phy_page(paddr, eaddr) do { } while (0)
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#define sh64_dcache_purge_user_range(mm, start, end) do { } while (0)
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#define sh64_dcache_purge_phy_page(paddr) do { } while (0)
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#define sh64_dcache_purge_virt_page(mm, eaddr) do { } while (0)
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#define sh64_dcache_purge_kernel_range(start, end) do { } while (0)
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#define sh64_dcache_wback_current_user_range(start, end) do { } while (0)
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#endif
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/*##########################################################################*/
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/* From here onwards, a rewrite of the implementation,
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by Richard.Curnow@superh.com.
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The major changes in this compared to the old version are;
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1. use more selective purging through OCBP instead of using ALLOCO to purge
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by natural replacement. This avoids purging out unrelated cache lines
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that happen to be in the same set.
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2. exploit the APIs copy_user_page and clear_user_page better
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3. be more selective about I-cache purging, in particular use invalidate_all
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more sparingly.
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*/
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/*##########################################################################
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SUPPORT FUNCTIONS
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##########################################################################*/
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/****************************************************************************/
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/* The following group of functions deal with mapping and unmapping a temporary
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page into the DTLB slot that have been set aside for our exclusive use. */
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/* In order to accomplish this, we use the generic interface for adding and
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removing a wired slot entry as defined in arch/sh/mm/tlb-sh5.c */
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/****************************************************************************/
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static unsigned long slot_own_flags;
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static inline void sh64_setup_dtlb_cache_slot(unsigned long eaddr, unsigned long asid, unsigned long paddr)
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{
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local_irq_save(slot_own_flags);
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sh64_setup_tlb_slot(dtlb_cache_slot, eaddr, asid, paddr);
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}
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static inline void sh64_teardown_dtlb_cache_slot(void)
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{
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sh64_teardown_tlb_slot(dtlb_cache_slot);
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local_irq_restore(slot_own_flags);
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}
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/****************************************************************************/
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#ifndef CONFIG_ICACHE_DISABLED
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static void __inline__ sh64_icache_inv_all(void)
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{
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unsigned long long addr, flag, data;
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unsigned int flags;
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addr=ICCR0;
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flag=ICCR0_ICI;
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data=0;
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/* Make this a critical section for safety (probably not strictly necessary.) */
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local_irq_save(flags);
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/* Without %1 it gets unexplicably wrong */
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asm volatile("getcfg %3, 0, %0\n\t"
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"or %0, %2, %0\n\t"
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"putcfg %3, 0, %0\n\t"
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"synci"
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: "=&r" (data)
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: "0" (data), "r" (flag), "r" (addr));
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local_irq_restore(flags);
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}
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static void sh64_icache_inv_kernel_range(unsigned long start, unsigned long end)
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{
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/* Invalidate range of addresses [start,end] from the I-cache, where
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* the addresses lie in the kernel superpage. */
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unsigned long long ullend, addr, aligned_start;
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#if (NEFF == 32)
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aligned_start = (unsigned long long)(signed long long)(signed long) start;
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#else
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#error "NEFF != 32"
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#endif
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aligned_start &= L1_CACHE_ALIGN_MASK;
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addr = aligned_start;
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#if (NEFF == 32)
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ullend = (unsigned long long) (signed long long) (signed long) end;
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#else
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#error "NEFF != 32"
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#endif
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while (addr <= ullend) {
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asm __volatile__ ("icbi %0, 0" : : "r" (addr));
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addr += L1_CACHE_BYTES;
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}
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}
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static void sh64_icache_inv_user_page(struct vm_area_struct *vma, unsigned long eaddr)
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{
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/* If we get called, we know that vma->vm_flags contains VM_EXEC.
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Also, eaddr is page-aligned. */
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unsigned long long addr, end_addr;
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unsigned long flags = 0;
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unsigned long running_asid, vma_asid;
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addr = eaddr;
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end_addr = addr + PAGE_SIZE;
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/* Check whether we can use the current ASID for the I-cache
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invalidation. For example, if we're called via
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access_process_vm->flush_cache_page->here, (e.g. when reading from
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/proc), 'running_asid' will be that of the reader, not of the
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victim.
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Also, note the risk that we might get pre-empted between the ASID
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compare and blocking IRQs, and before we regain control, the
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pid->ASID mapping changes. However, the whole cache will get
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invalidated when the mapping is renewed, so the worst that can
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happen is that the loop below ends up invalidating somebody else's
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cache entries.
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*/
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running_asid = get_asid();
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vma_asid = (vma->vm_mm->context & MMU_CONTEXT_ASID_MASK);
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if (running_asid != vma_asid) {
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local_irq_save(flags);
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switch_and_save_asid(vma_asid);
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}
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while (addr < end_addr) {
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/* Worth unrolling a little */
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asm __volatile__("icbi %0, 0" : : "r" (addr));
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asm __volatile__("icbi %0, 32" : : "r" (addr));
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asm __volatile__("icbi %0, 64" : : "r" (addr));
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asm __volatile__("icbi %0, 96" : : "r" (addr));
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addr += 128;
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}
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if (running_asid != vma_asid) {
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switch_and_save_asid(running_asid);
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local_irq_restore(flags);
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}
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}
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/****************************************************************************/
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static void sh64_icache_inv_user_page_range(struct mm_struct *mm,
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unsigned long start, unsigned long end)
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{
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/* Used for invalidating big chunks of I-cache, i.e. assume the range
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is whole pages. If 'start' or 'end' is not page aligned, the code
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is conservative and invalidates to the ends of the enclosing pages.
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This is functionally OK, just a performance loss. */
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/* See the comments below in sh64_dcache_purge_user_range() regarding
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the choice of algorithm. However, for the I-cache option (2) isn't
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available because there are no physical tags so aliases can't be
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resolved. The icbi instruction has to be used through the user
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mapping. Because icbi is cheaper than ocbp on a cache hit, it
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would be cheaper to use the selective code for a large range than is
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possible with the D-cache. Just assume 64 for now as a working
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figure.
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*/
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int n_pages;
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if (!mm) return;
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n_pages = ((end - start) >> PAGE_SHIFT);
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if (n_pages >= 64) {
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sh64_icache_inv_all();
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} else {
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unsigned long aligned_start;
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unsigned long eaddr;
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unsigned long after_last_page_start;
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unsigned long mm_asid, current_asid;
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unsigned long long flags = 0ULL;
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mm_asid = mm->context & MMU_CONTEXT_ASID_MASK;
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current_asid = get_asid();
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if (mm_asid != current_asid) {
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/* Switch ASID and run the invalidate loop under cli */
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local_irq_save(flags);
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switch_and_save_asid(mm_asid);
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}
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aligned_start = start & PAGE_MASK;
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after_last_page_start = PAGE_SIZE + ((end - 1) & PAGE_MASK);
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while (aligned_start < after_last_page_start) {
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struct vm_area_struct *vma;
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unsigned long vma_end;
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vma = find_vma(mm, aligned_start);
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if (!vma || (aligned_start <= vma->vm_end)) {
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/* Avoid getting stuck in an error condition */
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aligned_start += PAGE_SIZE;
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continue;
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}
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vma_end = vma->vm_end;
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if (vma->vm_flags & VM_EXEC) {
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/* Executable */
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eaddr = aligned_start;
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while (eaddr < vma_end) {
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sh64_icache_inv_user_page(vma, eaddr);
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eaddr += PAGE_SIZE;
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}
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}
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aligned_start = vma->vm_end; /* Skip to start of next region */
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}
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if (mm_asid != current_asid) {
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switch_and_save_asid(current_asid);
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local_irq_restore(flags);
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}
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}
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}
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static void sh64_icache_inv_user_small_range(struct mm_struct *mm,
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unsigned long start, int len)
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{
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/* Invalidate a small range of user context I-cache, not necessarily
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page (or even cache-line) aligned. */
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unsigned long long eaddr = start;
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unsigned long long eaddr_end = start + len;
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unsigned long current_asid, mm_asid;
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unsigned long long flags;
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unsigned long long epage_start;
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/* Since this is used inside ptrace, the ASID in the mm context
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typically won't match current_asid. We'll have to switch ASID to do
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this. For safety, and given that the range will be small, do all
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this under cli.
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Note, there is a hazard that the ASID in mm->context is no longer
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actually associated with mm, i.e. if the mm->context has started a
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new cycle since mm was last active. However, this is just a
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performance issue: all that happens is that we invalidate lines
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belonging to another mm, so the owning process has to refill them
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when that mm goes live again. mm itself can't have any cache
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entries because there will have been a flush_cache_all when the new
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mm->context cycle started. */
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/* Align to start of cache line. Otherwise, suppose len==8 and start
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was at 32N+28 : the last 4 bytes wouldn't get invalidated. */
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eaddr = start & L1_CACHE_ALIGN_MASK;
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eaddr_end = start + len;
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local_irq_save(flags);
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mm_asid = mm->context & MMU_CONTEXT_ASID_MASK;
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current_asid = switch_and_save_asid(mm_asid);
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epage_start = eaddr & PAGE_MASK;
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while (eaddr < eaddr_end)
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{
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asm __volatile__("icbi %0, 0" : : "r" (eaddr));
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eaddr += L1_CACHE_BYTES;
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}
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switch_and_save_asid(current_asid);
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local_irq_restore(flags);
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}
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static void sh64_icache_inv_current_user_range(unsigned long start, unsigned long end)
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{
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/* The icbi instruction never raises ITLBMISS. i.e. if there's not a
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cache hit on the virtual tag the instruction ends there, without a
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TLB lookup. */
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unsigned long long aligned_start;
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unsigned long long ull_end;
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unsigned long long addr;
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ull_end = end;
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/* Just invalidate over the range using the natural addresses. TLB
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miss handling will be OK (TBC). Since it's for the current process,
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either we're already in the right ASID context, or the ASIDs have
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been recycled since we were last active in which case we might just
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invalidate another processes I-cache entries : no worries, just a
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performance drop for him. */
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aligned_start = start & L1_CACHE_ALIGN_MASK;
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addr = aligned_start;
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while (addr < ull_end) {
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asm __volatile__ ("icbi %0, 0" : : "r" (addr));
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asm __volatile__ ("nop");
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asm __volatile__ ("nop");
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addr += L1_CACHE_BYTES;
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}
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}
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#endif /* !CONFIG_ICACHE_DISABLED */
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/****************************************************************************/
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#ifndef CONFIG_DCACHE_DISABLED
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/* Buffer used as the target of alloco instructions to purge data from cache
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sets by natural eviction. -- RPC */
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#define DUMMY_ALLOCO_AREA_SIZE L1_CACHE_SIZE_BYTES + (1024 * 4)
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static unsigned char dummy_alloco_area[DUMMY_ALLOCO_AREA_SIZE] __cacheline_aligned = { 0, };
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/****************************************************************************/
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static void __inline__ sh64_dcache_purge_sets(int sets_to_purge_base, int n_sets)
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{
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/* Purge all ways in a particular block of sets, specified by the base
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set number and number of sets. Can handle wrap-around, if that's
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needed. */
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int dummy_buffer_base_set;
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unsigned long long eaddr, eaddr0, eaddr1;
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int j;
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int set_offset;
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dummy_buffer_base_set = ((int)&dummy_alloco_area & cpu_data->dcache.idx_mask) >> cpu_data->dcache.entry_shift;
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set_offset = sets_to_purge_base - dummy_buffer_base_set;
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for (j=0; j<n_sets; j++, set_offset++) {
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set_offset &= (cpu_data->dcache.sets - 1);
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eaddr0 = (unsigned long long)dummy_alloco_area + (set_offset << cpu_data->dcache.entry_shift);
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/* Do one alloco which hits the required set per cache way. For
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write-back mode, this will purge the #ways resident lines. There's
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little point unrolling this loop because the allocos stall more if
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they're too close together. */
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eaddr1 = eaddr0 + cpu_data->dcache.way_ofs * cpu_data->dcache.ways;
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for (eaddr=eaddr0; eaddr<eaddr1; eaddr+=cpu_data->dcache.way_ofs) {
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asm __volatile__ ("alloco %0, 0" : : "r" (eaddr));
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asm __volatile__ ("synco"); /* TAKum03020 */
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}
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eaddr1 = eaddr0 + cpu_data->dcache.way_ofs * cpu_data->dcache.ways;
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for (eaddr=eaddr0; eaddr<eaddr1; eaddr+=cpu_data->dcache.way_ofs) {
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/* Load from each address. Required because alloco is a NOP if
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the cache is write-through. Write-through is a config option. */
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if (test_bit(SH_CACHE_MODE_WT, &(cpu_data->dcache.flags)))
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*(volatile unsigned char *)(int)eaddr;
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}
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}
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|
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/* Don't use OCBI to invalidate the lines. That costs cycles directly.
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If the dummy block is just left resident, it will naturally get
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evicted as required. */
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return;
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}
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|
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/****************************************************************************/
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|
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static void sh64_dcache_purge_all(void)
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{
|
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/* Purge the entire contents of the dcache. The most efficient way to
|
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achieve this is to use alloco instructions on a region of unused
|
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memory equal in size to the cache, thereby causing the current
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contents to be discarded by natural eviction. The alternative,
|
|
namely reading every tag, setting up a mapping for the corresponding
|
|
page and doing an OCBP for the line, would be much more expensive.
|
|
*/
|
|
|
|
sh64_dcache_purge_sets(0, cpu_data->dcache.sets);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
static void sh64_dcache_purge_kernel_range(unsigned long start, unsigned long end)
|
|
{
|
|
/* Purge the range of addresses [start,end] from the D-cache. The
|
|
addresses lie in the superpage mapping. There's no harm if we
|
|
overpurge at either end - just a small performance loss. */
|
|
unsigned long long ullend, addr, aligned_start;
|
|
#if (NEFF == 32)
|
|
aligned_start = (unsigned long long)(signed long long)(signed long) start;
|
|
#else
|
|
#error "NEFF != 32"
|
|
#endif
|
|
aligned_start &= L1_CACHE_ALIGN_MASK;
|
|
addr = aligned_start;
|
|
#if (NEFF == 32)
|
|
ullend = (unsigned long long) (signed long long) (signed long) end;
|
|
#else
|
|
#error "NEFF != 32"
|
|
#endif
|
|
while (addr <= ullend) {
|
|
asm __volatile__ ("ocbp %0, 0" : : "r" (addr));
|
|
addr += L1_CACHE_BYTES;
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* Assumes this address (+ (2**n_synbits) pages up from it) aren't used for
|
|
anything else in the kernel */
|
|
#define MAGIC_PAGE0_START 0xffffffffec000000ULL
|
|
|
|
static void sh64_dcache_purge_coloured_phy_page(unsigned long paddr, unsigned long eaddr)
|
|
{
|
|
/* Purge the physical page 'paddr' from the cache. It's known that any
|
|
cache lines requiring attention have the same page colour as the the
|
|
address 'eaddr'.
|
|
|
|
This relies on the fact that the D-cache matches on physical tags
|
|
when no virtual tag matches. So we create an alias for the original
|
|
page and purge through that. (Alternatively, we could have done
|
|
this by switching ASID to match the original mapping and purged
|
|
through that, but that involves ASID switching cost + probably a
|
|
TLBMISS + refill anyway.)
|
|
*/
|
|
|
|
unsigned long long magic_page_start;
|
|
unsigned long long magic_eaddr, magic_eaddr_end;
|
|
|
|
magic_page_start = MAGIC_PAGE0_START + (eaddr & CACHE_OC_SYN_MASK);
|
|
|
|
/* As long as the kernel is not pre-emptible, this doesn't need to be
|
|
under cli/sti. */
|
|
|
|
sh64_setup_dtlb_cache_slot(magic_page_start, get_asid(), paddr);
|
|
|
|
magic_eaddr = magic_page_start;
|
|
magic_eaddr_end = magic_eaddr + PAGE_SIZE;
|
|
while (magic_eaddr < magic_eaddr_end) {
|
|
/* Little point in unrolling this loop - the OCBPs are blocking
|
|
and won't go any quicker (i.e. the loop overhead is parallel
|
|
to part of the OCBP execution.) */
|
|
asm __volatile__ ("ocbp %0, 0" : : "r" (magic_eaddr));
|
|
magic_eaddr += L1_CACHE_BYTES;
|
|
}
|
|
|
|
sh64_teardown_dtlb_cache_slot();
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
static void sh64_dcache_purge_phy_page(unsigned long paddr)
|
|
{
|
|
/* Pure a page given its physical start address, by creating a
|
|
temporary 1 page mapping and purging across that. Even if we know
|
|
the virtual address (& vma or mm) of the page, the method here is
|
|
more elegant because it avoids issues of coping with page faults on
|
|
the purge instructions (i.e. no special-case code required in the
|
|
critical path in the TLB miss handling). */
|
|
|
|
unsigned long long eaddr_start, eaddr, eaddr_end;
|
|
int i;
|
|
|
|
/* As long as the kernel is not pre-emptible, this doesn't need to be
|
|
under cli/sti. */
|
|
|
|
eaddr_start = MAGIC_PAGE0_START;
|
|
for (i=0; i < (1 << CACHE_OC_N_SYNBITS); i++) {
|
|
sh64_setup_dtlb_cache_slot(eaddr_start, get_asid(), paddr);
|
|
|
|
eaddr = eaddr_start;
|
|
eaddr_end = eaddr + PAGE_SIZE;
|
|
while (eaddr < eaddr_end) {
|
|
asm __volatile__ ("ocbp %0, 0" : : "r" (eaddr));
|
|
eaddr += L1_CACHE_BYTES;
|
|
}
|
|
|
|
sh64_teardown_dtlb_cache_slot();
|
|
eaddr_start += PAGE_SIZE;
|
|
}
|
|
}
|
|
|
|
static void sh64_dcache_purge_user_pages(struct mm_struct *mm,
|
|
unsigned long addr, unsigned long end)
|
|
{
|
|
pgd_t *pgd;
|
|
pmd_t *pmd;
|
|
pte_t *pte;
|
|
pte_t entry;
|
|
spinlock_t *ptl;
|
|
unsigned long paddr;
|
|
|
|
if (!mm)
|
|
return; /* No way to find physical address of page */
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
if (pgd_bad(*pgd))
|
|
return;
|
|
|
|
pmd = pmd_offset(pgd, addr);
|
|
if (pmd_none(*pmd) || pmd_bad(*pmd))
|
|
return;
|
|
|
|
pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
|
|
do {
|
|
entry = *pte;
|
|
if (pte_none(entry) || !pte_present(entry))
|
|
continue;
|
|
paddr = pte_val(entry) & PAGE_MASK;
|
|
sh64_dcache_purge_coloured_phy_page(paddr, addr);
|
|
} while (pte++, addr += PAGE_SIZE, addr != end);
|
|
pte_unmap_unlock(pte - 1, ptl);
|
|
}
|
|
/****************************************************************************/
|
|
|
|
static void sh64_dcache_purge_user_range(struct mm_struct *mm,
|
|
unsigned long start, unsigned long end)
|
|
{
|
|
/* There are at least 5 choices for the implementation of this, with
|
|
pros (+), cons(-), comments(*):
|
|
|
|
1. ocbp each line in the range through the original user's ASID
|
|
+ no lines spuriously evicted
|
|
- tlbmiss handling (must either handle faults on demand => extra
|
|
special-case code in tlbmiss critical path), or map the page in
|
|
advance (=> flush_tlb_range in advance to avoid multiple hits)
|
|
- ASID switching
|
|
- expensive for large ranges
|
|
|
|
2. temporarily map each page in the range to a special effective
|
|
address and ocbp through the temporary mapping; relies on the
|
|
fact that SH-5 OCB* always do TLB lookup and match on ptags (they
|
|
never look at the etags)
|
|
+ no spurious evictions
|
|
- expensive for large ranges
|
|
* surely cheaper than (1)
|
|
|
|
3. walk all the lines in the cache, check the tags, if a match
|
|
occurs create a page mapping to ocbp the line through
|
|
+ no spurious evictions
|
|
- tag inspection overhead
|
|
- (especially for small ranges)
|
|
- potential cost of setting up/tearing down page mapping for
|
|
every line that matches the range
|
|
* cost partly independent of range size
|
|
|
|
4. walk all the lines in the cache, check the tags, if a match
|
|
occurs use 4 * alloco to purge the line (+3 other probably
|
|
innocent victims) by natural eviction
|
|
+ no tlb mapping overheads
|
|
- spurious evictions
|
|
- tag inspection overhead
|
|
|
|
5. implement like flush_cache_all
|
|
+ no tag inspection overhead
|
|
- spurious evictions
|
|
- bad for small ranges
|
|
|
|
(1) can be ruled out as more expensive than (2). (2) appears best
|
|
for small ranges. The choice between (3), (4) and (5) for large
|
|
ranges and the range size for the large/small boundary need
|
|
benchmarking to determine.
|
|
|
|
For now use approach (2) for small ranges and (5) for large ones.
|
|
|
|
*/
|
|
|
|
int n_pages;
|
|
|
|
n_pages = ((end - start) >> PAGE_SHIFT);
|
|
if (n_pages >= 64 || ((start ^ (end - 1)) & PMD_MASK)) {
|
|
#if 1
|
|
sh64_dcache_purge_all();
|
|
#else
|
|
unsigned long long set, way;
|
|
unsigned long mm_asid = mm->context & MMU_CONTEXT_ASID_MASK;
|
|
for (set = 0; set < cpu_data->dcache.sets; set++) {
|
|
unsigned long long set_base_config_addr = CACHE_OC_ADDRESS_ARRAY + (set << cpu_data->dcache.set_shift);
|
|
for (way = 0; way < cpu_data->dcache.ways; way++) {
|
|
unsigned long long config_addr = set_base_config_addr + (way << cpu_data->dcache.way_step_shift);
|
|
unsigned long long tag0;
|
|
unsigned long line_valid;
|
|
|
|
asm __volatile__("getcfg %1, 0, %0" : "=r" (tag0) : "r" (config_addr));
|
|
line_valid = tag0 & SH_CACHE_VALID;
|
|
if (line_valid) {
|
|
unsigned long cache_asid;
|
|
unsigned long epn;
|
|
|
|
cache_asid = (tag0 & cpu_data->dcache.asid_mask) >> cpu_data->dcache.asid_shift;
|
|
/* The next line needs some
|
|
explanation. The virtual tags
|
|
encode bits [31:13] of the virtual
|
|
address, bit [12] of the 'tag' being
|
|
implied by the cache set index. */
|
|
epn = (tag0 & cpu_data->dcache.epn_mask) | ((set & 0x80) << cpu_data->dcache.entry_shift);
|
|
|
|
if ((cache_asid == mm_asid) && (start <= epn) && (epn < end)) {
|
|
/* TODO : could optimise this
|
|
call by batching multiple
|
|
adjacent sets together. */
|
|
sh64_dcache_purge_sets(set, 1);
|
|
break; /* Don't waste time inspecting other ways for this set */
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
} else {
|
|
/* Small range, covered by a single page table page */
|
|
start &= PAGE_MASK; /* should already be so */
|
|
end = PAGE_ALIGN(end); /* should already be so */
|
|
sh64_dcache_purge_user_pages(mm, start, end);
|
|
}
|
|
return;
|
|
}
|
|
|
|
static void sh64_dcache_wback_current_user_range(unsigned long start, unsigned long end)
|
|
{
|
|
unsigned long long aligned_start;
|
|
unsigned long long ull_end;
|
|
unsigned long long addr;
|
|
|
|
ull_end = end;
|
|
|
|
/* Just wback over the range using the natural addresses. TLB miss
|
|
handling will be OK (TBC) : the range has just been written to by
|
|
the signal frame setup code, so the PTEs must exist.
|
|
|
|
Note, if we have CONFIG_PREEMPT and get preempted inside this loop,
|
|
it doesn't matter, even if the pid->ASID mapping changes whilst
|
|
we're away. In that case the cache will have been flushed when the
|
|
mapping was renewed. So the writebacks below will be nugatory (and
|
|
we'll doubtless have to fault the TLB entry/ies in again with the
|
|
new ASID), but it's a rare case.
|
|
*/
|
|
aligned_start = start & L1_CACHE_ALIGN_MASK;
|
|
addr = aligned_start;
|
|
while (addr < ull_end) {
|
|
asm __volatile__ ("ocbwb %0, 0" : : "r" (addr));
|
|
addr += L1_CACHE_BYTES;
|
|
}
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
/* These *MUST* lie in an area of virtual address space that's otherwise unused. */
|
|
#define UNIQUE_EADDR_START 0xe0000000UL
|
|
#define UNIQUE_EADDR_END 0xe8000000UL
|
|
|
|
static unsigned long sh64_make_unique_eaddr(unsigned long user_eaddr, unsigned long paddr)
|
|
{
|
|
/* Given a physical address paddr, and a user virtual address
|
|
user_eaddr which will eventually be mapped to it, create a one-off
|
|
kernel-private eaddr mapped to the same paddr. This is used for
|
|
creating special destination pages for copy_user_page and
|
|
clear_user_page */
|
|
|
|
static unsigned long current_pointer = UNIQUE_EADDR_START;
|
|
unsigned long coloured_pointer;
|
|
|
|
if (current_pointer == UNIQUE_EADDR_END) {
|
|
sh64_dcache_purge_all();
|
|
current_pointer = UNIQUE_EADDR_START;
|
|
}
|
|
|
|
coloured_pointer = (current_pointer & ~CACHE_OC_SYN_MASK) | (user_eaddr & CACHE_OC_SYN_MASK);
|
|
sh64_setup_dtlb_cache_slot(coloured_pointer, get_asid(), paddr);
|
|
|
|
current_pointer += (PAGE_SIZE << CACHE_OC_N_SYNBITS);
|
|
|
|
return coloured_pointer;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
static void sh64_copy_user_page_coloured(void *to, void *from, unsigned long address)
|
|
{
|
|
void *coloured_to;
|
|
|
|
/* Discard any existing cache entries of the wrong colour. These are
|
|
present quite often, if the kernel has recently used the page
|
|
internally, then given it up, then it's been allocated to the user.
|
|
*/
|
|
sh64_dcache_purge_coloured_phy_page(__pa(to), (unsigned long) to);
|
|
|
|
coloured_to = (void *) sh64_make_unique_eaddr(address, __pa(to));
|
|
sh64_page_copy(from, coloured_to);
|
|
|
|
sh64_teardown_dtlb_cache_slot();
|
|
}
|
|
|
|
static void sh64_clear_user_page_coloured(void *to, unsigned long address)
|
|
{
|
|
void *coloured_to;
|
|
|
|
/* Discard any existing kernel-originated lines of the wrong colour (as
|
|
above) */
|
|
sh64_dcache_purge_coloured_phy_page(__pa(to), (unsigned long) to);
|
|
|
|
coloured_to = (void *) sh64_make_unique_eaddr(address, __pa(to));
|
|
sh64_page_clear(coloured_to);
|
|
|
|
sh64_teardown_dtlb_cache_slot();
|
|
}
|
|
|
|
#endif /* !CONFIG_DCACHE_DISABLED */
|
|
|
|
/****************************************************************************/
|
|
|
|
/*##########################################################################
|
|
EXTERNALLY CALLABLE API.
|
|
##########################################################################*/
|
|
|
|
/* These functions are described in Documentation/cachetlb.txt.
|
|
Each one of these functions varies in behaviour depending on whether the
|
|
I-cache and/or D-cache are configured out.
|
|
|
|
Note that the Linux term 'flush' corresponds to what is termed 'purge' in
|
|
the sh/sh64 jargon for the D-cache, i.e. write back dirty data then
|
|
invalidate the cache lines, and 'invalidate' for the I-cache.
|
|
*/
|
|
|
|
#undef FLUSH_TRACE
|
|
|
|
void flush_cache_all(void)
|
|
{
|
|
/* Invalidate the entire contents of both caches, after writing back to
|
|
memory any dirty data from the D-cache. */
|
|
sh64_dcache_purge_all();
|
|
sh64_icache_inv_all();
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
void flush_cache_mm(struct mm_struct *mm)
|
|
{
|
|
/* Invalidate an entire user-address space from both caches, after
|
|
writing back dirty data (e.g. for shared mmap etc). */
|
|
|
|
/* This could be coded selectively by inspecting all the tags then
|
|
doing 4*alloco on any set containing a match (as for
|
|
flush_cache_range), but fork/exit/execve (where this is called from)
|
|
are expensive anyway. */
|
|
|
|
/* Have to do a purge here, despite the comments re I-cache below.
|
|
There could be odd-coloured dirty data associated with the mm still
|
|
in the cache - if this gets written out through natural eviction
|
|
after the kernel has reused the page there will be chaos.
|
|
*/
|
|
|
|
sh64_dcache_purge_all();
|
|
|
|
/* The mm being torn down won't ever be active again, so any Icache
|
|
lines tagged with its ASID won't be visible for the rest of the
|
|
lifetime of this ASID cycle. Before the ASID gets reused, there
|
|
will be a flush_cache_all. Hence we don't need to touch the
|
|
I-cache. This is similar to the lack of action needed in
|
|
flush_tlb_mm - see fault.c. */
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
|
|
unsigned long end)
|
|
{
|
|
struct mm_struct *mm = vma->vm_mm;
|
|
|
|
/* Invalidate (from both caches) the range [start,end) of virtual
|
|
addresses from the user address space specified by mm, after writing
|
|
back any dirty data.
|
|
|
|
Note, 'end' is 1 byte beyond the end of the range to flush. */
|
|
|
|
sh64_dcache_purge_user_range(mm, start, end);
|
|
sh64_icache_inv_user_page_range(mm, start, end);
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
void flush_cache_page(struct vm_area_struct *vma, unsigned long eaddr, unsigned long pfn)
|
|
{
|
|
/* Invalidate any entries in either cache for the vma within the user
|
|
address space vma->vm_mm for the page starting at virtual address
|
|
'eaddr'. This seems to be used primarily in breaking COW. Note,
|
|
the I-cache must be searched too in case the page in question is
|
|
both writable and being executed from (e.g. stack trampolines.)
|
|
|
|
Note, this is called with pte lock held.
|
|
*/
|
|
|
|
sh64_dcache_purge_phy_page(pfn << PAGE_SHIFT);
|
|
|
|
if (vma->vm_flags & VM_EXEC) {
|
|
sh64_icache_inv_user_page(vma, eaddr);
|
|
}
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
#ifndef CONFIG_DCACHE_DISABLED
|
|
|
|
void copy_user_page(void *to, void *from, unsigned long address, struct page *page)
|
|
{
|
|
/* 'from' and 'to' are kernel virtual addresses (within the superpage
|
|
mapping of the physical RAM). 'address' is the user virtual address
|
|
where the copy 'to' will be mapped after. This allows a custom
|
|
mapping to be used to ensure that the new copy is placed in the
|
|
right cache sets for the user to see it without having to bounce it
|
|
out via memory. Note however : the call to flush_page_to_ram in
|
|
(generic)/mm/memory.c:(break_cow) undoes all this good work in that one
|
|
very important case!
|
|
|
|
TBD : can we guarantee that on every call, any cache entries for
|
|
'from' are in the same colour sets as 'address' also? i.e. is this
|
|
always used just to deal with COW? (I suspect not). */
|
|
|
|
/* There are two possibilities here for when the page 'from' was last accessed:
|
|
* by the kernel : this is OK, no purge required.
|
|
* by the/a user (e.g. for break_COW) : need to purge.
|
|
|
|
If the potential user mapping at 'address' is the same colour as
|
|
'from' there is no need to purge any cache lines from the 'from'
|
|
page mapped into cache sets of colour 'address'. (The copy will be
|
|
accessing the page through 'from').
|
|
*/
|
|
|
|
if (((address ^ (unsigned long) from) & CACHE_OC_SYN_MASK) != 0) {
|
|
sh64_dcache_purge_coloured_phy_page(__pa(from), address);
|
|
}
|
|
|
|
if (((address ^ (unsigned long) to) & CACHE_OC_SYN_MASK) == 0) {
|
|
/* No synonym problem on destination */
|
|
sh64_page_copy(from, to);
|
|
} else {
|
|
sh64_copy_user_page_coloured(to, from, address);
|
|
}
|
|
|
|
/* Note, don't need to flush 'from' page from the cache again - it's
|
|
done anyway by the generic code */
|
|
}
|
|
|
|
void clear_user_page(void *to, unsigned long address, struct page *page)
|
|
{
|
|
/* 'to' is a kernel virtual address (within the superpage
|
|
mapping of the physical RAM). 'address' is the user virtual address
|
|
where the 'to' page will be mapped after. This allows a custom
|
|
mapping to be used to ensure that the new copy is placed in the
|
|
right cache sets for the user to see it without having to bounce it
|
|
out via memory.
|
|
*/
|
|
|
|
if (((address ^ (unsigned long) to) & CACHE_OC_SYN_MASK) == 0) {
|
|
/* No synonym problem on destination */
|
|
sh64_page_clear(to);
|
|
} else {
|
|
sh64_clear_user_page_coloured(to, address);
|
|
}
|
|
}
|
|
|
|
#endif /* !CONFIG_DCACHE_DISABLED */
|
|
|
|
/****************************************************************************/
|
|
|
|
void flush_dcache_page(struct page *page)
|
|
{
|
|
sh64_dcache_purge_phy_page(page_to_phys(page));
|
|
wmb();
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
void flush_icache_range(unsigned long start, unsigned long end)
|
|
{
|
|
/* Flush the range [start,end] of kernel virtual adddress space from
|
|
the I-cache. The corresponding range must be purged from the
|
|
D-cache also because the SH-5 doesn't have cache snooping between
|
|
the caches. The addresses will be visible through the superpage
|
|
mapping, therefore it's guaranteed that there no cache entries for
|
|
the range in cache sets of the wrong colour.
|
|
|
|
Primarily used for cohering the I-cache after a module has
|
|
been loaded. */
|
|
|
|
/* We also make sure to purge the same range from the D-cache since
|
|
flush_page_to_ram() won't be doing this for us! */
|
|
|
|
sh64_dcache_purge_kernel_range(start, end);
|
|
wmb();
|
|
sh64_icache_inv_kernel_range(start, end);
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
void flush_icache_user_range(struct vm_area_struct *vma,
|
|
struct page *page, unsigned long addr, int len)
|
|
{
|
|
/* Flush the range of user (defined by vma->vm_mm) address space
|
|
starting at 'addr' for 'len' bytes from the cache. The range does
|
|
not straddle a page boundary, the unique physical page containing
|
|
the range is 'page'. This seems to be used mainly for invalidating
|
|
an address range following a poke into the program text through the
|
|
ptrace() call from another process (e.g. for BRK instruction
|
|
insertion). */
|
|
|
|
sh64_dcache_purge_coloured_phy_page(page_to_phys(page), addr);
|
|
mb();
|
|
|
|
if (vma->vm_flags & VM_EXEC) {
|
|
sh64_icache_inv_user_small_range(vma->vm_mm, addr, len);
|
|
}
|
|
}
|
|
|
|
/*##########################################################################
|
|
ARCH/SH64 PRIVATE CALLABLE API.
|
|
##########################################################################*/
|
|
|
|
void flush_cache_sigtramp(unsigned long vaddr)
|
|
{
|
|
unsigned long end = vaddr + L1_CACHE_BYTES;
|
|
|
|
/* For the address range [start,end), write back the data from the
|
|
D-cache and invalidate the corresponding region of the I-cache for
|
|
the current process. Used to flush signal trampolines on the stack
|
|
to make them executable. */
|
|
|
|
sh64_dcache_wback_current_user_range(vaddr, end);
|
|
wmb();
|
|
sh64_icache_inv_current_user_range(vaddr, end);
|
|
}
|
|
|