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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/mm/cache-v7.S
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+/*
+ * linux/arch/arm/mm/cache-v7.S
+ *
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ * Copyright (C) 2005 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This is the "shell" of the ARMv7 processor support.
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+#include <asm/unwind.h>
+
+#include "proc-macros.S"
+
+/*
+ * The secondary kernel init calls v7_flush_dcache_all before it enables
+ * the L1; however, the L1 comes out of reset in an undefined state, so
+ * the clean + invalidate performed by v7_flush_dcache_all causes a bunch
+ * of cache lines with uninitialized data and uninitialized tags to get
+ * written out to memory, which does really unpleasant things to the main
+ * processor. We fix this by performing an invalidate, rather than a
+ * clean + invalidate, before jumping into the kernel.
+ *
+ * This function is cloned from arch/arm/mach-tegra/headsmp.S, and needs
+ * to be called for both secondary cores startup and primary core resume
+ * procedures.
+ */
+ENTRY(v7_invalidate_l1)
+ mov r0, #0
+ mcr p15, 2, r0, c0, c0, 0
+ mrc p15, 1, r0, c0, c0, 0
+
+ movw r1, #0x7fff
+ and r2, r1, r0, lsr #13
+
+ movw r1, #0x3ff
+
+ and r3, r1, r0, lsr #3 @ NumWays - 1
+ add r2, r2, #1 @ NumSets
+
+ and r0, r0, #0x7
+ add r0, r0, #4 @ SetShift
+
+ clz r1, r3 @ WayShift
+ add r4, r3, #1 @ NumWays
+1: sub r2, r2, #1 @ NumSets--
+ mov r3, r4 @ Temp = NumWays
+2: subs r3, r3, #1 @ Temp--
+ mov r5, r3, lsl r1
+ mov r6, r2, lsl r0
+ orr r5, r5, r6 @ Reg = (Temp<<WayShift)|(NumSets<<SetShift)
+ mcr p15, 0, r5, c7, c6, 2
+ bgt 2b
+ cmp r2, #0
+ bgt 1b
+ dsb st
+ isb
+ ret lr
+ENDPROC(v7_invalidate_l1)
+
+/*
+ * v7_flush_icache_all()
+ *
+ * Flush the whole I-cache.
+ *
+ * Registers:
+ * r0 - set to 0
+ */
+ENTRY(v7_flush_icache_all)
+ mov r0, #0
+ ALT_SMP(mcr p15, 0, r0, c7, c1, 0) @ invalidate I-cache inner shareable
+ ALT_UP(mcr p15, 0, r0, c7, c5, 0) @ I+BTB cache invalidate
+ ret lr
+ENDPROC(v7_flush_icache_all)
+
+ /*
+ * v7_flush_dcache_louis()
+ *
+ * Flush the D-cache up to the Level of Unification Inner Shareable
+ *
+ * Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
+ */
+
+ENTRY(v7_flush_dcache_louis)
+ dmb @ ensure ordering with previous memory accesses
+ mrc p15, 1, r0, c0, c0, 1 @ read clidr, r0 = clidr
+ALT_SMP(mov r3, r0, lsr #20) @ move LoUIS into position
+ALT_UP( mov r3, r0, lsr #26) @ move LoUU into position
+ ands r3, r3, #7 << 1 @ extract LoU*2 field from clidr
+ bne start_flush_levels @ LoU != 0, start flushing
+#ifdef CONFIG_ARM_ERRATA_643719
+ALT_SMP(mrc p15, 0, r2, c0, c0, 0) @ read main ID register
+ALT_UP( ret lr) @ LoUU is zero, so nothing to do
+ movw r1, #:lower16:(0x410fc090 >> 4) @ ID of ARM Cortex A9 r0p?
+ movt r1, #:upper16:(0x410fc090 >> 4)
+ teq r1, r2, lsr #4 @ test for errata affected core and if so...
+ moveq r3, #1 << 1 @ fix LoUIS value
+ beq start_flush_levels @ start flushing cache levels
+#endif
+ ret lr
+ENDPROC(v7_flush_dcache_louis)
+
+/*
+ * v7_flush_dcache_all()
+ *
+ * Flush the whole D-cache.
+ *
+ * Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
+ *
+ * - mm - mm_struct describing address space
+ */
+ENTRY(v7_flush_dcache_all)
+ dmb @ ensure ordering with previous memory accesses
+ mrc p15, 1, r0, c0, c0, 1 @ read clidr
+ mov r3, r0, lsr #23 @ move LoC into position
+ ands r3, r3, #7 << 1 @ extract LoC*2 from clidr
+ beq finished @ if loc is 0, then no need to clean
+start_flush_levels:
+ mov r10, #0 @ start clean at cache level 0
+flush_levels:
+ add r2, r10, r10, lsr #1 @ work out 3x current cache level
+ mov r1, r0, lsr r2 @ extract cache type bits from clidr
+ and r1, r1, #7 @ mask of the bits for current cache only
+ cmp r1, #2 @ see what cache we have at this level
+ blt skip @ skip if no cache, or just i-cache
+#ifdef CONFIG_PREEMPT
+ save_and_disable_irqs_notrace r9 @ make cssr&csidr read atomic
+#endif
+ mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
+ isb @ isb to sych the new cssr&csidr
+ mrc p15, 1, r1, c0, c0, 0 @ read the new csidr
+#ifdef CONFIG_PREEMPT
+ restore_irqs_notrace r9
+#endif
+ and r2, r1, #7 @ extract the length of the cache lines
+ add r2, r2, #4 @ add 4 (line length offset)
+ movw r4, #0x3ff
+ ands r4, r4, r1, lsr #3 @ find maximum number on the way size
+ clz r5, r4 @ find bit position of way size increment
+ movw r7, #0x7fff
+ ands r7, r7, r1, lsr #13 @ extract max number of the index size
+loop1:
+ mov r9, r7 @ create working copy of max index
+loop2:
+ ARM( orr r11, r10, r4, lsl r5 ) @ factor way and cache number into r11
+ THUMB( lsl r6, r4, r5 )
+ THUMB( orr r11, r10, r6 ) @ factor way and cache number into r11
+ ARM( orr r11, r11, r9, lsl r2 ) @ factor index number into r11
+ THUMB( lsl r6, r9, r2 )
+ THUMB( orr r11, r11, r6 ) @ factor index number into r11
+ mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way
+ subs r9, r9, #1 @ decrement the index
+ bge loop2
+ subs r4, r4, #1 @ decrement the way
+ bge loop1
+skip:
+ add r10, r10, #2 @ increment cache number
+ cmp r3, r10
+ bgt flush_levels
+finished:
+ mov r10, #0 @ swith back to cache level 0
+ mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
+ dsb st
+ isb
+ ret lr
+ENDPROC(v7_flush_dcache_all)
+
+/*
+ * v7_flush_cache_all()
+ *
+ * Flush the entire cache system.
+ * The data cache flush is now achieved using atomic clean / invalidates
+ * working outwards from L1 cache. This is done using Set/Way based cache
+ * maintenance instructions.
+ * The instruction cache can still be invalidated back to the point of
+ * unification in a single instruction.
+ *
+ */
+ENTRY(v7_flush_kern_cache_all)
+ ARM( stmfd sp!, {r4-r5, r7, r9-r11, lr} )
+ THUMB( stmfd sp!, {r4-r7, r9-r11, lr} )
+ bl v7_flush_dcache_all
+ mov r0, #0
+ ALT_SMP(mcr p15, 0, r0, c7, c1, 0) @ invalidate I-cache inner shareable
+ ALT_UP(mcr p15, 0, r0, c7, c5, 0) @ I+BTB cache invalidate
+ ARM( ldmfd sp!, {r4-r5, r7, r9-r11, lr} )
+ THUMB( ldmfd sp!, {r4-r7, r9-r11, lr} )
+ ret lr
+ENDPROC(v7_flush_kern_cache_all)
+
+ /*
+ * v7_flush_kern_cache_louis(void)
+ *
+ * Flush the data cache up to Level of Unification Inner Shareable.
+ * Invalidate the I-cache to the point of unification.
+ */
+ENTRY(v7_flush_kern_cache_louis)
+ ARM( stmfd sp!, {r4-r5, r7, r9-r11, lr} )
+ THUMB( stmfd sp!, {r4-r7, r9-r11, lr} )
+ bl v7_flush_dcache_louis
+ mov r0, #0
+ ALT_SMP(mcr p15, 0, r0, c7, c1, 0) @ invalidate I-cache inner shareable
+ ALT_UP(mcr p15, 0, r0, c7, c5, 0) @ I+BTB cache invalidate
+ ARM( ldmfd sp!, {r4-r5, r7, r9-r11, lr} )
+ THUMB( ldmfd sp!, {r4-r7, r9-r11, lr} )
+ ret lr
+ENDPROC(v7_flush_kern_cache_louis)
+
+/*
+ * v7_flush_cache_all()
+ *
+ * Flush all TLB entries in a particular address space
+ *
+ * - mm - mm_struct describing address space
+ */
+ENTRY(v7_flush_user_cache_all)
+ /*FALLTHROUGH*/
+
+/*
+ * v7_flush_cache_range(start, end, flags)
+ *
+ * Flush a range of TLB entries in the specified address space.
+ *
+ * - start - start address (may not be aligned)
+ * - end - end address (exclusive, may not be aligned)
+ * - flags - vm_area_struct flags describing address space
+ *
+ * It is assumed that:
+ * - we have a VIPT cache.
+ */
+ENTRY(v7_flush_user_cache_range)
+ ret lr
+ENDPROC(v7_flush_user_cache_all)
+ENDPROC(v7_flush_user_cache_range)
+
+/*
+ * v7_coherent_kern_range(start,end)
+ *
+ * Ensure that the I and D caches are coherent within specified
+ * region. This is typically used when code has been written to
+ * a memory region, and will be executed.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ *
+ * It is assumed that:
+ * - the Icache does not read data from the write buffer
+ */
+ENTRY(v7_coherent_kern_range)
+ /* FALLTHROUGH */
+
+/*
+ * v7_coherent_user_range(start,end)
+ *
+ * Ensure that the I and D caches are coherent within specified
+ * region. This is typically used when code has been written to
+ * a memory region, and will be executed.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ *
+ * It is assumed that:
+ * - the Icache does not read data from the write buffer
+ */
+ENTRY(v7_coherent_user_range)
+ UNWIND(.fnstart )
+ dcache_line_size r2, r3
+ sub r3, r2, #1
+ bic r12, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
+1:
+ USER( mcr p15, 0, r12, c7, c11, 1 ) @ clean D line to the point of unification
+ add r12, r12, r2
+ cmp r12, r1
+ blo 1b
+ dsb ishst
+ icache_line_size r2, r3
+ sub r3, r2, #1
+ bic r12, r0, r3
+2:
+ USER( mcr p15, 0, r12, c7, c5, 1 ) @ invalidate I line
+ add r12, r12, r2
+ cmp r12, r1
+ blo 2b
+ mov r0, #0
+ ALT_SMP(mcr p15, 0, r0, c7, c1, 6) @ invalidate BTB Inner Shareable
+ ALT_UP(mcr p15, 0, r0, c7, c5, 6) @ invalidate BTB
+ dsb ishst
+ isb
+ ret lr
+
+/*
+ * Fault handling for the cache operation above. If the virtual address in r0
+ * isn't mapped, fail with -EFAULT.
+ */
+9001:
+#ifdef CONFIG_ARM_ERRATA_775420
+ dsb
+#endif
+ mov r0, #-EFAULT
+ ret lr
+ UNWIND(.fnend )
+ENDPROC(v7_coherent_kern_range)
+ENDPROC(v7_coherent_user_range)
+
+/*
+ * v7_flush_kern_dcache_area(void *addr, size_t size)
+ *
+ * Ensure that the data held in the page kaddr is written back
+ * to the page in question.
+ *
+ * - addr - kernel address
+ * - size - region size
+ */
+ENTRY(v7_flush_kern_dcache_area)
+ dcache_line_size r2, r3
+ add r1, r0, r1
+ sub r3, r2, #1
+ bic r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
+1:
+ mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line / unified line
+ add r0, r0, r2
+ cmp r0, r1
+ blo 1b
+ dsb st
+ ret lr
+ENDPROC(v7_flush_kern_dcache_area)
+
+/*
+ * v7_dma_inv_range(start,end)
+ *
+ * Invalidate the data cache within the specified region; we will
+ * be performing a DMA operation in this region and we want to
+ * purge old data in the cache.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+v7_dma_inv_range:
+ dcache_line_size r2, r3
+ sub r3, r2, #1
+ tst r0, r3
+ bic r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
+ mcrne p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line
+
+ tst r1, r3
+ bic r1, r1, r3
+ mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D / U line
+1:
+ mcr p15, 0, r0, c7, c6, 1 @ invalidate D / U line
+ add r0, r0, r2
+ cmp r0, r1
+ blo 1b
+ dsb st
+ ret lr
+ENDPROC(v7_dma_inv_range)
+
+/*
+ * v7_dma_clean_range(start,end)
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+v7_dma_clean_range:
+ dcache_line_size r2, r3
+ sub r3, r2, #1
+ bic r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
+1:
+ mcr p15, 0, r0, c7, c10, 1 @ clean D / U line
+ add r0, r0, r2
+ cmp r0, r1
+ blo 1b
+ dsb st
+ ret lr
+ENDPROC(v7_dma_clean_range)
+
+/*
+ * v7_dma_flush_range(start,end)
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+ENTRY(v7_dma_flush_range)
+ dcache_line_size r2, r3
+ sub r3, r2, #1
+ bic r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
+1:
+ mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line
+ add r0, r0, r2
+ cmp r0, r1
+ blo 1b
+ dsb st
+ ret lr
+ENDPROC(v7_dma_flush_range)
+
+/*
+ * dma_map_area(start, size, dir)
+ * - start - kernel virtual start address
+ * - size - size of region
+ * - dir - DMA direction
+ */
+ENTRY(v7_dma_map_area)
+ add r1, r1, r0
+ teq r2, #DMA_FROM_DEVICE
+ beq v7_dma_inv_range
+ b v7_dma_clean_range
+ENDPROC(v7_dma_map_area)
+
+/*
+ * dma_unmap_area(start, size, dir)
+ * - start - kernel virtual start address
+ * - size - size of region
+ * - dir - DMA direction
+ */
+ENTRY(v7_dma_unmap_area)
+ add r1, r1, r0
+ teq r2, #DMA_TO_DEVICE
+ bne v7_dma_inv_range
+ ret lr
+ENDPROC(v7_dma_unmap_area)
+
+ __INITDATA
+
+ @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
+ define_cache_functions v7