119 строки
2.6 KiB
ArmAsm
119 строки
2.6 KiB
ArmAsm
/*
|
|
* arch/blackfin/lib/ins.S - ins{bwl} using hardware loops
|
|
*
|
|
* Copyright 2004-2008 Analog Devices Inc.
|
|
* Copyright (C) 2005 Bas Vermeulen, BuyWays BV <bas@buyways.nl>
|
|
* Licensed under the GPL-2 or later.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/blackfin.h>
|
|
|
|
.align 2
|
|
|
|
#ifdef CONFIG_IPIPE
|
|
# define DO_CLI \
|
|
[--sp] = rets; \
|
|
[--sp] = (P5:0); \
|
|
sp += -12; \
|
|
call ___ipipe_disable_root_irqs_hw; \
|
|
sp += 12; \
|
|
(P5:0) = [sp++];
|
|
# define CLI_INNER_NOP
|
|
#else
|
|
# define DO_CLI cli R3;
|
|
# define CLI_INNER_NOP nop; nop; nop;
|
|
#endif
|
|
|
|
#ifdef CONFIG_IPIPE
|
|
# define DO_STI \
|
|
sp += -12; \
|
|
call ___ipipe_enable_root_irqs_hw; \
|
|
sp += 12; \
|
|
2: rets = [sp++];
|
|
#else
|
|
# define DO_STI 2: sti R3;
|
|
#endif
|
|
|
|
#ifdef CONFIG_BFIN_INS_LOWOVERHEAD
|
|
# define CLI_OUTER DO_CLI;
|
|
# define STI_OUTER DO_STI;
|
|
# define CLI_INNER 1:
|
|
# if ANOMALY_05000416
|
|
# define STI_INNER nop; 2: nop;
|
|
# else
|
|
# define STI_INNER 2:
|
|
# endif
|
|
#else
|
|
# define CLI_OUTER
|
|
# define STI_OUTER
|
|
# define CLI_INNER 1: DO_CLI; CLI_INNER_NOP;
|
|
# define STI_INNER DO_STI;
|
|
#endif
|
|
|
|
/*
|
|
* Reads on the Blackfin are speculative. In Blackfin terms, this means they
|
|
* can be interrupted at any time (even after they have been issued on to the
|
|
* external bus), and re-issued after the interrupt occurs.
|
|
*
|
|
* If a FIFO is sitting on the end of the read, it will see two reads,
|
|
* when the core only sees one. The FIFO receives the read which is cancelled,
|
|
* and not delivered to the core.
|
|
*
|
|
* To solve this, interrupts are turned off before reads occur to I/O space.
|
|
* There are 3 versions of all these functions
|
|
* - turns interrupts off every read (higher overhead, but lower latency)
|
|
* - turns interrupts off every loop (low overhead, but longer latency)
|
|
* - DMA version, which do not suffer from this issue. DMA versions have
|
|
* different name (prefixed by dma_ ), and are located in
|
|
* ../kernel/bfin_dma.c
|
|
* Using the dma related functions are recommended for transferring large
|
|
* buffers in/out of FIFOs.
|
|
*/
|
|
|
|
#define COMMON_INS(func, ops) \
|
|
ENTRY(_ins##func) \
|
|
P0 = R0; /* P0 = port */ \
|
|
CLI_OUTER; /* 3 instructions before first read access */ \
|
|
P1 = R1; /* P1 = address */ \
|
|
P2 = R2; /* P2 = count */ \
|
|
SSYNC; \
|
|
\
|
|
LSETUP(1f, 2f) LC0 = P2; \
|
|
CLI_INNER; \
|
|
ops; \
|
|
STI_INNER; \
|
|
\
|
|
STI_OUTER; \
|
|
RTS; \
|
|
ENDPROC(_ins##func)
|
|
|
|
COMMON_INS(l, \
|
|
R0 = [P0]; \
|
|
[P1++] = R0; \
|
|
)
|
|
|
|
COMMON_INS(w, \
|
|
R0 = W[P0]; \
|
|
W[P1++] = R0; \
|
|
)
|
|
|
|
COMMON_INS(w_8, \
|
|
R0 = W[P0]; \
|
|
B[P1++] = R0; \
|
|
R0 = R0 >> 8; \
|
|
B[P1++] = R0; \
|
|
)
|
|
|
|
COMMON_INS(b, \
|
|
R0 = B[P0]; \
|
|
B[P1++] = R0; \
|
|
)
|
|
|
|
COMMON_INS(l_16, \
|
|
R0 = [P0]; \
|
|
W[P1++] = R0; \
|
|
R0 = R0 >> 16; \
|
|
W[P1++] = R0; \
|
|
)
|