u-boot/arch/arc/lib/cache.c
Eugeniy Paltsev 6b85b26e4b ARC: Cache: Refactor arc_ioc_setup()
Move all checks before cache flush and IOC setup.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2018-03-21 17:06:55 +03:00

716 lines
19 KiB
C

/*
* Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <common.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <asm/arcregs.h>
#include <asm/arc-bcr.h>
#include <asm/cache.h>
/*
* [ NOTE 1 ]:
* Data cache (L1 D$ or SL$) entire invalidate operation or data cache disable
* operation may result in unexpected behavior and data loss even if we flush
* data cache right before invalidation. That may happens if we store any context
* on stack (like we store BLINK register on stack before function call).
* BLINK register is the register where return address is automatically saved
* when we do function call with instructions like 'bl'.
*
* There is the real example:
* We may hang in the next code as we store any BLINK register on stack in
* invalidate_dcache_all() function.
*
* void flush_dcache_all() {
* __dc_entire_op(OP_FLUSH);
* // Other code //
* }
*
* void invalidate_dcache_all() {
* __dc_entire_op(OP_INV);
* // Other code //
* }
*
* void foo(void) {
* flush_dcache_all();
* invalidate_dcache_all();
* }
*
* Now let's see what really happens during that code execution:
*
* foo()
* |->> call flush_dcache_all
* [return address is saved to BLINK register]
* [push BLINK] (save to stack) ![point 1]
* |->> call __dc_entire_op(OP_FLUSH)
* [return address is saved to BLINK register]
* [flush L1 D$]
* return [jump to BLINK]
* <<------
* [other flush_dcache_all code]
* [pop BLINK] (get from stack)
* return [jump to BLINK]
* <<------
* |->> call invalidate_dcache_all
* [return address is saved to BLINK register]
* [push BLINK] (save to stack) ![point 2]
* |->> call __dc_entire_op(OP_FLUSH)
* [return address is saved to BLINK register]
* [invalidate L1 D$] ![point 3]
* // Oops!!!
* // We lose return address from invalidate_dcache_all function:
* // we save it to stack and invalidate L1 D$ after that!
* return [jump to BLINK]
* <<------
* [other invalidate_dcache_all code]
* [pop BLINK] (get from stack)
* // we don't have this data in L1 dcache as we invalidated it in [point 3]
* // so we get it from next memory level (for example DDR memory)
* // but in the memory we have value which we save in [point 1], which
* // is return address from flush_dcache_all function (instead of
* // address from current invalidate_dcache_all function which we
* // saved in [point 2] !)
* return [jump to BLINK]
* <<------
* // As BLINK points to invalidate_dcache_all, we call it again and
* // loop forever.
*
* Fortunately we may fix that by using flush & invalidation of D$ with a single
* one instruction (instead of flush and invalidation instructions pair) and
* enabling force function inline with '__attribute__((always_inline))' gcc
* attribute to avoid any function call (and BLINK store) between cache flush
* and disable.
*
*
* [ NOTE 2 ]:
* As of today we only support the following cache configurations on ARC.
* Other configurations may exist in HW (for example, since version 3.0 HS
* supports SL$ (L2 system level cache) disable) but we don't support it in SW.
* Configuration 1:
* ______________________
* | |
* | ARC CPU |
* |______________________|
* ___|___ ___|___
* | | | |
* | L1 I$ | | L1 D$ |
* |_______| |_______|
* on/off on/off
* ___|______________|____
* | |
* | main memory |
* |______________________|
*
* Configuration 2:
* ______________________
* | |
* | ARC CPU |
* |______________________|
* ___|___ ___|___
* | | | |
* | L1 I$ | | L1 D$ |
* |_______| |_______|
* on/off on/off
* ___|______________|____
* | |
* | L2 (SL$) |
* |______________________|
* always must be on
* ___|______________|____
* | |
* | main memory |
* |______________________|
*
* Configuration 3:
* ______________________
* | |
* | ARC CPU |
* |______________________|
* ___|___ ___|___
* | | | |
* | L1 I$ | | L1 D$ |
* |_______| |_______|
* on/off must be on
* ___|______________|____ _______
* | | | |
* | L2 (SL$) |-----| IOC |
* |______________________| |_______|
* always must be on on/off
* ___|______________|____
* | |
* | main memory |
* |______________________|
*/
DECLARE_GLOBAL_DATA_PTR;
/* Bit values in IC_CTRL */
#define IC_CTRL_CACHE_DISABLE BIT(0)
/* Bit values in DC_CTRL */
#define DC_CTRL_CACHE_DISABLE BIT(0)
#define DC_CTRL_INV_MODE_FLUSH BIT(6)
#define DC_CTRL_FLUSH_STATUS BIT(8)
#define OP_INV BIT(0)
#define OP_FLUSH BIT(1)
#define OP_FLUSH_N_INV (OP_FLUSH | OP_INV)
/* Bit val in SLC_CONTROL */
#define SLC_CTRL_DIS 0x001
#define SLC_CTRL_IM 0x040
#define SLC_CTRL_BUSY 0x100
#define SLC_CTRL_RGN_OP_INV 0x200
#define CACHE_LINE_MASK (~(gd->arch.l1_line_sz - 1))
/*
* We don't want to use '__always_inline' macro here as it can be redefined
* to simple 'inline' in some cases which breaks stuff. See [ NOTE 1 ] for more
* details about the reasons we need to use always_inline functions.
*/
#define inlined_cachefunc inline __attribute__((always_inline))
static inlined_cachefunc void __ic_entire_invalidate(void);
static inlined_cachefunc void __dc_entire_op(const int cacheop);
static inline bool pae_exists(void)
{
/* TODO: should we compare mmu version from BCR and from CONFIG? */
#if (CONFIG_ARC_MMU_VER >= 4)
union bcr_mmu_4 mmu4;
mmu4.word = read_aux_reg(ARC_AUX_MMU_BCR);
if (mmu4.fields.pae)
return true;
#endif /* (CONFIG_ARC_MMU_VER >= 4) */
return false;
}
static inlined_cachefunc bool icache_exists(void)
{
union bcr_di_cache ibcr;
ibcr.word = read_aux_reg(ARC_BCR_IC_BUILD);
return !!ibcr.fields.ver;
}
static inlined_cachefunc bool icache_enabled(void)
{
if (!icache_exists())
return false;
return !(read_aux_reg(ARC_AUX_IC_CTRL) & IC_CTRL_CACHE_DISABLE);
}
static inlined_cachefunc bool dcache_exists(void)
{
union bcr_di_cache dbcr;
dbcr.word = read_aux_reg(ARC_BCR_DC_BUILD);
return !!dbcr.fields.ver;
}
static inlined_cachefunc bool dcache_enabled(void)
{
if (!dcache_exists())
return false;
return !(read_aux_reg(ARC_AUX_DC_CTRL) & DC_CTRL_CACHE_DISABLE);
}
static inlined_cachefunc bool slc_exists(void)
{
if (is_isa_arcv2()) {
union bcr_generic sbcr;
sbcr.word = read_aux_reg(ARC_BCR_SLC);
return !!sbcr.fields.ver;
}
return false;
}
static inlined_cachefunc bool slc_data_bypass(void)
{
/*
* If L1 data cache is disabled SL$ is bypassed and all load/store
* requests are sent directly to main memory.
*/
return !dcache_enabled();
}
static inline bool ioc_exists(void)
{
if (is_isa_arcv2()) {
union bcr_clust_cfg cbcr;
cbcr.word = read_aux_reg(ARC_BCR_CLUSTER);
return cbcr.fields.c;
}
return false;
}
static inline bool ioc_enabled(void)
{
/*
* We check only CONFIG option instead of IOC HW state check as IOC
* must be disabled by default.
*/
if (is_ioc_enabled())
return ioc_exists();
return false;
}
static inlined_cachefunc void __slc_entire_op(const int op)
{
unsigned int ctrl;
if (!slc_exists())
return;
ctrl = read_aux_reg(ARC_AUX_SLC_CTRL);
if (!(op & OP_FLUSH)) /* i.e. OP_INV */
ctrl &= ~SLC_CTRL_IM; /* clear IM: Disable flush before Inv */
else
ctrl |= SLC_CTRL_IM;
write_aux_reg(ARC_AUX_SLC_CTRL, ctrl);
if (op & OP_INV) /* Inv or flush-n-inv use same cmd reg */
write_aux_reg(ARC_AUX_SLC_INVALIDATE, 0x1);
else
write_aux_reg(ARC_AUX_SLC_FLUSH, 0x1);
/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
read_aux_reg(ARC_AUX_SLC_CTRL);
/* Important to wait for flush to complete */
while (read_aux_reg(ARC_AUX_SLC_CTRL) & SLC_CTRL_BUSY);
}
static void slc_upper_region_init(void)
{
/*
* ARC_AUX_SLC_RGN_START1 and ARC_AUX_SLC_RGN_END1 register exist
* only if PAE exists in current HW. So we had to check pae_exist
* before using them.
*/
if (!pae_exists())
return;
/*
* ARC_AUX_SLC_RGN_END1 and ARC_AUX_SLC_RGN_START1 are always == 0
* as we don't use PAE40.
*/
write_aux_reg(ARC_AUX_SLC_RGN_END1, 0);
write_aux_reg(ARC_AUX_SLC_RGN_START1, 0);
}
static void __slc_rgn_op(unsigned long paddr, unsigned long sz, const int op)
{
#ifdef CONFIG_ISA_ARCV2
unsigned int ctrl;
unsigned long end;
if (!slc_exists())
return;
/*
* The Region Flush operation is specified by CTRL.RGN_OP[11..9]
* - b'000 (default) is Flush,
* - b'001 is Invalidate if CTRL.IM == 0
* - b'001 is Flush-n-Invalidate if CTRL.IM == 1
*/
ctrl = read_aux_reg(ARC_AUX_SLC_CTRL);
/* Don't rely on default value of IM bit */
if (!(op & OP_FLUSH)) /* i.e. OP_INV */
ctrl &= ~SLC_CTRL_IM; /* clear IM: Disable flush before Inv */
else
ctrl |= SLC_CTRL_IM;
if (op & OP_INV)
ctrl |= SLC_CTRL_RGN_OP_INV; /* Inv or flush-n-inv */
else
ctrl &= ~SLC_CTRL_RGN_OP_INV;
write_aux_reg(ARC_AUX_SLC_CTRL, ctrl);
/*
* Lower bits are ignored, no need to clip
* END needs to be setup before START (latter triggers the operation)
* END can't be same as START, so add (l2_line_sz - 1) to sz
*/
end = paddr + sz + gd->arch.slc_line_sz - 1;
/*
* Upper addresses (ARC_AUX_SLC_RGN_END1 and ARC_AUX_SLC_RGN_START1)
* are always == 0 as we don't use PAE40, so we only setup lower ones
* (ARC_AUX_SLC_RGN_END and ARC_AUX_SLC_RGN_START)
*/
write_aux_reg(ARC_AUX_SLC_RGN_END, end);
write_aux_reg(ARC_AUX_SLC_RGN_START, paddr);
/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
read_aux_reg(ARC_AUX_SLC_CTRL);
while (read_aux_reg(ARC_AUX_SLC_CTRL) & SLC_CTRL_BUSY);
#endif /* CONFIG_ISA_ARCV2 */
}
static void arc_ioc_setup(void)
{
/* IOC Aperture start is equal to DDR start */
unsigned int ap_base = CONFIG_SYS_SDRAM_BASE;
/* IOC Aperture size is equal to DDR size */
long ap_size = CONFIG_SYS_SDRAM_SIZE;
/* Unsupported configuration. See [ NOTE 2 ] for more details. */
if (!slc_exists())
panic("Try to enable IOC but SLC is not present");
/* Unsupported configuration. See [ NOTE 2 ] for more details. */
if (!dcache_enabled())
panic("Try to enable IOC but L1 D$ is disabled");
if (!is_power_of_2(ap_size) || ap_size < 4096)
panic("IOC Aperture size must be power of 2 and bigger 4Kib");
/* IOC Aperture start must be aligned to the size of the aperture */
if (ap_base % ap_size != 0)
panic("IOC Aperture start must be aligned to the size of the aperture");
flush_n_invalidate_dcache_all();
/*
* IOC Aperture size decoded as 2 ^ (SIZE + 2) KB,
* so setting 0x11 implies 512M, 0x12 implies 1G...
*/
write_aux_reg(ARC_AUX_IO_COH_AP0_SIZE,
order_base_2(ap_size / 1024) - 2);
write_aux_reg(ARC_AUX_IO_COH_AP0_BASE, ap_base >> 12);
write_aux_reg(ARC_AUX_IO_COH_PARTIAL, 1);
write_aux_reg(ARC_AUX_IO_COH_ENABLE, 1);
}
static void read_decode_cache_bcr_arcv2(void)
{
#ifdef CONFIG_ISA_ARCV2
union bcr_slc_cfg slc_cfg;
if (slc_exists()) {
slc_cfg.word = read_aux_reg(ARC_AUX_SLC_CONFIG);
gd->arch.slc_line_sz = (slc_cfg.fields.lsz == 0) ? 128 : 64;
/*
* We don't support configuration where L1 I$ or L1 D$ is
* absent but SL$ exists. See [ NOTE 2 ] for more details.
*/
if (!icache_exists() || !dcache_exists())
panic("Unsupported cache configuration: SLC exists but one of L1 caches is absent");
}
#endif /* CONFIG_ISA_ARCV2 */
}
void read_decode_cache_bcr(void)
{
int dc_line_sz = 0, ic_line_sz = 0;
union bcr_di_cache ibcr, dbcr;
ibcr.word = read_aux_reg(ARC_BCR_IC_BUILD);
if (ibcr.fields.ver) {
gd->arch.l1_line_sz = ic_line_sz = 8 << ibcr.fields.line_len;
if (!ic_line_sz)
panic("Instruction exists but line length is 0\n");
}
dbcr.word = read_aux_reg(ARC_BCR_DC_BUILD);
if (dbcr.fields.ver) {
gd->arch.l1_line_sz = dc_line_sz = 16 << dbcr.fields.line_len;
if (!dc_line_sz)
panic("Data cache exists but line length is 0\n");
}
if (ic_line_sz && dc_line_sz && (ic_line_sz != dc_line_sz))
panic("Instruction and data cache line lengths differ\n");
}
void cache_init(void)
{
read_decode_cache_bcr();
if (is_isa_arcv2())
read_decode_cache_bcr_arcv2();
if (is_isa_arcv2() && ioc_enabled())
arc_ioc_setup();
if (is_isa_arcv2() && slc_exists())
slc_upper_region_init();
}
int icache_status(void)
{
return icache_enabled();
}
void icache_enable(void)
{
if (icache_exists())
write_aux_reg(ARC_AUX_IC_CTRL, read_aux_reg(ARC_AUX_IC_CTRL) &
~IC_CTRL_CACHE_DISABLE);
}
void icache_disable(void)
{
if (!icache_exists())
return;
__ic_entire_invalidate();
write_aux_reg(ARC_AUX_IC_CTRL, read_aux_reg(ARC_AUX_IC_CTRL) |
IC_CTRL_CACHE_DISABLE);
}
/* IC supports only invalidation */
static inlined_cachefunc void __ic_entire_invalidate(void)
{
if (!icache_enabled())
return;
/* Any write to IC_IVIC register triggers invalidation of entire I$ */
write_aux_reg(ARC_AUX_IC_IVIC, 1);
/*
* As per ARC HS databook (see chapter 5.3.3.2)
* it is required to add 3 NOPs after each write to IC_IVIC.
*/
__builtin_arc_nop();
__builtin_arc_nop();
__builtin_arc_nop();
read_aux_reg(ARC_AUX_IC_CTRL); /* blocks */
}
void invalidate_icache_all(void)
{
__ic_entire_invalidate();
/*
* If SL$ is bypassed for data it is used only for instructions,
* so we need to invalidate it too.
* TODO: HS 3.0 supports SLC disable so we need to check slc
* enable/disable status here.
*/
if (is_isa_arcv2() && slc_data_bypass())
__slc_entire_op(OP_INV);
}
int dcache_status(void)
{
return dcache_enabled();
}
void dcache_enable(void)
{
if (!dcache_exists())
return;
write_aux_reg(ARC_AUX_DC_CTRL, read_aux_reg(ARC_AUX_DC_CTRL) &
~(DC_CTRL_INV_MODE_FLUSH | DC_CTRL_CACHE_DISABLE));
}
void dcache_disable(void)
{
if (!dcache_exists())
return;
__dc_entire_op(OP_FLUSH_N_INV);
/*
* As SLC will be bypassed for data after L1 D$ disable we need to
* flush it first before L1 D$ disable. Also we invalidate SLC to
* avoid any inconsistent data problems after enabling L1 D$ again with
* dcache_enable function.
*/
if (is_isa_arcv2())
__slc_entire_op(OP_FLUSH_N_INV);
write_aux_reg(ARC_AUX_DC_CTRL, read_aux_reg(ARC_AUX_DC_CTRL) |
DC_CTRL_CACHE_DISABLE);
}
/* Common Helper for Line Operations on D-cache */
static inline void __dcache_line_loop(unsigned long paddr, unsigned long sz,
const int cacheop)
{
unsigned int aux_cmd;
int num_lines;
/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
aux_cmd = cacheop & OP_INV ? ARC_AUX_DC_IVDL : ARC_AUX_DC_FLDL;
sz += paddr & ~CACHE_LINE_MASK;
paddr &= CACHE_LINE_MASK;
num_lines = DIV_ROUND_UP(sz, gd->arch.l1_line_sz);
while (num_lines-- > 0) {
#if (CONFIG_ARC_MMU_VER == 3)
write_aux_reg(ARC_AUX_DC_PTAG, paddr);
#endif
write_aux_reg(aux_cmd, paddr);
paddr += gd->arch.l1_line_sz;
}
}
static inlined_cachefunc void __before_dc_op(const int op)
{
unsigned int ctrl;
ctrl = read_aux_reg(ARC_AUX_DC_CTRL);
/* IM bit implies flush-n-inv, instead of vanilla inv */
if (op == OP_INV)
ctrl &= ~DC_CTRL_INV_MODE_FLUSH;
else
ctrl |= DC_CTRL_INV_MODE_FLUSH;
write_aux_reg(ARC_AUX_DC_CTRL, ctrl);
}
static inlined_cachefunc void __after_dc_op(const int op)
{
if (op & OP_FLUSH) /* flush / flush-n-inv both wait */
while (read_aux_reg(ARC_AUX_DC_CTRL) & DC_CTRL_FLUSH_STATUS);
}
static inlined_cachefunc void __dc_entire_op(const int cacheop)
{
int aux;
if (!dcache_enabled())
return;
__before_dc_op(cacheop);
if (cacheop & OP_INV) /* Inv or flush-n-inv use same cmd reg */
aux = ARC_AUX_DC_IVDC;
else
aux = ARC_AUX_DC_FLSH;
write_aux_reg(aux, 0x1);
__after_dc_op(cacheop);
}
static inline void __dc_line_op(unsigned long paddr, unsigned long sz,
const int cacheop)
{
if (!dcache_enabled())
return;
__before_dc_op(cacheop);
__dcache_line_loop(paddr, sz, cacheop);
__after_dc_op(cacheop);
}
void invalidate_dcache_range(unsigned long start, unsigned long end)
{
if (start >= end)
return;
/*
* ARCv1 -> call __dc_line_op
* ARCv2 && L1 D$ disabled -> nothing
* ARCv2 && L1 D$ enabled && IOC enabled -> nothing
* ARCv2 && L1 D$ enabled && no IOC -> call __dc_line_op; call __slc_rgn_op
*/
if (!is_isa_arcv2() || !ioc_enabled())
__dc_line_op(start, end - start, OP_INV);
if (is_isa_arcv2() && !ioc_enabled() && !slc_data_bypass())
__slc_rgn_op(start, end - start, OP_INV);
}
void flush_dcache_range(unsigned long start, unsigned long end)
{
if (start >= end)
return;
/*
* ARCv1 -> call __dc_line_op
* ARCv2 && L1 D$ disabled -> nothing
* ARCv2 && L1 D$ enabled && IOC enabled -> nothing
* ARCv2 && L1 D$ enabled && no IOC -> call __dc_line_op; call __slc_rgn_op
*/
if (!is_isa_arcv2() || !ioc_enabled())
__dc_line_op(start, end - start, OP_FLUSH);
if (is_isa_arcv2() && !ioc_enabled() && !slc_data_bypass())
__slc_rgn_op(start, end - start, OP_FLUSH);
}
void flush_cache(unsigned long start, unsigned long size)
{
flush_dcache_range(start, start + size);
}
/*
* As invalidate_dcache_all() is not used in generic U-Boot code and as we
* don't need it in arch/arc code alone (invalidate without flush) we implement
* flush_n_invalidate_dcache_all (flush and invalidate in 1 operation) because
* it's much safer. See [ NOTE 1 ] for more details.
*/
void flush_n_invalidate_dcache_all(void)
{
__dc_entire_op(OP_FLUSH_N_INV);
if (is_isa_arcv2() && !slc_data_bypass())
__slc_entire_op(OP_FLUSH_N_INV);
}
void flush_dcache_all(void)
{
__dc_entire_op(OP_FLUSH);
if (is_isa_arcv2() && !slc_data_bypass())
__slc_entire_op(OP_FLUSH);
}
/*
* This is function to cleanup all caches (and therefore sync I/D caches) which
* can be used for cleanup before linux launch or to sync caches during
* relocation.
*/
void sync_n_cleanup_cache_all(void)
{
__dc_entire_op(OP_FLUSH_N_INV);
/*
* If SL$ is bypassed for data it is used only for instructions,
* and we shouldn't flush it. So invalidate it instead of flush_n_inv.
*/
if (is_isa_arcv2()) {
if (slc_data_bypass())
__slc_entire_op(OP_INV);
else
__slc_entire_op(OP_FLUSH_N_INV);
}
__ic_entire_invalidate();
}