/*
* ARC Cache Management
*
* Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* 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.
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/cache.h>
#include <linux/mmu_context.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <linux/pagemap.h>
#include <asm/cacheflush.h>
#include <asm/cachectl.h>
#include <asm/setup.h>
static int l2_line_sz;
static int ioc_exists;
int slc_enable = 1, ioc_enable = 1;
unsigned long perip_base = ARC_UNCACHED_ADDR_SPACE; /* legacy value for boot */
unsigned long perip_end = 0xFFFFFFFF; /* legacy value */
void (*_cache_line_loop_ic_fn)(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int cacheop);
void (*__dma_cache_wback_inv)(phys_addr_t start, unsigned long sz);
void (*__dma_cache_inv)(phys_addr_t start, unsigned long sz);
void (*__dma_cache_wback)(phys_addr_t start, unsigned long sz);
char *arc_cache_mumbojumbo(int c, char *buf, int len)
{
int n = 0;
struct cpuinfo_arc_cache *p;
#define PR_CACHE(p, cfg, str) \
if (!(p)->line_len) \
n += scnprintf(buf + n, len - n, str"\t\t: N/A\n"); \
else \
n += scnprintf(buf + n, len - n, \
str"\t\t: %uK, %dway/set, %uB Line, %s%s%s\n", \
(p)->sz_k, (p)->assoc, (p)->line_len, \
(p)->vipt ? "VIPT" : "PIPT", \
(p)->alias ? " aliasing" : "", \
IS_USED_CFG(cfg));
PR_CACHE(&cpuinfo_arc700[c].icache, [31mCONFIG_ARC_HAS_ICACHE[0m, "I-Cache");
PR_CACHE(&cpuinfo_arc700[c].dcache, [31mCONFIG_ARC_HAS_DCACHE[0m, "D-Cache");
p = &cpuinfo_arc700[c].slc;
if (p->line_len)
n += scnprintf(buf + n, len - n,
"SLC\t\t: %uK, %uB Line%s\n",
p->sz_k, p->line_len, IS_USED_RUN(slc_enable));
n += scnprintf(buf + n, len - n, "Peripherals\t: %#lx%s%s\n",
perip_base,
IS_AVAIL3(ioc_exists, ioc_enable, ", IO-Coherency "));
return buf;
}
/*
* Read the Cache Build Confuration Registers, Decode them and save into
* the cpuinfo structure for later use.
* No Validation done here, simply read/convert the BCRs
*/
static void read_decode_cache_bcr_arcv2(int cpu)
{
struct cpuinfo_arc_cache *p_slc = &cpuinfo_arc700[cpu].slc;
struct bcr_generic sbcr;
struct bcr_slc_cfg {
#ifdef [31mCONFIG_CPU_BIG_ENDIAN[0m
unsigned int pad:24, way:2, lsz:2, sz:4;
#else
unsigned int sz:4, lsz:2, way:2, pad:24;
#endif
} slc_cfg;
struct bcr_clust_cfg {
#ifdef [31mCONFIG_CPU_BIG_ENDIAN[0m
unsigned int pad:7, c:1, num_entries:8, num_cores:8, ver:8;
#else
unsigned int ver:8, num_cores:8, num_entries:8, c:1, pad:7;
#endif
} cbcr;
struct bcr_volatile {
#ifdef [31mCONFIG_CPU_BIG_ENDIAN[0m
unsigned int start:4, limit:4, pad:22, order:1, disable:1;
#else
unsigned int disable:1, order:1, pad:22, limit:4, start:4;
#endif
} vol;
READ_BCR(ARC_REG_SLC_BCR, sbcr);
if (sbcr.ver) {
READ_BCR(ARC_REG_SLC_CFG, slc_cfg);
p_slc->sz_k = 128 << slc_cfg.sz;
l2_line_sz = p_slc->line_len = (slc_cfg.lsz == 0) ? 128 : 64;
}
READ_BCR(ARC_REG_CLUSTER_BCR, cbcr);
if (cbcr.c)
ioc_exists = 1;
else
ioc_enable = 0;
/* HS 2.0 didn't have AUX_VOL */
if (cpuinfo_arc700[cpu].core.family > 0x51) {
READ_BCR(AUX_VOL, vol);
perip_base = vol.start << 28;
/* HS 3.0 has limit and strict-ordering fields */
if (cpuinfo_arc700[cpu].core.family > 0x52)
perip_end = (vol.limit << 28) - 1;
}
}
void read_decode_cache_bcr(void)
{
struct cpuinfo_arc_cache *p_ic, *p_dc;
unsigned int cpu = smp_processor_id();
struct bcr_cache {
#ifdef [31mCONFIG_CPU_BIG_ENDIAN[0m
unsigned int pad:12, line_len:4, sz:4, config:4, ver:8;
#else
unsigned int ver:8, config:4, sz:4, line_len:4, pad:12;
#endif
} ibcr, dbcr;
p_ic = &cpuinfo_arc700[cpu].icache;
READ_BCR(ARC_REG_IC_BCR, ibcr);
if (!ibcr.ver)
goto dc_chk;
if (ibcr.ver <= 3) {
BUG_ON(ibcr.config != 3);
p_ic->assoc = 2; /* Fixed to 2w set assoc */
} else if (ibcr.ver >= 4) {
p_ic->assoc = 1 << ibcr.config; /* 1,2,4,8 */
}
p_ic->line_len = 8 << ibcr.line_len;
p_ic->sz_k = 1 << (ibcr.sz - 1);
p_ic->vipt = 1;
p_ic->alias = p_ic->sz_k/p_ic->assoc/TO_KB(PAGE_SIZE) > 1;
dc_chk:
p_dc = &cpuinfo_arc700[cpu].dcache;
READ_BCR(ARC_REG_DC_BCR, dbcr);
if (!dbcr.ver)
goto slc_chk;
if (dbcr.ver <= 3) {
BUG_ON(dbcr.config != 2);
p_dc->assoc = 4; /* Fixed to 4w set assoc */
p_dc->vipt = 1;
p_dc->alias = p_dc->sz_k/p_dc->assoc/TO_KB(PAGE_SIZE) > 1;
} else if (dbcr.ver >= 4) {
p_dc->assoc = 1 << dbcr.config; /* 1,2,4,8 */
p_dc->vipt = 0;
p_dc->alias = 0; /* PIPT so can't VIPT alias */
}
p_dc->line_len = 16 << dbcr.line_len;
p_dc->sz_k = 1 << (dbcr.sz - 1);
slc_chk:
if (is_isa_arcv2())
read_decode_cache_bcr_arcv2(cpu);
}
/*
* Line Operation on {I,D}-Cache
*/
#define OP_INV 0x1
#define OP_FLUSH 0x2
#define OP_FLUSH_N_INV 0x3
#define OP_INV_IC 0x4
/*
* I-Cache Aliasing in ARC700 VIPT caches (MMU v1-v3)
*
* ARC VIPT I-cache uses vaddr to index into cache and paddr to match the tag.
* The orig Cache Management Module "CDU" only required paddr to invalidate a
* certain line since it sufficed as index in Non-Aliasing VIPT cache-geometry.
* Infact for distinct V1,V2,P: all of {V1-P},{V2-P},{P-P} would end up fetching
* the exact same line.
*
* However for larger Caches (way-size > page-size) - i.e. in Aliasing config,
* paddr alone could not be used to correctly index the cache.
*
* ------------------
* MMU v1/v2 (Fixed Page Size 8k)
* ------------------
* The solution was to provide CDU with these additonal vaddr bits. These
* would be bits [x:13], x would depend on cache-geometry, 13 comes from
* standard page size of 8k.
* H/w folks chose [17:13] to be a future safe range, and moreso these 5 bits
* of vaddr could easily be "stuffed" in the paddr as bits [4:0] since the
* orig 5 bits of paddr were anyways ignored by CDU line ops, as they
* represent the offset within cache-line. The adv of using this "clumsy"
* interface for additional info was no new reg was needed in CDU programming
* model.
*
* 17:13 represented the max num of bits passable, actual bits needed were
* fewer, based on the num-of-aliases possible.
* -for 2 alias possibility, only bit 13 needed (32K cache)
* -for 4 alias possibility, bits 14:13 needed (64K cache)
*
* ------------------
* MMU v3
* ------------------
* This ver of MMU supports variable page sizes (1k-16k): although Linux will
* only support 8k (default), 16k and 4k.
* However from hardware perspective, smaller page sizes aggravate aliasing
* meaning more vaddr bits needed to disambiguate the cache-line-op ;
* the existing scheme of piggybacking won't work for certain configurations.
* Two new registers IC_PTAG and DC_PTAG inttoduced.
* "tag" bits are provided in PTAG, index bits in existing IVIL/IVDL/FLDL regs
*/
static inline
void __cache_line_loop_v2(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int op)
{
unsigned int aux_cmd;
int num_lines;
const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
if (op == OP_INV_IC) {
aux_cmd = ARC_REG_IC_IVIL;
} else {
/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
}
/* Ensure we properly floor/ceil the non-line aligned/sized requests
* and have @paddr - aligned to cache line and integral @num_lines.
* This however can be avoided for page sized since:
* -@paddr will be cache-line aligned already (being page aligned)
* -@sz will be integral multiple of line size (being page sized).
*/
if (!full_page) {
sz += paddr & ~CACHE_LINE_MASK;
paddr &= CACHE_LINE_MASK;
vaddr &= CACHE_LINE_MASK;
}
num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
/* MMUv2 and before: paddr contains stuffed vaddrs bits */
paddr |= (vaddr >> PAGE_SHIFT) & 0x1F;
while (num_lines-- > 0) {
write_aux_reg(aux_cmd, paddr);
paddr += L1_CACHE_BYTES;
}
}
/*
* For ARC700 MMUv3 I-cache and D-cache flushes
* - ARC700 programming model requires paddr and vaddr be passed in seperate
* AUX registers (*_IV*L and *_PTAG respectively) irrespective of whether the
* caches actually alias or not.
* - For HS38, only the aliasing I-cache configuration uses the PTAG reg
* (non aliasing I-cache version doesn't; while D-cache can't possibly alias)
*/
static inline
void __cache_line_loop_v3(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int op)
{
unsigned int aux_cmd, aux_tag;
int num_lines;
const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
if (op == OP_INV_IC) {
aux_cmd = ARC_REG_IC_IVIL;
aux_tag = ARC_REG_IC_PTAG;
} else {
aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
aux_tag = ARC_REG_DC_PTAG;
}
/* Ensure we properly floor/ceil the non-line aligned/sized requests
* and have @paddr - aligned to cache line and integral @num_lines.
* This however can be avoided for page sized since:
* -@paddr will be cache-line aligned already (being page aligned)
* -@sz will be integral multiple of line size (being page sized).
*/
if (!full_page) {
sz += paddr & ~CACHE_LINE_MASK;
paddr &= CACHE_LINE_MASK;
vaddr &= CACHE_LINE_MASK;
}
num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
/*
* MMUv3, cache ops require paddr in PTAG reg
* if V-P const for loop, PTAG can be written once outside loop
*/
if (full_page)
write_aux_reg(aux_tag, paddr);
/*
* This is technically for MMU v4, using the MMU v3 programming model
* Special work for HS38 aliasing I-cache configuration with PAE40
* - upper 8 bits of paddr need to be written into PTAG_HI
* - (and needs to be written before the lower 32 bits)
* Note that PTAG_HI is hoisted outside the line loop
*/
if (is_pae40_enabled() && op == OP_INV_IC)
write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
while (num_lines-- > 0) {
if (!full_page) {
write_aux_reg(aux_tag, paddr);
paddr += L1_CACHE_BYTES;
}
write_aux_reg(aux_cmd, vaddr);
vaddr += L1_CACHE_BYTES;
}
}
/*
* In HS38x (MMU v4), I-cache is VIPT (can alias), D-cache is PIPT
* Here's how cache ops are implemented
*
* - D-cache: only paddr needed (in DC_IVDL/DC_FLDL)
* - I-cache Non Aliasing: Despite VIPT, only paddr needed (in IC_IVIL)
* - I-cache Aliasing: Both vaddr and paddr needed (in IC_IVIL, IC_PTAG
* respectively, similar to MMU v3 programming model, hence
* __cache_line_loop_v3() is used)
*
* If PAE40 is enabled, independent of aliasing considerations, the higher bits
* needs to be written into PTAG_HI
*/
static inline
void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int cacheop)
{
unsigned int aux_cmd;
int num_lines;
const int full_page_op = __builtin_constant_p(sz) && sz == PAGE_SIZE;
if (cacheop == OP_INV_IC) {
aux_cmd = ARC_REG_IC_IVIL;
} else {
/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
aux_cmd = cacheop & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
}
/* Ensure we properly floor/ceil the non-line aligned/sized requests
* and have @paddr - aligned to cache line and integral @num_lines.
* This however can be avoided for page sized since:
* -@paddr will be cache-line aligned already (being page aligned)
* -@sz will be integral multiple of line size (being page sized).
*/
if (!full_page_op) {
sz += paddr & ~CACHE_LINE_MASK;
paddr &= CACHE_LINE_MASK;
}
num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
/*
* For HS38 PAE40 configuration
* - upper 8 bits of paddr need to be written into PTAG_HI
* - (and needs to be written before the lower 32 bits)
*/
if (is_pae40_enabled()) {
if (cacheop == OP_INV_IC)
/*
* Non aliasing I-cache in HS38,
* aliasing I-cache handled in __cache_line_loop_v3()
*/
write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
else
write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
}
while (num_lines-- > 0) {
write_aux_reg(aux_cmd, paddr);
paddr += L1_CACHE_BYTES;
}
}
#if (CONFIG_ARC_MMU_VER < 3)
#define __cache_line_loop __cache_line_loop_v2
#elif (CONFIG_ARC_MMU_VER == 3)
#define __cache_line_loop __cache_line_loop_v3
#elif (CONFIG_ARC_MMU_VER > 3)
#define __cache_line_loop __cache_line_loop_v4
#endif
#ifdef [31mCONFIG_ARC_HAS_DCACHE[0m
/***************************************************************
* Machine specific helpers for Entire D-Cache or Per Line ops
*/
static inline void __before_dc_op(const int op)
{
if (op == OP_FLUSH_N_INV) {
/* Dcache provides 2 cmd: FLUSH or INV
* INV inturn has sub-modes: DISCARD or FLUSH-BEFORE
* flush-n-inv is achieved by INV cmd but with IM=1
* So toggle INV sub-mode depending on op request and default
*/
const unsigned int ctl = ARC_REG_DC_CTRL;
write_aux_reg(ctl, read_aux_reg(ctl) | DC_CTRL_INV_MODE_FLUSH);
}
}
static inline void __after_dc_op(const int op)
{
if (op & OP_FLUSH) {
const unsigned int ctl = ARC_REG_DC_CTRL;
unsigned int reg;
/* flush / flush-n-inv both wait */
while ((reg = read_aux_reg(ctl)) & DC_CTRL_FLUSH_STATUS)
;
/* Switch back to default Invalidate mode */
if (op == OP_FLUSH_N_INV)
write_aux_reg(ctl, reg & ~DC_CTRL_INV_MODE_FLUSH);
}
}
/*
* Operation on Entire D-Cache
* @op = {OP_INV, OP_FLUSH, OP_FLUSH_N_INV}
* Note that constant propagation ensures all the checks are gone
* in generated code
*/
static inline void __dc_entire_op(const int op)
{
int aux;
__before_dc_op(op);
if (op & OP_INV) /* Inv or flush-n-inv use same cmd reg */
aux = ARC_REG_DC_IVDC;
else
aux = ARC_REG_DC_FLSH;
write_aux_reg(aux, 0x1);
__after_dc_op(op);
}
static inline void __dc_disable(void)
{
const int r = ARC_REG_DC_CTRL;
__dc_entire_op(OP_FLUSH_N_INV);
write_aux_reg(r, read_aux_reg(r) | DC_CTRL_DIS);
}
static void __dc_enable(void)
{
const int r = ARC_REG_DC_CTRL;
write_aux_reg(r, read_aux_reg(r) & ~DC_CTRL_DIS);
}
/* For kernel mappings cache operation: index is same as paddr */
#define __dc_line_op_k(p, sz, op) __dc_line_op(p, p, sz, op)
/*
* D-Cache Line ops: Per Line INV (discard or wback+discard) or FLUSH (wback)
*/
static inline void __dc_line_op(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int op)
{
unsigned long flags;
local_irq_save(flags);
__before_dc_op(op);
__cache_line_loop(paddr, vaddr, sz, op);
__after_dc_op(op);
local_irq_restore(flags);
}
#else
#define __dc_entire_op(op)
#define __dc_disable()
#define __dc_enable()
#define __dc_line_op(paddr, vaddr, sz, op)
#define __dc_line_op_k(paddr, sz, op)
#endif /* CONFIG_ARC_HAS_DCACHE */
#ifdef [31mCONFIG_ARC_HAS_ICACHE[0m
static inline void __ic_entire_inv(void)
{
write_aux_reg(ARC_REG_IC_IVIC, 1);
read_aux_reg(ARC_REG_IC_CTRL); /* blocks */
}
static inline void
__ic_line_inv_vaddr_local(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz)
{
unsigned long flags;
local_irq_save(flags);
(*_cache_line_loop_ic_fn)(paddr, vaddr, sz, OP_INV_IC);
local_irq_restore(flags);
}
#ifndef [31mCONFIG_SMP[0m
#define __ic_line_inv_vaddr(p, v, s) __ic_line_inv_vaddr_local(p, v, s)
#else
struct ic_inv_args {
phys_addr_t paddr, vaddr;
int sz;
};
static void __ic_line_inv_vaddr_helper(void *info)
{
struct ic_inv_args *ic_inv = info;
__ic_line_inv_vaddr_local(ic_inv->paddr, ic_inv->vaddr, ic_inv->sz);
}
static void __ic_line_inv_vaddr(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz)
{
struct ic_inv_args ic_inv = {
.paddr = paddr,
.vaddr = vaddr,
.sz = sz
};
on_each_cpu(__ic_line_inv_vaddr_helper, &ic_inv, 1);
}
#endif /* CONFIG_SMP */
#else /* !CONFIG_ARC_HAS_ICACHE */
#define __ic_entire_inv()
#define __ic_line_inv_vaddr(pstart, vstart, sz)
#endif /* CONFIG_ARC_HAS_ICACHE */
noinline void slc_op(phys_addr_t paddr, unsigned long sz, const int op)
{
#ifdef [31mCONFIG_ISA_ARCV2[0m
/*
* SLC is shared between all cores and concurrent aux operations from
* multiple cores need to be serialized using a spinlock
* A concurrent operation can be silently ignored and/or the old/new
* operation can remain incomplete forever (lockup in SLC_CTRL_BUSY loop
* below)
*/
static DEFINE_SPINLOCK(lock);
unsigned long flags;
unsigned int ctrl;
spin_lock_irqsave(&lock, flags);
/*
* 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_REG_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_REG_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
*/
write_aux_reg(ARC_REG_SLC_RGN_END, (paddr + sz + l2_line_sz - 1));
write_aux_reg(ARC_REG_SLC_RGN_START, paddr);
while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
spin_unlock_irqrestore(&lock, flags);
#endif
}
noinline static void slc_entire_op(const int op)
{
unsigned int ctrl, r = ARC_REG_SLC_CTRL;
ctrl = read_aux_reg(r);
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(r, ctrl);
write_aux_reg(ARC_REG_SLC_INVALIDATE, 1);
/* Important to wait for flush to complete */
while (read_aux_reg(r) & SLC_CTRL_BUSY);
}
static inline void arc_slc_disable(void)
{
const int r = ARC_REG_SLC_CTRL;
slc_entire_op(OP_FLUSH_N_INV);
write_aux_reg(r, read_aux_reg(r) | SLC_CTRL_DIS);
}
static inline void arc_slc_enable(void)
{
const int r = ARC_REG_SLC_CTRL;
write_aux_reg(r, read_aux_reg(r) & ~SLC_CTRL_DIS);
}
/***********************************************************
* Exported APIs
*/
/*
* Handle cache congruency of kernel and userspace mappings of page when kernel
* writes-to/reads-from
*
* The idea is to defer flushing of kernel mapping after a WRITE, possible if:
* -dcache is NOT aliasing, hence any U/K-mappings of page are congruent
* -U-mapping doesn't exist yet for page (finalised in update_mmu_cache)
* -In SMP, if hardware caches are coherent
*
* There's a corollary case, where kernel READs from a userspace mapped page.
* If the U-mapping is not congruent to to K-mapping, former needs flushing.
*/
void flush_dcache_page(struct page *page)
{
struct address_space *mapping;
if (!cache_is_vipt_aliasing()) {
clear_bit(PG_dc_clean, &page->flags);
return;
}
/* don't handle anon pages here */
mapping = page_mapping(page);
if (!mapping)
return;
/*
* pagecache page, file not yet mapped to userspace
* Make a note that K-mapping is dirty
*/
if (!mapping_mapped(mapping)) {
clear_bit(PG_dc_clean, &page->flags);
} else if (page_mapcount(page)) {
/* kernel reading from page with U-mapping */
phys_addr_t paddr = (unsigned long)page_address(page);
unsigned long vaddr = page->index << PAGE_SHIFT;
if (addr_not_cache_congruent(paddr, vaddr))
__flush_dcache_page(paddr, vaddr);
}
}
EXPORT_SYMBOL(flush_dcache_page);
/*
* DMA ops for systems with L1 cache only
* Make memory coherent with L1 cache by flushing/invalidating L1 lines
*/
static void __dma_cache_wback_inv_l1(phys_addr_t start, unsigned long sz)
{
__dc_line_op_k(start, sz, OP_FLUSH_N_INV);
}
static void __dma_cache_inv_l1(phys_addr_t start, unsigned long sz)
{
__dc_line_op_k(start, sz, OP_INV);
}
static void __dma_cache_wback_l1(phys_addr_t start, unsigned long sz)
{
__dc_line_op_k(start, sz, OP_FLUSH);
}
/*
* DMA ops for systems with both L1 and L2 caches, but without IOC
* Both L1 and L2 lines need to be explicitly flushed/invalidated
*/
static void __dma_cache_wback_inv_slc(phys_addr_t start, unsigned long sz)
{
__dc_line_op_k(start, sz, OP_FLUSH_N_INV);
slc_op(start, sz, OP_FLUSH_N_INV);
}
static void __dma_cache_inv_slc(phys_addr_t start, unsigned long sz)
{
__dc_line_op_k(start, sz, OP_INV);
slc_op(start, sz, OP_INV);
}
static void __dma_cache_wback_slc(phys_addr_t start, unsigned long sz)
{
__dc_line_op_k(start, sz, OP_FLUSH);
slc_op(start, sz, OP_FLUSH);
}
/*
* DMA ops for systems with IOC
* IOC hardware snoops all DMA traffic keeping the caches consistent with
* memory - eliding need for any explicit cache maintenance of DMA buffers
*/
static void __dma_cache_wback_inv_ioc(phys_addr_t start, unsigned long sz) {}
static void __dma_cache_inv_ioc(phys_addr_t start, unsigned long sz) {}
static void __dma_cache_wback_ioc(phys_addr_t start, unsigned long sz) {}
/*
* Exported DMA API
*/
void dma_cache_wback_inv(phys_addr_t start, unsigned long sz)
{
__dma_cache_wback_inv(start, sz);
}
EXPORT_SYMBOL(dma_cache_wback_inv);
void dma_cache_inv(phys_addr_t start, unsigned long sz)
{
__dma_cache_inv(start, sz);
}
EXPORT_SYMBOL(dma_cache_inv);
void dma_cache_wback(phys_addr_t start, unsigned long sz)
{
__dma_cache_wback(start, sz);
}
EXPORT_SYMBOL(dma_cache_wback);
/*
* This is API for making I/D Caches consistent when modifying
* kernel code (loadable modules, kprobes, kgdb...)
* This is called on insmod, with kernel virtual address for CODE of
* the module. ARC cache maintenance ops require PHY address thus we
* need to convert vmalloc addr to PHY addr
*/
void flush_icache_range(unsigned long kstart, unsigned long kend)
{
unsigned int tot_sz;
WARN(kstart < TASK_SIZE, "%s() can't handle user vaddr", __func__);
/* Shortcut for bigger flush ranges.
* Here we don't care if this was kernel virtual or phy addr
*/
tot_sz = kend - kstart;
if (tot_sz > PAGE_SIZE) {
flush_cache_all();
return;
}
/* Case: Kernel Phy addr (0x8000_0000 onwards) */
if (likely(kstart > PAGE_OFFSET)) {
/*
* The 2nd arg despite being paddr will be used to index icache
* This is OK since no alternate virtual mappings will exist
* given the callers for this case: kprobe/kgdb in built-in
* kernel code only.
*/
__sync_icache_dcache(kstart, kstart, kend - kstart);
return;
}
/*
* Case: Kernel Vaddr (0x7000_0000 to 0x7fff_ffff)
* (1) ARC Cache Maintenance ops only take Phy addr, hence special
* handling of kernel vaddr.
*
* (2) Despite @tot_sz being < PAGE_SIZE (bigger cases handled already),
* it still needs to handle a 2 page scenario, where the range
* straddles across 2 virtual pages and hence need for loop
*/
while (tot_sz > 0) {
unsigned int off, sz;
unsigned long phy, pfn;
off = kstart % PAGE_SIZE;
pfn = vmalloc_to_pfn((void *)kstart);
phy = (pfn << PAGE_SHIFT) + off;
sz = min_t(unsigned int, tot_sz, PAGE_SIZE - off);
__sync_icache_dcache(phy, kstart, sz);
kstart += sz;
tot_sz -= sz;
}
}
EXPORT_SYMBOL(flush_icache_range);
/*
* General purpose helper to make I and D cache lines consistent.
* @paddr is phy addr of region
* @vaddr is typically user vaddr (breakpoint) or kernel vaddr (vmalloc)
* However in one instance, when called by kprobe (for a breakpt in
* builtin kernel code) @vaddr will be paddr only, meaning CDU operation will
* use a paddr to index the cache (despite VIPT). This is fine since since a
* builtin kernel page will not have any virtual mappings.
* kprobe on loadable module will be kernel vaddr.
*/
void __sync_icache_dcache(phys_addr_t paddr, unsigned long vaddr, int len)
{
__dc_line_op(paddr, vaddr, len, OP_FLUSH_N_INV);
__ic_line_inv_vaddr(paddr, vaddr, len);
}
/* wrapper to compile time eliminate alignment checks in flush loop */
void __inv_icache_page(phys_addr_t paddr, unsigned long vaddr)
{
__ic_line_inv_vaddr(paddr, vaddr, PAGE_SIZE);
}
/*
* wrapper to clearout kernel or userspace mappings of a page
* For kernel mappings @vaddr == @paddr
*/
void __flush_dcache_page(phys_addr_t paddr, unsigned long vaddr)
{
__dc_line_op(paddr, vaddr & PAGE_MASK, PAGE_SIZE, OP_FLUSH_N_INV);
}
noinline void flush_cache_all(void)
{
unsigned long flags;
local_irq_save(flags);
__ic_entire_inv();
__dc_entire_op(OP_FLUSH_N_INV);
local_irq_restore(flags);
}
#ifdef [31mCONFIG_ARC_CACHE_VIPT_ALIASING[0m
void flush_cache_mm(struct mm_struct *mm)
{
flush_cache_all();
}
void flush_cache_page(struct vm_area_struct *vma, unsigned long u_vaddr,
unsigned long pfn)
{
unsigned int paddr = pfn << PAGE_SHIFT;
u_vaddr &= PAGE_MASK;
__flush_dcache_page(paddr, u_vaddr);
if (vma->vm_flags & VM_EXEC)
__inv_icache_page(paddr, u_vaddr);
}
void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
flush_cache_all();
}
void flush_anon_page(struct vm_area_struct *vma, struct page *page,
unsigned long u_vaddr)
{
/* TBD: do we really need to clear the kernel mapping */
__flush_dcache_page(page_address(page), u_vaddr);
__flush_dcache_page(page_address(page), page_address(page));
}
#endif
void copy_user_highpage(struct page *to, struct page *from,
unsigned long u_vaddr, struct vm_area_struct *vma)
{
void *kfrom = kmap_atomic(from);
void *kto = kmap_atomic(to);
int clean_src_k_mappings = 0;
/*
* If SRC page was already mapped in userspace AND it's U-mapping is
* not congruent with K-mapping, sync former to physical page so that
* K-mapping in memcpy below, sees the right data
*
* Note that while @u_vaddr refers to DST page's userspace vaddr, it is
* equally valid for SRC page as well
*
* For !VIPT cache, all of this gets compiled out as
* addr_not_cache_congruent() is 0
*/
if (page_mapcount(from) && addr_not_cache_congruent(kfrom, u_vaddr)) {
__flush_dcache_page((unsigned long)kfrom, u_vaddr);
clean_src_k_mappings = 1;
}
copy_page(kto, kfrom);
/*
* Mark DST page K-mapping as dirty for a later finalization by
* update_mmu_cache(). Although the finalization could have been done
* here as well (given that both vaddr/paddr are available).
* But update_mmu_cache() already has code to do that for other
* non copied user pages (e.g. read faults which wire in pagecache page
* directly).
*/
clear_bit(PG_dc_clean, &to->flags);
/*
* if SRC was already usermapped and non-congruent to kernel mapping
* sync the kernel mapping back to physical page
*/
if (clean_src_k_mappings) {
__flush_dcache_page((unsigned long)kfrom, (unsigned long)kfrom);
set_bit(PG_dc_clean, &from->flags);
} else {
clear_bit(PG_dc_clean, &from->flags);
}
kunmap_atomic(kto);
kunmap_atomic(kfrom);
}
void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
{
clear_page(to);
clear_bit(PG_dc_clean, &page->flags);
}
/**********************************************************************
* Explicit Cache flush request from user space via syscall
* Needed for JITs which generate code on the fly
*/
SYSCALL_DEFINE3(cacheflush, uint32_t, start, uint32_t, sz, uint32_t, flags)
{
/* TBD: optimize this */
flush_cache_all();
return 0;
}
/*
* IO-Coherency (IOC) setup rules:
*
* 1. Needs to be at system level, so only once by Master core
* Non-Masters need not be accessing caches at that time
* - They are either HALT_ON_RESET and kick started much later or
* - if run on reset, need to ensure that arc_platform_smp_wait_to_boot()
* doesn't perturb caches or coherency unit
*
* 2. caches (L1 and SLC) need to be purged (flush+inv) before setting up IOC,
* otherwise any straggler data might behave strangely post IOC enabling
*
* 3. All Caches need to be disabled when setting up IOC to elide any in-flight
* Coherency transactions
*/
noinline void __init arc_ioc_setup(void)
{
unsigned int ap_sz;
/* Flush + invalidate + disable L1 dcache */
__dc_disable();
/* Flush + invalidate SLC */
if (read_aux_reg(ARC_REG_SLC_BCR))
slc_entire_op(OP_FLUSH_N_INV);
/* IOC Aperture start: TDB: handle non default CONFIG_LINUX_LINK_BASE */
write_aux_reg(ARC_REG_IO_COH_AP0_BASE, 0x80000);
/*
* IOC Aperture size:
* decoded as 2 ^ (SIZE + 2) KB: so setting 0x11 implies 512M
* TBD: fix for PGU + 1GB of low mem
* TBD: fix for PAE
*/
ap_sz = order_base_2(arc_get_mem_sz()/1024) - 2;
write_aux_reg(ARC_REG_IO_COH_AP0_SIZE, ap_sz);
write_aux_reg(ARC_REG_IO_COH_PARTIAL, 1);
write_aux_reg(ARC_REG_IO_COH_ENABLE, 1);
/* Re-enable L1 dcache */
__dc_enable();
}
void __init arc_cache_init_master(void)
{
unsigned int __maybe_unused cpu = smp_processor_id();
if (IS_ENABLED([31mCONFIG_ARC_HAS_ICACHE[0m)) {
struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
if (!ic->line_len)
panic("cache support enabled but non-existent cache\n");
if (ic->line_len != L1_CACHE_BYTES)
panic("ICache line [%d] != kernel Config [%d]",
ic->line_len, L1_CACHE_BYTES);
/*
* In MMU v4 (HS38x) the aliasing icache config uses IVIL/PTAG
* pair to provide vaddr/paddr respectively, just as in MMU v3
*/
if (is_isa_arcv2() && ic->alias)
_cache_line_loop_ic_fn = __cache_line_loop_v3;
else
_cache_line_loop_ic_fn = __cache_line_loop;
}
if (IS_ENABLED([31mCONFIG_ARC_HAS_DCACHE[0m)) {
struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
if (!dc->line_len)
panic("cache support enabled but non-existent cache\n");
if (dc->line_len != L1_CACHE_BYTES)
panic("DCache line [%d] != kernel Config [%d]",
dc->line_len, L1_CACHE_BYTES);
/* check for D-Cache aliasing on ARCompact: ARCv2 has PIPT */
if (is_isa_arcompact()) {
int handled = IS_ENABLED([31mCONFIG_ARC_CACHE_VIPT_ALIASING[0m);
int num_colors = dc->sz_k/dc->assoc/TO_KB(PAGE_SIZE);
if (dc->alias) {
if (!handled)
panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
if (CACHE_COLORS_NUM != num_colors)
panic("CACHE_COLORS_NUM not optimized for config\n");
} else if (!dc->alias && handled) {
panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
}
}
}
/* Note that SLC disable not formally supported till HS 3.0 */
if (is_isa_arcv2() && l2_line_sz && !slc_enable)
arc_slc_disable();
if (is_isa_arcv2() && ioc_enable)
arc_ioc_setup();
if (is_isa_arcv2() && ioc_enable) {
__dma_cache_wback_inv = __dma_cache_wback_inv_ioc;
__dma_cache_inv = __dma_cache_inv_ioc;
__dma_cache_wback = __dma_cache_wback_ioc;
} else if (is_isa_arcv2() && l2_line_sz && slc_enable) {
__dma_cache_wback_inv = __dma_cache_wback_inv_slc;
__dma_cache_inv = __dma_cache_inv_slc;
__dma_cache_wback = __dma_cache_wback_slc;
} else {
__dma_cache_wback_inv = __dma_cache_wback_inv_l1;
__dma_cache_inv = __dma_cache_inv_l1;
__dma_cache_wback = __dma_cache_wback_l1;
}
}
void __ref arc_cache_init(void)
{
unsigned int __maybe_unused cpu = smp_processor_id();
char str[256];
printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
/*
* Only master CPU needs to execute rest of function:
* - Assume SMP so all cores will have same cache config so
* any geomtry checks will be same for all
* - IOC setup / dma callbacks only need to be setup once
*/
if (!cpu)
arc_cache_init_master();
}