// SPDX-License-Identifier: GPL-2.0-only
/*
* ARC Cache Management
*
* Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*/
#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>
#ifdef CONFIG_ISA_ARCV2
#define USE_RGN_FLSH 1
#endif
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 */
static struct cpuinfo_arc_cache {
unsigned int sz_k, line_len, colors;
} ic_info, dc_info, slc_info;
void (*_cache_line_loop_ic_fn)(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int op, const int full_page);
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);
static int read_decode_cache_bcr_arcv2(int c, char *buf, int len)
{
struct cpuinfo_arc_cache *p_slc = &slc_info;
struct bcr_identity ident;
struct bcr_generic sbcr;
struct bcr_clust_cfg cbcr;
struct bcr_volatile vol;
int n = 0;
READ_BCR(ARC_REG_SLC_BCR, sbcr);
if (sbcr.ver) {
struct bcr_slc_cfg slc_cfg;
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;
n += scnprintf(buf + n, len - n,
"SLC\t\t: %uK, %uB Line%s\n",
p_slc->sz_k, p_slc->line_len, IS_USED_RUN(slc_enable));
}
READ_BCR(ARC_REG_CLUSTER_BCR, cbcr);
if (cbcr.c) {
ioc_exists = 1;
/*
* As for today we don't support both IOC and ZONE_HIGHMEM enabled
* simultaneously. This happens because as of today IOC aperture covers
* only ZONE_NORMAL (low mem) and any dma transactions outside this
* region won't be HW coherent.
* If we want to use both IOC and ZONE_HIGHMEM we can use
* bounce_buffer to handle dma transactions to HIGHMEM.
* Also it is possible to modify dma_direct cache ops or increase IOC
* aperture size if we are planning to use HIGHMEM without PAE.
*/
if (IS_ENABLED(CONFIG_HIGHMEM) || is_pae40_enabled())
ioc_enable = 0;
} else {
ioc_enable = 0;
}
READ_BCR(AUX_IDENTITY, ident);
/* HS 2.0 didn't have AUX_VOL */
if (ident.family > 0x51) {
READ_BCR(AUX_VOL, vol);
perip_base = vol.start << 28;
/* HS 3.0 has limit and strict-ordering fields */
if (ident.family > 0x52)
perip_end = (vol.limit << 28) - 1;
}
n += scnprintf(buf + n, len - n, "Peripherals\t: %#lx%s%s\n",
perip_base,
IS_AVAIL3(ioc_exists, ioc_enable, ", IO-Coherency (per-device) "));
return n;
}
int arc_cache_mumbojumbo(int c, char *buf, int len)
{
struct cpuinfo_arc_cache *p_ic = &ic_info, *p_dc = &dc_info;
struct bcr_cache ibcr, dbcr;
int vipt, assoc;
int n = 0;
READ_BCR(ARC_REG_IC_BCR, ibcr);
if (!ibcr.ver)
goto dc_chk;
if (is_isa_arcompact() && (ibcr.ver <= 3)) {
BUG_ON(ibcr.config != 3);
assoc = 2; /* Fixed to 2w set assoc */
} else if (is_isa_arcv2() && (ibcr.ver >= 4)) {
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->colors = p_ic->sz_k/assoc/TO_KB(PAGE_SIZE);
n += scnprintf(buf + n, len - n,
"I-Cache\t\t: %uK, %dway/set, %uB Line, VIPT%s%s\n",
p_ic->sz_k, assoc, p_ic->line_len,
p_ic->colors > 1 ? " aliasing" : "",
IS_USED_CFG(CONFIG_ARC_HAS_ICACHE));
dc_chk:
READ_BCR(ARC_REG_DC_BCR, dbcr);
if (!dbcr.ver)
goto slc_chk;
if (is_isa_arcompact() && (dbcr.ver <= 3)) {
BUG_ON(dbcr.config != 2);
vipt = 1;
assoc = 4; /* Fixed to 4w set assoc */
p_dc->colors = p_dc->sz_k/assoc/TO_KB(PAGE_SIZE);
} else if (is_isa_arcv2() && (dbcr.ver >= 4)) {
vipt = 0;
assoc = 1 << dbcr.config; /* 1,2,4,8 */
p_dc->colors = 1; /* PIPT so can't VIPT alias */
}
p_dc->line_len = 16 << dbcr.line_len;
p_dc->sz_k = 1 << (dbcr.sz - 1);
n += scnprintf(buf + n, len - n,
"D-Cache\t\t: %uK, %dway/set, %uB Line, %s%s%s\n",
p_dc->sz_k, assoc, p_dc->line_len,
vipt ? "VIPT" : "PIPT",
p_dc->colors > 1 ? " aliasing" : "",
IS_USED_CFG(CONFIG_ARC_HAS_DCACHE));
slc_chk:
if (is_isa_arcv2())
n += read_decode_cache_bcr_arcv2(c, buf + n, len - n);
return n;
}
/*
* 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
/*
* Cache Flush programming model
*
* ARC700 MMUv3 I$ and D$ are both VIPT and can potentially alias.
* Programming model requires both paddr and vaddr irrespecive of aliasing
* considerations:
* - vaddr in {I,D}C_IV?L
* - paddr in {I,D}C_PTAG
*
* In HS38x (MMUv4), D$ is PIPT, I$ is VIPT and can still alias.
* Programming model is different for aliasing vs. non-aliasing I$
* - D$ / Non-aliasing I$: only paddr in {I,D}C_IV?L
* - Aliasing I$: same as ARC700 above (so MMUv3 routine used for MMUv4 I$)
*
* - If PAE40 is enabled, independent of aliasing considerations, the higher
* bits needs to be written into PTAG_HI
*/
static inline
void __cache_line_loop_v3(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int op, const int full_page)
{
unsigned int aux_cmd, aux_tag;
int num_lines;
if (op == OP_INV_IC) {
aux_cmd = ARC_REG_IC_IVIL;
aux_tag = ARC_REG_IC_PTAG;
} else {
aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
aux_tag = ARC_REG_DC_PTAG;
}
/* Ensure we properly floor/ceil the non-line aligned/sized requests
* and have @paddr - aligned to cache line and integral @num_lines.
* This however can be avoided for page sized since:
* -@paddr will be cache-line aligned already (being page aligned)
* -@sz will be integral multiple of line size (being page sized).
*/
if (!full_page) {
sz += paddr & ~CACHE_LINE_MASK;
paddr &= CACHE_LINE_MASK;
vaddr &= CACHE_LINE_MASK;
}
num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
/*
* MMUv3, cache ops require paddr in PTAG reg
* if V-P const for loop, PTAG can be written once outside loop
*/
if (full_page)
write_aux_reg(aux_tag, paddr);
/*
* This is technically for MMU v4, using the MMU v3 programming model
* Special work for HS38 aliasing I-cache configuration with PAE40
* - upper 8 bits of paddr need to be written into PTAG_HI
* - (and needs to be written before the lower 32 bits)
* Note that PTAG_HI is hoisted outside the line loop
*/
if (is_pae40_enabled() && op == OP_INV_IC)
write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
while (num_lines-- > 0) {
if (!full_page) {
write_aux_reg(aux_tag, paddr);
paddr += L1_CACHE_BYTES;
}
write_aux_reg(aux_cmd, vaddr);
vaddr += L1_CACHE_BYTES;
}
}
#ifndef USE_RGN_FLSH
/*
*/
static inline
void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int op, const int full_page)
{
unsigned int aux_cmd;
int num_lines;
if (op == OP_INV_IC) {
aux_cmd = ARC_REG_IC_IVIL;
} else {
/* d$ 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;
}
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 (op == 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;
}
}
#else
/*
* optimized flush operation which takes a region as opposed to iterating per line
*/
static inline
void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int op, const int full_page)
{
unsigned int s, e;
/* Only for Non aliasing I-cache in HS38 */
if (op == OP_INV_IC) {
s = ARC_REG_IC_IVIR;
e = ARC_REG_IC_ENDR;
} else {
s = ARC_REG_DC_STARTR;
e = ARC_REG_DC_ENDR;
}
if (!full_page) {
/* for any leading gap between @paddr and start of cache line */
sz += paddr & ~CACHE_LINE_MASK;
paddr &= CACHE_LINE_MASK;
/*
* account for any trailing gap to end of cache line
* this is equivalent to DIV_ROUND_UP() in line ops above
*/
sz += L1_CACHE_BYTES - 1;
}
if (is_pae40_enabled()) {
/* TBD: check if crossing 4TB boundary */
if (op == OP_INV_IC)
write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
else
write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
}
/* ENDR needs to be set ahead of START */
write_aux_reg(e, paddr + sz); /* ENDR is exclusive */
write_aux_reg(s, paddr);
/* caller waits on DC_CTRL.FS */
}
#endif
#ifdef CONFIG_ARC_MMU_V3
#define __cache_line_loop __cache_line_loop_v3
#else
#define __cache_line_loop __cache_line_loop_v4
#endif
#ifdef CONFIG_ARC_HAS_DCACHE
/***************************************************************
* Machine specific helpers for Entire D-Cache or Per Line ops
*/
#ifndef USE_RGN_FLSH
/*
* this version avoids extra read/write of DC_CTRL for flush or invalid ops
* in the non region flush regime (such as for ARCompact)
*/
static inline void __before_dc_op(const int op)
{
if (op == OP_FLUSH_N_INV) {
/* Dcache provides 2 cmd: FLUSH or INV
* INV in turn 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);
}
}
#else
static inline void __before_dc_op(const int op)
{
const unsigned int ctl = ARC_REG_DC_CTRL;
unsigned int val = read_aux_reg(ctl);
if (op == OP_FLUSH_N_INV) {
val |= DC_CTRL_INV_MODE_FLUSH;
}
if (op != OP_INV_IC) {
/*
* Flush / Invalidate is provided by DC_CTRL.RNG_OP 0 or 1
* combined Flush-n-invalidate uses DC_CTRL.IM = 1 set above
*/
val &= ~DC_CTRL_RGN_OP_MSK;
if (op & OP_INV)
val |= DC_CTRL_RGN_OP_INV;
}
write_aux_reg(ctl, val);
}
#endif
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)
{
const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
unsigned long flags;
local_irq_save(flags);
__before_dc_op(op);
__cache_line_loop(paddr, vaddr, sz, op, full_page);
__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 CONFIG_ARC_HAS_ICACHE
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)
{
const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
unsigned long flags;
local_irq_save(flags);
(*_cache_line_loop_ic_fn)(paddr, vaddr, sz, OP_INV_IC, full_page);
local_irq_restore(flags);
}
#ifndef CONFIG_SMP
#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 */
static noinline void slc_op_rgn(phys_addr_t paddr, unsigned long sz, const int op)
{
#ifdef CONFIG_ISA_ARCV2
/*
* 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;
phys_addr_t end;
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
*/
end = paddr + sz + l2_line_sz - 1;
if (is_pae40_enabled())
write_aux_reg(ARC_REG_SLC_RGN_END1, upper_32_bits(end));
write_aux_reg(ARC_REG_SLC_RGN_END, lower_32_bits(end));
if (is_pae40_enabled())
write_aux_reg(ARC_REG_SLC_RGN_START1, upper_32_bits(paddr));
write_aux_reg(ARC_REG_SLC_RGN_START, lower_32_bits(paddr));
/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
read_aux_reg(ARC_REG_SLC_CTRL);
while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
spin_unlock_irqrestore(&lock, flags);
#endif
}
static __maybe_unused noinline void slc_op_line(phys_addr_t paddr, unsigned long sz, const int op)
{
#ifdef CONFIG_ISA_ARCV2
/*
* 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);
const unsigned long SLC_LINE_MASK = ~(l2_line_sz - 1);
unsigned int ctrl, cmd;
unsigned long flags;
int num_lines;
spin_lock_irqsave(&lock, flags);
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;
write_aux_reg(ARC_REG_SLC_CTRL, ctrl);
cmd = op & OP_INV ? ARC_AUX_SLC_IVDL : ARC_AUX_SLC_FLDL;
sz += paddr & ~SLC_LINE_MASK;
paddr &= SLC_LINE_MASK;
num_lines = DIV_ROUND_UP(sz, l2_line_sz);
while (num_lines-- > 0) {
write_aux_reg(cmd, paddr);
paddr += l2_line_sz;
}
/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
read_aux_reg(ARC_REG_SLC_CTRL);
while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
spin_unlock_irqrestore(&lock, flags);
#endif
}
#define slc_op(paddr, sz, op) slc_op_rgn(paddr, sz, op)
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);
if (op & OP_INV) /* Inv or flush-n-inv use same cmd reg */
write_aux_reg(ARC_REG_SLC_INVALIDATE, 0x1);
else
write_aux_reg(ARC_REG_SLC_FLUSH, 0x1);
/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
read_aux_reg(r);
/* 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 K-mapping, former needs flushing.
*/
void flush_dcache_folio(struct folio *folio)
{
struct address_space *mapping;
if (!cache_is_vipt_aliasing()) {
clear_bit(PG_dc_clean, &folio->flags);
return;
}
/* don't handle anon pages here */
mapping = folio_flush_mapping(folio);
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, &folio->flags);
} else if (folio_mapped(folio)) {
/* kernel reading from page with U-mapping */
phys_addr_t paddr = (unsigned long)folio_address(folio);
unsigned long vaddr = folio_pos(folio);
/*
* vaddr is not actually the virtual address, but is
* congruent to every user mapping.
*/
if (addr_not_cache_congruent(paddr, vaddr))
__flush_dcache_pages(paddr, vaddr,
folio_nr_pages(folio));
}
}
EXPORT_SYMBOL(flush_dcache_folio);
void flush_dcache_page(struct page *page)
{
return flush_dcache_folio(page_folio(page));
}
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);
}
/*
* 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 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_pages(phys_addr_t paddr, unsigned long vaddr, unsigned nr)
{
__ic_line_inv_vaddr(paddr, vaddr, nr * PAGE_SIZE);
}
/*
* wrapper to clearout kernel or userspace mappings of a page
* For kernel mappings @vaddr == @paddr
*/
void __flush_dcache_pages(phys_addr_t paddr, unsigned long vaddr, unsigned nr)
{
__dc_line_op(paddr, vaddr & PAGE_MASK, nr * 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 CONFIG_ARC_CACHE_VIPT_ALIASING
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)
{
phys_addr_t paddr = pfn << PAGE_SHIFT;
u_vaddr &= PAGE_MASK;
__flush_dcache_pages(paddr, u_vaddr, 1);
if (vma->vm_flags & VM_EXEC)
__inv_icache_pages(paddr, u_vaddr, 1);
}
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_pages((phys_addr_t)page_address(page), u_vaddr, 1);
__flush_dcache_pages((phys_addr_t)page_address(page),
(phys_addr_t)page_address(page), 1);
}
#endif
void copy_user_highpage(struct page *to, struct page *from,
unsigned long u_vaddr, struct vm_area_struct *vma)
{
struct folio *src = page_folio(from);
struct folio *dst = page_folio(to);
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_pages((unsigned long)kfrom, u_vaddr, 1);
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, &dst->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_pages((unsigned long)kfrom,
(unsigned long)kfrom, 1);
} else {
clear_bit(PG_dc_clean, &src->flags);
}
kunmap_atomic(kto);
kunmap_atomic(kfrom);
}
void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
{
struct folio *folio = page_folio(page);
clear_page(to);
clear_bit(PG_dc_clean, &folio->flags);
}
EXPORT_SYMBOL(clear_user_page);
/**********************************************************************
* 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
*/
static noinline void __init arc_ioc_setup(void)
{
unsigned int ioc_base, mem_sz;
/*
* If IOC was already enabled (due to bootloader) it technically needs to
* be reconfigured with aperture base,size corresponding to Linux memory map
* which will certainly be different than uboot's. But disabling and
* reenabling IOC when DMA might be potentially active is tricky business.
* To avoid random memory issues later, just panic here and ask user to
* upgrade bootloader to one which doesn't enable IOC
*/
if (read_aux_reg(ARC_REG_IO_COH_ENABLE) & ARC_IO_COH_ENABLE_BIT)
panic("IOC already enabled, please upgrade bootloader!\n");
if (!ioc_enable)
return;
/* 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);
/*
* currently IOC Aperture covers entire DDR
* TBD: fix for PGU + 1GB of low mem
* TBD: fix for PAE
*/
mem_sz = arc_get_mem_sz();
if (!is_power_of_2(mem_sz) || mem_sz < 4096)
panic("IOC Aperture size must be power of 2 larger than 4KB");
/*
* IOC Aperture size decoded as 2 ^ (SIZE + 2) KB,
* so setting 0x11 implies 512MB, 0x12 implies 1GB...
*/
write_aux_reg(ARC_REG_IO_COH_AP0_SIZE, order_base_2(mem_sz >> 10) - 2);
/* for now assume kernel base is start of IOC aperture */
ioc_base = CONFIG_LINUX_RAM_BASE;
if (ioc_base % mem_sz != 0)
panic("IOC Aperture start must be aligned to the size of the aperture");
write_aux_reg(ARC_REG_IO_COH_AP0_BASE, ioc_base >> 12);
write_aux_reg(ARC_REG_IO_COH_PARTIAL, ARC_IO_COH_PARTIAL_BIT);
write_aux_reg(ARC_REG_IO_COH_ENABLE, ARC_IO_COH_ENABLE_BIT);
/* Re-enable L1 dcache */
__dc_enable();
}
/*
* Cache related boot time checks/setups only needed on master CPU:
* - Geometry checks (kernel build and hardware agree: e.g. L1_CACHE_BYTES)
* Assume SMP only, so all cores will have same cache config. A check on
* one core suffices for all
* - IOC setup / dma callbacks only need to be done once
*/
static noinline void __init arc_cache_init_master(void)
{
if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) {
struct cpuinfo_arc_cache *ic = &ic_info;
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->colors > 1)
_cache_line_loop_ic_fn = __cache_line_loop_v3;
else
_cache_line_loop_ic_fn = __cache_line_loop;
}
if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) {
struct cpuinfo_arc_cache *dc = &dc_info;
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(CONFIG_ARC_CACHE_VIPT_ALIASING);
if (dc->colors > 1) {
if (!handled)
panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
if (CACHE_COLORS_NUM != dc->colors)
panic("CACHE_COLORS_NUM not optimized for config\n");
} else if (handled && dc->colors == 1) {
panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
}
}
}
/*
* Check that SMP_CACHE_BYTES (and hence ARCH_DMA_MINALIGN) is larger
* or equal to any cache line length.
*/
BUILD_BUG_ON_MSG(L1_CACHE_BYTES > SMP_CACHE_BYTES,
"SMP_CACHE_BYTES must be >= any cache line length");
if (is_isa_arcv2() && (l2_line_sz > SMP_CACHE_BYTES))
panic("L2 Cache line [%d] > kernel Config [%d]\n",
l2_line_sz, SMP_CACHE_BYTES);
/* 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_exists)
arc_ioc_setup();
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;
}
/*
* In case of IOC (say IOC+SLC case), pointers above could still be set
* but end up not being relevant as the first function in chain is not
* called at all for devices using coherent DMA.
* arch_sync_dma_for_cpu() -> dma_cache_*() -> __dma_cache_*()
*/
}
void __ref arc_cache_init(void)
{
unsigned int __maybe_unused cpu = smp_processor_id();
if (!cpu)
arc_cache_init_master();
/*
* In PAE regime, TLB and cache maintenance ops take wider addresses
* And even if PAE is not enabled in kernel, the upper 32-bits still need
* to be zeroed to keep the ops sane.
* As an optimization for more common !PAE enabled case, zero them out
* once at init, rather than checking/setting to 0 for every runtime op
*/
if (is_isa_arcv2() && pae40_exist_but_not_enab()) {
if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE))
write_aux_reg(ARC_REG_IC_PTAG_HI, 0);
if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE))
write_aux_reg(ARC_REG_DC_PTAG_HI, 0);
if (l2_line_sz) {
write_aux_reg(ARC_REG_SLC_RGN_END1, 0);
write_aux_reg(ARC_REG_SLC_RGN_START1, 0);
}
}
}