| /* |
| * 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; |
| int ioc_exists; |
| volatile int slc_enable = 1, ioc_enable = 1; |
| unsigned long perip_base = ARC_UNCACHED_ADDR_SPACE; /* legacy value for boot */ |
| |
| 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)->ver) \ |
| 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, CONFIG_ARC_HAS_ICACHE, "I-Cache"); |
| PR_CACHE(&cpuinfo_arc700[c].dcache, CONFIG_ARC_HAS_DCACHE, "D-Cache"); |
| |
| if (!is_isa_arcv2()) |
| return buf; |
| |
| p = &cpuinfo_arc700[c].slc; |
| if (p->ver) |
| 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)); |
| |
| if (ioc_exists) |
| n += scnprintf(buf + n, len - n, "IOC\t\t:%s\n", |
| IS_DISABLED_RUN(ioc_enable)); |
| |
| 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 uncached_space; |
| struct bcr_generic sbcr; |
| |
| struct bcr_slc_cfg { |
| #ifdef CONFIG_CPU_BIG_ENDIAN |
| 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 CONFIG_CPU_BIG_ENDIAN |
| 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; |
| |
| READ_BCR(ARC_REG_SLC_BCR, sbcr); |
| if (sbcr.ver) { |
| READ_BCR(ARC_REG_SLC_CFG, slc_cfg); |
| p_slc->ver = sbcr.ver; |
| 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_enable) |
| ioc_exists = 1; |
| |
| /* Legacy Data Uncached BCR is deprecated from v3 onwards */ |
| READ_BCR(ARC_REG_D_UNCACH_BCR, uncached_space); |
| if (uncached_space.ver > 2) |
| perip_base = read_aux_reg(AUX_NON_VOL) & 0xF0000000; |
| } |
| |
| void read_decode_cache_bcr(void) |
| { |
| struct cpuinfo_arc_cache *p_ic, *p_dc; |
| unsigned int cpu = smp_processor_id(); |
| struct bcr_cache { |
| #ifdef CONFIG_CPU_BIG_ENDIAN |
| 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->ver = ibcr.ver; |
| 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); |
| p_dc->ver = dbcr.ver; |
| |
| 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 aggrevate 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 |
| * Also reused for HS38 aliasing I-cache configuration |
| */ |
| 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 configuratino 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 CONFIG_ARC_HAS_DCACHE |
| |
| /*************************************************************** |
| * 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); |
| } |
| |
| /* 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_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) |
| { |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| (*_cache_line_loop_ic_fn)(paddr, vaddr, sz, OP_INV_IC); |
| 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 */ |
| |
| noinline void slc_op(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; |
| |
| 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 |
| } |
| |
| /*********************************************************** |
| * 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_CACHE_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 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) |
| { |
| 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; |
| } |
| |
| void arc_cache_init(void) |
| { |
| unsigned int __maybe_unused cpu = smp_processor_id(); |
| char str[256]; |
| |
| printk(arc_cache_mumbojumbo(0, str, sizeof(str))); |
| |
| if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) { |
| struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache; |
| |
| if (!ic->ver) |
| 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); |
| |
| if (ic->ver != CONFIG_ARC_MMU_VER) |
| panic("Cache ver [%d] doesn't match MMU ver [%d]\n", |
| ic->ver, CONFIG_ARC_MMU_VER); |
| |
| /* |
| * In MMU v4 (HS38x) the alising 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(CONFIG_ARC_HAS_DCACHE)) { |
| struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache; |
| |
| if (!dc->ver) |
| 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->alias && !handled) |
| panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n"); |
| else if (!dc->alias && handled) |
| panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n"); |
| } |
| } |
| |
| if (is_isa_arcv2() && l2_line_sz && !slc_enable) { |
| |
| /* IM set : flush before invalidate */ |
| write_aux_reg(ARC_REG_SLC_CTRL, |
| read_aux_reg(ARC_REG_SLC_CTRL) | SLC_CTRL_IM); |
| |
| write_aux_reg(ARC_REG_SLC_INVALIDATE, 1); |
| |
| /* Important to wait for flush to complete */ |
| while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY); |
| write_aux_reg(ARC_REG_SLC_CTRL, |
| read_aux_reg(ARC_REG_SLC_CTRL) | SLC_CTRL_DISABLE); |
| } |
| |
| if (is_isa_arcv2() && ioc_exists) { |
| /* IO coherency base - 0x8z */ |
| write_aux_reg(ARC_REG_IO_COH_AP0_BASE, 0x80000); |
| /* IO coherency aperture size - 512Mb: 0x8z-0xAz */ |
| write_aux_reg(ARC_REG_IO_COH_AP0_SIZE, 0x11); |
| /* Enable partial writes */ |
| write_aux_reg(ARC_REG_IO_COH_PARTIAL, 1); |
| /* Enable IO coherency */ |
| write_aux_reg(ARC_REG_IO_COH_ENABLE, 1); |
| |
| __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; |
| } |
| } |