diff options
Diffstat (limited to 'drivers/iommu/arm-smmu-v3.c')
-rw-r--r-- | drivers/iommu/arm-smmu-v3.c | 984 |
1 files changed, 745 insertions, 239 deletions
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 6f0e13fa5e1a..8da93e730d6f 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -181,12 +181,13 @@ #define ARM_SMMU_MEMATTR_DEVICE_nGnRE 0x1 #define ARM_SMMU_MEMATTR_OIWB 0xf -#define Q_IDX(q, p) ((p) & ((1 << (q)->max_n_shift) - 1)) -#define Q_WRP(q, p) ((p) & (1 << (q)->max_n_shift)) -#define Q_OVERFLOW_FLAG (1 << 31) -#define Q_OVF(q, p) ((p) & Q_OVERFLOW_FLAG) +#define Q_IDX(llq, p) ((p) & ((1 << (llq)->max_n_shift) - 1)) +#define Q_WRP(llq, p) ((p) & (1 << (llq)->max_n_shift)) +#define Q_OVERFLOW_FLAG (1U << 31) +#define Q_OVF(p) ((p) & Q_OVERFLOW_FLAG) #define Q_ENT(q, p) ((q)->base + \ - Q_IDX(q, p) * (q)->ent_dwords) + Q_IDX(&((q)->llq), p) * \ + (q)->ent_dwords) #define Q_BASE_RWA (1UL << 62) #define Q_BASE_ADDR_MASK GENMASK_ULL(51, 5) @@ -306,6 +307,15 @@ #define CMDQ_ERR_CERROR_ABT_IDX 2 #define CMDQ_ERR_CERROR_ATC_INV_IDX 3 +#define CMDQ_PROD_OWNED_FLAG Q_OVERFLOW_FLAG + +/* + * This is used to size the command queue and therefore must be at least + * BITS_PER_LONG so that the valid_map works correctly (it relies on the + * total number of queue entries being a multiple of BITS_PER_LONG). + */ +#define CMDQ_BATCH_ENTRIES BITS_PER_LONG + #define CMDQ_0_OP GENMASK_ULL(7, 0) #define CMDQ_0_SSV (1UL << 11) @@ -368,9 +378,8 @@ #define PRIQ_1_ADDR_MASK GENMASK_ULL(63, 12) /* High-level queue structures */ -#define ARM_SMMU_POLL_TIMEOUT_US 100 -#define ARM_SMMU_CMDQ_SYNC_TIMEOUT_US 1000000 /* 1s! */ -#define ARM_SMMU_CMDQ_SYNC_SPIN_COUNT 10 +#define ARM_SMMU_POLL_TIMEOUT_US 1000000 /* 1s! */ +#define ARM_SMMU_POLL_SPIN_COUNT 10 #define MSI_IOVA_BASE 0x8000000 #define MSI_IOVA_LENGTH 0x100000 @@ -472,13 +481,29 @@ struct arm_smmu_cmdq_ent { #define CMDQ_OP_CMD_SYNC 0x46 struct { - u32 msidata; u64 msiaddr; } sync; }; }; +struct arm_smmu_ll_queue { + union { + u64 val; + struct { + u32 prod; + u32 cons; + }; + struct { + atomic_t prod; + atomic_t cons; + } atomic; + u8 __pad[SMP_CACHE_BYTES]; + } ____cacheline_aligned_in_smp; + u32 max_n_shift; +}; + struct arm_smmu_queue { + struct arm_smmu_ll_queue llq; int irq; /* Wired interrupt */ __le64 *base; @@ -486,17 +511,23 @@ struct arm_smmu_queue { u64 q_base; size_t ent_dwords; - u32 max_n_shift; - u32 prod; - u32 cons; u32 __iomem *prod_reg; u32 __iomem *cons_reg; }; +struct arm_smmu_queue_poll { + ktime_t timeout; + unsigned int delay; + unsigned int spin_cnt; + bool wfe; +}; + struct arm_smmu_cmdq { struct arm_smmu_queue q; - spinlock_t lock; + atomic_long_t *valid_map; + atomic_t owner_prod; + atomic_t lock; }; struct arm_smmu_evtq { @@ -576,8 +607,6 @@ struct arm_smmu_device { int gerr_irq; int combined_irq; - u32 sync_nr; - u8 prev_cmd_opcode; unsigned long ias; /* IPA */ unsigned long oas; /* PA */ @@ -596,12 +625,6 @@ struct arm_smmu_device { struct arm_smmu_strtab_cfg strtab_cfg; - /* Hi16xx adds an extra 32 bits of goodness to its MSI payload */ - union { - u32 sync_count; - u64 padding; - }; - /* IOMMU core code handle */ struct iommu_device iommu; }; @@ -614,7 +637,7 @@ struct arm_smmu_master { struct list_head domain_head; u32 *sids; unsigned int num_sids; - bool ats_enabled :1; + bool ats_enabled; }; /* SMMU private data for an IOMMU domain */ @@ -631,6 +654,7 @@ struct arm_smmu_domain { struct io_pgtable_ops *pgtbl_ops; bool non_strict; + atomic_t nr_ats_masters; enum arm_smmu_domain_stage stage; union { @@ -685,85 +709,97 @@ static void parse_driver_options(struct arm_smmu_device *smmu) } /* Low-level queue manipulation functions */ -static bool queue_full(struct arm_smmu_queue *q) +static bool queue_has_space(struct arm_smmu_ll_queue *q, u32 n) +{ + u32 space, prod, cons; + + prod = Q_IDX(q, q->prod); + cons = Q_IDX(q, q->cons); + + if (Q_WRP(q, q->prod) == Q_WRP(q, q->cons)) + space = (1 << q->max_n_shift) - (prod - cons); + else + space = cons - prod; + + return space >= n; +} + +static bool queue_full(struct arm_smmu_ll_queue *q) { return Q_IDX(q, q->prod) == Q_IDX(q, q->cons) && Q_WRP(q, q->prod) != Q_WRP(q, q->cons); } -static bool queue_empty(struct arm_smmu_queue *q) +static bool queue_empty(struct arm_smmu_ll_queue *q) { return Q_IDX(q, q->prod) == Q_IDX(q, q->cons) && Q_WRP(q, q->prod) == Q_WRP(q, q->cons); } -static void queue_sync_cons(struct arm_smmu_queue *q) +static bool queue_consumed(struct arm_smmu_ll_queue *q, u32 prod) { - q->cons = readl_relaxed(q->cons_reg); + return ((Q_WRP(q, q->cons) == Q_WRP(q, prod)) && + (Q_IDX(q, q->cons) > Q_IDX(q, prod))) || + ((Q_WRP(q, q->cons) != Q_WRP(q, prod)) && + (Q_IDX(q, q->cons) <= Q_IDX(q, prod))); } -static void queue_inc_cons(struct arm_smmu_queue *q) +static void queue_sync_cons_out(struct arm_smmu_queue *q) { - u32 cons = (Q_WRP(q, q->cons) | Q_IDX(q, q->cons)) + 1; - - q->cons = Q_OVF(q, q->cons) | Q_WRP(q, cons) | Q_IDX(q, cons); - /* * Ensure that all CPU accesses (reads and writes) to the queue * are complete before we update the cons pointer. */ mb(); - writel_relaxed(q->cons, q->cons_reg); + writel_relaxed(q->llq.cons, q->cons_reg); +} + +static void queue_inc_cons(struct arm_smmu_ll_queue *q) +{ + u32 cons = (Q_WRP(q, q->cons) | Q_IDX(q, q->cons)) + 1; + q->cons = Q_OVF(q->cons) | Q_WRP(q, cons) | Q_IDX(q, cons); } -static int queue_sync_prod(struct arm_smmu_queue *q) +static int queue_sync_prod_in(struct arm_smmu_queue *q) { int ret = 0; u32 prod = readl_relaxed(q->prod_reg); - if (Q_OVF(q, prod) != Q_OVF(q, q->prod)) + if (Q_OVF(prod) != Q_OVF(q->llq.prod)) ret = -EOVERFLOW; - q->prod = prod; + q->llq.prod = prod; return ret; } -static void queue_inc_prod(struct arm_smmu_queue *q) +static u32 queue_inc_prod_n(struct arm_smmu_ll_queue *q, int n) { - u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + 1; - - q->prod = Q_OVF(q, q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod); - writel(q->prod, q->prod_reg); + u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + n; + return Q_OVF(q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod); } -/* - * Wait for the SMMU to consume items. If sync is true, wait until the queue - * is empty. Otherwise, wait until there is at least one free slot. - */ -static int queue_poll_cons(struct arm_smmu_queue *q, bool sync, bool wfe) +static void queue_poll_init(struct arm_smmu_device *smmu, + struct arm_smmu_queue_poll *qp) { - ktime_t timeout; - unsigned int delay = 1, spin_cnt = 0; - - /* Wait longer if it's a CMD_SYNC */ - timeout = ktime_add_us(ktime_get(), sync ? - ARM_SMMU_CMDQ_SYNC_TIMEOUT_US : - ARM_SMMU_POLL_TIMEOUT_US); + qp->delay = 1; + qp->spin_cnt = 0; + qp->wfe = !!(smmu->features & ARM_SMMU_FEAT_SEV); + qp->timeout = ktime_add_us(ktime_get(), ARM_SMMU_POLL_TIMEOUT_US); +} - while (queue_sync_cons(q), (sync ? !queue_empty(q) : queue_full(q))) { - if (ktime_compare(ktime_get(), timeout) > 0) - return -ETIMEDOUT; +static int queue_poll(struct arm_smmu_queue_poll *qp) +{ + if (ktime_compare(ktime_get(), qp->timeout) > 0) + return -ETIMEDOUT; - if (wfe) { - wfe(); - } else if (++spin_cnt < ARM_SMMU_CMDQ_SYNC_SPIN_COUNT) { - cpu_relax(); - continue; - } else { - udelay(delay); - delay *= 2; - spin_cnt = 0; - } + if (qp->wfe) { + wfe(); + } else if (++qp->spin_cnt < ARM_SMMU_POLL_SPIN_COUNT) { + cpu_relax(); + } else { + udelay(qp->delay); + qp->delay *= 2; + qp->spin_cnt = 0; } return 0; @@ -777,16 +813,6 @@ static void queue_write(__le64 *dst, u64 *src, size_t n_dwords) *dst++ = cpu_to_le64(*src++); } -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) -{ - if (queue_full(q)) - return -ENOSPC; - - queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); - queue_inc_prod(q); - return 0; -} - static void queue_read(__le64 *dst, u64 *src, size_t n_dwords) { int i; @@ -797,11 +823,12 @@ static void queue_read(__le64 *dst, u64 *src, size_t n_dwords) static int queue_remove_raw(struct arm_smmu_queue *q, u64 *ent) { - if (queue_empty(q)) + if (queue_empty(&q->llq)) return -EAGAIN; - queue_read(ent, Q_ENT(q, q->cons), q->ent_dwords); - queue_inc_cons(q); + queue_read(ent, Q_ENT(q, q->llq.cons), q->ent_dwords); + queue_inc_cons(&q->llq); + queue_sync_cons_out(q); return 0; } @@ -868,20 +895,14 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent) cmd[1] |= FIELD_PREP(CMDQ_PRI_1_RESP, ent->pri.resp); break; case CMDQ_OP_CMD_SYNC: - if (ent->sync.msiaddr) + if (ent->sync.msiaddr) { cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_IRQ); - else + cmd[1] |= ent->sync.msiaddr & CMDQ_SYNC_1_MSIADDR_MASK; + } else { cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_SEV); + } cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_MSH, ARM_SMMU_SH_ISH); cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_MSIATTR, ARM_SMMU_MEMATTR_OIWB); - /* - * Commands are written little-endian, but we want the SMMU to - * receive MSIData, and thus write it back to memory, in CPU - * byte order, so big-endian needs an extra byteswap here. - */ - cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_MSIDATA, - cpu_to_le32(ent->sync.msidata)); - cmd[1] |= ent->sync.msiaddr & CMDQ_SYNC_1_MSIADDR_MASK; break; default: return -ENOENT; @@ -890,6 +911,27 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent) return 0; } +static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu, + u32 prod) +{ + struct arm_smmu_queue *q = &smmu->cmdq.q; + struct arm_smmu_cmdq_ent ent = { + .opcode = CMDQ_OP_CMD_SYNC, + }; + + /* + * Beware that Hi16xx adds an extra 32 bits of goodness to its MSI + * payload, so the write will zero the entire command on that platform. + */ + if (smmu->features & ARM_SMMU_FEAT_MSI && + smmu->features & ARM_SMMU_FEAT_COHERENCY) { + ent.sync.msiaddr = q->base_dma + Q_IDX(&q->llq, prod) * + q->ent_dwords * 8; + } + + arm_smmu_cmdq_build_cmd(cmd, &ent); +} + static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu) { static const char *cerror_str[] = { @@ -948,109 +990,456 @@ static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu) queue_write(Q_ENT(q, cons), cmd, q->ent_dwords); } -static void arm_smmu_cmdq_insert_cmd(struct arm_smmu_device *smmu, u64 *cmd) +/* + * Command queue locking. + * This is a form of bastardised rwlock with the following major changes: + * + * - The only LOCK routines are exclusive_trylock() and shared_lock(). + * Neither have barrier semantics, and instead provide only a control + * dependency. + * + * - The UNLOCK routines are supplemented with shared_tryunlock(), which + * fails if the caller appears to be the last lock holder (yes, this is + * racy). All successful UNLOCK routines have RELEASE semantics. + */ +static void arm_smmu_cmdq_shared_lock(struct arm_smmu_cmdq *cmdq) { - struct arm_smmu_queue *q = &smmu->cmdq.q; - bool wfe = !!(smmu->features & ARM_SMMU_FEAT_SEV); + int val; + + /* + * We can try to avoid the cmpxchg() loop by simply incrementing the + * lock counter. When held in exclusive state, the lock counter is set + * to INT_MIN so these increments won't hurt as the value will remain + * negative. + */ + if (atomic_fetch_inc_relaxed(&cmdq->lock) >= 0) + return; + + do { + val = atomic_cond_read_relaxed(&cmdq->lock, VAL >= 0); + } while (atomic_cmpxchg_relaxed(&cmdq->lock, val, val + 1) != val); +} + +static void arm_smmu_cmdq_shared_unlock(struct arm_smmu_cmdq *cmdq) +{ + (void)atomic_dec_return_release(&cmdq->lock); +} - smmu->prev_cmd_opcode = FIELD_GET(CMDQ_0_OP, cmd[0]); +static bool arm_smmu_cmdq_shared_tryunlock(struct arm_smmu_cmdq *cmdq) +{ + if (atomic_read(&cmdq->lock) == 1) + return false; - while (queue_insert_raw(q, cmd) == -ENOSPC) { - if (queue_poll_cons(q, false, wfe)) - dev_err_ratelimited(smmu->dev, "CMDQ timeout\n"); + arm_smmu_cmdq_shared_unlock(cmdq); + return true; +} + +#define arm_smmu_cmdq_exclusive_trylock_irqsave(cmdq, flags) \ +({ \ + bool __ret; \ + local_irq_save(flags); \ + __ret = !atomic_cmpxchg_relaxed(&cmdq->lock, 0, INT_MIN); \ + if (!__ret) \ + local_irq_restore(flags); \ + __ret; \ +}) + +#define arm_smmu_cmdq_exclusive_unlock_irqrestore(cmdq, flags) \ +({ \ + atomic_set_release(&cmdq->lock, 0); \ + local_irq_restore(flags); \ +}) + + +/* + * Command queue insertion. + * This is made fiddly by our attempts to achieve some sort of scalability + * since there is one queue shared amongst all of the CPUs in the system. If + * you like mixed-size concurrency, dependency ordering and relaxed atomics, + * then you'll *love* this monstrosity. + * + * The basic idea is to split the queue up into ranges of commands that are + * owned by a given CPU; the owner may not have written all of the commands + * itself, but is responsible for advancing the hardware prod pointer when + * the time comes. The algorithm is roughly: + * + * 1. Allocate some space in the queue. At this point we also discover + * whether the head of the queue is currently owned by another CPU, + * or whether we are the owner. + * + * 2. Write our commands into our allocated slots in the queue. + * + * 3. Mark our slots as valid in arm_smmu_cmdq.valid_map. + * + * 4. If we are an owner: + * a. Wait for the previous owner to finish. + * b. Mark the queue head as unowned, which tells us the range + * that we are responsible for publishing. + * c. Wait for all commands in our owned range to become valid. + * d. Advance the hardware prod pointer. + * e. Tell the next owner we've finished. + * + * 5. If we are inserting a CMD_SYNC (we may or may not have been an + * owner), then we need to stick around until it has completed: + * a. If we have MSIs, the SMMU can write back into the CMD_SYNC + * to clear the first 4 bytes. + * b. Otherwise, we spin waiting for the hardware cons pointer to + * advance past our command. + * + * The devil is in the details, particularly the use of locking for handling + * SYNC completion and freeing up space in the queue before we think that it is + * full. + */ +static void __arm_smmu_cmdq_poll_set_valid_map(struct arm_smmu_cmdq *cmdq, + u32 sprod, u32 eprod, bool set) +{ + u32 swidx, sbidx, ewidx, ebidx; + struct arm_smmu_ll_queue llq = { + .max_n_shift = cmdq->q.llq.max_n_shift, + .prod = sprod, + }; + + ewidx = BIT_WORD(Q_IDX(&llq, eprod)); + ebidx = Q_IDX(&llq, eprod) % BITS_PER_LONG; + + while (llq.prod != eprod) { + unsigned long mask; + atomic_long_t *ptr; + u32 limit = BITS_PER_LONG; + + swidx = BIT_WORD(Q_IDX(&llq, llq.prod)); + sbidx = Q_IDX(&llq, llq.prod) % BITS_PER_LONG; + + ptr = &cmdq->valid_map[swidx]; + + if ((swidx == ewidx) && (sbidx < ebidx)) + limit = ebidx; + + mask = GENMASK(limit - 1, sbidx); + + /* + * The valid bit is the inverse of the wrap bit. This means + * that a zero-initialised queue is invalid and, after marking + * all entries as valid, they become invalid again when we + * wrap. + */ + if (set) { + atomic_long_xor(mask, ptr); + } else { /* Poll */ + unsigned long valid; + + valid = (ULONG_MAX + !!Q_WRP(&llq, llq.prod)) & mask; + atomic_long_cond_read_relaxed(ptr, (VAL & mask) == valid); + } + + llq.prod = queue_inc_prod_n(&llq, limit - sbidx); } } -static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, - struct arm_smmu_cmdq_ent *ent) +/* Mark all entries in the range [sprod, eprod) as valid */ +static void arm_smmu_cmdq_set_valid_map(struct arm_smmu_cmdq *cmdq, + u32 sprod, u32 eprod) +{ + __arm_smmu_cmdq_poll_set_valid_map(cmdq, sprod, eprod, true); +} + +/* Wait for all entries in the range [sprod, eprod) to become valid */ +static void arm_smmu_cmdq_poll_valid_map(struct arm_smmu_cmdq *cmdq, + u32 sprod, u32 eprod) +{ + __arm_smmu_cmdq_poll_set_valid_map(cmdq, sprod, eprod, false); +} + +/* Wait for the command queue to become non-full */ +static int arm_smmu_cmdq_poll_until_not_full(struct arm_smmu_device *smmu, + struct arm_smmu_ll_queue *llq) { - u64 cmd[CMDQ_ENT_DWORDS]; unsigned long flags; + struct arm_smmu_queue_poll qp; + struct arm_smmu_cmdq *cmdq = &smmu->cmdq; + int ret = 0; - if (arm_smmu_cmdq_build_cmd(cmd, ent)) { - dev_warn(smmu->dev, "ignoring unknown CMDQ opcode 0x%x\n", - ent->opcode); - return; + /* + * Try to update our copy of cons by grabbing exclusive cmdq access. If + * that fails, spin until somebody else updates it for us. + */ + if (arm_smmu_cmdq_exclusive_trylock_irqsave(cmdq, flags)) { + WRITE_ONCE(cmdq->q.llq.cons, readl_relaxed(cmdq->q.cons_reg)); + arm_smmu_cmdq_exclusive_unlock_irqrestore(cmdq, flags); + llq->val = READ_ONCE(cmdq->q.llq.val); + return 0; } - spin_lock_irqsave(&smmu->cmdq.lock, flags); - arm_smmu_cmdq_insert_cmd(smmu, cmd); - spin_unlock_irqrestore(&smmu->cmdq.lock, flags); + queue_poll_init(smmu, &qp); + do { + llq->val = READ_ONCE(smmu->cmdq.q.llq.val); + if (!queue_full(llq)) + break; + + ret = queue_poll(&qp); + } while (!ret); + + return ret; } /* - * The difference between val and sync_idx is bounded by the maximum size of - * a queue at 2^20 entries, so 32 bits is plenty for wrap-safe arithmetic. + * Wait until the SMMU signals a CMD_SYNC completion MSI. + * Must be called with the cmdq lock held in some capacity. */ -static int __arm_smmu_sync_poll_msi(struct arm_smmu_device *smmu, u32 sync_idx) +static int __arm_smmu_cmdq_poll_until_msi(struct arm_smmu_device *smmu, + struct arm_smmu_ll_queue *llq) { - ktime_t timeout; - u32 val; + int ret = 0; + struct arm_smmu_queue_poll qp; + struct arm_smmu_cmdq *cmdq = &smmu->cmdq; + u32 *cmd = (u32 *)(Q_ENT(&cmdq->q, llq->prod)); - timeout = ktime_add_us(ktime_get(), ARM_SMMU_CMDQ_SYNC_TIMEOUT_US); - val = smp_cond_load_acquire(&smmu->sync_count, - (int)(VAL - sync_idx) >= 0 || - !ktime_before(ktime_get(), timeout)); + queue_poll_init(smmu, &qp); - return (int)(val - sync_idx) < 0 ? -ETIMEDOUT : 0; + /* + * The MSI won't generate an event, since it's being written back + * into the command queue. + */ + qp.wfe = false; + smp_cond_load_relaxed(cmd, !VAL || (ret = queue_poll(&qp))); + llq->cons = ret ? llq->prod : queue_inc_prod_n(llq, 1); + return ret; } -static int __arm_smmu_cmdq_issue_sync_msi(struct arm_smmu_device *smmu) +/* + * Wait until the SMMU cons index passes llq->prod. + * Must be called with the cmdq lock held in some capacity. + */ +static int __arm_smmu_cmdq_poll_until_consumed(struct arm_smmu_device *smmu, + struct arm_smmu_ll_queue *llq) { - u64 cmd[CMDQ_ENT_DWORDS]; - unsigned long flags; - struct arm_smmu_cmdq_ent ent = { - .opcode = CMDQ_OP_CMD_SYNC, - .sync = { - .msiaddr = virt_to_phys(&smmu->sync_count), - }, - }; + struct arm_smmu_queue_poll qp; + struct arm_smmu_cmdq *cmdq = &smmu->cmdq; + u32 prod = llq->prod; + int ret = 0; + + queue_poll_init(smmu, &qp); + llq->val = READ_ONCE(smmu->cmdq.q.llq.val); + do { + if (queue_consumed(llq, prod)) + break; - spin_lock_irqsave(&smmu->cmdq.lock, flags); + ret = queue_poll(&qp); - /* Piggy-back on the previous command if it's a SYNC */ - if (smmu->prev_cmd_opcode == CMDQ_OP_CMD_SYNC) { - ent.sync.msidata = smmu->sync_nr; - } else { - ent.sync.msidata = ++smmu->sync_nr; - arm_smmu_cmdq_build_cmd(cmd, &ent); - arm_smmu_cmdq_insert_cmd(smmu, cmd); - } + /* + * This needs to be a readl() so that our subsequent call + * to arm_smmu_cmdq_shared_tryunlock() can fail accurately. + * + * Specifically, we need to ensure that we observe all + * shared_lock()s by other CMD_SYNCs that share our owner, + * so that a failing call to tryunlock() means that we're + * the last one out and therefore we can safely advance + * cmdq->q.llq.cons. Roughly speaking: + * + * CPU 0 CPU1 CPU2 (us) + * + * if (sync) + * shared_lock(); + * + * dma_wmb(); + * set_valid_map(); + * + * if (owner) { + * poll_valid_map(); + * <control dependency> + * writel(prod_reg); + * + * readl(cons_reg); + * tryunlock(); + * + * Requires us to see CPU 0's shared_lock() acquisition. + */ + llq->cons = readl(cmdq->q.cons_reg); + } while (!ret); - spin_unlock_irqrestore(&smmu->cmdq.lock, flags); + return ret; +} + +static int arm_smmu_cmdq_poll_until_sync(struct arm_smmu_device *smmu, + struct arm_smmu_ll_queue *llq) +{ + if (smmu->features & ARM_SMMU_FEAT_MSI && + smmu->features & ARM_SMMU_FEAT_COHERENCY) + return __arm_smmu_cmdq_poll_until_msi(smmu, llq); - return __arm_smmu_sync_poll_msi(smmu, ent.sync.msidata); + return __arm_smmu_cmdq_poll_until_consumed(smmu, llq); } -static int __arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu) +static void arm_smmu_cmdq_write_entries(struct arm_smmu_cmdq *cmdq, u64 *cmds, + u32 prod, int n) { - u64 cmd[CMDQ_ENT_DWORDS]; + int i; + struct arm_smmu_ll_queue llq = { + .max_n_shift = cmdq->q.llq.max_n_shift, + .prod = prod, + }; + + for (i = 0; i < n; ++i) { + u64 *cmd = &cmds[i * CMDQ_ENT_DWORDS]; + + prod = queue_inc_prod_n(&llq, i); + queue_write(Q_ENT(&cmdq->q, prod), cmd, CMDQ_ENT_DWORDS); + } +} + +/* + * This is the actual insertion function, and provides the following + * ordering guarantees to callers: + * + * - There is a dma_wmb() before publishing any commands to the queue. + * This can be relied upon to order prior writes to data structures + * in memory (such as a CD or an STE) before the command. + * + * - On completion of a CMD_SYNC, there is a control dependency. + * This can be relied upon to order subsequent writes to memory (e.g. + * freeing an IOVA) after completion of the CMD_SYNC. + * + * - Command insertion is totally ordered, so if two CPUs each race to + * insert their own list of commands then all of the commands from one + * CPU will appear before any of the commands from the other CPU. + */ +static int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu, + u64 *cmds, int n, bool sync) +{ + u64 cmd_sync[CMDQ_ENT_DWORDS]; + u32 prod; unsigned long flags; - bool wfe = !!(smmu->features & ARM_SMMU_FEAT_SEV); - struct arm_smmu_cmdq_ent ent = { .opcode = CMDQ_OP_CMD_SYNC }; - int ret; + bool owner; + struct arm_smmu_cmdq *cmdq = &smmu->cmdq; + struct arm_smmu_ll_queue llq = { + .max_n_shift = cmdq->q.llq.max_n_shift, + }, head = llq; + int ret = 0; - arm_smmu_cmdq_build_cmd(cmd, &ent); + /* 1. Allocate some space in the queue */ + local_irq_save(flags); + llq.val = READ_ONCE(cmdq->q.llq.val); + do { + u64 old; + + while (!queue_has_space(&llq, n + sync)) { + local_irq_restore(flags); + if (arm_smmu_cmdq_poll_until_not_full(smmu, &llq)) + dev_err_ratelimited(smmu->dev, "CMDQ timeout\n"); + local_irq_save(flags); + } + + head.cons = llq.cons; + head.prod = queue_inc_prod_n(&llq, n + sync) | + CMDQ_PROD_OWNED_FLAG; - spin_lock_irqsave(&smmu->cmdq.lock, flags); - arm_smmu_cmdq_insert_cmd(smmu, cmd); - ret = queue_poll_cons(&smmu->cmdq.q, true, wfe); - spin_unlock_irqrestore(&smmu->cmdq.lock, flags); + old = cmpxchg_relaxed(&cmdq->q.llq.val, llq.val, head.val); + if (old == llq.val) + break; + + llq.val = old; + } while (1); + owner = !(llq.prod & CMDQ_PROD_OWNED_FLAG); + head.prod &= ~CMDQ_PROD_OWNED_FLAG; + llq.prod &= ~CMDQ_PROD_OWNED_FLAG; + + /* + * 2. Write our commands into the queue + * Dependency ordering from the cmpxchg() loop above. + */ + arm_smmu_cmdq_write_entries(cmdq, cmds, llq.prod, n); + if (sync) { + prod = queue_inc_prod_n(&llq, n); + arm_smmu_cmdq_build_sync_cmd(cmd_sync, smmu, prod); + queue_write(Q_ENT(&cmdq->q, prod), cmd_sync, CMDQ_ENT_DWORDS); + + /* + * In order to determine completion of our CMD_SYNC, we must + * ensure that the queue can't wrap twice without us noticing. + * We achieve that by taking the cmdq lock as shared before + * marking our slot as valid. + */ + arm_smmu_cmdq_shared_lock(cmdq); + } + + /* 3. Mark our slots as valid, ensuring commands are visible first */ + dma_wmb(); + arm_smmu_cmdq_set_valid_map(cmdq, llq.prod, head.prod); + + /* 4. If we are the owner, take control of the SMMU hardware */ + if (owner) { + /* a. Wait for previous owner to finish */ + atomic_cond_read_relaxed(&cmdq->owner_prod, VAL == llq.prod); + + /* b. Stop gathering work by clearing the owned flag */ + prod = atomic_fetch_andnot_relaxed(CMDQ_PROD_OWNED_FLAG, + &cmdq->q.llq.atomic.prod); + prod &= ~CMDQ_PROD_OWNED_FLAG; + + /* + * c. Wait for any gathered work to be written to the queue. + * Note that we read our own entries so that we have the control + * dependency required by (d). + */ + arm_smmu_cmdq_poll_valid_map(cmdq, llq.prod, prod); + + /* + * d. Advance the hardware prod pointer + * Control dependency ordering from the entries becoming valid. + */ + writel_relaxed(prod, cmdq->q.prod_reg); + + /* + * e. Tell the next owner we're done + * Make sure we've updated the hardware first, so that we don't + * race to update prod and potentially move it backwards. + */ + atomic_set_release(&cmdq->owner_prod, prod); + } + + /* 5. If we are inserting a CMD_SYNC, we must wait for it to complete */ + if (sync) { + llq.prod = queue_inc_prod_n(&llq, n); + ret = arm_smmu_cmdq_poll_until_sync(smmu, &llq); + if (ret) { + dev_err_ratelimited(smmu->dev, + "CMD_SYNC timeout at 0x%08x [hwprod 0x%08x, hwcons 0x%08x]\n", + llq.prod, + readl_relaxed(cmdq->q.prod_reg), + readl_relaxed(cmdq->q.cons_reg)); + } + + /* + * Try to unlock the cmq lock. This will fail if we're the last + * reader, in which case we can safely update cmdq->q.llq.cons + */ + if (!arm_smmu_cmdq_shared_tryunlock(cmdq)) { + WRITE_ONCE(cmdq->q.llq.cons, llq.cons); + arm_smmu_cmdq_shared_unlock(cmdq); + } + } + local_irq_restore(flags); return ret; } -static int arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu) +static int arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, + struct arm_smmu_cmdq_ent *ent) { - int ret; - bool msi = (smmu->features & ARM_SMMU_FEAT_MSI) && - (smmu->features & ARM_SMMU_FEAT_COHERENCY); + u64 cmd[CMDQ_ENT_DWORDS]; - ret = msi ? __arm_smmu_cmdq_issue_sync_msi(smmu) - : __arm_smmu_cmdq_issue_sync(smmu); - if (ret) - dev_err_ratelimited(smmu->dev, "CMD_SYNC timeout\n"); - return ret; + if (arm_smmu_cmdq_build_cmd(cmd, ent)) { + dev_warn(smmu->dev, "ignoring unknown CMDQ opcode 0x%x\n", + ent->opcode); + return -EINVAL; + } + + return arm_smmu_cmdq_issue_cmdlist(smmu, cmd, 1, false); +} + +static int arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu) +{ + return arm_smmu_cmdq_issue_cmdlist(smmu, NULL, 0, true); } /* Context descriptor manipulation functions */ @@ -1186,8 +1575,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid, ste_live = true; break; case STRTAB_STE_0_CFG_ABORT: - if (disable_bypass) - break; + BUG_ON(!disable_bypass); + break; default: BUG(); /* STE corruption */ } @@ -1305,6 +1694,7 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev) int i; struct arm_smmu_device *smmu = dev; struct arm_smmu_queue *q = &smmu->evtq.q; + struct arm_smmu_ll_queue *llq = &q->llq; u64 evt[EVTQ_ENT_DWORDS]; do { @@ -1322,12 +1712,13 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev) * Not much we can do on overflow, so scream and pretend we're * trying harder. */ - if (queue_sync_prod(q) == -EOVERFLOW) + if (queue_sync_prod_in(q) == -EOVERFLOW) dev_err(smmu->dev, "EVTQ overflow detected -- events lost\n"); - } while (!queue_empty(q)); + } while (!queue_empty(llq)); /* Sync our overflow flag, as we believe we're up to speed */ - q->cons = Q_OVF(q, q->prod) | Q_WRP(q, q->cons) | Q_IDX(q, q->cons); + llq->cons = Q_OVF(llq->prod) | Q_WRP(llq, llq->cons) | + Q_IDX(llq, llq->cons); return IRQ_HANDLED; } @@ -1373,19 +1764,21 @@ static irqreturn_t arm_smmu_priq_thread(int irq, void *dev) { struct arm_smmu_device *smmu = dev; struct arm_smmu_queue *q = &smmu->priq.q; + struct arm_smmu_ll_queue *llq = &q->llq; u64 evt[PRIQ_ENT_DWORDS]; do { while (!queue_remove_raw(q, evt)) arm_smmu_handle_ppr(smmu, evt); - if (queue_sync_prod(q) == -EOVERFLOW) + if (queue_sync_prod_in(q) == -EOVERFLOW) dev_err(smmu->dev, "PRIQ overflow detected -- requests lost\n"); - } while (!queue_empty(q)); + } while (!queue_empty(llq)); /* Sync our overflow flag, as we believe we're up to speed */ - q->cons = Q_OVF(q, q->prod) | Q_WRP(q, q->cons) | Q_IDX(q, q->cons); - writel(q->cons, q->cons_reg); + llq->cons = Q_OVF(llq->prod) | Q_WRP(llq, llq->cons) | + Q_IDX(llq, llq->cons); + queue_sync_cons_out(q); return IRQ_HANDLED; } @@ -1534,6 +1927,23 @@ static int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_ATS)) return 0; + /* + * Ensure that we've completed prior invalidation of the main TLBs + * before we read 'nr_ats_masters' in case of a concurrent call to + * arm_smmu_enable_ats(): + * + * // unmap() // arm_smmu_enable_ats() + * TLBI+SYNC atomic_inc(&nr_ats_masters); + * smp_mb(); [...] + * atomic_read(&nr_ats_masters); pci_enable_ats() // writel() + * + * Ensures that we always see the incremented 'nr_ats_masters' count if + * ATS was enabled at the PCI device before completion of the TLBI. + */ + smp_mb(); + if (!atomic_read(&smmu_domain->nr_ats_masters)) + return 0; + arm_smmu_atc_inv_to_cmd(ssid, iova, size, &cmd); spin_lock_irqsave(&smmu_domain->devices_lock, flags); @@ -1545,13 +1955,6 @@ static int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, } /* IO_PGTABLE API */ -static void arm_smmu_tlb_sync(void *cookie) -{ - struct arm_smmu_domain *smmu_domain = cookie; - - arm_smmu_cmdq_issue_sync(smmu_domain->smmu); -} - static void arm_smmu_tlb_inv_context(void *cookie) { struct arm_smmu_domain *smmu_domain = cookie; @@ -1570,25 +1973,32 @@ static void arm_smmu_tlb_inv_context(void *cookie) /* * NOTE: when io-pgtable is in non-strict mode, we may get here with * PTEs previously cleared by unmaps on the current CPU not yet visible - * to the SMMU. We are relying on the DSB implicit in queue_inc_prod() - * to guarantee those are observed before the TLBI. Do be careful, 007. + * to the SMMU. We are relying on the dma_wmb() implicit during cmd + * insertion to guarantee those are observed before the TLBI. Do be + * careful, 007. */ arm_smmu_cmdq_issue_cmd(smmu, &cmd); arm_smmu_cmdq_issue_sync(smmu); + arm_smmu_atc_inv_domain(smmu_domain, 0, 0, 0); } -static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, - size_t granule, bool leaf, void *cookie) +static void arm_smmu_tlb_inv_range(unsigned long iova, size_t size, + size_t granule, bool leaf, + struct arm_smmu_domain *smmu_domain) { - struct arm_smmu_domain *smmu_domain = cookie; + u64 cmds[CMDQ_BATCH_ENTRIES * CMDQ_ENT_DWORDS]; struct arm_smmu_device *smmu = smmu_domain->smmu; + unsigned long start = iova, end = iova + size; + int i = 0; struct arm_smmu_cmdq_ent cmd = { .tlbi = { .leaf = leaf, - .addr = iova, }, }; + if (!size) + return; + if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) { cmd.opcode = CMDQ_OP_TLBI_NH_VA; cmd.tlbi.asid = smmu_domain->s1_cfg.cd.asid; @@ -1597,16 +2007,54 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid; } - do { - arm_smmu_cmdq_issue_cmd(smmu, &cmd); - cmd.tlbi.addr += granule; - } while (size -= granule); + while (iova < end) { + if (i == CMDQ_BATCH_ENTRIES) { + arm_smmu_cmdq_issue_cmdlist(smmu, cmds, i, false); + i = 0; + } + + cmd.tlbi.addr = iova; + arm_smmu_cmdq_build_cmd(&cmds[i * CMDQ_ENT_DWORDS], &cmd); + iova += granule; + i++; + } + + arm_smmu_cmdq_issue_cmdlist(smmu, cmds, i, true); + + /* + * Unfortunately, this can't be leaf-only since we may have + * zapped an entire table. + */ + arm_smmu_atc_inv_domain(smmu_domain, 0, start, size); +} + +static void arm_smmu_tlb_inv_page_nosync(struct iommu_iotlb_gather *gather, + unsigned long iova, size_t granule, + void *cookie) +{ + struct arm_smmu_domain *smmu_domain = cookie; + struct iommu_domain *domain = &smmu_domain->domain; + + iommu_iotlb_gather_add_page(domain, gather, iova, granule); } -static const struct iommu_gather_ops arm_smmu_gather_ops = { +static void arm_smmu_tlb_inv_walk(unsigned long iova, size_t size, + size_t granule, void *cookie) +{ + arm_smmu_tlb_inv_range(iova, size, granule, false, cookie); +} + +static void arm_smmu_tlb_inv_leaf(unsigned long iova, size_t size, + size_t granule, void *cookie) +{ + arm_smmu_tlb_inv_range(iova, size, granule, true, cookie); +} + +static const struct iommu_flush_ops arm_smmu_flush_ops = { .tlb_flush_all = arm_smmu_tlb_inv_context, - .tlb_add_flush = arm_smmu_tlb_inv_range_nosync, - .tlb_sync = arm_smmu_tlb_sync, + .tlb_flush_walk = arm_smmu_tlb_inv_walk, + .tlb_flush_leaf = arm_smmu_tlb_inv_leaf, + .tlb_add_page = arm_smmu_tlb_inv_page_nosync, }; /* IOMMU API */ @@ -1796,7 +2244,7 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain) .ias = ias, .oas = oas, .coherent_walk = smmu->features & ARM_SMMU_FEAT_COHERENCY, - .tlb = &arm_smmu_gather_ops, + .tlb = &arm_smmu_flush_ops, .iommu_dev = smmu->dev, }; @@ -1863,44 +2311,65 @@ static void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master) |