[RFC CFT 4/6] iommu/arm-smmu-v3: Move low-level queue fields out of arm_smmu_queue

Will Deacon
2019-06-11T13:46:40Z

In preparation for rewriting the command queue insertion code to use a
new algorithm, introduce a new arm_smmu_ll_queue structure which contains
only the information necessary to perform queue arithmetic for a queue
and will later be extended so that we can perform complex atomic
manipulation on some of the fields.

No functional change.

Signed-off-by: Will Deacon <will.deacon@arm.com>
---
drivers/iommu/arm-smmu-v3.c | 88 ++++++++++++++++++++++++---------------------
1 file changed, 47 insertions(+), 41 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 1b7e8fe26c41..d72da799bd0a 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -181,8 +181,8 @@
#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_IDX(q, p) ((p) & ((1 << (q)->llq.max_n_shift) - 1))
+#define Q_WRP(q, p) ((p) & (1 << (q)->llq.max_n_shift))
#define Q_OVERFLOW_FLAG (1 << 31)
#define Q_OVF(p) ((p) & Q_OVERFLOW_FLAG)
#define Q_ENT(q, p) ((q)->base + \
@@ -472,7 +472,14 @@ struct arm_smmu_cmdq_ent {
};
};

+struct arm_smmu_ll_queue {
+ u32 prod;
+ u32 cons;
+ u32 max_n_shift;
+};
+
struct arm_smmu_queue {
+ struct arm_smmu_ll_queue llq;
int irq; /* Wired interrupt */

__le64 *base;
@@ -480,9 +487,6 @@ 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;
@@ -681,19 +685,19 @@ static void parse_driver_options(struct arm_smmu_device *smmu)
/* Low-level queue manipulation functions */
static bool queue_full(struct arm_smmu_queue *q)
{
- return Q_IDX(q, q->prod) == Q_IDX(q, q->cons) &&
- Q_WRP(q, q->prod) != Q_WRP(q, q->cons);
+ return Q_IDX(q, q->llq.prod) == Q_IDX(q, q->llq.cons) &&
+ Q_WRP(q, q->llq.prod) != Q_WRP(q, q->llq.cons);
}

static bool queue_empty(struct arm_smmu_queue *q)
{
- return Q_IDX(q, q->prod) == Q_IDX(q, q->cons) &&
- Q_WRP(q, q->prod) == Q_WRP(q, q->cons);
+ return Q_IDX(q, q->llq.prod) == Q_IDX(q, q->llq.cons) &&
+ Q_WRP(q, q->llq.prod) == Q_WRP(q, q->llq.cons);
}

static void queue_sync_cons_in(struct arm_smmu_queue *q)
{
- q->cons = readl_relaxed(q->cons_reg);
+ q->llq.cons = readl_relaxed(q->cons_reg);
}

static void queue_sync_cons_out(struct arm_smmu_queue *q)
@@ -703,13 +707,13 @@ static void queue_sync_cons_out(struct arm_smmu_queue *q)
* 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_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);
+ u32 cons = (Q_WRP(q, q->llq.cons) | Q_IDX(q, q->llq.cons)) + 1;
+ q->llq.cons = Q_OVF(q->llq.cons) | Q_WRP(q, cons) | Q_IDX(q, cons);
}

static int queue_sync_prod_in(struct arm_smmu_queue *q)
@@ -717,22 +721,22 @@ static int queue_sync_prod_in(struct arm_smmu_queue *q)
int ret = 0;
u32 prod = readl_relaxed(q->prod_reg);

- if (Q_OVF(prod) != Q_OVF(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_sync_prod_out(struct arm_smmu_queue *q)
{
- writel(q->prod, q->prod_reg);
+ writel(q->llq.prod, q->prod_reg);
}

static void queue_inc_prod(struct arm_smmu_queue *q)
{
- u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + 1;
- q->prod = Q_OVF(q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod);
+ u32 prod = (Q_WRP(q, q->llq.prod) | Q_IDX(q, q->llq.prod)) + 1;
+ q->llq.prod = Q_OVF(q->llq.prod) | Q_WRP(q, prod) | Q_IDX(q, prod);
}

/*
@@ -781,7 +785,7 @@ 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_write(Q_ENT(q, q->llq.prod), ent, q->ent_dwords);
queue_inc_prod(q);
queue_sync_prod_out(q);
return 0;
@@ -800,7 +804,7 @@ static int queue_remove_raw(struct arm_smmu_queue *q, u64 *ent)
if (queue_empty(q))
return -EAGAIN;

- queue_read(ent, Q_ENT(q, q->cons), q->ent_dwords);
+ queue_read(ent, Q_ENT(q, q->llq.cons), q->ent_dwords);
queue_inc_cons(q);
queue_sync_cons_out(q);
return 0;
@@ -1328,7 +1332,8 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev)
} while (!queue_empty(q));

/* Sync our overflow flag, as we believe we're up to speed */
- q->cons = Q_OVF(q->prod) | Q_WRP(q, q->cons) | Q_IDX(q, q->cons);
+ q->llq.cons = Q_OVF(q->llq.prod) | Q_WRP(q, q->llq.cons) |
+ Q_IDX(q, q->llq.cons);
return IRQ_HANDLED;
}

@@ -1385,8 +1390,9 @@ static irqreturn_t arm_smmu_priq_thread(int irq, void *dev)
} while (!queue_empty(q));

/* Sync our overflow flag, as we believe we're up to speed */
- q->cons = Q_OVF(q->prod) | Q_WRP(q, q->cons) | Q_IDX(q, q->cons);
- writel(q->cons, q->cons_reg);
+ q->llq.cons = Q_OVF(q->llq.prod) | Q_WRP(q, q->llq.cons) |
+ Q_IDX(q, q->llq.cons);
+ writel(q->llq.cons, q->cons_reg);
return IRQ_HANDLED;
}

@@ -2287,13 +2293,13 @@ static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
size_t qsz;

do {
- qsz = ((1 << q->max_n_shift) * dwords) << 3;
+ qsz = ((1 << q->llq.max_n_shift) * dwords) << 3;
q->base = dmam_alloc_coherent(smmu->dev, qsz, &q->base_dma,
GFP_KERNEL);
if (q->base || qsz < PAGE_SIZE)
break;

- q->max_n_shift--;
+ q->llq.max_n_shift--;
} while (1);

if (!q->base) {
@@ -2305,7 +2311,7 @@ static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,

if (!WARN_ON(q->base_dma & (qsz - 1))) {
dev_info(smmu->dev, "allocated %u entries for %s\n",
- 1 << q->max_n_shift, name);
+ 1 << q->llq.max_n_shift, name);
}

q->prod_reg = arm_smmu_page1_fixup(prod_off, smmu);
@@ -2314,9 +2320,9 @@ static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,

q->q_base = Q_BASE_RWA;
q->q_base |= q->base_dma & Q_BASE_ADDR_MASK;
- q->q_base |= FIELD_PREP(Q_BASE_LOG2SIZE, q->max_n_shift);
+ q->q_base |= FIELD_PREP(Q_BASE_LOG2SIZE, q->llq.max_n_shift);

- q->prod = q->cons = 0;
+ q->llq.prod = q->llq.cons = 0;
return 0;
}

@@ -2709,8 +2715,8 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)

/* Command queue */
writeq_relaxed(smmu->cmdq.q.q_base, smmu->base + ARM_SMMU_CMDQ_BASE);
- writel_relaxed(smmu->cmdq.q.prod, smmu->base + ARM_SMMU_CMDQ_PROD);
- writel_relaxed(smmu->cmdq.q.cons, smmu->base + ARM_SMMU_CMDQ_CONS);
+ writel_relaxed(smmu->cmdq.q.llq.prod, smmu->base + ARM_SMMU_CMDQ_PROD);
+ writel_relaxed(smmu->cmdq.q.llq.cons, smmu->base + ARM_SMMU_CMDQ_CONS);

enables = CR0_CMDQEN;
ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
@@ -2737,9 +2743,9 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)

/* Event queue */
writeq_relaxed(smmu->evtq.q.q_base, smmu->base + ARM_SMMU_EVTQ_BASE);
- writel_relaxed(smmu->evtq.q.prod,
+ writel_relaxed(smmu->evtq.q.llq.prod,
arm_smmu_page1_fixup(ARM_SMMU_EVTQ_PROD, smmu));
- writel_relaxed(smmu->evtq.q.cons,
+ writel_relaxed(smmu->evtq.q.llq.cons,
arm_smmu_page1_fixup(ARM_SMMU_EVTQ_CONS, smmu));

enables |= CR0_EVTQEN;
@@ -2754,9 +2760,9 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
if (smmu->features & ARM_SMMU_FEAT_PRI) {
writeq_relaxed(smmu->priq.q.q_base,
smmu->base + ARM_SMMU_PRIQ_BASE);
- writel_relaxed(smmu->priq.q.prod,
+ writel_relaxed(smmu->priq.q.llq.prod,
arm_smmu_page1_fixup(ARM_SMMU_PRIQ_PROD, smmu));
- writel_relaxed(smmu->priq.q.cons,
+ writel_relaxed(smmu->priq.q.llq.cons,
arm_smmu_page1_fixup(ARM_SMMU_PRIQ_CONS, smmu));

enables |= CR0_PRIQEN;
@@ -2910,18 +2916,18 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
}

/* Queue sizes, capped to ensure natural alignment */
- smmu->cmdq.q.max_n_shift = min_t(u32, CMDQ_MAX_SZ_SHIFT,
- FIELD_GET(IDR1_CMDQS, reg));
- if (!smmu->cmdq.q.max_n_shift) {
+ smmu->cmdq.q.llq.max_n_shift = min_t(u32, CMDQ_MAX_SZ_SHIFT,
+ FIELD_GET(IDR1_CMDQS, reg));
+ if (!smmu->cmdq.q.llq.max_n_shift) {
/* Odd alignment restrictions on the base, so ignore for now */
dev_err(smmu->dev, "unit-length command queue not supported\n");
return -ENXIO;
}

- smmu->evtq.q.max_n_shift = min_t(u32, EVTQ_MAX_SZ_SHIFT,
- FIELD_GET(IDR1_EVTQS, reg));
- smmu->priq.q.max_n_shift = min_t(u32, PRIQ_MAX_SZ_SHIFT,
- FIELD_GET(IDR1_PRIQS, reg));
+ smmu->evtq.q.llq.max_n_shift = min_t(u32, EVTQ_MAX_SZ_SHIFT,
+ FIELD_GET(IDR1_EVTQS, reg));
+ smmu->priq.q.llq.max_n_shift = min_t(u32, PRIQ_MAX_SZ_SHIFT,
+ FIELD_GET(IDR1_PRIQS, reg));

/* SID/SSID sizes */
smmu->ssid_bits = FIELD_GET(IDR1_SSIDSIZE, reg);