Hi Robin,
Echoing what we do for Stream Map Entries, maintain a software shadow
state for context bank configuration. With this in place, we are mere
moments away from blissfully easy suspend/resume support.
---
Since the runtime PM discussion has come back again, I figured it was
probably about time to finish off my plan for system PM. Lightly tested
on Juno (MMU-401) with hibernation.
Robin.
drivers/iommu/arm-smmu.c | 159 +++++++++++++++++++++++++++++------------------
1 file changed, 97 insertions(+), 62 deletions(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index bc89b4d6c043..86897b7b81d8 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -338,6 +338,13 @@ struct arm_smmu_smr {
bool valid;
};
+struct arm_smmu_cb {
+ u64 ttbr[2];
+ u32 tcr[2];
+ u32 mair[2];
+ struct arm_smmu_cfg *cfg;
+};
+
When i was trying this sometime back [1], was
saving and using the pgtbl->cfg and domain->cfg for
restoring the context. But this looks correct to make
a actual shadow once and use it later all the time.
Will also try some testing today.
Reviewed-by: ***@codeaurora.org
[1] https://patchwork.kernel.org/patch/9389717/
Regards,
Sricharan
struct arm_smmu_master_cfg {
struct arm_smmu_device *smmu;
s16 smendx[];
@@ -380,6 +387,7 @@ struct arm_smmu_device {
u32 num_context_banks;
u32 num_s2_context_banks;
DECLARE_BITMAP(context_map, ARM_SMMU_MAX_CBS);
+ struct arm_smmu_cb *cbs;
atomic_t irptndx;
u32 num_mapping_groups;
@@ -768,17 +776,69 @@ static irqreturn_t arm_smmu_global_fault(int irq, void *dev)
static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
struct io_pgtable_cfg *pgtbl_cfg)
{
- u32 reg, reg2;
- u64 reg64;
- bool stage1;
struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
- struct arm_smmu_device *smmu = smmu_domain->smmu;
+ struct arm_smmu_cb *cb = &smmu_domain->smmu->cbs[cfg->cbndx];
+ bool stage1 = cfg->cbar != CBAR_TYPE_S2_TRANS;
+
+ cb->cfg = cfg;
+
+ /* TTBCR */
+ if (stage1) {
+ if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_S) {
+ cb->tcr[0] = pgtbl_cfg->arm_v7s_cfg.tcr;
+ } else {
+ cb->tcr[0] = pgtbl_cfg->arm_lpae_s1_cfg.tcr;
+ cb->tcr[1] = pgtbl_cfg->arm_lpae_s1_cfg.tcr >> 32;
+ cb->tcr[1] |= TTBCR2_SEP_UPSTREAM;
+ if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH64)
+ cb->tcr[1] |= TTBCR2_AS;
+ }
+ } else {
+ cb->tcr[0] = pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
+ }
+
+ /* TTBRs */
+ if (stage1) {
+ if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_S) {
+ cb->ttbr[0] = pgtbl_cfg->arm_v7s_cfg.ttbr[0];
+ cb->ttbr[1] = pgtbl_cfg->arm_v7s_cfg.ttbr[1];
+ } else {
+ cb->ttbr[0] = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0];
+ cb->ttbr[1] = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[1];
+ }
+ } else {
+ cb->ttbr[0] = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
+ }
+
+ /* MAIRs (stage-1 only) */
+ if (stage1) {
+ if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_S) {
+ cb->mair[0] = pgtbl_cfg->arm_v7s_cfg.prrr;
+ cb->mair[1] = pgtbl_cfg->arm_v7s_cfg.nmrr;
+ } else {
+ cb->mair[0] = pgtbl_cfg->arm_lpae_s1_cfg.mair[0];
+ cb->mair[1] = pgtbl_cfg->arm_lpae_s1_cfg.mair[1];
+ }
+ }
+}
+
+static void arm_smmu_write_context_bank(struct arm_smmu_device *smmu, int idx)
+{
+ u32 reg;
+ bool stage1;
+ struct arm_smmu_cb *cb = &smmu->cbs[idx];
+ struct arm_smmu_cfg *cfg = cb->cfg;
+ struct arm_smmu_cfg default_cfg = {0};
void __iomem *cb_base, *gr1_base;
+ if (!cfg)
+ cfg = &default_cfg;
+
gr1_base = ARM_SMMU_GR1(smmu);
stage1 = cfg->cbar != CBAR_TYPE_S2_TRANS;
- cb_base = ARM_SMMU_CB(smmu, cfg->cbndx);
+ cb_base = ARM_SMMU_CB(smmu, idx);
+ /* CBA2R */
if (smmu->version > ARM_SMMU_V1) {
if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH64)
reg = CBA2R_RW64_64BIT;
@@ -788,7 +848,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
if (smmu->features & ARM_SMMU_FEAT_VMID16)
reg |= cfg->vmid << CBA2R_VMID_SHIFT;
- writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBA2R(cfg->cbndx));
+ writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBA2R(idx));
}
/* CBAR */
@@ -807,72 +867,43 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
/* 8-bit VMIDs live in CBAR */
reg |= cfg->vmid << CBAR_VMID_SHIFT;
}
- writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBAR(cfg->cbndx));
+ writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBAR(idx));
/*
* TTBCR
* We must write this before the TTBRs, since it determines the
* access behaviour of some fields (in particular, ASID[15:8]).
*/
- if (stage1) {
- if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_S) {
- reg = pgtbl_cfg->arm_v7s_cfg.tcr;
- reg2 = 0;
- } else {
- reg = pgtbl_cfg->arm_lpae_s1_cfg.tcr;
- reg2 = pgtbl_cfg->arm_lpae_s1_cfg.tcr >> 32;
- reg2 |= TTBCR2_SEP_UPSTREAM;
- if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH64)
- reg2 |= TTBCR2_AS;
- }
- if (smmu->version > ARM_SMMU_V1)
- writel_relaxed(reg2, cb_base + ARM_SMMU_CB_TTBCR2);
- } else {
- reg = pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
- }
- writel_relaxed(reg, cb_base + ARM_SMMU_CB_TTBCR);
+ if (stage1 && smmu->version > ARM_SMMU_V1)
+ writel_relaxed(cb->tcr[1], cb_base + ARM_SMMU_CB_TTBCR2);
+ writel_relaxed(cb->tcr[0], cb_base + ARM_SMMU_CB_TTBCR);
/* TTBRs */
- if (stage1) {
- if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_S) {
- reg = pgtbl_cfg->arm_v7s_cfg.ttbr[0];
- writel_relaxed(reg, cb_base + ARM_SMMU_CB_TTBR0);
- reg = pgtbl_cfg->arm_v7s_cfg.ttbr[1];
- writel_relaxed(reg, cb_base + ARM_SMMU_CB_TTBR1);
- writel_relaxed(cfg->asid, cb_base + ARM_SMMU_CB_CONTEXTIDR);
- } else {
- reg64 = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0];
- reg64 |= (u64)cfg->asid << TTBRn_ASID_SHIFT;
- writeq_relaxed(reg64, cb_base + ARM_SMMU_CB_TTBR0);
- reg64 = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[1];
- reg64 |= (u64)cfg->asid << TTBRn_ASID_SHIFT;
- writeq_relaxed(reg64, cb_base + ARM_SMMU_CB_TTBR1);
- }
+ if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_S) {
+ writel_relaxed(cfg->asid, cb_base + ARM_SMMU_CB_CONTEXTIDR);
+ writel_relaxed(cb->ttbr[0], cb_base + ARM_SMMU_CB_TTBR0);
+ writel_relaxed(cb->ttbr[1], cb_base + ARM_SMMU_CB_TTBR1);
} else {
- reg64 = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
- writeq_relaxed(reg64, cb_base + ARM_SMMU_CB_TTBR0);
+ writeq_relaxed(cb->ttbr[0], cb_base + ARM_SMMU_CB_TTBR0);
+ writeq_relaxed(cb->ttbr[1], cb_base + ARM_SMMU_CB_TTBR1);
}
/* MAIRs (stage-1 only) */
if (stage1) {
- if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_S) {
- reg = pgtbl_cfg->arm_v7s_cfg.prrr;
- reg2 = pgtbl_cfg->arm_v7s_cfg.nmrr;
- } else {
- reg = pgtbl_cfg->arm_lpae_s1_cfg.mair[0];
- reg2 = pgtbl_cfg->arm_lpae_s1_cfg.mair[1];
- }
- writel_relaxed(reg, cb_base + ARM_SMMU_CB_S1_MAIR0);
- writel_relaxed(reg2, cb_base + ARM_SMMU_CB_S1_MAIR1);
+ writel_relaxed(cb->mair[0], cb_base + ARM_SMMU_CB_S1_MAIR0);
+ writel_relaxed(cb->mair[1], cb_base + ARM_SMMU_CB_S1_MAIR1);
}
/* SCTLR */
- reg = SCTLR_CFIE | SCTLR_CFRE | SCTLR_AFE | SCTLR_TRE | SCTLR_M;
- if (stage1)
- reg |= SCTLR_S1_ASIDPNE;
-#ifdef __BIG_ENDIAN
- reg |= SCTLR_E;
-#endif
+ if (!cb->cfg) {
+ reg = 0;
+ } else {
+ reg = SCTLR_CFIE | SCTLR_CFRE | SCTLR_AFE | SCTLR_TRE | SCTLR_M;
+ if (stage1)
+ reg |= SCTLR_S1_ASIDPNE;
+ if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+ reg |= SCTLR_E;
+ }
writel_relaxed(reg, cb_base + ARM_SMMU_CB_SCTLR);
}
@@ -1035,6 +1066,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
/* Initialise the context bank with our page table cfg */
arm_smmu_init_context_bank(smmu_domain, &pgtbl_cfg);
+ arm_smmu_write_context_bank(smmu, cfg->cbndx);
/*
* Request context fault interrupt. Do this last to avoid the
@@ -1067,7 +1099,6 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
struct arm_smmu_device *smmu = smmu_domain->smmu;
struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
- void __iomem *cb_base;
int irq;
if (!smmu || domain->type == IOMMU_DOMAIN_IDENTITY)
@@ -1077,8 +1108,8 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
* Disable the context bank and free the page tables before freeing
* it.
*/
- cb_base = ARM_SMMU_CB(smmu, cfg->cbndx);
- writel_relaxed(0, cb_base + ARM_SMMU_CB_SCTLR);
+ smmu->cbs[cfg->cbndx] = (struct arm_smmu_cb){0};
+ arm_smmu_write_context_bank(smmu, cfg->cbndx);
if (cfg->irptndx != INVALID_IRPTNDX) {
irq = smmu->irqs[smmu->num_global_irqs + cfg->irptndx];
@@ -1722,7 +1753,6 @@ static struct iommu_ops arm_smmu_ops = {
static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
{
void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
- void __iomem *cb_base;
int i;
u32 reg, major;
@@ -1758,8 +1788,9 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
/* Make sure all context banks are disabled and clear CB_FSR */
for (i = 0; i < smmu->num_context_banks; ++i) {
- cb_base = ARM_SMMU_CB(smmu, i);
- writel_relaxed(0, cb_base + ARM_SMMU_CB_SCTLR);
+ void __iomem *cb_base = ARM_SMMU_CB(smmu, i);
+
+ arm_smmu_write_context_bank(smmu, i);
writel_relaxed(FSR_FAULT, cb_base + ARM_SMMU_CB_FSR);
/*
* Disable MMU-500's not-particularly-beneficial next-page
@@ -1964,6 +1995,10 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
smmu->cavium_id_base -= smmu->num_context_banks;
dev_notice(smmu->dev, "\tenabling workaround for Cavium erratum 27704\n");
}
+ smmu->cbs = devm_kcalloc(smmu->dev, smmu->num_context_banks,
+ sizeof(*smmu->cbs), GFP_KERNEL);
+ if (!smmu->cbs)
+ return -ENOMEM;
/* ID2 */
id = readl_relaxed(gr0_base + ARM_SMMU_GR0_ID2);
--
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