From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Joerg Roedel <joro@8bytes.org>,
Thierry Reding <thierry.reding@gmail.com>,
Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: linux-arm-kernel@lists.infradead.org,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
Jonathan Marek <jonathan@marek.ca>,
linux-arm-msm@vger.kernel.org,
John Stultz <john.stultz@linaro.org>,
Vinod Koul <vkoul@kernel.org>
Subject: [PATCH v2 5/5] iommu/arm-smmu: Setup identity domain for boot mappings
Date: Thu, 16 Jul 2020 17:16:19 -0700 [thread overview]
Message-ID: <20200717001619.325317-6-bjorn.andersson@linaro.org> (raw)
In-Reply-To: <20200717001619.325317-1-bjorn.andersson@linaro.org>
With many Qualcomm platforms not having functional S2CR BYPASS a
temporary IOMMU domain, without translation, needs to be allocated in
order to allow these memory transactions.
Unfortunately the boot loader uses the first few context banks, so
rather than overwriting a active bank the last context bank is used and
streams are diverted here during initialization.
This also performs the readback of SMR registers for the Qualcomm
platform, to trigger the mechanism.
This is based on prior work by Thierry Reding and Laurentiu Tudor.
Tested-by: John Stultz <john.stultz@linaro.org>
Tested-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
Changes since v1:
- Rebased to avoid conflict
- Picked up tested-by
drivers/iommu/arm-smmu-qcom.c | 11 +++++
drivers/iommu/arm-smmu.c | 79 +++++++++++++++++++++++++++++++++--
drivers/iommu/arm-smmu.h | 3 ++
3 files changed, 89 insertions(+), 4 deletions(-)
diff --git a/drivers/iommu/arm-smmu-qcom.c b/drivers/iommu/arm-smmu-qcom.c
index 10eb024981d1..147af11049eb 100644
--- a/drivers/iommu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm-smmu-qcom.c
@@ -26,6 +26,7 @@ static const struct of_device_id qcom_smmu_client_of_match[] __maybe_unused = {
static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu)
{
unsigned int last_s2cr = ARM_SMMU_GR0_S2CR(smmu->num_mapping_groups - 1);
+ u32 smr;
u32 reg;
int i;
@@ -56,6 +57,16 @@ static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu)
}
}
+ for (i = 0; i < smmu->num_mapping_groups; i++) {
+ smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(i));
+
+ if (FIELD_GET(ARM_SMMU_SMR_VALID, smr)) {
+ smmu->smrs[i].id = FIELD_GET(ARM_SMMU_SMR_ID, smr);
+ smmu->smrs[i].mask = FIELD_GET(ARM_SMMU_SMR_MASK, smr);
+ smmu->smrs[i].valid = true;
+ }
+ }
+
return 0;
}
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 08a650fe02e3..69bd8ee03516 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -652,7 +652,8 @@ static void arm_smmu_write_context_bank(struct arm_smmu_device *smmu, int idx)
}
static int arm_smmu_init_domain_context(struct iommu_domain *domain,
- struct arm_smmu_device *smmu)
+ struct arm_smmu_device *smmu,
+ bool boot_domain)
{
int irq, start, ret = 0;
unsigned long ias, oas;
@@ -770,6 +771,15 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
ret = -EINVAL;
goto out_unlock;
}
+
+ /*
+ * Use the last context bank for identity mappings during boot, to
+ * avoid overwriting in-use bank configuration while we're setting up
+ * the new mappings.
+ */
+ if (boot_domain)
+ start = smmu->num_context_banks - 1;
+
ret = __arm_smmu_alloc_bitmap(smmu->context_map, start,
smmu->num_context_banks);
if (ret < 0)
@@ -1149,7 +1159,10 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct arm_smmu_master_cfg *cfg;
struct arm_smmu_device *smmu;
+ bool free_identity_domain = false;
+ int idx;
int ret;
+ int i;
if (!fwspec || fwspec->ops != &arm_smmu_ops) {
dev_err(dev, "cannot attach to SMMU, is it on the same bus?\n");
@@ -1174,7 +1187,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
return ret;
/* Ensure that the domain is finalised */
- ret = arm_smmu_init_domain_context(domain, smmu);
+ ret = arm_smmu_init_domain_context(domain, smmu, false);
if (ret < 0)
goto rpm_put;
@@ -1190,9 +1203,33 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
goto rpm_put;
}
+ /* Decrement use counter for any references to the identity domain */
+ mutex_lock(&smmu->stream_map_mutex);
+ if (smmu->identity) {
+ struct arm_smmu_domain *identity = to_smmu_domain(smmu->identity);
+
+ for_each_cfg_sme(cfg, fwspec, i, idx) {
+ if (smmu->s2crs[idx].cbndx == identity->cfg.cbndx) {
+ smmu->num_identity_masters--;
+ if (smmu->num_identity_masters == 0)
+ free_identity_domain = true;
+ }
+ }
+ }
+ mutex_unlock(&smmu->stream_map_mutex);
+
/* Looks ok, so add the device to the domain */
ret = arm_smmu_domain_add_master(smmu_domain, cfg, fwspec);
+ /*
+ * The last stream map to reference the identity domain has been
+ * overwritten, so it's now okay to free it.
+ */
+ if (free_identity_domain) {
+ arm_smmu_domain_free(smmu->identity);
+ smmu->identity = NULL;
+ }
+
/*
* Setup an autosuspend delay to avoid bouncing runpm state.
* Otherwise, if a driver for a suspended consumer device
@@ -1922,17 +1959,51 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
static int arm_smmu_setup_identity(struct arm_smmu_device *smmu)
{
+ struct device *dev = smmu->dev;
+ int cbndx = 0xff;
+ int type = S2CR_TYPE_BYPASS;
+ int ret;
int i;
+ if (smmu->qcom_bypass_quirk) {
+ /* Create a IDENTITY domain to use for all inherited streams */
+ smmu->identity = arm_smmu_domain_alloc(IOMMU_DOMAIN_IDENTITY);
+ if (!smmu->identity) {
+ dev_err(dev, "failed to create identity domain\n");
+ return -ENOMEM;
+ }
+
+ smmu->identity->pgsize_bitmap = smmu->pgsize_bitmap;
+ smmu->identity->type = IOMMU_DOMAIN_IDENTITY;
+ smmu->identity->ops = &arm_smmu_ops;
+
+ ret = arm_smmu_init_domain_context(smmu->identity, smmu, true);
+ if (ret < 0) {
+ dev_err(dev, "failed to initialize identity domain: %d\n", ret);
+ return ret;
+ }
+
+ type = S2CR_TYPE_TRANS;
+ cbndx = to_smmu_domain(smmu->identity)->cfg.cbndx;
+ }
+
for (i = 0; i < smmu->num_mapping_groups; i++) {
if (smmu->smrs[i].valid) {
- smmu->s2crs[i].type = S2CR_TYPE_BYPASS;
+ smmu->s2crs[i].type = type;
smmu->s2crs[i].privcfg = S2CR_PRIVCFG_DEFAULT;
- smmu->s2crs[i].cbndx = 0xff;
+ smmu->s2crs[i].cbndx = cbndx;
smmu->s2crs[i].count++;
+
+ smmu->num_identity_masters++;
}
}
+ /* If no mappings where found, free the identiy domain again */
+ if (smmu->identity && !smmu->num_identity_masters) {
+ arm_smmu_domain_free(smmu->identity);
+ smmu->identity = NULL;
+ }
+
return 0;
}
diff --git a/drivers/iommu/arm-smmu.h b/drivers/iommu/arm-smmu.h
index bcd160d01c53..37257ede86fa 100644
--- a/drivers/iommu/arm-smmu.h
+++ b/drivers/iommu/arm-smmu.h
@@ -321,6 +321,9 @@ struct arm_smmu_device {
/* IOMMU core code handle */
struct iommu_device iommu;
+ struct iommu_domain *identity;
+ unsigned int num_identity_masters;
+
bool qcom_bypass_quirk;
};
--
2.26.2
next prev parent reply other threads:[~2020-07-17 0:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 0:16 [PATCH v2 0/5] iommu/arm-smmu: Support maintaining bootloader mappings Bjorn Andersson
2020-07-17 0:16 ` [PATCH v2 1/5] iommu/arm-smmu: Make all valid stream mappings BYPASS Bjorn Andersson
2020-07-17 0:16 ` [PATCH v2 2/5] iommu/arm-smmu: Emulate bypass by using context banks Bjorn Andersson
2020-07-20 8:58 ` Will Deacon
2020-07-20 15:51 ` Jordan Crouse
2020-07-17 0:16 ` [PATCH v2 3/5] iommu/arm-smmu: Move SMR and S2CR definitions to header file Bjorn Andersson
2020-07-17 0:16 ` [PATCH v2 4/5] iommu/arm-smmu-qcom: Consistently initialize stream mappings Bjorn Andersson
2020-07-17 0:16 ` Bjorn Andersson [this message]
2020-07-20 9:03 ` [PATCH v2 5/5] iommu/arm-smmu: Setup identity domain for boot mappings Will Deacon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200717001619.325317-6-bjorn.andersson@linaro.org \
--to=bjorn.andersson@linaro.org \
--cc=iommu@lists.linux-foundation.org \
--cc=john.stultz@linaro.org \
--cc=jonathan@marek.ca \
--cc=joro@8bytes.org \
--cc=laurentiu.tudor@nxp.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=robin.murphy@arm.com \
--cc=thierry.reding@gmail.com \
--cc=vkoul@kernel.org \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).