[PATCH v3] arm64: SMMU-v2: Workaround for Cavium ThunderX erratum 28168
Geetha sowjanya
gakula at caviumnetworks.com
Tue Dec 20 03:06:33 PST 2016
From: Tirumalesh Chalamarla <tchalamarla at caviumnetworks.com>
This patch implements Cavium ThunderX erratum 28168.
PCI requires stores complete in order. Due to erratum #28168
PCI-inbound MSI-X store to the interrupt controller are delivered
to the interrupt controller before older PCI-inbound memory stores
are committed.
Doing a sync on SMMU will make sure all prior data transfers are
completed before invoking ISR.
changes from v2:
- added entry in Documentation/arm64/silicon-errata.txt
- moved registration of the preflow_handler into
msi_domain_ops.msi_finish() handler.
- create linux/arm.smmu.h to expose smmu API.
Signed-off-by: Tirumalesh Chalamarla <Tirumalesh.Chalamarla at cavium.com>
---
Documentation/arm64/silicon-errata.txt | 1 +
arch/arm64/Kconfig | 12 ++++++++
arch/arm64/include/asm/cpucaps.h | 3 +-
arch/arm64/kernel/cpu_errata.c | 16 +++++++++++
drivers/iommu/arm-smmu.c | 22 +++++++++++++++
drivers/irqchip/irq-gic-v3-its-pci-msi.c | 48 +++++++++++++++++++++++++++++++-
include/linux/arm-smmu.h | 8 ++++++
7 files changed, 108 insertions(+), 2 deletions(-)
create mode 100644 include/linux/arm-smmu.h
diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index 405da11..1311f90 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -61,5 +61,6 @@ stable kernels.
| Cavium | ThunderX GICv3 | #23154 | CAVIUM_ERRATUM_23154 |
| Cavium | ThunderX Core | #27456 | CAVIUM_ERRATUM_27456 |
| Cavium | ThunderX SMMUv2 | #27704 | N/A |
+| Cavium | ThunderX PCI | #28168 | CAVIUM_ERRATUM_28168 |
| | | | |
| Freescale/NXP | LS2080A/LS1043A | A-008585 | FSL_ERRATUM_A008585 |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 969ef88..cb647f4 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -474,6 +474,18 @@ config CAVIUM_ERRATUM_27456
If unsure, say Y.
+config CAVIUM_ERRATUM_28168
+ bool "Cavium erratum 28168: Make sure DMA data transfer is done before MSIX"
+ depends on ARM64 && ARM_SMMU
+ default y
+ select IRQ_PREFLOW_FASTEOI
+ help
+ Due to erratum #28168 PCI-inbound MSI-X store to the interrupt
+ controller are delivered to the interrupt controller before older
+ PCI-inbound memory stores are committed. Doing a sync on SMMU
+ will make sure all prior data transfers are done before invoking ISR.
+
+ If unsure, say Y.
endmenu
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 87b4465..6975a01 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -34,7 +34,8 @@
#define ARM64_HAS_32BIT_EL0 13
#define ARM64_HYP_OFFSET_LOW 14
#define ARM64_MISMATCHED_CACHE_LINE_SIZE 15
+#define ARM64_WORKAROUND_CAVIUM_28168 16
-#define ARM64_NCAPS 16
+#define ARM64_NCAPS 17
#endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index b75e917..fac6d74 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -123,6 +123,22 @@ static int cpu_enable_trap_ctr_access(void *__unused)
MIDR_RANGE(MIDR_THUNDERX_81XX, 0x00, 0x00),
},
#endif
+#ifdef CONFIG_CAVIUM_ERRATUM_28168
+ {
+ /* Cavium ThunderX, T88 pass 1.x - 2.1 */
+ .desc = "Cavium erratum 28168",
+ .capability = ARM64_WORKAROUND_CAVIUM_28168,
+ MIDR_RANGE(MIDR_THUNDERX, 0x00,
+ (1 << MIDR_VARIANT_SHIFT) | 1),
+ },
+ {
+ /* Cavium ThunderX, T81 pass 1.0 */
+ .desc = "Cavium erratum 28168",
+ .capability = ARM64_WORKAROUND_CAVIUM_28168,
+ MIDR_RANGE(MIDR_THUNDERX_81XX, 0x00, 0x00),
+ },
+#endif
+
{
.desc = "Mismatched cache line size",
.capability = ARM64_MISMATCHED_CACHE_LINE_SIZE,
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 06167da..451b393 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -49,6 +49,8 @@
#include <linux/spinlock.h>
#include <linux/amba/bus.h>
+#include <linux/arm-smmu.h>
+
#include "io-pgtable.h"
@@ -577,6 +579,26 @@ static void __arm_smmu_tlb_sync(struct arm_smmu_device *smmu)
}
}
+#ifdef CONFIG_CAVIUM_ERRATUM_28168
+/*
+ * Cavium ThunderX erratum 28168
+ *
+ * Due to erratum #28168 PCI-inbound MSI-X store to the interrupt
+ * controller are delivered to the interrupt controller before older
+ * PCI-inbound memory stores are committed. Doing a sync on SMMU
+ * will make sure all prior data transfers are completed before
+ * invoking ISR.
+ *
+ */
+void dev_smmu_tlb_sync(struct device *dev)
+{
+ struct iommu_fwspec *fwspec = dev->iommu_fwspec;
+ struct arm_smmu_device *smmu = fwspec_smmu(fwspec);
+
+ if (smmu)
+ __arm_smmu_tlb_sync(smmu);
+}
+#endif
static void arm_smmu_tlb_sync(void *cookie)
{
struct arm_smmu_domain *smmu_domain = cookie;
diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index aee1c60..36ce696 100644
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -20,6 +20,7 @@
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
+#include <linux/arm-smmu.h>
static void its_mask_msi_irq(struct irq_data *d)
{
@@ -86,11 +87,53 @@ static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
/* ITS specific DeviceID, as the core ITS ignores dev. */
info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);
-
+ info->scratchpad[1].ptr = &pdev->dev;
return msi_info->ops->msi_prepare(domain->parent,
dev, dev_alias.count, info);
}
+#ifdef CONFIG_CAVIUM_ERRATUM_28168
+#define THUNDER_PME_DEVICE_ID 0xA100
+
+static void cavium_irq_preflow_handler(struct irq_data *data)
+{
+ struct pci_dev *pdev;
+
+ pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data));
+ dev_smmu_tlb_sync(&pdev->dev);
+}
+static void cavium_its_pci_msi_finish(msi_alloc_info_t *info, int ret)
+{
+ struct device *dev = info->scratchpad[1].ptr;
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct device *parent_dev;
+ struct msi_desc *desc;
+
+ if (ret)
+ return;
+
+ if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) {
+ for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
+ pdev = to_pci_dev(parent_dev);
+ if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT)
+ continue;
+
+ if (pdev->device == THUNDER_PME_DEVICE_ID)
+ for_each_pci_msi_entry(desc, to_pci_dev(dev))
+ __irq_set_preflow_handler(desc->irq, cavium_irq_preflow_handler);
+ break;
+ }
+ }
+}
+#else
+static void cavium_irq_preflow_handler(struct irq_data *data)
+{
+}
+static void cavium_its_pci_msi_finish(msi_alloc_info_t *info, int ret)
+{
+}
+#endif
+
static struct msi_domain_ops its_pci_msi_ops = {
.msi_prepare = its_pci_msi_prepare,
};
@@ -118,6 +161,9 @@ static int __init its_pci_msi_init_one(struct fwnode_handle *handle,
return -ENXIO;
}
+ if (cpus_have_cap(ARM64_WORKAROUND_CAVIUM_28168))
+ its_pci_msi_ops.msi_finish = cavium_its_pci_msi_finish;
+
if (!pci_msi_create_irq_domain(handle, &its_pci_msi_domain_info,
parent)) {
pr_err("%s: Unable to create PCI domain\n", name);
diff --git a/include/linux/arm-smmu.h b/include/linux/arm-smmu.h
new file mode 100644
index 0000000..d3f5dff
--- /dev/null
+++ b/include/linux/arm-smmu.h
@@ -0,0 +1,8 @@
+#ifndef _ARM_SMMU_H
+#define _ARM_SMMU_H
+
+#include<linux/pci.h>
+
+extern void dev_smmu_tlb_sync(struct device *dev);
+
+#endif /* _ARM_SMMU_H */
--
1.9.1
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