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iommu/arm-smmu-v3: Don't reserve implementation defined register space

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Some SMMUv3 implementation embed the Perf Monitor Group Registers (PMCG)
inside the first 64kB region of the SMMU. Since PMCG are managed by a
separate driver, this layout causes resource reservation conflicts
during boot.

To avoid this conflict, don't reserve the MMIO regions that are
implementation defined. Although devm_ioremap_resource() still works on
full pages under the hood, this way we benefit from resource conflict
checks.

Fixes: 7d839b4b9e ("perf/smmuv3: Add arm64 smmuv3 pmu driver")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200513110255.597203-1-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Jean-Philippe Brucker 2020-05-13 13:02:57 +02:00 committed by Will Deacon
parent d100ff3843
commit 52f3fab006
1 changed files with 31 additions and 4 deletions
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35
drivers/iommu/arm-smmu-v3.c
View file

@ -171,6 +171,8 @@
#define ARM_SMMU_PRIQ_IRQ_CFG1 0xd8
#define ARM_SMMU_PRIQ_IRQ_CFG2 0xdc
#define ARM_SMMU_REG_SZ 0xe00
/* Common MSI config fields */
#define MSI_CFG0_ADDR_MASK GENMASK_ULL(51, 2)
#define MSI_CFG2_SH GENMASK(5, 4)
@ -628,6 +630,7 @@ struct arm_smmu_strtab_cfg {
struct arm_smmu_device {
struct device *dev;
void __iomem *base;
void __iomem *page1;
#define ARM_SMMU_FEAT_2_LVL_STRTAB (1 << 0)
#define ARM_SMMU_FEAT_2_LVL_CDTAB (1 << 1)
@ -733,9 +736,8 @@ static struct arm_smmu_option_prop arm_smmu_options[] = {
static inline void __iomem *arm_smmu_page1_fixup(unsigned long offset,
struct arm_smmu_device *smmu)
{
if ((offset > SZ_64K) &&
(smmu->options & ARM_SMMU_OPT_PAGE0_REGS_ONLY))
offset -= SZ_64K;
if (offset > SZ_64K)
return smmu->page1 + offset - SZ_64K;
return smmu->base + offset;
}
@ -4001,6 +4003,18 @@ err_reset_pci_ops: __maybe_unused;
return err;
}
static void __iomem *arm_smmu_ioremap(struct device *dev, resource_size_t start,
resource_size_t size)
{
struct resource res = {
.flags = IORESOURCE_MEM,
.start = start,
.end = start + size - 1,
};
return devm_ioremap_resource(dev, &res);
}
static int arm_smmu_device_probe(struct platform_device *pdev)
{
int irq, ret;
@ -4036,10 +4050,23 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
}
ioaddr = res->start;
smmu->base = devm_ioremap_resource(dev, res);
/*
* Don't map the IMPLEMENTATION DEFINED regions, since they may contain
* the PMCG registers which are reserved by the PMU driver.
*/
smmu->base = arm_smmu_ioremap(dev, ioaddr, ARM_SMMU_REG_SZ);
if (IS_ERR(smmu->base))
return PTR_ERR(smmu->base);
if (arm_smmu_resource_size(smmu) > SZ_64K) {
smmu->page1 = arm_smmu_ioremap(dev, ioaddr + SZ_64K,
ARM_SMMU_REG_SZ);
if (IS_ERR(smmu->page1))
return PTR_ERR(smmu->page1);
} else {
smmu->page1 = smmu->base;
}
/* Interrupt lines */
irq = platform_get_irq_byname_optional(pdev, "combined");