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<meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On May 6, 2020, at 10:46 AM, Jean-Philippe Brucker <<a href="mailto:jean-philippe@linaro.org" class="">jean-philippe@linaro.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">Some SMMUv3 implementation embed the Perf Monitor Group Registers (PMCG)<br class="">inside the first 64kB region of the SMMU. Since PMCG are managed by a<br class="">separate driver, this layout causes resource reservation conflicts<br class="">during boot.<br class=""><br class="">To avoid this conflict, only reserve the MMIO region we actually use:<br class="">the first 0xe0 bytes of page 0 and the first 0xd0 bytes of page 1.<br class="">Although devm_ioremap() still works on full pages under the hood, this<br class="">way we benefit from resource conflict checks.<br class=""><br class="">Signed-off-by: Jean-Philippe Brucker <<a href="mailto:jean-philippe@linaro.org" class="">jean-philippe@linaro.org</a>><br class="">---<br class="">A nicer (and hopefully working) solution to the problem dicussed here:<br class=""><a href="https://lore.kernel.org/linux-iommu/20200421155745.19815-1-jean-philippe@linaro.org/" class="">https://lore.kernel.org/linux-iommu/20200421155745.19815-1-jean-philippe@linaro.org/</a><br class="">---<br class=""> drivers/iommu/arm-smmu-v3.c | 50 +++++++++++++++++++++++++++++++++----<br class=""> 1 file changed, 45 insertions(+), 5 deletions(-)<br class=""><br class="">diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c<br class="">index 82508730feb7a1..fc85cdd5b62cca 100644<br class="">--- a/drivers/iommu/arm-smmu-v3.c<br class="">+++ b/drivers/iommu/arm-smmu-v3.c<br class="">@@ -171,6 +171,9 @@<br class=""> #define ARM_SMMU_PRIQ_IRQ_CFG1<span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>0xd8<br class=""> #define ARM_SMMU_PRIQ_IRQ_CFG2<span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>0xdc<br class=""><br class="">+#define ARM_SMMU_PAGE0_REG_SZ<span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>0xe0<br class="">+#define ARM_SMMU_PAGE1_REG_SZ<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre">    </span>0xd0<br class="">+<br class=""> /* Common MSI config fields */<br class=""> #define MSI_CFG0_ADDR_MASK<span class="Apple-tab-span" style="white-space:pre">  </span><span class="Apple-tab-span" style="white-space:pre">    </span>GENMASK_ULL(51, 2)<br class=""> #define MSI_CFG2_SH<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>GENMASK(5, 4)<br class="">@@ -628,6 +631,7 @@ struct arm_smmu_strtab_cfg {<br class=""> struct arm_smmu_device {<br class=""> <span class="Apple-tab-span" style="white-space:pre">  </span>struct device<span class="Apple-tab-span" style="white-space:pre">       </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>*dev;<br class=""> <span class="Apple-tab-span" style="white-space:pre"> </span>void __iomem<span class="Apple-tab-span" style="white-space:pre">        </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>*base;<br class="">+<span class="Apple-tab-span" style="white-space:pre">    </span>void __iomem<span class="Apple-tab-span" style="white-space:pre">        </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>*page1;<br class=""><br class=""> #define ARM_SMMU_FEAT_2_LVL_STRTAB<span class="Apple-tab-span" style="white-space:pre">        </span>(1 << 0)<br class=""> #define ARM_SMMU_FEAT_2_LVL_CDTAB<span class="Apple-tab-span" style="white-space:pre">       </span>(1 << 1)<br class="">@@ -733,11 +737,14 @@ static struct arm_smmu_option_prop arm_smmu_options[] = {<br class=""> static inline void __iomem *arm_smmu_page1_fixup(unsigned long offset,<br class=""> <span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span> struct arm_smmu_device *smmu)<br class=""> {<br class="">-<span class="Apple-tab-span" style="white-space:pre"> </span>if ((offset > SZ_64K) &&<br class="">-<span class="Apple-tab-span" style="white-space:pre">   </span>    (smmu->options & ARM_SMMU_OPT_PAGE0_REGS_ONLY))<br class="">-<span class="Apple-tab-span" style="white-space:pre">     </span><span class="Apple-tab-span" style="white-space:pre">    </span>offset -= SZ_64K;<br class="">+<span class="Apple-tab-span" style="white-space:pre"> </span>void __iomem *base = smmu->base;<br class=""><br class="">-<span class="Apple-tab-span" style="white-space:pre">      </span>return smmu->base + offset;<br class="">+<span class="Apple-tab-span" style="white-space:pre">        </span>if (offset > SZ_64K) {<br class="">+<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre">    </span>offset -= SZ_64K;<br class="">+<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre">    </span>if (smmu->page1)<br class="">+<span class="Apple-tab-span" style="white-space:pre">       </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>base = smmu->page1;<br class="">+<span class="Apple-tab-span" style="white-space:pre">    </span>}<br class="">+<span class="Apple-tab-span" style="white-space:pre"> </span>return base + offset;<br class=""> }<br class=""><br class=""> static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)<br class="">@@ -4021,6 +4028,28 @@ err_reset_pci_ops: __maybe_unused;<br class=""> <span class="Apple-tab-span" style="white-space:pre">  </span>return err;<br class=""> }<br class=""><br class="">+static void __iomem *arm_smmu_ioremap(struct device *dev,<br class="">+<span class="Apple-tab-span" style="white-space:pre">        </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>      resource_size_t start,<br class="">+<span class="Apple-tab-span" style="white-space:pre">     </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>      resource_size_t size)<br class="">+{<br class="">+<span class="Apple-tab-span" style="white-space:pre">   </span>void __iomem *dest_ptr;<br class="">+<span class="Apple-tab-span" style="white-space:pre">   </span>struct resource *res;<br class="">+<br class="">+<span class="Apple-tab-span" style="white-space:pre">   </span>res = devm_request_mem_region(dev, start, size, dev_name(dev));<br class="">+<span class="Apple-tab-span" style="white-space:pre">   </span>if (!res) {<br class="">+<span class="Apple-tab-span" style="white-space:pre">       </span><span class="Apple-tab-span" style="white-space:pre">    </span>dev_err(dev, "can't request SMMU region %pa\n", &start);<br class="">+<span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>return IOMEM_ERR_PTR(-EINVAL);<br class="">+<span class="Apple-tab-span" style="white-space:pre">    </span>}<br class="">+<br class="">+<span class="Apple-tab-span" style="white-space:pre">       </span>dest_ptr = devm_ioremap(dev, start, size);<br class="">+<span class="Apple-tab-span" style="white-space:pre">        </span>if (!dest_ptr) {<br class="">+<span class="Apple-tab-span" style="white-space:pre">  </span><span class="Apple-tab-span" style="white-space:pre">    </span>dev_err(dev, "ioremap failed for SMMU region %pR\n", res);<br class="">+<span class="Apple-tab-span" style="white-space:pre">      </span><span class="Apple-tab-span" style="white-space:pre">    </span>devm_release_mem_region(dev, start, size);<br class="">+<span class="Apple-tab-span" style="white-space:pre">        </span><span class="Apple-tab-span" style="white-space:pre">    </span>dest_ptr = IOMEM_ERR_PTR(-ENOMEM);<br class="">+<span class="Apple-tab-span" style="white-space:pre">        </span>}<br class="">+<span class="Apple-tab-span" style="white-space:pre"> </span>return dest_ptr;<br class="">+}<br class="">+<br class=""> static int arm_smmu_device_probe(struct platform_device *pdev)<br class=""> {<br class=""> <span class="Apple-tab-span" style="white-space:pre">      </span>int irq, ret;<br class="">@@ -4056,10 +4085,21 @@ static int arm_smmu_device_probe(struct platform_device *pdev)<br class=""> <span class="Apple-tab-span" style="white-space:pre">  </span>}<br class=""> <span class="Apple-tab-span" style="white-space:pre">     </span>ioaddr = res->start;<br class=""><br class="">-<span class="Apple-tab-span" style="white-space:pre">  </span>smmu->base = devm_ioremap_resource(dev, res);<br class="">+<span class="Apple-tab-span" style="white-space:pre">  </span>/*<br class="">+<span class="Apple-tab-span" style="white-space:pre">        </span> * Only map what we need, because the IMPLEMENTATION DEFINED registers<br class="">+<span class="Apple-tab-span" style="white-space:pre">    </span> * may be used for the PMCGs, which are reserved by the PMU driver.<br class="">+<span class="Apple-tab-span" style="white-space:pre">       </span> */<br class="">+<span class="Apple-tab-span" style="white-space:pre">       </span>smmu->base = arm_smmu_ioremap(dev, ioaddr, ARM_SMMU_PAGE0_REG_SZ);<br class=""> <span class="Apple-tab-span" style="white-space:pre"> </span>if (IS_ERR(smmu->base))<br class=""> <span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>return PTR_ERR(smmu->base);<br class=""><br class="">+<span class="Apple-tab-span" style="white-space:pre">       </span>if (arm_smmu_resource_size(smmu) > SZ_64K) {<br class="">+<span class="Apple-tab-span" style="white-space:pre">   </span><span class="Apple-tab-span" style="white-space:pre">    </span>smmu->page1 = arm_smmu_ioremap(dev, ioaddr + SZ_64K,<br class="">+<span class="Apple-tab-span" style="white-space:pre">       </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>       ARM_SMMU_PAGE1_REG_SZ);<br class="">+<span class="Apple-tab-span" style="white-space:pre">      </span><span class="Apple-tab-span" style="white-space:pre">    </span>if (IS_ERR(smmu->page1))<br class="">+<span class="Apple-tab-span" style="white-space:pre">       </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>return PTR_ERR(smmu->page1);<br class="">+<span class="Apple-tab-span" style="white-space:pre">   </span>}<br class="">+<br class=""> <span class="Apple-tab-span" style="white-space:pre">   </span>/* Interrupt lines */<br class=""><br class=""> <span class="Apple-tab-span" style="white-space:pre">    </span>irq = platform_get_irq_byname_optional(pdev, "combined");<br class="">— <br class="">2.26.2<br class=""><br class=""></div></div></blockquote></div><div><br class=""></div>Tested-by: Tuan Phan <<a href="mailto:tuanphan@os.amperecomputing.com" class="">tuanphan@os.amperecomputing.com</a>><div class=""><br class=""></div></body></html>