From patchwork Mon Jan 23 12:17:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 13112011 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A370AC38142 for ; Mon, 23 Jan 2023 12:17:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231512AbjAWMRt (ORCPT ); Mon, 23 Jan 2023 07:17:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231621AbjAWMRr (ORCPT ); Mon, 23 Jan 2023 07:17:47 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADDC8FF for ; Mon, 23 Jan 2023 04:17:44 -0800 (PST) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4P0ptt0RDLz6J68f; Mon, 23 Jan 2023 20:14:30 +0800 (CST) Received: from SecurePC-101-06.china.huawei.com (10.122.247.231) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Mon, 23 Jan 2023 12:17:42 +0000 From: Jonathan Cameron To: CC: Ben Widawsky , , , Ira Weiny , Dave Jiang , , Fan Ni Subject: [RFC PATCH 1/2] hw/pci: Add pcie_count_ds_port() and pcie_find_port_first() helpers Date: Mon, 23 Jan 2023 12:17:11 +0000 Message-ID: <20230123121712.29892-2-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230123121712.29892-1-Jonathan.Cameron@huawei.com> References: <20230123121712.29892-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.122.247.231] X-ClientProxiedBy: lhrpeml100001.china.huawei.com (7.191.160.183) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org These two helpers enable host bridges to operate differently depending on the number of downstream ports, in particular if there is only a single port. Useful for CXL where HDM address decoders are allowed to be implicit in the host bridge if there is only a single root port. Signed-off-by: Jonathan Cameron --- hw/pci/pcie_port.c | 38 ++++++++++++++++++++++++++++++++++++++ include/hw/pci/pcie_port.h | 2 ++ 2 files changed, 40 insertions(+) diff --git a/hw/pci/pcie_port.c b/hw/pci/pcie_port.c index 687e4e763a..b709777e0c 100644 --- a/hw/pci/pcie_port.c +++ b/hw/pci/pcie_port.c @@ -161,6 +161,44 @@ PCIDevice *pcie_find_port_by_pn(PCIBus *bus, uint8_t pn) return NULL; } +/* Find first port in devfn number */ +PCIDevice *pcie_find_port_first(PCIBus *bus) +{ + int devfn; + + for (devfn = 0; devfn < ARRAY_SIZE(bus->devices); devfn++) { + PCIDevice *d = bus->devices[devfn]; + + if (!d || !pci_is_express(d) || !d->exp.exp_cap) { + continue; + } + + if (object_dynamic_cast(OBJECT(d), TYPE_PCIE_PORT)) { + return d; + } + } + + return NULL; +} + +int pcie_count_ds_ports(PCIBus *bus) +{ + int dsp_count = 0; + int devfn; + + for (devfn = 0; devfn < ARRAY_SIZE(bus->devices); devfn++) { + PCIDevice *d = bus->devices[devfn]; + + if (!d || !pci_is_express(d) || !d->exp.exp_cap) { + continue; + } + if (object_dynamic_cast(OBJECT(d), TYPE_PCIE_PORT)) { + dsp_count++; + } + } + return dsp_count; +} + static const TypeInfo pcie_port_type_info = { .name = TYPE_PCIE_PORT, .parent = TYPE_PCI_BRIDGE, diff --git a/include/hw/pci/pcie_port.h b/include/hw/pci/pcie_port.h index fd484afb30..2cbad72555 100644 --- a/include/hw/pci/pcie_port.h +++ b/include/hw/pci/pcie_port.h @@ -41,6 +41,8 @@ struct PCIEPort { void pcie_port_init_reg(PCIDevice *d); PCIDevice *pcie_find_port_by_pn(PCIBus *bus, uint8_t pn); +PCIDevice *pcie_find_port_first(PCIBus *bus); +int pcie_count_ds_ports(PCIBus *bus); #define TYPE_PCIE_SLOT "pcie-slot" OBJECT_DECLARE_SIMPLE_TYPE(PCIESlot, PCIE_SLOT) From patchwork Mon Jan 23 12:17:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 13112012 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4251C05027 for ; Mon, 23 Jan 2023 12:18:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231673AbjAWMSW (ORCPT ); Mon, 23 Jan 2023 07:18:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231675AbjAWMSV (ORCPT ); Mon, 23 Jan 2023 07:18:21 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B3881A4A5 for ; Mon, 23 Jan 2023 04:18:15 -0800 (PST) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4P0ptV5Zzlz6J7YR; Mon, 23 Jan 2023 20:14:10 +0800 (CST) Received: from SecurePC-101-06.china.huawei.com (10.122.247.231) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Mon, 23 Jan 2023 12:18:13 +0000 From: Jonathan Cameron To: CC: Ben Widawsky , , , Ira Weiny , Dave Jiang , , Fan Ni Subject: [RFC PATCH 2/2] hw/pxb-cxl: Support passthrough HDM Decoders unless overridden Date: Mon, 23 Jan 2023 12:17:12 +0000 Message-ID: <20230123121712.29892-3-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230123121712.29892-1-Jonathan.Cameron@huawei.com> References: <20230123121712.29892-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.122.247.231] X-ClientProxiedBy: lhrpeml100002.china.huawei.com (7.191.160.241) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org The CXL r3.0 specification allows for there to be no HDM decoders on CXL Host Bridges if they have only a single root port. Instead, all accesses directed to the host bridge (as specified in CXL Fixed Memory Windows) are assumed to be routed to the single root port. Linux currently assumes this implementation choice. So to simplify testing, make QEMU emulation also default to no HDM decoders under these particular circumstances, but provide a hdm_for_passthrough boolean option to have HDM decoders as previously. Technically this is breaking backwards compatibility, but given the only known software stack used with the QEMU emulation is the Linux kernel and this configuration did not work before this change, there are unlikely to be any complaints that it now works. The option is retained to allow testing of software that does allow for these HDM decoders to exist, once someone writes it. Reported-by: Fan Ni Signed-off-by: Jonathan Cameron --- hw/cxl/cxl-host.c | 31 +++++++++++++-------- hw/pci-bridge/pci_expander_bridge.c | 43 +++++++++++++++++++++++++---- include/hw/cxl/cxl.h | 1 + include/hw/cxl/cxl_component.h | 1 + include/hw/pci/pci_bridge.h | 1 + 5 files changed, 60 insertions(+), 17 deletions(-) diff --git a/hw/cxl/cxl-host.c b/hw/cxl/cxl-host.c index 3c1ec8732a..6e923ceeaf 100644 --- a/hw/cxl/cxl-host.c +++ b/hw/cxl/cxl-host.c @@ -146,21 +146,28 @@ static PCIDevice *cxl_cfmws_find_device(CXLFixedWindow *fw, hwaddr addr) return NULL; } - hb_cstate = cxl_get_hb_cstate(hb); - if (!hb_cstate) { - return NULL; - } + if (cxl_get_hb_passthrough(hb)) { + rp = pcie_find_port_first(hb->bus); + if (!rp) { + return NULL; + } + } else { + hb_cstate = cxl_get_hb_cstate(hb); + if (!hb_cstate) { + return NULL; + } - cache_mem = hb_cstate->crb.cache_mem_registers; + cache_mem = hb_cstate->crb.cache_mem_registers; - target_found = cxl_hdm_find_target(cache_mem, addr, &target); - if (!target_found) { - return NULL; - } + target_found = cxl_hdm_find_target(cache_mem, addr, &target); + if (!target_found) { + return NULL; + } - rp = pcie_find_port_by_pn(hb->bus, target); - if (!rp) { - return NULL; + rp = pcie_find_port_by_pn(hb->bus, target); + if (!rp) { + return NULL; + } } d = pci_bridge_get_sec_bus(PCI_BRIDGE(rp))->devices[0]; diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c index e752a21292..e2aabc12aa 100644 --- a/hw/pci-bridge/pci_expander_bridge.c +++ b/hw/pci-bridge/pci_expander_bridge.c @@ -15,6 +15,7 @@ #include "hw/pci/pci.h" #include "hw/pci/pci_bus.h" #include "hw/pci/pci_host.h" +#include "hw/pci/pcie_port.h" #include "hw/qdev-properties.h" #include "hw/pci/pci_bridge.h" #include "hw/pci-bridge/pci_expander_bridge.h" @@ -79,6 +80,13 @@ CXLComponentState *cxl_get_hb_cstate(PCIHostState *hb) return &host->cxl_cstate; } +bool cxl_get_hb_passthrough(PCIHostState *hb) +{ + CXLHost *host = PXB_CXL_HOST(hb); + + return host->passthrough; +} + static int pxb_bus_num(PCIBus *bus) { PXBDev *pxb = convert_to_pxb(bus->parent_dev); @@ -289,15 +297,31 @@ static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin) return pin - PCI_SLOT(pxb->devfn); } -static void pxb_dev_reset(DeviceState *dev) +static void pxb_cxl_dev_reset(DeviceState *dev) { CXLHost *cxl = PXB_CXL_DEV(dev)->cxl.cxl_host_bridge; CXLComponentState *cxl_cstate = &cxl->cxl_cstate; + PCIHostState *hb = PCI_HOST_BRIDGE(cxl); uint32_t *reg_state = cxl_cstate->crb.cache_mem_registers; uint32_t *write_msk = cxl_cstate->crb.cache_mem_regs_write_mask; + int dsp_count = 0; cxl_component_register_init_common(reg_state, write_msk, CXL2_ROOT_PORT); - ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY, TARGET_COUNT, 8); + /* + * The CXL specification allows for host bridges with no HDM decoders + * if they only have a single root port. + */ + if (!PXB_DEV(dev)->hdm_for_passthrough) { + dsp_count = pcie_count_ds_ports(hb->bus); + } + /* Initial reset will have 0 dsp so wait until > 0 */ + if (dsp_count == 1) { + cxl->passthrough = true; + /* Set Capability ID in header to NONE */ + ARRAY_FIELD_DP32(reg_state, CXL_HDM_CAPABILITY_HEADER, ID, 0); + } else { + ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY, TARGET_COUNT, 8); + } } static gint pxb_compare(gconstpointer a, gconstpointer b) @@ -481,9 +505,18 @@ static void pxb_cxl_dev_realize(PCIDevice *dev, Error **errp) } pxb_dev_realize_common(dev, CXL, errp); - pxb_dev_reset(DEVICE(dev)); + pxb_cxl_dev_reset(DEVICE(dev)); } +static Property pxb_cxl_dev_properties[] = { + /* Note: 0 is not a legal PXB bus number. */ + DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0), + DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED), + DEFINE_PROP_BOOL("bypass_iommu", PXBDev, bypass_iommu, false), + DEFINE_PROP_BOOL("hdm_for_passthrough", PXBDev, hdm_for_passthrough, false), + DEFINE_PROP_END_OF_LIST(), +}; + static void pxb_cxl_dev_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); @@ -497,12 +530,12 @@ static void pxb_cxl_dev_class_init(ObjectClass *klass, void *data) */ dc->desc = "CXL Host Bridge"; - device_class_set_props(dc, pxb_dev_properties); + device_class_set_props(dc, pxb_cxl_dev_properties); set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories); /* Host bridges aren't hotpluggable. FIXME: spec reference */ dc->hotpluggable = false; - dc->reset = pxb_dev_reset; + dc->reset = pxb_cxl_dev_reset; } static const TypeInfo pxb_cxl_dev_info = { diff --git a/include/hw/cxl/cxl.h b/include/hw/cxl/cxl.h index 716f0f0f2a..9c8185ae88 100644 --- a/include/hw/cxl/cxl.h +++ b/include/hw/cxl/cxl.h @@ -50,6 +50,7 @@ struct CXLHost { PCIHostState parent_obj; CXLComponentState cxl_cstate; + bool passthrough; }; #define TYPE_PXB_CXL_HOST "pxb-cxl-host" diff --git a/include/hw/cxl/cxl_component.h b/include/hw/cxl/cxl_component.h index 870faeb6dd..97e45e6747 100644 --- a/include/hw/cxl/cxl_component.h +++ b/include/hw/cxl/cxl_component.h @@ -251,6 +251,7 @@ static inline hwaddr cxl_decode_ig(int ig) } CXLComponentState *cxl_get_hb_cstate(PCIHostState *hb); +bool cxl_get_hb_passthrough(PCIHostState *hb); void cxl_doe_cdat_init(CXLComponentState *cxl_cstate, Error **errp); void cxl_doe_cdat_release(CXLComponentState *cxl_cstate); diff --git a/include/hw/pci/pci_bridge.h b/include/hw/pci/pci_bridge.h index 63a7521567..81a058bb2c 100644 --- a/include/hw/pci/pci_bridge.h +++ b/include/hw/pci/pci_bridge.h @@ -92,6 +92,7 @@ struct PXBDev { uint8_t bus_nr; uint16_t numa_node; bool bypass_iommu; + bool hdm_for_passthrough; struct cxl_dev { CXLHost *cxl_host_bridge; /* Pointer to a CXLHost */ } cxl;