From mboxrd@z Thu Jan 1 00:00:00 1970 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 C876CC433F5 for ; Wed, 24 Nov 2021 22:18:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245598AbhKXWVu (ORCPT ); Wed, 24 Nov 2021 17:21:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243516AbhKXWVt (ORCPT ); Wed, 24 Nov 2021 17:21:49 -0500 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 505A3C06173E for ; Wed, 24 Nov 2021 14:18:38 -0800 (PST) Received: by mail-pj1-x102f.google.com with SMTP id y14-20020a17090a2b4e00b001a5824f4918so6152809pjc.4 for ; Wed, 24 Nov 2021 14:18:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=t136RXUUjljW+zq+0uABWBZU7E88tMGuF++JYX1S51w=; b=RsBMDNpQ094UksOy23GRpmiXc2C9+Ne9lh98ax8D8VVELglTix32+b9fzA5X0uRWrU NCIJ+eQ2C5GI4r+10ghhCEnbQ4mR7kPlQPPZLtMnfBC6AuclcDxklfCkJVfFtbieB+Dk S3QuNYG0r5BQLa4eqOrYJMcIBsE4RIyGL360Vtr00sprQmKtIuxa/J7JIqqs+K0Sd0Wq oeecZY4NikmNaKr9sSfCTmPX533FmOmtUTzCvI9N5oTfq/6M5Pm/Vm5aivVqKlou33E0 1PPl+8IDBMyDDACKRFAO92VrR8OmMyU9R832mAihE18S3aGRjQF2DQaBEQOe0fOLgtN2 Hyaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=t136RXUUjljW+zq+0uABWBZU7E88tMGuF++JYX1S51w=; b=YFOedNowIP2ufOU0ui6ifm33AWV+Dm0cLKi3BtvXNbTNyT2aScq0jvRNpa+zYwOUPv ftZCE9SH9ga8yy8jqs5ftqWiTIcWxY8pkJITqOteQafSimzSCk+K7OTy8ZOnP2qvmTch 9WEc/jA1zcJ4u4clPf3jXQgRgiwTUznjPgHWEw2dT0H+btR7ySJK4tE+w/DM5qaUx5Kw xRHhlDi/EnQ3DyU3p7yD/ds1A3E+TkJqJeank0Mn0UTZLsQmQh1gR0eDoNz+aa8Sdklg NJwyCTkoj88d1Hjq+CAlT+QgWvkrgCwcBdyE6RmrJrWxqP+FK+YRapeAwDJy9iVzuBtd oPFg== X-Gm-Message-State: AOAM531biVolitoNWPg/SkVqaOK9sd3XLjPbJOpdIU8Fo/U4WJEeGsAc QXJMtV62YSc00TWEf5ldqxClCtusNxsE4Hp1BuEl4w== X-Google-Smtp-Source: ABdhPJwzZ+etC3NasPHDxICacataNUohNOput2FltlBEMwd2pZ5AxT9KapbtXD7bbmb8I/niJVyJiPfXACUugzFcJ8s= X-Received: by 2002:a17:902:7fcd:b0:142:8ab3:ec0e with SMTP id t13-20020a1709027fcd00b001428ab3ec0emr23105992plb.4.1637792317776; Wed, 24 Nov 2021 14:18:37 -0800 (PST) MIME-Version: 1.0 References: <20211120000250.1663391-1-ben.widawsky@intel.com> <20211120000250.1663391-9-ben.widawsky@intel.com> In-Reply-To: <20211120000250.1663391-9-ben.widawsky@intel.com> From: Dan Williams Date: Wed, 24 Nov 2021 14:18:27 -0800 Message-ID: Subject: Re: [PATCH 08/23] cxl/acpi: Map component registers for Root Ports To: Ben Widawsky Cc: linux-cxl@vger.kernel.org, Linux PCI , Alison Schofield , Ira Weiny , Jonathan Cameron , Vishal Verma Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Nov 19, 2021 at 4:03 PM Ben Widawsky wrote: > > This implements the TODO in cxl_acpi for mapping component registers. > cxl_acpi becomes the second consumer of CXL register block enumeration > (cxl_pci being the first). Moving the functionality to cxl_core allows > both of these drivers to use the functionality. Equally importantly it > allows cxl_core to use the functionality in the future. > > CXL 2.0 root ports are similar to CXL 2.0 Downstream Ports with the main > distinction being they're a part of the CXL 2.0 host bridge. While > mapping their component registers is not immediately useful for the CXL > drivers, the movement of register block enumeration into core is a vital > step towards HDM decoder programming. > > Signed-off-by: Ben Widawsky > > --- > Changes since RFCv2: > - Squash commits together (Dan) > - Reword commit message to account for above. > --- > drivers/cxl/acpi.c | 10 ++++++-- > drivers/cxl/core/regs.c | 54 +++++++++++++++++++++++++++++++++++++++++ > drivers/cxl/cxl.h | 4 +++ > drivers/cxl/pci.c | 52 --------------------------------------- > drivers/cxl/pci.h | 4 +++ > 5 files changed, 70 insertions(+), 54 deletions(-) > > diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c > index 3163167ecc3a..7cfa8b568013 100644 > --- a/drivers/cxl/acpi.c > +++ b/drivers/cxl/acpi.c > @@ -7,6 +7,7 @@ > #include > #include > #include "cxl.h" > +#include "pci.h" > > /* Encode defined in CXL 2.0 8.2.5.12.7 HDM Decoder Control Register */ > #define CFMWS_INTERLEAVE_WAYS(x) (1 << (x)->interleave_ways) > @@ -134,11 +135,13 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, > > __mock int match_add_root_ports(struct pci_dev *pdev, void *data) > { > + resource_size_t creg = CXL_RESOURCE_NONE; > struct cxl_walk_context *ctx = data; > struct pci_bus *root_bus = ctx->root; > struct cxl_port *port = ctx->port; > int type = pci_pcie_type(pdev); > struct device *dev = ctx->dev; > + struct cxl_register_map map; > u32 lnkcap, port_num; > int rc; > > @@ -152,9 +155,12 @@ __mock int match_add_root_ports(struct pci_dev *pdev, void *data) > &lnkcap) != PCIBIOS_SUCCESSFUL) > return 0; > > - /* TODO walk DVSEC to find component register base */ > + rc = cxl_find_regblock(pdev, CXL_REGLOC_RBI_COMPONENT, &map); > + if (!rc) > + creg = cxl_reg_block(pdev, &map); A couple comments: the difference between cxl_find_regblock() and cxl_reg_block() is not obvious from the names. Setting aside why one is regblock and the other is reg_block I would expect a name like cxl_regmap_to_base() is easier to read. It occurs to me that if cxl_find_regblock() failures are optional it would be nice if cxl_regmap_to_base() returns CXL_RESOURCE_NONE if the map is not populated. Then this can unconditionally call cxl_regmap_to_base(). > + > port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap); > - rc = cxl_add_dport(port, &pdev->dev, port_num, CXL_RESOURCE_NONE); > + rc = cxl_add_dport(port, &pdev->dev, port_num, creg); > if (rc) { > ctx->error = rc; > return rc; > diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c > index e37e23bf4355..41a0245867ea 100644 > --- a/drivers/cxl/core/regs.c > +++ b/drivers/cxl/core/regs.c > @@ -5,6 +5,7 @@ > #include > #include > #include > +#include > > /** > * DOC: cxl registers > @@ -247,3 +248,56 @@ int cxl_map_device_regs(struct pci_dev *pdev, > return 0; > } > EXPORT_SYMBOL_NS_GPL(cxl_map_device_regs, CXL); > + > +static void cxl_decode_regblock(u32 reg_lo, u32 reg_hi, > + struct cxl_register_map *map) > +{ > + map->block_offset = ((u64)reg_hi << 32) | > + (reg_lo & CXL_DVSEC_REG_LOCATOR_BLOCK_OFF_LOW_MASK); > + map->barno = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BIR_MASK, reg_lo); > + map->reg_type = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BLOCK_ID_MASK, reg_lo); > +} > + > +/** > + * cxl_find_regblock() - Locate register blocks by type > + * @pdev: The CXL PCI device to enumerate. > + * @type: Register Block Indicator id > + * @map: Enumeration output, clobbered on error > + * > + * Return: 0 if register block enumerated, negative error code otherwise > + * > + * A CXL DVSEC may additional point one or more register blocks, search > + * for them by @type. > + */ > +int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type, > + struct cxl_register_map *map) > +{ > + u32 regloc_size, regblocks; > + int regloc, i; > + > + regloc = pci_find_dvsec_capability(pdev, PCI_DVSEC_VENDOR_ID_CXL, > + CXL_DVSEC_REG_LOCATOR); > + if (!regloc) > + return -ENXIO; > + > + pci_read_config_dword(pdev, regloc + PCI_DVSEC_HEADER1, ®loc_size); > + regloc_size = FIELD_GET(PCI_DVSEC_HEADER1_LENGTH_MASK, regloc_size); > + > + regloc += CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET; > + regblocks = (regloc_size - CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET) / 8; > + > + for (i = 0; i < regblocks; i++, regloc += 8) { > + u32 reg_lo, reg_hi; > + > + pci_read_config_dword(pdev, regloc, ®_lo); > + pci_read_config_dword(pdev, regloc + 4, ®_hi); > + > + cxl_decode_regblock(reg_lo, reg_hi, map); > + > + if (map->reg_type == type) > + return 0; > + } > + > + return -ENODEV; > +} > +EXPORT_SYMBOL_NS_GPL(cxl_find_regblock, CXL); > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > index ab4596f0b751..7150a9694f66 100644 > --- a/drivers/cxl/cxl.h > +++ b/drivers/cxl/cxl.h > @@ -145,6 +145,10 @@ int cxl_map_device_regs(struct pci_dev *pdev, > struct cxl_device_regs *regs, > struct cxl_register_map *map); > > +enum cxl_regloc_type; > +int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type, > + struct cxl_register_map *map); > + > #define CXL_RESOURCE_NONE ((resource_size_t) -1) > #define CXL_TARGET_STRLEN 20 > > diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c > index 711bf4514480..d2c743a31b0c 100644 > --- a/drivers/cxl/pci.c > +++ b/drivers/cxl/pci.c > @@ -433,58 +433,6 @@ static int cxl_map_regs(struct cxl_dev_state *cxlds, struct cxl_register_map *ma > return 0; > } > > -static void cxl_decode_regblock(u32 reg_lo, u32 reg_hi, > - struct cxl_register_map *map) > -{ > - map->block_offset = ((u64)reg_hi << 32) | > - (reg_lo & CXL_DVSEC_REG_LOCATOR_BLOCK_OFF_LOW_MASK); > - map->barno = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BIR_MASK, reg_lo); > - map->reg_type = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BLOCK_ID_MASK, reg_lo); > -} > - > -/** > - * cxl_find_regblock() - Locate register blocks by type > - * @pdev: The CXL PCI device to enumerate. > - * @type: Register Block Indicator id > - * @map: Enumeration output, clobbered on error > - * > - * Return: 0 if register block enumerated, negative error code otherwise > - * > - * A CXL DVSEC may point to one or more register blocks, search for them > - * by @type. > - */ > -static int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type, > - struct cxl_register_map *map) > -{ > - u32 regloc_size, regblocks; > - int regloc, i; > - > - regloc = pci_find_dvsec_capability(pdev, PCI_DVSEC_VENDOR_ID_CXL, > - CXL_DVSEC_REG_LOCATOR); > - if (!regloc) > - return -ENXIO; > - > - pci_read_config_dword(pdev, regloc + PCI_DVSEC_HEADER1, ®loc_size); > - regloc_size = FIELD_GET(PCI_DVSEC_HEADER1_LENGTH_MASK, regloc_size); > - > - regloc += CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET; > - regblocks = (regloc_size - CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET) / 8; > - > - for (i = 0; i < regblocks; i++, regloc += 8) { > - u32 reg_lo, reg_hi; > - > - pci_read_config_dword(pdev, regloc, ®_lo); > - pci_read_config_dword(pdev, regloc + 4, ®_hi); > - > - cxl_decode_regblock(reg_lo, reg_hi, map); > - > - if (map->reg_type == type) > - return 0; > - } > - > - return -ENODEV; > -} > - > static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type, > struct cxl_register_map *map) > { > diff --git a/drivers/cxl/pci.h b/drivers/cxl/pci.h > index 8ae2b4adc59d..a4b506bb37d1 100644 > --- a/drivers/cxl/pci.h > +++ b/drivers/cxl/pci.h > @@ -47,4 +47,8 @@ enum cxl_regloc_type { > CXL_REGLOC_RBI_TYPES > }; > > +#define cxl_reg_block(pdev, map) \ > + ((resource_size_t)(pci_resource_start(pdev, (map)->barno) + \ > + (map)->block_offset)) > + I see no reason for this to be macro. It's also a bug timebomb if someone in the future does something like: cxl_reg_block(pdev, map++); ...because the macro references its arguments more than once.