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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CD20C2BB1D for ; Tue, 14 Apr 2020 20:45:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 163CF2064A for ; Tue, 14 Apr 2020 20:45:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2633342AbgDNUpI (ORCPT ); Tue, 14 Apr 2020 16:45:08 -0400 Received: from mga17.intel.com ([192.55.52.151]:48108 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2633346AbgDNUpG (ORCPT ); Tue, 14 Apr 2020 16:45:06 -0400 IronPort-SDR: 4s95xHZK0vs+KGa2r6HWIFekU2woGXGVxlBhwSO/2FiThZJayBqogYtMoTMXoVwRsRaGb38byC tAlHUszwLwPg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2020 13:45:04 -0700 IronPort-SDR: +hlPP0H27cZ0v8imdLy16PaU8ghA+51nPkSbmoE/mpaYRau5bDaKTwXIzKQjeDGVyasQB9FrD9 AOHpQcxh9tFg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,384,1580803200"; d="scan'208";a="288336387" Received: from unknown (HELO localhost.lm.intel.com) ([10.232.116.40]) by fmsmga002.fm.intel.com with ESMTP; 14 Apr 2020 13:45:04 -0700 From: Jon Derrick To: Cc: Bjorn Helgaas , Thomas Petazzoni , Russell King , Jon Derrick Subject: [PATCH 5/5] PCI: pci-bridge-emul: Eliminate the 'reserved' member Date: Tue, 14 Apr 2020 16:30:05 -0400 Message-Id: <20200414203005.5166-6-jonathan.derrick@intel.com> X-Mailer: git-send-email 2.18.1 In-Reply-To: <20200414203005.5166-1-jonathan.derrick@intel.com> References: <20200414203005.5166-1-jonathan.derrick@intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Per PCIe 5.0 r1.0, Terms and Acronyms, Page 80: Reserved register fields must be read only and must return 0 (all 0's for multi-bit fields) when read. Reserved encodings for register and packet fields must not be used. Any implementation dependence on a Reserved field value or encoding will result in an implementation that is not PCI Express-compliant. This patch ensures reads will return 0 for any bit not in the Read-Only, Read-Write, or Write-1-to-Clear bitmasks. Signed-off-by: Jon Derrick --- drivers/pci/pci-bridge-emul.c | 30 +++++++++++++----------------- 1 file changed, 13 insertions(+), 17 deletions(-) diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c index 5c0dffa601f3..aa563c8fd81e 100644 --- a/drivers/pci/pci-bridge-emul.c +++ b/drivers/pci/pci-bridge-emul.c @@ -24,6 +24,17 @@ #define PCI_CAP_PCIE_START PCI_BRIDGE_CONF_END #define PCI_CAP_PCIE_END (PCI_CAP_PCIE_START + PCI_EXP_SLTSTA2 + 2) +/** + * struct pci_bridge_reg_behavior - register bits behaviors + * @ro: Read-Only bits + * @rw: Read-Write bits + * @w1c: Write-1-to-Clear bits + * + * Reads and Writes will be filtered by specified behavior. All other bits not + * declared are assumed 'Reserved' and will return 0 on reads, per PCIe 5.0: + * "Reserved register fields must be read only and must return 0 (all 0's for + * multi-bit fields) when read". + */ struct pci_bridge_reg_behavior { /* Read-only bits */ u32 ro; @@ -33,9 +44,6 @@ struct pci_bridge_reg_behavior { /* Write-1-to-clear bits */ u32 w1c; - - /* Reserved bits (hardwired to 0) */ - u32 rsvd; }; static const struct pci_bridge_reg_behavior pci_regs_behavior[] = { @@ -49,7 +57,6 @@ static const struct pci_bridge_reg_behavior pci_regs_behavior[] = { PCI_COMMAND_FAST_BACK) | (PCI_STATUS_CAP_LIST | PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK | PCI_STATUS_DEVSEL_MASK) << 16), - .rsvd = GENMASK(15, 10) | ((BIT(6) | GENMASK(3, 0)) << 16), .w1c = PCI_STATUS_ERROR_BITS << 16, }, [PCI_CLASS_REVISION / 4] = { .ro = ~0 }, @@ -96,8 +103,6 @@ static const struct pci_bridge_reg_behavior pci_regs_behavior[] = { GENMASK(11, 8) | GENMASK(3, 0)), .w1c = PCI_STATUS_ERROR_BITS << 16, - - .rsvd = ((BIT(6) | GENMASK(4, 0)) << 16), }, [PCI_MEMORY_BASE / 4] = { @@ -130,12 +135,10 @@ static const struct pci_bridge_reg_behavior pci_regs_behavior[] = { [PCI_CAPABILITY_LIST / 4] = { .ro = GENMASK(7, 0), - .rsvd = GENMASK(31, 8), }, [PCI_ROM_ADDRESS1 / 4] = { .rw = GENMASK(31, 11) | BIT(0), - .rsvd = GENMASK(10, 1), }, /* @@ -158,8 +161,6 @@ static const struct pci_bridge_reg_behavior pci_regs_behavior[] = { .ro = (GENMASK(15, 8) | ((PCI_BRIDGE_CTL_FAST_BACK) << 16)), .w1c = BIT(10) << 16, - - .rsvd = (GENMASK(15, 12) | BIT(4)) << 16, }, }; @@ -186,13 +187,11 @@ static const struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = { */ .w1c = (BIT(6) | GENMASK(3, 0)) << 16, .ro = GENMASK(5, 4) << 16, - .rsvd = GENMASK(15, 7) << 16, }, [PCI_EXP_LNKCAP / 4] = { /* All bits are RO, except bit 23 which is reserved */ .ro = lower_32_bits(~BIT(23)), - .rsvd = BIT(23), }, [PCI_EXP_LNKCTL / 4] = { @@ -206,7 +205,6 @@ static const struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = { .rw = GENMASK(15, 14) | GENMASK(11, 3) | GENMASK(1, 0), .ro = GENMASK(13, 0) << 16, .w1c = GENMASK(15, 14) << 16, - .rsvd = GENMASK(13, 12) | BIT(2), }, [PCI_EXP_SLTCAP / 4] = { @@ -224,7 +222,6 @@ static const struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = { .rw = GENMASK(14, 0), .w1c = (BIT(8) | GENMASK(4, 0)) << 16, .ro = GENMASK(7, 5) << 16, - .rsvd = BIT(15) | (GENMASK(15, 9) << 16), }, [PCI_EXP_RTCTL / 4] = { @@ -236,7 +233,6 @@ static const struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = { */ .rw = GENMASK(4, 0), .ro = BIT(0) << 16, - .rsvd = GENMASK(15, 5) | (GENMASK(15, 1) << 16), }, [PCI_EXP_RTSTA / 4] = { @@ -246,7 +242,6 @@ static const struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = { */ .ro = BIT(17) | GENMASK(15, 0), .w1c = BIT(16), - .rsvd = GENMASK(31, 18), }, }; @@ -354,7 +349,8 @@ int pci_bridge_emul_conf_read(struct pci_bridge_emul *bridge, int where, * Make sure we never return any reserved bit with a value * different from 0. */ - *value &= ~behavior[reg / 4].rsvd; + *value &= behavior[reg / 4].ro | behavior[reg / 4].rw | + behavior[reg / 4].w1c; if (size == 1) *value = (*value >> (8 * (where & 3))) & 0xff; -- 2.18.1