From: Sasha Levin <sashal@kernel.org> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oliver O'Halloran <oohall@gmail.com>, kernel test robot <lkp@intel.com>, Michael Ellerman <mpe@ellerman.id.au>, Sasha Levin <sashal@kernel.org>, linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 4.19 06/21] powerpc/pci: Add ppc_md.discover_phbs() Date: Tue, 2 Mar 2021 06:58:20 -0500 [thread overview] Message-ID: <20210302115835.63269-6-sashal@kernel.org> (raw) In-Reply-To: <20210302115835.63269-1-sashal@kernel.org> From: Oliver O'Halloran <oohall@gmail.com> [ Upstream commit 5537fcb319d016ce387f818dd774179bc03217f5 ] On many powerpc platforms the discovery and initalisation of pci_controllers (PHBs) happens inside of setup_arch(). This is very early in boot (pre-initcalls) and means that we're initialising the PHB long before many basic kernel services (slab allocator, debugfs, a real ioremap) are available. On PowerNV this causes an additional problem since we map the PHB registers with ioremap(). As of commit d538aadc2718 ("powerpc/ioremap: warn on early use of ioremap()") a warning is printed because we're using the "incorrect" API to setup and MMIO mapping in searly boot. The kernel does provide early_ioremap(), but that is not intended to create long-lived MMIO mappings and a seperate warning is printed by generic code if early_ioremap() mappings are "leaked." This is all fixable with dumb hacks like using early_ioremap() to setup the initial mapping then replacing it with a real ioremap later on in boot, but it does raise the question: Why the hell are we setting up the PHB's this early in boot? The old and wise claim it's due to "hysterical rasins." Aside from amused grapes there doesn't appear to be any real reason to maintain the current behaviour. Already most of the newer embedded platforms perform PHB discovery in an arch_initcall and between the end of setup_arch() and the start of initcalls none of the generic kernel code does anything PCI related. On powerpc scanning PHBs occurs in a subsys_initcall so it should be possible to move the PHB discovery to a core, postcore or arch initcall. This patch adds the ppc_md.discover_phbs hook and a core_initcall stub that calls it. The core_initcalls are the earliest to be called so this will any possibly issues with dependency between initcalls. This isn't just an academic issue either since on pseries and PowerNV EEH init occurs in an arch_initcall and depends on the pci_controllers being available, similarly the creation of pci_dns occurs at core_initcall_sync (i.e. between core and postcore initcalls). These problems need to be addressed seperately. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> [mpe: Make discover_phbs() static] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201103043523.916109-1-oohall@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/powerpc/include/asm/machdep.h | 3 +++ arch/powerpc/kernel/pci-common.c | 10 ++++++++++ 2 files changed, 13 insertions(+) diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h index a47de82fb8e2..bda87cbf106d 100644 --- a/arch/powerpc/include/asm/machdep.h +++ b/arch/powerpc/include/asm/machdep.h @@ -71,6 +71,9 @@ struct machdep_calls { int (*pcibios_root_bridge_prepare)(struct pci_host_bridge *bridge); + /* finds all the pci_controllers present at boot */ + void (*discover_phbs)(void); + /* To setup PHBs when using automatic OF platform driver for PCI */ int (*pci_setup_phb)(struct pci_controller *host); diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index 88e4f69a09e5..74628aca2bf1 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -1671,3 +1671,13 @@ static void fixup_hide_host_resource_fsl(struct pci_dev *dev) } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MOTOROLA, PCI_ANY_ID, fixup_hide_host_resource_fsl); DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_FREESCALE, PCI_ANY_ID, fixup_hide_host_resource_fsl); + + +static int __init discover_phbs(void) +{ + if (ppc_md.discover_phbs) + ppc_md.discover_phbs(); + + return 0; +} +core_initcall(discover_phbs); -- 2.30.1
WARNING: multiple messages have this Message-ID (diff)
From: Sasha Levin <sashal@kernel.org> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sasha Levin <sashal@kernel.org>, linuxppc-dev@lists.ozlabs.org, Oliver O'Halloran <oohall@gmail.com>, kernel test robot <lkp@intel.com> Subject: [PATCH AUTOSEL 4.19 06/21] powerpc/pci: Add ppc_md.discover_phbs() Date: Tue, 2 Mar 2021 06:58:20 -0500 [thread overview] Message-ID: <20210302115835.63269-6-sashal@kernel.org> (raw) In-Reply-To: <20210302115835.63269-1-sashal@kernel.org> From: Oliver O'Halloran <oohall@gmail.com> [ Upstream commit 5537fcb319d016ce387f818dd774179bc03217f5 ] On many powerpc platforms the discovery and initalisation of pci_controllers (PHBs) happens inside of setup_arch(). This is very early in boot (pre-initcalls) and means that we're initialising the PHB long before many basic kernel services (slab allocator, debugfs, a real ioremap) are available. On PowerNV this causes an additional problem since we map the PHB registers with ioremap(). As of commit d538aadc2718 ("powerpc/ioremap: warn on early use of ioremap()") a warning is printed because we're using the "incorrect" API to setup and MMIO mapping in searly boot. The kernel does provide early_ioremap(), but that is not intended to create long-lived MMIO mappings and a seperate warning is printed by generic code if early_ioremap() mappings are "leaked." This is all fixable with dumb hacks like using early_ioremap() to setup the initial mapping then replacing it with a real ioremap later on in boot, but it does raise the question: Why the hell are we setting up the PHB's this early in boot? The old and wise claim it's due to "hysterical rasins." Aside from amused grapes there doesn't appear to be any real reason to maintain the current behaviour. Already most of the newer embedded platforms perform PHB discovery in an arch_initcall and between the end of setup_arch() and the start of initcalls none of the generic kernel code does anything PCI related. On powerpc scanning PHBs occurs in a subsys_initcall so it should be possible to move the PHB discovery to a core, postcore or arch initcall. This patch adds the ppc_md.discover_phbs hook and a core_initcall stub that calls it. The core_initcalls are the earliest to be called so this will any possibly issues with dependency between initcalls. This isn't just an academic issue either since on pseries and PowerNV EEH init occurs in an arch_initcall and depends on the pci_controllers being available, similarly the creation of pci_dns occurs at core_initcall_sync (i.e. between core and postcore initcalls). These problems need to be addressed seperately. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> [mpe: Make discover_phbs() static] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201103043523.916109-1-oohall@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/powerpc/include/asm/machdep.h | 3 +++ arch/powerpc/kernel/pci-common.c | 10 ++++++++++ 2 files changed, 13 insertions(+) diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h index a47de82fb8e2..bda87cbf106d 100644 --- a/arch/powerpc/include/asm/machdep.h +++ b/arch/powerpc/include/asm/machdep.h @@ -71,6 +71,9 @@ struct machdep_calls { int (*pcibios_root_bridge_prepare)(struct pci_host_bridge *bridge); + /* finds all the pci_controllers present at boot */ + void (*discover_phbs)(void); + /* To setup PHBs when using automatic OF platform driver for PCI */ int (*pci_setup_phb)(struct pci_controller *host); diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index 88e4f69a09e5..74628aca2bf1 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -1671,3 +1671,13 @@ static void fixup_hide_host_resource_fsl(struct pci_dev *dev) } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MOTOROLA, PCI_ANY_ID, fixup_hide_host_resource_fsl); DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_FREESCALE, PCI_ANY_ID, fixup_hide_host_resource_fsl); + + +static int __init discover_phbs(void) +{ + if (ppc_md.discover_phbs) + ppc_md.discover_phbs(); + + return 0; +} +core_initcall(discover_phbs); -- 2.30.1
next prev parent reply other threads:[~2021-03-02 13:46 UTC|newest] Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-03-02 11:58 [PATCH AUTOSEL 4.19 01/21] i2c: rcar: optimize cacheline to minimize HW race condition Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 02/21] udf: fix silent AED tagLocation corruption Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 03/21] mmc: mxs-mmc: Fix a resource leak in an error handling path in 'mxs_mmc_probe()' Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 04/21] mmc: sdhci-of-dwcmshc: set SDHCI_QUIRK2_PRESET_VALUE_BROKEN Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 05/21] mmc: mediatek: fix race condition between msdc_request_timeout and irq Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` Sasha Levin [this message] 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 06/21] powerpc/pci: Add ppc_md.discover_phbs() Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 07/21] powerpc: improve handling of unrecoverable system reset Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 08/21] powerpc/perf: Record counter overflow always if SAMPLE_IP is unset Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 09/21] sparc32: Limit memblock allocation to low memory Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 10/21] sparc64: Use arch_validate_flags() to validate ADI flag Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 11/21] x86, build: use objtool mcount Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 12/21] PCI: xgene-msi: Fix race in installing chained irq handler Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 13/21] misc: eeprom_93xx46: Add quirk to support Microchip 93LC46B eeprom Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 14/21] PCI: mediatek: Add missing of_node_put() to fix reference leak Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 15/21] drm/msm/a5xx: Remove overwriting A5XX_PC_DBG_ECO_CNTL register Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 16/21] PCI: Fix pci_register_io_range() memory leak Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 17/21] i40e: Fix memory leak in i40e_probe Sasha Levin 2021-03-02 11:58 ` [Intel-wired-lan] " Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 18/21] s390/smp: __smp_rescan_cpus() - move cpumask away from stack Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 19/21] scsi: libiscsi: Fix iscsi_prep_scsi_cmd_pdu() error handling Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 20/21] scsi: target: core: Add cmd length set before cmd complete Sasha Levin 2021-03-02 11:58 ` Sasha Levin 2021-03-02 11:58 ` [PATCH AUTOSEL 4.19 21/21] scsi: target: core: Prevent underflow for service actions Sasha Levin
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