From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: devicetree@vger.kernel.org, linux-efi@vger.kernel.org,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
catalin.marinas@arm.com, will.deacon@arm.com,
linux-kernel@vger.kernel.org, xen-devel@lists.xen.org,
"open list:ACPI" <linux-acpi@vger.kernel.org>,
stefano.stabellini@citrix.com, david.vrabel@citrix.com,
Shannon Zhao <zhaoshenglong@huawei.com>,
peter.huangpeng@huawei.com, Len Brown <lenb@kernel.org>,
linux-arm-kernel@lists.infradead.org, shannon.zhao@linaro.org
Subject: Re: [PATCH v8 01/17] Xen: ACPI: Hide UART used by Xen
Date: Sat, 26 Mar 2016 12:44:31 +0000 [thread overview]
Message-ID: <alpine.DEB.2.02.1603261238130.18380__6681.86777406863$1458996452$gmane$org@kaball.uk.xensource.com> (raw)
In-Reply-To: <20160325171547.GB29822@localhost>
On Fri, 25 Mar 2016, Bjorn Helgaas wrote:
> On Fri, Mar 25, 2016 at 04:05:49PM +0800, Shannon Zhao wrote:
> > From: Shannon Zhao <shannon.zhao@linaro.org>
> >
> > ACPI 6.0 introduces a new table STAO to list the devices which are used
> > by Xen and can't be used by Dom0. On Xen virtual platforms, the physical
> > UART is used by Xen. So here it hides UART from Dom0.
> >
> > CC: "Rafael J. Wysocki" <rjw@rjwysocki.net> (supporter:ACPI)
> > CC: Len Brown <lenb@kernel.org> (supporter:ACPI)
> > CC: linux-acpi@vger.kernel.org (open list:ACPI)
> > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> > ---
> > drivers/acpi/scan.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 68 insertions(+)
> >
> > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> > index 5f28cf7..5420cc5 100644
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -45,6 +45,7 @@ static LIST_HEAD(acpi_scan_handlers_list);
> > DEFINE_MUTEX(acpi_device_lock);
> > LIST_HEAD(acpi_wakeup_device_list);
> > static DEFINE_MUTEX(acpi_hp_context_lock);
> > +static u64 spcr_uart_addr;
> >
> > struct acpi_dep_data {
> > struct list_head node;
> > @@ -1453,6 +1454,41 @@ static int acpi_add_single_object(struct acpi_device **child,
> > return 0;
> > }
> >
> > +static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
> > + void *context)
> > +{
> > + struct resource *res = context;
> > +
> > + if (acpi_dev_resource_memory(ares, res))
> > + return AE_CTRL_TERMINATE;
> > +
> > + return AE_OK;
> > +}
> > +
> > +static bool acpi_device_should_be_hidden(acpi_handle handle)
> > +{
> > + acpi_status status;
> > + struct resource res;
> > +
> > + /* Check if it should ignore the UART device */
> > + if (spcr_uart_addr != 0) {
> > + if (!acpi_has_method(handle, METHOD_NAME__CRS))
> > + return false;
> > +
> > + status = acpi_walk_resources(handle, METHOD_NAME__CRS,
> > + acpi_get_resource_memory, &res);
> > + if (ACPI_FAILURE(status))
> > + return false;
> > +
> > + if (res.start == spcr_uart_addr) {
> > + printk(KERN_INFO PREFIX "The UART device in SPCR table will be hidden\n");
>
> Can we at least print out the ACPI device path and address here for
> debugging purposes? IMHO, kernel messages that contain only static
> text are always dubious. There's almost always a useful address, IRQ,
> return value, etc., that could be included.
>
> > + return true;
> > + }
> > + }
> > +
> > + return false;
> > +}
> > +
> > static int acpi_bus_type_and_status(acpi_handle handle, int *type,
> > unsigned long long *sta)
> > {
> > @@ -1466,6 +1502,9 @@ static int acpi_bus_type_and_status(acpi_handle handle, int *type,
> > switch (acpi_type) {
> > case ACPI_TYPE_ANY: /* for ACPI_ROOT_OBJECT */
> > case ACPI_TYPE_DEVICE:
> > + if (acpi_device_should_be_hidden(handle))
> > + return -ENODEV;
> > +
> > *type = ACPI_BUS_TYPE_DEVICE;
> > status = acpi_bus_get_status_handle(handle, sta);
> > if (ACPI_FAILURE(status))
> > @@ -1916,9 +1955,24 @@ static int acpi_bus_scan_fixed(void)
> > return result < 0 ? result : 0;
> > }
> >
> > +static void __init acpi_get_spcr_uart_addr(void)
> > +{
> > + acpi_status status;
> > + struct acpi_table_spcr *spcr_ptr;
> > +
> > + status = acpi_get_table(ACPI_SIG_SPCR, 0,
> > + (struct acpi_table_header **)&spcr_ptr);
> > + if (ACPI_SUCCESS(status))
> > + spcr_uart_addr = spcr_ptr->serial_port.address;
> > + else
> > + printk(KERN_WARNING PREFIX "STAO table present, but SPCR is missing\n");
> > +}
> > +
> > int __init acpi_scan_init(void)
> > {
> > int result;
> > + acpi_status status;
> > + struct acpi_table_stao *stao_ptr;
> >
> > acpi_pci_root_init();
> > acpi_pci_link_init();
> > @@ -1934,6 +1988,20 @@ int __init acpi_scan_init(void)
> >
> > acpi_scan_add_handler(&generic_device_handler);
> >
> > + /*
> > + * If there is STAO table, check whether it needs to ignore the UART
> > + * device in SPCR table.
> > + */
> > + status = acpi_get_table(ACPI_SIG_STAO, 0,
> > + (struct acpi_table_header **)&stao_ptr);
> > + if (ACPI_SUCCESS(status)) {
> > + if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
> > + printk(KERN_INFO PREFIX "STAO Name List not yet supported.");
> > +
> > + if (stao_ptr->ignore_uart)
> > + acpi_get_spcr_uart_addr();
> > + }
>
> This all seems sort of ad hoc. Are UARTs the only things that can be
> listed in STAO? If STAO can contain things other than UARTs, are we
> going to see more patches adding special-case code like this?
The UART (specifically the UART described by the SPCR table) is the only
object which needs special-casing. Everything else is covered by ACPI
namespace paths (which is what the message above is about, given that it
is not supported by this patch).
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2016-03-26 12:44 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1458830676-27075-1-git-send-email-shannon.zhao@linaro.org>
2016-03-24 14:44 ` [PATCH v7 01/17] Xen: ACPI: Hide UART used by Xen Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 02/17] xen/grant-table: Move xlated_setup_gnttab_pages to common place Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 03/17] Xen: xlate: Use page_to_xen_pfn instead of page_to_pfn Shannon Zhao
2016-03-29 16:28 ` Julien Grall
[not found] ` <56FAAD48.2010401@arm.com>
2016-03-30 7:38 ` Shannon Zhao
[not found] ` <56FB8258.7030303@huawei.com>
2016-03-30 11:22 ` Julien Grall
[not found] ` <56FBB709.5050802@arm.com>
2016-03-30 12:42 ` Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 04/17] arm/xen: Use xen_xlate_map_ballooned_pages to setup grant table Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 05/17] xen: memory : Add new XENMAPSPACE type XENMAPSPACE_dev_mmio Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 06/17] Xen: ARM: Add support for mapping platform device mmio Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 07/17] Xen: ARM: Add support for mapping AMBA " Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 08/17] Xen: public/hvm: sync changes of HVM_PARAM_CALLBACK_VIA ABI from Xen Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 09/17] xen/hvm/params: Add a new delivery type for event-channel in HVM_PARAM_CALLBACK_IRQ Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 10/17] arm/xen: Get event-channel irq through HVM_PARAM when booting with ACPI Shannon Zhao
2016-03-29 16:35 ` Julien Grall
[not found] ` <56FAAEED.7060108@arm.com>
2016-03-30 7:34 ` Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 11/17] ARM: XEN: Move xen_early_init() before efi_init() Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 12/17] ARM64: ACPI: Check if it runs on Xen to enable or disable ACPI Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 13/17] ARM: Xen: Document UEFI support on Xen ARM virtual platforms Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 14/17] XEN: EFI: Move x86 specific codes to architecture directory Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 15/17] ARM64: XEN: Add a function to initialize Xen specific UEFI runtime services Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 16/17] FDT: Add a helper to get the subnode by given name Shannon Zhao
2016-03-24 14:44 ` [PATCH v7 17/17] Xen: EFI: Parse DT parameters for Xen specific UEFI Shannon Zhao
[not found] ` <1458830676-27075-2-git-send-email-shannon.zhao@linaro.org>
2016-03-24 15:08 ` [PATCH v7 01/17] Xen: ACPI: Hide UART used by Xen Rafael J. Wysocki
[not found] ` <CAJZ5v0iGHj1Hb3s=uJ34j0m88+3xtBQhbX47got=z1Ah_=LrkQ@mail.gmail.com>
2016-03-25 7:38 ` Shannon Zhao
2016-03-25 8:05 ` [PATCH v8 " Shannon Zhao
[not found] ` <1458893149-17388-1-git-send-email-zhaoshenglong@huawei.com>
2016-03-25 17:00 ` Rafael J. Wysocki
2016-03-25 17:15 ` Bjorn Helgaas
[not found] ` <7418231.W9aSFKr1zs@vostro.rjw.lan>
2016-03-26 13:14 ` Stefano Stabellini
[not found] ` <20160325171547.GB29822@localhost>
2016-03-26 12:44 ` Stefano Stabellini [this message]
2016-03-29 8:00 ` Shannon Zhao
2016-03-29 8:08 ` [RESEND PATCH v9 " Shannon Zhao
[not found] ` <1458830676-27075-12-git-send-email-shannon.zhao@linaro.org>
2016-03-26 12:54 ` [PATCH v7 11/17] ARM: XEN: Move xen_early_init() before efi_init() Stefano Stabellini
[not found] ` <alpine.DEB.2.02.1603261252510.18380@kaball.uk.xensource.com>
2016-03-29 16:07 ` Will Deacon
[not found] ` <20160329160756.GG6745@arm.com>
2016-03-31 11:12 ` Stefano Stabellini
[not found] ` <1458830676-27075-13-git-send-email-shannon.zhao@linaro.org>
2016-03-26 12:56 ` [PATCH v7 12/17] ARM64: ACPI: Check if it runs on Xen to enable or disable ACPI Stefano Stabellini
2016-03-29 16:18 ` Will Deacon
[not found] ` <20160329161837.GH6745@arm.com>
2016-03-29 16:31 ` Mark Rutland
[not found] ` <20160329163147.GB27223@leverpostej>
2016-03-30 7:19 ` Shannon Zhao
[not found] ` <56FB7E00.7030400@huawei.com>
2016-03-31 11:04 ` Stefano Stabellini
[not found] ` <alpine.DEB.2.02.1603311155450.11739@kaball.uk.xensource.com>
2016-03-31 11:44 ` Ard Biesheuvel
[not found] ` <CAKv+Gu-wPq_FzO3sm7bhSFuu7EVxHWB_v6HOn1GqNbdaE-iBoQ@mail.gmail.com>
2016-03-31 12:42 ` Mark Rutland
[not found] ` <20160331124216.GE26532@leverpostej>
2016-04-01 9:25 ` Shannon Zhao
[not found] ` <56FE3E85.60403@huawei.com>
2016-04-01 9:32 ` Shannon Zhao
[not found] ` <1458830676-27075-14-git-send-email-shannon.zhao@linaro.org>
2016-03-29 17:21 ` [PATCH v7 13/17] ARM: Xen: Document UEFI support on Xen ARM virtual platforms Julien Grall
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='alpine.DEB.2.02.1603261238130.18380__6681.86777406863$1458996452$gmane$org@kaball.uk.xensource.com' \
--to=stefano.stabellini@eu.citrix.com \
--cc=catalin.marinas@arm.com \
--cc=david.vrabel@citrix.com \
--cc=devicetree@vger.kernel.org \
--cc=helgaas@kernel.org \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peter.huangpeng@huawei.com \
--cc=rjw@rjwysocki.net \
--cc=shannon.zhao@linaro.org \
--cc=stefano.stabellini@citrix.com \
--cc=will.deacon@arm.com \
--cc=xen-devel@lists.xen.org \
--cc=zhaoshenglong@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).