From: Tomasz Nowicki <tn@semihalf.com>
To: Bjorn Helgaas <helgaas@kernel.org>, ddaney@caviumnetworks.com
Cc: will.deacon@arm.com, catalin.marinas@arm.com, rafael@kernel.org,
Lorenzo.Pieralisi@arm.com, arnd@arndb.de, hanjun.guo@linaro.org,
okaya@codeaurora.org, jchandra@broadcom.com, cov@codeaurora.org,
dhdang@apm.com, ard.biesheuvel@linaro.org,
robert.richter@caviumnetworks.com, mw@semihalf.com,
Liviu.Dudau@arm.com, wangyijing@huawei.com, msalter@redhat.com,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linaro-acpi@lists.linaro.org, jcm@redhat.com,
andrea.gallo@linaro.org, jeremy.linton@arm.com,
liudongdong3@huawei.com, gabriele.paoloni@huawei.com,
jhugo@codeaurora.org, linux-acpi@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH V6 3/5] PCI: thunder-pem: Allow to probe PEM-specific register range for ACPI case
Date: Tue, 20 Sep 2016 09:23:21 +0200 [thread overview]
Message-ID: <49f53bfc-4421-a8b0-694c-bce7e61e1c9e@semihalf.com> (raw)
In-Reply-To: <20160919180900.GB13775@localhost>
On 19.09.2016 20:09, Bjorn Helgaas wrote:
> On Fri, Sep 09, 2016 at 09:24:05PM +0200, Tomasz Nowicki wrote:
>> thunder-pem driver stands for being ACPI based PCI host controller.
>> However, there is no standard way to describe its PEM-specific register
>> ranges in ACPI tables. Thus we add thunder_pem_init() ACPI extension
>> to obtain hardcoded addresses from static resource array.
>> Although it is not pretty, it prevents from creating standard mechanism to
>> handle similar cases in future.
>>
>> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
>> ---
>> drivers/pci/host/pci-thunder-pem.c | 61 ++++++++++++++++++++++++++++++--------
>> 1 file changed, 48 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c
>> index 6abaf80..b048761 100644
>> --- a/drivers/pci/host/pci-thunder-pem.c
>> +++ b/drivers/pci/host/pci-thunder-pem.c
>> @@ -18,6 +18,7 @@
>> #include <linux/init.h>
>> #include <linux/of_address.h>
>> #include <linux/of_pci.h>
>> +#include <linux/pci-acpi.h>
>> #include <linux/pci-ecam.h>
>> #include <linux/platform_device.h>
>>
>> @@ -284,6 +285,40 @@ static int thunder_pem_config_write(struct pci_bus *bus, unsigned int devfn,
>> return pci_generic_config_write(bus, devfn, where, size, val);
>> }
>>
>> +#ifdef CONFIG_ACPI
>> +static struct resource thunder_pem_reg_res[] = {
>> + [4] = DEFINE_RES_MEM(0x87e0c0000000UL, SZ_16M),
>> + [5] = DEFINE_RES_MEM(0x87e0c1000000UL, SZ_16M),
>> + [6] = DEFINE_RES_MEM(0x87e0c2000000UL, SZ_16M),
>> + [7] = DEFINE_RES_MEM(0x87e0c3000000UL, SZ_16M),
>> + [8] = DEFINE_RES_MEM(0x87e0c4000000UL, SZ_16M),
>> + [9] = DEFINE_RES_MEM(0x87e0c5000000UL, SZ_16M),
>> + [14] = DEFINE_RES_MEM(0x97e0c0000000UL, SZ_16M),
>> + [15] = DEFINE_RES_MEM(0x97e0c1000000UL, SZ_16M),
>> + [16] = DEFINE_RES_MEM(0x97e0c2000000UL, SZ_16M),
>> + [17] = DEFINE_RES_MEM(0x97e0c3000000UL, SZ_16M),
>> + [18] = DEFINE_RES_MEM(0x97e0c4000000UL, SZ_16M),
>> + [19] = DEFINE_RES_MEM(0x97e0c5000000UL, SZ_16M),
>
> 1) The "correct" way to discover the resources consumed by an ACPI
> device is to use the _CRS method. I know there are some issues
> there for bridges (not the fault of ThunderX!) because there's not
> a good way to distinguish windows from resources consumed directly
> by the bridge.
>
> But we should either do this correctly, or include a comment about
> why we're doing it wrong, so we don't give the impression that this
> is the right way to do it.
>
> I seem to recall some discussion about why we're doing it this way,
> but I don't remember the details. It'd be nice to include a
> summary here.
OK I will. The reason why we cannot use _CRS for this case is that
CONSUMER flag was not use consistently for the bridge so far.
>
> 2) This is a little weird because here we define the resource size as
> 16MB, in the OF case we get the resource size from OF, in either
> case we ioremap 64K of it, and then as far as I can tell, we only
> ever access PEM_CFG_WR and PEM_CFG_RD, at offsets 0x28 and 0x30
> into the space.
>
> If the hardware actually decodes the entire 16MB, we should ioremap
> the whole 16MB. (Strictly speaking, drivers only need to ioremap
> the parts they're using, but in this case nobody claims the entire
> resource because of deficiencies in the ACPI and OF cores, so the
> driver should ioremap the entire thing to help prevent conflicts
> with other devices.)
>
> It'd be nice if we didn't have the 64KB magic number. I think
> using devm_ioremap_resource() would be nice.
I agree.
David, is there anything which prevents us from using
devm_ioremap_resource() here with SZ_16M size?
Tomasz
next prev parent reply other threads:[~2016-09-20 7:23 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-09 19:24 [PATCH V6 0/5] ECAM quirks handling for ARM64 platforms Tomasz Nowicki
2016-09-09 19:24 ` [PATCH V6 1/5] PCI/ACPI: Extend pci_mcfg_lookup() responsibilities Tomasz Nowicki
2016-09-09 19:24 ` [PATCH V6 2/5] PCI/ACPI: Check platform specific ECAM quirks Tomasz Nowicki
2016-09-12 22:24 ` Duc Dang
2016-09-12 22:47 ` Duc Dang
2016-09-13 5:58 ` Tomasz Nowicki
2016-09-13 6:37 ` Tomasz Nowicki
2016-09-13 2:36 ` Dongdong Liu
2016-09-13 6:32 ` Tomasz Nowicki
2016-09-13 11:38 ` Dongdong Liu
2016-09-14 12:40 ` Lorenzo Pieralisi
2016-09-15 10:58 ` Lorenzo Pieralisi
2016-09-16 9:02 ` Gabriele Paoloni
2016-09-16 12:27 ` Christopher Covington
2016-09-16 13:42 ` Gabriele Paoloni
2016-09-09 19:24 ` [PATCH V6 3/5] PCI: thunder-pem: Allow to probe PEM-specific register range for ACPI case Tomasz Nowicki
2016-09-19 18:09 ` Bjorn Helgaas
2016-09-20 7:23 ` Tomasz Nowicki [this message]
2016-09-20 13:33 ` Bjorn Helgaas
2016-09-20 13:40 ` Ard Biesheuvel
2016-09-20 14:05 ` Bjorn Helgaas
2016-09-20 15:09 ` Ard Biesheuvel
2016-09-20 19:17 ` Bjorn Helgaas
2016-09-21 14:05 ` Lorenzo Pieralisi
2016-09-21 18:04 ` Bjorn Helgaas
2016-09-21 18:58 ` Duc Dang
2016-09-21 19:18 ` Bjorn Helgaas
2016-09-23 10:53 ` Tomasz Nowicki
2016-09-22 9:49 ` Lorenzo Pieralisi
2016-09-22 11:10 ` Gabriele Paoloni
2016-09-22 12:44 ` Lorenzo Pieralisi
2016-09-22 18:31 ` Bjorn Helgaas
2016-09-22 22:10 ` Bjorn Helgaas
2016-09-23 10:11 ` Lorenzo Pieralisi
2016-09-23 10:58 ` Gabriele Paoloni
2017-09-14 14:06 ` Ard Biesheuvel
2017-09-26 8:23 ` Gabriele Paoloni
2016-09-22 14:20 ` Christopher Covington
2016-09-21 14:10 ` Gabriele Paoloni
2016-09-21 18:59 ` Bjorn Helgaas
2016-09-22 11:12 ` Gabriele Paoloni
2016-09-09 19:24 ` [PATCH V6 4/5] PCI: thunder: Enable ACPI PCI controller for ThunderX pass2.x silicon version Tomasz Nowicki
2016-09-19 15:45 ` Bjorn Helgaas
2016-09-20 7:06 ` Tomasz Nowicki
2016-09-20 13:08 ` Bjorn Helgaas
2016-09-21 8:05 ` Tomasz Nowicki
2016-09-09 19:24 ` [PATCH V6 5/5] PCI: thunder: Enable ACPI PCI controller for ThunderX pass1.x " Tomasz Nowicki
2016-09-09 19:30 ` [PATCH V6 0/5] ECAM quirks handling for ARM64 platforms Tomasz Nowicki
2016-09-20 19:26 ` Bjorn Helgaas
2016-09-21 1:15 ` cov
2016-09-21 13:11 ` Bjorn Helgaas
2016-09-21 14:07 ` Sinan Kaya
2016-09-21 17:31 ` Bjorn Helgaas
2016-09-21 17:34 ` Sinan Kaya
2016-09-21 22:38 ` [PATCHv2] PCI: QDF2432 32 bit config space accessors Christopher Covington
2016-10-31 21:48 ` Bjorn Helgaas
2016-11-01 13:06 ` cov
2016-11-02 16:08 ` Bjorn Helgaas
2016-11-02 16:36 ` Sinan Kaya
2016-11-03 14:00 ` Bjorn Helgaas
2016-11-03 16:58 ` Sinan Kaya
2016-11-03 17:06 ` Sinan Kaya
2016-11-03 20:43 ` Bjorn Helgaas
2016-11-03 23:49 ` Sinan Kaya
2016-12-02 4:58 ` Jon Masters
2016-11-02 16:41 ` Bjorn Helgaas
2016-11-09 19:25 ` Christopher Covington
2016-11-09 20:06 ` Bjorn Helgaas
2016-11-09 20:29 ` Ard Biesheuvel
2016-11-09 22:49 ` Bjorn Helgaas
2016-11-10 10:25 ` Ard Biesheuvel
2016-11-10 13:57 ` Lorenzo Pieralisi
2016-11-10 17:42 ` Bjorn Helgaas
2016-12-02 5:12 ` Jon Masters
2016-09-21 22:40 ` [PATCH V6 0/5] ECAM quirks handling for ARM64 platforms Christopher Covington
2016-09-22 23:08 ` Bjorn Helgaas
2016-09-23 18:41 ` Christopher Covington
2016-09-23 19:17 ` Bjorn Helgaas
2016-09-23 19:22 ` Christopher Covington
2016-11-24 11:05 ` [PATCH V6 1/1] ARM64/PCI: Manage controller-specific information on the host controller basis Tomasz Nowicki
2016-11-29 23:40 ` Bjorn Helgaas
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