[RFC PATCH V5 5/5] PCI: thunder-pem: Support quirky configuration space access for ACPI based PCI host controller
Tomasz Nowicki
tn at semihalf.com
Tue Sep 6 11:01:18 PDT 2016
On 05.09.2016 04:34, Bjorn Helgaas wrote:
> On Mon, Aug 08, 2016 at 03:05:41PM +0200, Tomasz Nowicki wrote:
>> Add infrastructure to support ThunderX PEM specific PCI configuration space
>> access for ACPI based PCI host controller. This involves:
>> 1. New initialization call thunder_pem_cfg_init() to create configuration
>> space mapping based on hardcoded range addresses
>> 2. thunder_pem_init() ACPI extension to obtain hardcoded addresses for
>> PEM specific register ranges
>> 3. New quirk entry (for common quirk array) which identifies platform and
>> calls thunder_pem_cfg_init() from [1]
>
> Is it possible to split this up a little bit? I *hope* most quirks
> aren't as complicated as all this. It'd be nice to make the actual
> quirk patches as small as possible so they can be easily copied and
> adapted.
Yes this is a complicated quirk example. Next time I will include a
simple one as well.
Also, I will split this patch as you suggested.
>
> Another question below...
>
>> Signed-off-by: Tomasz Nowicki <tn at semihalf.com>
>> ---
>> drivers/pci/host/mcfg-quirks.c | 7 +++
>> drivers/pci/host/mcfg-quirks.h | 4 ++
>> drivers/pci/host/pci-thunder-pem.c | 96 ++++++++++++++++++++++++++++++++------
>> 3 files changed, 94 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/pci/host/mcfg-quirks.c b/drivers/pci/host/mcfg-quirks.c
>> index aa9907b..2993a72 100644
>> --- a/drivers/pci/host/mcfg-quirks.c
>> +++ b/drivers/pci/host/mcfg-quirks.c
>> @@ -44,6 +44,13 @@ struct pci_cfg_fixup {
>>
>> static struct pci_cfg_fixup mcfg_quirks[] __initconst = {
>> /* { OEM_ID, OEM_TABLE_ID, REV, DOMAIN, BUS_RANGE, pci_ops, init_hook }, */
>> +#ifdef CONFIG_PCI_HOST_THUNDER_PEM
>> + /* Pass2.0 */
>> + { "CAVIUM", "THUNDERX", 1, MCFG_DOM_RANGE(4, 9), MCFG_BUS_ANY, NULL,
>> + thunder_pem_cfg_init },
>> + { "CAVIUM", "THUNDERX", 1, MCFG_DOM_RANGE(14, 19), MCFG_BUS_ANY, NULL,
>> + thunder_pem_cfg_init },
>> +#endif
>> };
>>
>> static bool pci_mcfg_fixup_match(struct pci_cfg_fixup *f,
>> diff --git a/drivers/pci/host/mcfg-quirks.h b/drivers/pci/host/mcfg-quirks.h
>> index 45cbd16..411c667 100644
>> --- a/drivers/pci/host/mcfg-quirks.h
>> +++ b/drivers/pci/host/mcfg-quirks.h
>> @@ -16,5 +16,9 @@
>> #define __MCFG_QUIRKS_H__
>>
>> /* MCFG quirks initialize call list */
>> +#ifdef CONFIG_PCI_HOST_THUNDER_PEM
>> +struct pci_config_window *
>> +thunder_pem_cfg_init(struct acpi_pci_root *root, struct pci_ops *ops);
>> +#endif
>>
>> #endif /* __MCFG_QUIRKS_H__ */
>> diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c
>> index 6abaf80..3f06e49 100644
>> --- a/drivers/pci/host/pci-thunder-pem.c
>> +++ b/drivers/pci/host/pci-thunder-pem.c
>> @@ -18,9 +18,12 @@
>> #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>
>>
>> +#include "mcfg-quirks.h"
>> +
>> #define PEM_CFG_WR 0x28
>> #define PEM_CFG_RD 0x30
>>
>> @@ -284,6 +287,37 @@ 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),
>> +};
>> +
>> +static struct resource *thunder_pem_acpi_res(struct pci_config_window *cfg)
>> +{
>> + struct acpi_device *adev = to_acpi_device(cfg->parent);
>> + struct acpi_pci_root *root = acpi_driver_data(adev);
>> +
>> + return &thunder_pem_reg_res[root->segment];
>> +}
>> +#else
>> +static struct resource *thunder_pem_acpi_res(struct pci_config_window *cfg)
>> +{
>> + return NULL;
>> +}
>> +#endif
>> +
>> static int thunder_pem_init(struct pci_config_window *cfg)
>> {
>> struct device *dev = cfg->parent;
>> @@ -292,24 +326,24 @@ static int thunder_pem_init(struct pci_config_window *cfg)
>> struct thunder_pem_pci *pem_pci;
>> struct platform_device *pdev;
>>
>> - /* Only OF support for now */
>> - if (!dev->of_node)
>> - return -EINVAL;
>> -
>> pem_pci = devm_kzalloc(dev, sizeof(*pem_pci), GFP_KERNEL);
>> if (!pem_pci)
>> return -ENOMEM;
>>
>> - pdev = to_platform_device(dev);
>> -
>> - /*
>> - * The second register range is the PEM bridge to the PCIe
>> - * bus. It has a different config access method than those
>> - * devices behind the bridge.
>> - */
>> - res_pem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>> + if (acpi_disabled) {
>> + pdev = to_platform_device(dev);
>> +
>> + /*
>> + * The second register range is the PEM bridge to the PCIe
>> + * bus. It has a different config access method than those
>> + * devices behind the bridge.
>> + */
>> + res_pem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>> + } else {
>> + res_pem = thunder_pem_acpi_res(cfg);
>> + }
>> if (!res_pem) {
>> - dev_err(dev, "missing \"reg[1]\"property\n");
>> + dev_err(dev, "missing configuration region\n");
>> return -EINVAL;
>> }
>>
>> @@ -360,3 +394,39 @@ static struct platform_driver thunder_pem_driver = {
>> .probe = thunder_pem_probe,
>> };
>> builtin_platform_driver(thunder_pem_driver);
>> +
>> +#ifdef CONFIG_ACPI
>> +
>> +static struct resource thunder_pem_cfg_res[] = {
>> + [4] = DEFINE_RES_MEM(0x88001f000000UL, 0x39 * SZ_16M),
>> + [5] = DEFINE_RES_MEM(0x884057000000UL, 0x39 * SZ_16M),
>> + [6] = DEFINE_RES_MEM(0x88808f000000UL, 0x39 * SZ_16M),
>> + [7] = DEFINE_RES_MEM(0x89001f000000UL, 0x39 * SZ_16M),
>> + [8] = DEFINE_RES_MEM(0x894057000000UL, 0x39 * SZ_16M),
>> + [9] = DEFINE_RES_MEM(0x89808f000000UL, 0x39 * SZ_16M),
>> + [14] = DEFINE_RES_MEM(0x98001f000000UL, 0x39 * SZ_16M),
>> + [15] = DEFINE_RES_MEM(0x984057000000UL, 0x39 * SZ_16M),
>> + [16] = DEFINE_RES_MEM(0x98808f000000UL, 0x39 * SZ_16M),
>> + [17] = DEFINE_RES_MEM(0x99001f000000UL, 0x39 * SZ_16M),
>> + [18] = DEFINE_RES_MEM(0x994057000000UL, 0x39 * SZ_16M),
>> + [19] = DEFINE_RES_MEM(0x99808f000000UL, 0x39 * SZ_16M),
>> +};
>> +
>> +struct pci_config_window *
>> +thunder_pem_cfg_init(struct acpi_pci_root *root, struct pci_ops *ops)
>> +{
>> + struct resource *bus_res = &root->secondary;
>> + u16 seg = root->segment;
>> + struct pci_config_window *cfg;
>> +
>> + cfg = pci_ecam_create(&root->device->dev, &thunder_pem_cfg_res[seg],
>> + bus_res, &pci_thunder_pem_ops);
>
> What happens when root->segment is not one of the values defined in
> thunder_pem_cfg_res[], say "0"? I *think* pci_ecam_create() will see
> cfgres as all zeros, and the request_resource_conflict() will probably
> fail. That doesn't seem like a very graceful way to report a firmware
> error.
Right, I will fix it. Thanks.
Tomasz
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