Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1409222 > unrolled thread

[PATCH V8 0/9] Support for ARM64 ACPI based PCI host controller

Back to article view | Back to linux.kernel

Contents

  [PATCH V8 0/9] Support for ARM64 ACPI based PCI host controller Tomasz Nowicki <tn@semihalf.com> - 2016-05-30 17:20 +0200
    [PATCH V8 4/9] acpi, pci: Support IO resources when parsing PCI host bridge resources. Tomasz Nowicki <tn@semihalf.com> - 2016-05-30 17:20 +0200
    [PATCH V8 9/9] pci, acpi: ARM64 support for ACPI based generic PCI host controller Tomasz Nowicki <tn@semihalf.com> - 2016-05-30 17:20 +0200
      Re: [PATCH V8 9/9] pci, acpi: ARM64 support for ACPI based generic PCI host controller Arnd Bergmann <arnd@arndb.de> - 2016-05-30 17:40 +0200
        Re: [PATCH V8 9/9] pci, acpi: ARM64 support for ACPI based generic  PCI host controller Jayachandran C <jchandra@broadcom.com> - 2016-05-30 18:20 +0200

#1409222 — [PATCH V8 0/9] Support for ARM64 ACPI based PCI host controller

From the functionality point of view this series may be split into the
following logic parts:
1. Export ECAM API and add parent device to pci_config_window
2. Add IO resources handling to PCI core code
3. Support for generic domain assignment based on ACPI
4. New MCFG driver
5. Implement ARM64 ACPI based PCI host controller driver under arch/arm64/

Patches has been built on top of 4.7-rc1 and can be found here:
git@github.com:semihalf-nowicki-tomasz/linux.git (pci-acpi-v8)

This has been tested on Cavium ThunderX server. Any help in reviewing and
testing is very appreciated.

v7 -> v8
- move code from drivers/acpi/pci_root_generic.c to arch/arm64/kernel/pci.c
- minor changes around domain assignment
- pci_mcfg.c improvements for parsing MCFG tables and lookup its entries

v6 -> v7
- drop quirks handling
- changes for ACPI companion and domain number assignment approach
- implement arch pcibios_{add|remove}_bus and call acpi_pci_{add|remove}_bus from there
- cleanups around nomenclature
- use resources oriented API for ECAM
- fix for based address calculation before mapping ECAM region
- remove useless lock for MCFG lookup
- move MCFG stuff to separated file pci_mcfg.c
- drop MCFG entries caching
- rebase against 4.6-rc7

v5 -> v6
- drop idea of x86 MMCONFIG code refactoring
- integrate JC's patches which introduce new ECAM API:
  https://lkml.org/lkml/2016/4/11/907
  git: https://github.com/jchandra-brcm/linux/ (arm64-acpi-pci-v3)
- integrate Sinan's fix for releasing IO resources, see patch [06/13]
- added ACPI support for ThunderX ECAM and PEM drivers
- rebase against 4.6-rc2

v4 -> v5
- drop MCFG refactoring group patches 1-6 from series v4 and integrate Jayachandran's patch
  https://patchwork.ozlabs.org/patch/575525/
- rewrite PCI legacy IRQs allocation
- squash two patches 11 and 12 from series v4, fixed bisection issue
- changelog improvements
- rebase against 4.5-rc3

v3 -> v4
- drop Jiang's fix http://lkml.iu.edu/hypermail/linux/kernel/1601.1/04318.html
- add Lorenzo's fix patch 19/24
- ACPI PCI bus domain number assigning cleanup
- change resource management, we now claim and reassign resources
- improvements for applying quirks
- drop Matthew's http://www.spinics.net/lists/linux-pci/msg45950.html dependency
- rebase against 4.5-rc1

v2 -> v3
- fix legacy IRQ assigning and IO ports registration
- remove reference to arch specific companion device for ia64
- move ACPI PCI host controller driver to pci_root.c
- drop generic domain assignment for x86 and ia64 as I am not
  able to run all necessary test variants
- drop patch which cleaned legacy IRQ assignment since it belongs to
  Mathew's series:
  https://patchwork.ozlabs.org/patch/557504/
- extend MCFG quirk code
- rebase against 4.4

v1 -> v2
- move non-arch specific piece of code to dirver/acpi/ directory
- fix IO resource handling
- introduce PCI config accessors quirks matching
- moved ACPI_COMPANION_SET to generic code

v1 - https://lkml.org/lkml/2015/10/27/504
v2 - https://lkml.org/lkml/2015/12/16/246
v3 - http://lkml.iu.edu/hypermail/linux/kernel/1601.1/04308.html
v4 - https://lkml.org/lkml/2016/2/4/646
v5 - https://lkml.org/lkml/2016/2/16/426
v6 - https://lkml.org/lkml/2016/4/15/594

Jayachandran C (2):
  PCI: ecam: move ecam.h to linux/include/pci-ecam.h
  PCI: ecam: Add parent device field to pci_config_window

Tomasz Nowicki (7):
  pci: Add new function to unmap IO resources.
  acpi, pci: Support IO resources when parsing PCI host bridge
    resources.
  pci, acpi: add acpi hook to assign domain number.
  arm64, pci, acpi: ACPI support for legacy IRQs parsing and
    consolidation with DT code.
  acpi: Add generic MCFG table handling
  arm64, pci, acpi: Provide ACPI-specific prerequisites for PCI bus
    enumeration.
  pci, acpi: ARM64 support for ACPI based generic PCI host controller

 arch/arm64/Kconfig                  |   2 +
 arch/arm64/kernel/pci.c             | 143 ++++++++++++++++++++++++++++++++++--
 drivers/acpi/Kconfig                |   3 +
 drivers/acpi/Makefile               |   1 +
 drivers/acpi/pci_mcfg.c             |  94 ++++++++++++++++++++++++
 drivers/acpi/pci_root.c             |  39 ++++++++++
 drivers/pci/ecam.c                  |   6 +-
 drivers/pci/ecam.h                  |  67 -----------------
 drivers/pci/host/pci-host-common.c  |   3 +-
 drivers/pci/host/pci-host-generic.c |   3 +-
 drivers/pci/host/pci-thunder-ecam.c |   3 +-
 drivers/pci/host/pci-thunder-pem.c  |   6 +-
 drivers/pci/pci.c                   |  29 +++++++-
 include/linux/pci-acpi.h            |   2 +
 include/linux/pci-ecam.h            |  67 +++++++++++++++++
 include/linux/pci.h                 |   9 ++-
 16 files changed, 387 insertions(+), 90 deletions(-)
 create mode 100644 drivers/acpi/pci_mcfg.c
 delete mode 100644 drivers/pci/ecam.h
 create mode 100644 include/linux/pci-ecam.h

-- 
1.9.1

[toc] | [next] | [standalone]

#1409223 — [PATCH V8 4/9] acpi, pci: Support IO resources when parsing PCI host bridge resources.

Platforms that have memory mapped IO port (such as ARM64) need special
handling for PCI I/O resources. For host bridge's resource probing case
these resources need to be fixed up with pci_register_io_range/pci_remap_iospace etc.

The same I/O resources need to be released after hotplug
removal so that it can be re-added back by the pci_remap_iospace
function during insertion. As a consequence we unmap I/O resources
with pci_unmap_iospace when we release host bridge resources.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
---
 drivers/acpi/pci_root.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index ae3fe4e..ee3b728 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -720,6 +720,40 @@ next:
 	}
 }
 
+#ifdef PCI_IOBASE
+static void acpi_pci_root_remap_iospace(struct resource_entry *entry)
+{
+	struct resource *res = entry->res;
+	resource_size_t cpu_addr = res->start;
+	resource_size_t pci_addr = cpu_addr - entry->offset;
+	resource_size_t length = resource_size(res);
+	unsigned long port;
+
+	if (pci_register_io_range(cpu_addr, length))
+		goto err;
+
+	port = pci_address_to_pio(cpu_addr);
+	if (port == (unsigned long)-1)
+		goto err;
+
+	res->start = port;
+	res->end = port + length - 1;
+	entry->offset = port - pci_addr;
+
+	if (pci_remap_iospace(res, cpu_addr) < 0)
+		goto err;
+
+	pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
+	return;
+err:
+	res->flags |= IORESOURCE_DISABLED;
+}
+#else
+static void acpi_pci_root_remap_iospace(struct resource_entry *entry)
+{
+}
+#endif
+
 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 {
 	int ret;
@@ -740,6 +774,9 @@ int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 			"no IO and memory resources present in _CRS\n");
 	else {
 		resource_list_for_each_entry_safe(entry, tmp, list) {
+			if (entry->res->flags & IORESOURCE_IO)
+				acpi_pci_root_remap_iospace(entry);
+
 			if (entry->res->flags & IORESOURCE_DISABLED)
 				resource_list_destroy_entry(entry);
 			else
@@ -811,6 +848,8 @@ static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
 
 	resource_list_for_each_entry(entry, &bridge->windows) {
 		res = entry->res;
+		if (res->flags & IORESOURCE_IO)
+			pci_unmap_iospace(res);
 		if (res->parent &&
 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 			release_resource(res);
-- 
1.9.1

[toc] | [prev] | [next] | [standalone]

#1409225 — [PATCH V8 9/9] pci, acpi: ARM64 support for ACPI based generic PCI host controller

This patch implements pci_acpi_scan_root call so that ARM64 can start
using ACPI to setup and enumerate PCI buses.

The implementation of pci_acpi_scan_root() looks up config space regions
through MCFG interface. Then ECAM library is doing a new mapping
and attach generic ECAM ops which are used for accessing config space.

On ARM64, ACPI and DT can be enabled together, and in that case
we need to use generic domains. In order to do that we implement
ARM64 specific way of retrieving domain number from pci_config_window
structure.

Since we enable PCI for ACPI we need to implement raw_pci_{read|write}
at the same time. ARM64 provides RAW accessors as long as there is
correlated valid pci_bus structure, but not before.

Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
---
 arch/arm64/Kconfig      |   2 +
 arch/arm64/kernel/pci.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++--
 include/linux/pci.h     |   5 ++
 3 files changed, 122 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 76747d9..87c48ad 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -3,6 +3,7 @@ config ARM64
 	select ACPI_CCA_REQUIRED if ACPI
 	select ACPI_GENERIC_GSI if ACPI
 	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
+	select ACPI_MCFG if ACPI
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_ELF_RANDOMIZE
@@ -96,6 +97,7 @@ config ARM64
 	select OF_EARLY_FLATTREE
 	select OF_NUMA if NUMA && OF
 	select OF_RESERVED_MEM
+	select PCI_ECAM if ACPI
 	select PERF_USE_VMALLOC
 	select POWER_RESET
 	select POWER_SUPPLY
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index 3663be1..39f2a40 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -17,7 +17,9 @@
 #include <linux/mm.h>
 #include <linux/of_pci.h>
 #include <linux/of_platform.h>
+#include <linux/pci.h>
 #include <linux/pci-acpi.h>
+#include <linux/pci-ecam.h>
 #include <linux/slab.h>
 
 /*
@@ -71,13 +73,21 @@ int pcibios_alloc_irq(struct pci_dev *dev)
 int raw_pci_read(unsigned int domain, unsigned int bus,
 		  unsigned int devfn, int reg, int len, u32 *val)
 {
-	return -ENXIO;
+	struct pci_bus *b = pci_find_bus(domain, bus);
+
+	if (!b)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	return b->ops->read(b, devfn, reg, len, val);
 }
 
 int raw_pci_write(unsigned int domain, unsigned int bus,
 		unsigned int devfn, int reg, int len, u32 val)
 {
-	return -ENXIO;
+	struct pci_bus *b = pci_find_bus(domain, bus);
+
+	if (!b)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	return b->ops->write(b, devfn, reg, len, val);
 }
 
 #ifdef CONFIG_NUMA
@@ -91,11 +101,111 @@ EXPORT_SYMBOL(pcibus_to_node);
 #endif
 
 #ifdef CONFIG_ACPI
-/* Root bridge scanning */
+
+struct acpi_pci_generic_root_info {
+	struct acpi_pci_root_info	common;
+	struct pci_config_window	*cfg;	/* config space mapping */
+};
+
+int acpi_pci_bus_domain_nr(struct pci_bus *bus)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+	struct acpi_device *adev = to_acpi_device(cfg->parent);
+	struct acpi_pci_root *root = acpi_driver_data(adev);
+
+	return root->segment;
+}
+
+int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
+{
+	if (!acpi_disabled) {
+		struct pci_config_window *cfg = bridge->bus->sysdata;
+		struct acpi_device *adev = to_acpi_device(cfg->parent);
+		ACPI_COMPANION_SET(&bridge->dev, adev);
+	}
+
+	return 0;
+}
+
+/*
+ * Lookup the bus range for the domain in MCFG, and set up config space
+ * mapping.
+ */
+static int pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root,
+				       struct acpi_pci_generic_root_info *ri)
+{
+	struct resource *bus_res = &root->secondary;
+	u16 seg = root->segment;
+	struct pci_config_window *cfg;
+	struct resource cfgres;
+	unsigned int bsz;
+	int err;
+
+	err = pci_mcfg_lookup(root);
+	if (err) {
+		pr_err("%04x:%pR MCFG region not found\n", seg, bus_res);
+		return err;
+	}
+
+	bsz = 1 << pci_generic_ecam_ops.bus_shift;
+	cfgres.start = root->mcfg_addr + bus_res->start * bsz;
+	cfgres.end = cfgres.start + resource_size(bus_res) * bsz - 1;
+	cfgres.flags = IORESOURCE_MEM;
+	cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res,
+			      &pci_generic_ecam_ops);
+	if (IS_ERR(cfg)) {
+		pr_err("%04x:%pR error %ld mapping CAM\n", seg, bus_res,
+		       PTR_ERR(cfg));
+		return PTR_ERR(cfg);
+	}
+
+	ri->cfg = cfg;
+	return 0;
+}
+
+/* release_info: free resrouces allocated by init_info */
+static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
+{
+	struct acpi_pci_generic_root_info *ri;
+
+	ri = container_of(ci, struct acpi_pci_generic_root_info, common);
+	pci_ecam_free(ri->cfg);
+	kfree(ri);
+}
+
+static struct acpi_pci_root_ops acpi_pci_root_ops = {
+	.release_info = pci_acpi_generic_release_info,
+};
+
+/* Interface called from ACPI code to setup PCI host controller */
 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 {
-	/* TODO: Should be revisited when implementing PCI on ACPI */
-	return NULL;
+	int node = acpi_get_node(root->device->handle);
+	struct acpi_pci_generic_root_info *ri;
+	struct pci_bus *bus, *child;
+	int err;
+
+	ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
+	if (!ri)
+		return NULL;
+
+	err = pci_acpi_setup_ecam_mapping(root, ri);
+	if (err)
+		return NULL;
+
+	acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
+	bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
+				   ri->cfg);
+	if (!bus)
+		return NULL;
+
+	pci_bus_size_bridges(bus);
+	pci_bus_assign_resources(bus);
+
+	list_for_each_entry(child, &bus->children, node)
+		pcie_bus_configure_settings(child);
+
+	return bus;
 }
 
 void pcibios_add_bus(struct pci_bus *bus)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9661c85..f66d188 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1390,7 +1390,12 @@ static inline int pci_domain_nr(struct pci_bus *bus)
 {
 	return bus->domain_nr;
 }
+/* Arch specific ACPI hook to set-up domain number */
+#ifdef CONFIG_ACPI
+int acpi_pci_bus_domain_nr(struct pci_bus *bus);
+#else
 static inline int acpi_pci_bus_domain_nr(struct pci_bus *bus) { return -1; }
+#endif
 void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent);
 #else
 static inline void pci_bus_assign_domain_nr(struct pci_bus *bus,
-- 
1.9.1

[toc] | [prev] | [next] | [standalone]

#1409238 — Re: [PATCH V8 9/9] pci, acpi: ARM64 support for ACPI based generic PCI host controller

On Monday, May 30, 2016 5:14:22 PM CEST Tomasz Nowicki wrote:
> +       bsz = 1 << pci_generic_ecam_ops.bus_shift;
> +       cfgres.start = root->mcfg_addr + bus_res->start * bsz;
> +       cfgres.end = cfgres.start + resource_size(bus_res) * bsz - 1;
> +       cfgres.flags = IORESOURCE_MEM;
> +       cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res,
> +                             &pci_generic_ecam_ops);
> +       if (IS_ERR(cfg)) {
> +               pr_err("%04x:%pR error %ld mapping CAM\n", seg, bus_res,
> +                      PTR_ERR(cfg));
> +               return PTR_ERR(cfg);
> +       }
> +
> +       ri->cfg = cfg;
> +       return 0;
> +}

I wonder if we could do this a little simpler and just put a pointer
to the mmconfig space into struct pci_host_bridge, and then have a trivial
map_bus function alongside pci_generic_config_read/pci_generic_config_write.

As this code is specific to arch/arm64, we don't need any of the complexity
of drivers/pci/ecam.c, which basically only exists to work around the
limited virtual address space of 32-bit machines.

	Arnd

[toc] | [prev] | [next] | [standalone]

#1409263 — Re: [PATCH V8 9/9] pci, acpi: ARM64 support for ACPI based generic PCI host controller

On Mon, May 30, 2016 at 9:08 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Monday, May 30, 2016 5:14:22 PM CEST Tomasz Nowicki wrote:
>> +       bsz = 1 << pci_generic_ecam_ops.bus_shift;
>> +       cfgres.start = root->mcfg_addr + bus_res->start * bsz;
>> +       cfgres.end = cfgres.start + resource_size(bus_res) * bsz - 1;
>> +       cfgres.flags = IORESOURCE_MEM;
>> +       cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res,
>> +                             &pci_generic_ecam_ops);
>> +       if (IS_ERR(cfg)) {
>> +               pr_err("%04x:%pR error %ld mapping CAM\n", seg, bus_res,
>> +                      PTR_ERR(cfg));
>> +               return PTR_ERR(cfg);
>> +       }
>> +
>> +       ri->cfg = cfg;
>> +       return 0;
>> +}
>
> I wonder if we could do this a little simpler and just put a pointer
> to the mmconfig space into struct pci_host_bridge, and then have a trivial
> map_bus function alongside pci_generic_config_read/pci_generic_config_write.
>
> As this code is specific to arch/arm64, we don't need any of the complexity
> of drivers/pci/ecam.c, which basically only exists to work around the
> limited virtual address space of 32-bit machines.

The map_bus provided by pci-ecam.h is already trivial in 64bit case,
it was written so that it could be optimized at compile time. The
pci_ecam_create is a useful to have here instead of redoing the
request_resource/ioremap sequence.

The struct pci_config_window can be moved into struct
pci_host_bridge (or a wrapper of pci_host_bridge) when we have
the setup to point bus->sysdata to something like that. The ECAM
API can be fixed up to handle that case as well. I did not make
any changes since the pci_host_bridge discussion is still going on.

JC.

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web