[PATCH v3 4/9] x86, pci, acpi: Move arch-agnostic MMCONFIG (aka ECAM) and ACPI code out of arch/x86/ directory

Mark Salter msalter at redhat.com
Fri Mar 13 09:35:00 PDT 2015


On Tue, 2015-03-10 at 12:35 +0100, Tomasz Nowicki wrote:
> ECAM standard and MCFG table are architecture independent and it makes
> sense to share common code across all architectures. Both are going to
> corresponding files - ecam.c and mcfg.c
> 
> While we are here, rename pci_parse_mcfg to acpi_parse_mcfg.
> We already have acpi_parse_mcfg prototype which is used nowhere.
> At the same time, we need pci_parse_mcfg been global so acpi_parse_mcfg
> can be used perfectly here.
> 
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki at linaro.org>
> ---
>  arch/x86/Kconfig               |   2 +
>  arch/x86/include/asm/pci_x86.h |  33 -----
>  arch/x86/pci/acpi.c            |   1 +
>  arch/x86/pci/mmconfig-shared.c | 296 +----------------------------------------
>  arch/x86/pci/mmconfig_32.c     |   1 +
>  arch/x86/pci/mmconfig_64.c     |   1 +
>  arch/x86/pci/numachip.c        |   1 +
>  drivers/acpi/Makefile          |   1 +
>  drivers/acpi/mcfg.c            |  81 +++++++++++
>  drivers/pci/Kconfig            |   4 +
>  drivers/pci/Makefile           |   5 +
>  drivers/pci/ecam.c             | 243 +++++++++++++++++++++++++++++++++
>  include/linux/ecam.h           |  51 +++++++
>  13 files changed, 394 insertions(+), 326 deletions(-)
>  create mode 100644 drivers/acpi/mcfg.c
>  create mode 100644 drivers/pci/ecam.c
>  create mode 100644 include/linux/ecam.h
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index c2fb8a8..dd926f4 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -2276,6 +2276,7 @@ config PCI_DIRECT
>  
>  config PCI_MMCONFIG
>  	def_bool y
> +	select PCI_ECAM
>  	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
>  
>  config PCI_OLPC
> @@ -2293,6 +2294,7 @@ config PCI_DOMAINS
>  
>  config PCI_MMCONFIG
>  	bool "Support mmconfig PCI config space access"
> +	select PCI_ECAM
>  	depends on X86_64 && PCI && ACPI
>  
>  config PCI_CNB20LE_QUIRK
> diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
> index c57c225..e8a237f 100644
> --- a/arch/x86/include/asm/pci_x86.h
> +++ b/arch/x86/include/asm/pci_x86.h
> @@ -122,41 +122,8 @@ extern int pci_legacy_init(void);
>  extern void pcibios_fixup_irqs(void);
>  
>  /* pci-mmconfig.c */
> -
> -/* "PCI MMCONFIG %04x [bus %02x-%02x]" */
> -#define PCI_MMCFG_RESOURCE_NAME_LEN (22 + 4 + 2 + 2)
> -
> -struct pci_mmcfg_region {
> -	struct list_head list;
> -	struct resource res;
> -	u64 address;
> -	char __iomem *virt;
> -	u16 segment;
> -	u8 start_bus;
> -	u8 end_bus;
> -	char name[PCI_MMCFG_RESOURCE_NAME_LEN];
> -};
> -
> -struct pci_mmcfg_mmio_ops {
> -	u32 (*read)(int len, void __iomem *addr);
> -	void (*write)(int len, void __iomem *addr, u32 value);
> -};
> -
> -extern int __init pci_mmcfg_arch_init(void);
> -extern void __init pci_mmcfg_arch_free(void);
> -extern int pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg);
> -extern void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg);
>  extern int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
>  			       phys_addr_t addr);
> -extern int pci_mmconfig_delete(u16 seg, u8 start, u8 end);
> -extern struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus);
> -extern u32 pci_mmio_read(int len, void __iomem *addr);
> -extern void pci_mmio_write(int len, void __iomem *addr, u32 value);
> -extern void pci_mmconfig_register_mmio(struct pci_mmcfg_mmio_ops *ops);
> -
> -extern struct list_head pci_mmcfg_list;
> -
> -#define PCI_MMCFG_BUS_OFFSET(bus)      ((bus) << 20)
>  
>  /*
>   * AMD Fam10h CPUs are buggy, and cannot access MMIO config space
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index 6ac2738..5dfccef 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -4,6 +4,7 @@
>  #include <linux/irq.h>
>  #include <linux/dmi.h>
>  #include <linux/slab.h>
> +#include <linux/ecam.h>
>  #include <asm/numa.h>
>  #include <asm/pci_x86.h>
>  
> diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
> index 685cd4c..5064302 100644
> --- a/arch/x86/pci/mmconfig-shared.c
> +++ b/arch/x86/pci/mmconfig-shared.c
> @@ -18,6 +18,7 @@
>  #include <linux/slab.h>
>  #include <linux/mutex.h>
>  #include <linux/rculist.h>
> +#include <linux/ecam.h>
>  #include <asm/e820.h>
>  #include <asm/pci_x86.h>
>  #include <asm/acpi.h>
> @@ -27,52 +28,6 @@
>  /* Indicate if the mmcfg resources have been placed into the resource table. */
>  static bool pci_mmcfg_running_state;
>  static bool pci_mmcfg_arch_init_failed;
> -static DEFINE_MUTEX(pci_mmcfg_lock);
> -
> -LIST_HEAD(pci_mmcfg_list);
> -
> -static u32
> -pci_mmconfig_generic_read(int len, void __iomem *addr)
> -{
> -	u32 data = 0;
> -
> -	switch (len) {
> -	case 1:
> -		data = readb(addr);
> -		break;
> -	case 2:
> -		data = readw(addr);
> -		break;
> -	case 4:
> -		data = readl(addr);
> -		break;
> -	}
> -
> -	return data;
> -}
> -
> -static void
> -pci_mmconfig_generic_write(int len, void __iomem *addr, u32 value)
> -{
> -	switch (len) {
> -	case 1:
> -		writeb(value, addr);
> -		break;
> -	case 2:
> -		writew(value, addr);
> -		break;
> -	case 4:
> -		writel(value, addr);
> -		break;
> -	}
> -}
> -
> -static struct pci_mmcfg_mmio_ops pci_mmcfg_mmio_default = {
> -	.read = pci_mmconfig_generic_read,
> -	.write = pci_mmconfig_generic_write,
> -};
> -
> -static struct pci_mmcfg_mmio_ops *pci_mmcfg_mmio = &pci_mmcfg_mmio_default;
>  
>  static u32
>  pci_mmconfig_amd_read(int len, void __iomem *addr)
> @@ -115,128 +70,6 @@ static struct pci_mmcfg_mmio_ops pci_mmcfg_mmio_amd_fam10h = {
>  	.write = pci_mmconfig_amd_write,
>  };
>  
> -void
> -pci_mmconfig_register_mmio(struct pci_mmcfg_mmio_ops *ops)
> -{
> -	pci_mmcfg_mmio = ops;
> -}
> -
> -u32
> -pci_mmio_read(int len, void __iomem *addr)
> -{
> -	if (!pci_mmcfg_mmio) {
> -		pr_err("PCI config space has no accessors !");
> -		return 0;
> -	}
> -
> -	return pci_mmcfg_mmio->read(len, addr);
> -}
> -
> -void
> -pci_mmio_write(int len, void __iomem *addr, u32 value)
> -{
> -	if (!pci_mmcfg_mmio) {
> -		pr_err("PCI config space has no accessors !");
> -		return;
> -	}
> -
> -	pci_mmcfg_mmio->write(len, addr, value);
> -}
> -
> -static void __init pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
> -{
> -	if (cfg->res.parent)
> -		release_resource(&cfg->res);
> -	list_del(&cfg->list);
> -	kfree(cfg);
> -}
> -
> -static void __init free_all_mmcfg(void)
> -{
> -	struct pci_mmcfg_region *cfg, *tmp;
> -
> -	pci_mmcfg_arch_free();
> -	list_for_each_entry_safe(cfg, tmp, &pci_mmcfg_list, list)
> -		pci_mmconfig_remove(cfg);
> -}
> -
> -static void list_add_sorted(struct pci_mmcfg_region *new)
> -{
> -	struct pci_mmcfg_region *cfg;
> -
> -	/* keep list sorted by segment and starting bus number */
> -	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) {
> -		if (cfg->segment > new->segment ||
> -		    (cfg->segment == new->segment &&
> -		     cfg->start_bus >= new->start_bus)) {
> -			list_add_tail_rcu(&new->list, &cfg->list);
> -			return;
> -		}
> -	}
> -	list_add_tail_rcu(&new->list, &pci_mmcfg_list);
> -}
> -
> -static struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
> -						   int end, u64 addr)
> -{
> -	struct pci_mmcfg_region *new;
> -	struct resource *res;
> -
> -	if (addr == 0)
> -		return NULL;
> -
> -	new = kzalloc(sizeof(*new), GFP_KERNEL);
> -	if (!new)
> -		return NULL;
> -
> -	new->address = addr;
> -	new->segment = segment;
> -	new->start_bus = start;
> -	new->end_bus = end;
> -
> -	res = &new->res;
> -	res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
> -	res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
> -	res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
> -	snprintf(new->name, PCI_MMCFG_RESOURCE_NAME_LEN,
> -		 "PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
> -	res->name = new->name;
> -
> -	return new;
> -}
> -
> -static struct pci_mmcfg_region *__init pci_mmconfig_add(int segment, int start,
> -							int end, u64 addr)
> -{
> -	struct pci_mmcfg_region *new;
> -
> -	new = pci_mmconfig_alloc(segment, start, end, addr);
> -	if (new) {
> -		mutex_lock(&pci_mmcfg_lock);
> -		list_add_sorted(new);
> -		mutex_unlock(&pci_mmcfg_lock);
> -
> -		pr_info(PREFIX
> -		       "MMCONFIG for domain %04x [bus %02x-%02x] at %pR "
> -		       "(base %#lx)\n",
> -		       segment, start, end, &new->res, (unsigned long)addr);
> -	}
> -
> -	return new;
> -}
> -
> -struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
> -{
> -	struct pci_mmcfg_region *cfg;
> -
> -	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
> -		if (cfg->segment == segment &&
> -		    cfg->start_bus <= bus && bus <= cfg->end_bus)
> -			return cfg;
> -
> -	return NULL;
> -}
> -
>  static const char *__init pci_mmcfg_e7520(void)
>  {
>  	u32 win;
> @@ -657,73 +490,6 @@ static void __init pci_mmcfg_reject_broken(int early)
>  	}
>  }
>  
> -static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
> -					struct acpi_mcfg_allocation *cfg)
> -{
> -	int year;
> -
> -	if (cfg->address < 0xFFFFFFFF)
> -		return 0;
> -
> -	if (!strncmp(mcfg->header.oem_id, "SGI", 3))
> -		return 0;
> -
> -	if (mcfg->header.revision >= 1) {
> -		if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
> -		    year >= 2010)
> -			return 0;
> -	}
> -
> -	pr_err(PREFIX "MCFG region for %04x [bus %02x-%02x] at %#llx "
> -	       "is above 4GB, ignored\n", cfg->pci_segment,
> -	       cfg->start_bus_number, cfg->end_bus_number, cfg->address);
> -	return -EINVAL;
> -}

This looks very arch-specific. Shouldn't this be only generic checks
with some hook for architectures to add arch-specific checks?

> -
> -static int __init pci_parse_mcfg(struct acpi_table_header *header)
> -{
> -	struct acpi_table_mcfg *mcfg;
> -	struct acpi_mcfg_allocation *cfg_table, *cfg;
> -	unsigned long i;
> -	int entries;
> -
> -	if (!header)
> -		return -EINVAL;
> -
> -	mcfg = (struct acpi_table_mcfg *)header;
> -
> -	/* how many config structures do we have */
> -	free_all_mmcfg();
> -	entries = 0;
> -	i = header->length - sizeof(struct acpi_table_mcfg);
> -	while (i >= sizeof(struct acpi_mcfg_allocation)) {
> -		entries++;
> -		i -= sizeof(struct acpi_mcfg_allocation);
> -	}
> -	if (entries == 0) {
> -		pr_err(PREFIX "MMCONFIG has no entries\n");
> -		return -ENODEV;
> -	}
> -
> -	cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
> -	for (i = 0; i < entries; i++) {
> -		cfg = &cfg_table[i];
> -		if (acpi_mcfg_check_entry(mcfg, cfg)) {
> -			free_all_mmcfg();
> -			return -ENODEV;
> -		}
> -
> -		if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
> -				   cfg->end_bus_number, cfg->address) == NULL) {
> -			pr_warn(PREFIX "no memory for MCFG entries\n");
> -			free_all_mmcfg();
> -			return -ENOMEM;
> -		}
> -	}
> -
> -	return 0;
> -}
> -
>  #ifdef CONFIG_ACPI_APEI
>  extern int (*arch_apei_filter_addr)(int (*func)(__u64 start, __u64 size,
>  				     void *data), void *data);
> @@ -782,7 +548,7 @@ void __init pci_mmcfg_early_init(void)
>  		if (pci_mmcfg_check_hostbridge())
>  			known_bridge = 1;
>  		else
> -			acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
> +			acpi_sfi_table_parse(ACPI_SIG_MCFG, acpi_parse_mcfg);
>  		__pci_mmcfg_init(1);
>  
>  		set_apei_filter();
> @@ -800,7 +566,7 @@ void __init pci_mmcfg_late_init(void)
>  
>  	/* MMCONFIG hasn't been enabled yet, try again */
>  	if (pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF) {
> -		acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
> +		acpi_sfi_table_parse(ACPI_SIG_MCFG, acpi_parse_mcfg);
>  		__pci_mmcfg_init(0);
>  	}
>  }
> @@ -834,39 +600,6 @@ static int __init pci_mmcfg_late_insert_resources(void)
>   */
>  late_initcall(pci_mmcfg_late_insert_resources);
>  
> -static int pci_mmconfig_inject(struct pci_mmcfg_region *cfg)
> -{
> -	struct pci_mmcfg_region *cfg_conflict;
> -	int err = 0;
> -
> -	mutex_lock(&pci_mmcfg_lock);
> -	cfg_conflict = pci_mmconfig_lookup(cfg->segment, cfg->start_bus);
> -	if (cfg_conflict) {
> -		if (cfg_conflict->end_bus < cfg->end_bus)
> -			pr_info(FW_INFO "MMCONFIG for "
> -				"domain %04x [bus %02x-%02x] "
> -				"only partially covers this bridge\n",
> -				cfg_conflict->segment, cfg_conflict->start_bus,
> -				cfg_conflict->end_bus);
> -		err = -EEXIST;
> -		goto out;
> -	}
> -
> -	if (pci_mmcfg_arch_map(cfg)) {
> -		pr_warn("fail to map MMCONFIG %pR.\n", &cfg->res);
> -		err = -ENOMEM;
> -		goto out;
> -	} else {
> -		list_add_sorted(cfg);
> -		pr_info("MMCONFIG at %pR (base %#lx)\n",
> -			&cfg->res, (unsigned long)cfg->address);
> -
> -	}
> -out:
> -	mutex_unlock(&pci_mmcfg_lock);
> -	return err;
> -}
> -
>  /* Add MMCFG information for host bridges */
>  int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
>  			phys_addr_t addr)
> @@ -915,26 +648,3 @@ error:
>  	kfree(cfg);
>  	return rc;
>  }
> -
> -/* Delete MMCFG information for host bridges */
> -int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
> -{
> -	struct pci_mmcfg_region *cfg;
> -
> -	mutex_lock(&pci_mmcfg_lock);
> -	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
> -		if (cfg->segment == seg && cfg->start_bus == start &&
> -		    cfg->end_bus == end) {
> -			list_del_rcu(&cfg->list);
> -			synchronize_rcu();
> -			pci_mmcfg_arch_unmap(cfg);
> -			if (cfg->res.parent)
> -				release_resource(&cfg->res);
> -			mutex_unlock(&pci_mmcfg_lock);
> -			kfree(cfg);
> -			return 0;
> -		}
> -	mutex_unlock(&pci_mmcfg_lock);
> -
> -	return -ENOENT;
> -}
> diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
> index 4b3d025..5cf6291 100644
> --- a/arch/x86/pci/mmconfig_32.c
> +++ b/arch/x86/pci/mmconfig_32.c
> @@ -12,6 +12,7 @@
>  #include <linux/pci.h>
>  #include <linux/init.h>
>  #include <linux/rcupdate.h>
> +#include <linux/ecam.h>
>  #include <asm/e820.h>
>  #include <asm/pci_x86.h>
>  
> diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
> index 032593d..b62ff18 100644
> --- a/arch/x86/pci/mmconfig_64.c
> +++ b/arch/x86/pci/mmconfig_64.c
> @@ -10,6 +10,7 @@
>  #include <linux/acpi.h>
>  #include <linux/bitmap.h>
>  #include <linux/rcupdate.h>
> +#include <linux/ecam.h>
>  #include <asm/e820.h>
>  #include <asm/pci_x86.h>
>  
> diff --git a/arch/x86/pci/numachip.c b/arch/x86/pci/numachip.c
> index 5047e9b..01868b6 100644
> --- a/arch/x86/pci/numachip.c
> +++ b/arch/x86/pci/numachip.c
> @@ -13,6 +13,7 @@
>   *
>   */
>  
> +#include <linux/ecam.h>
>  #include <linux/pci.h>
>  #include <asm/pci_x86.h>
>  
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 623b117..39498a1 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -67,6 +67,7 @@ obj-$(CONFIG_ACPI_BUTTON)	+= button.o
>  obj-$(CONFIG_ACPI_FAN)		+= fan.o
>  obj-$(CONFIG_ACPI_VIDEO)	+= video.o
>  obj-$(CONFIG_ACPI_PCI_SLOT)	+= pci_slot.o
> +obj-$(CONFIG_PCI_MMCONFIG)	+= mcfg.o
>  obj-$(CONFIG_ACPI_PROCESSOR)	+= processor.o
>  obj-y				+= container.o
>  obj-$(CONFIG_ACPI_THERMAL)	+= thermal.o
> diff --git a/drivers/acpi/mcfg.c b/drivers/acpi/mcfg.c
> new file mode 100644
> index 0000000..a2e2326
> --- /dev/null
> +++ b/drivers/acpi/mcfg.c
> @@ -0,0 +1,81 @@
> +/*
> + * MCFG ACPI table parser.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/dmi.h>
> +#include <linux/ecam.h>
> +
> +#define	PREFIX	"MCFG: "
> +
> +static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
> +					struct acpi_mcfg_allocation *cfg)
> +{
> +	int year;
> +
> +	if (cfg->address < 0xFFFFFFFF)
> +		return 0;
> +
> +	if (!strncmp(mcfg->header.oem_id, "SGI", 3))
> +		return 0;
> +
> +	if (mcfg->header.revision >= 1) {
> +		if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
> +		    year >= 2010)
> +			return 0;
> +	}
> +
> +	pr_err(PREFIX "MCFG region for %04x [bus %02x-%02x] at %#llx "
> +	       "is above 4GB, ignored\n", cfg->pci_segment,
> +	       cfg->start_bus_number, cfg->end_bus_number, cfg->address);
> +	return -EINVAL;
> +}
> +
> +int __init acpi_parse_mcfg(struct acpi_table_header *header)
> +{
> +	struct acpi_table_mcfg *mcfg;
> +	struct acpi_mcfg_allocation *cfg_table, *cfg;
> +	unsigned long i;
> +	int entries;
> +
> +	if (!header)
> +		return -EINVAL;
> +
> +	mcfg = (struct acpi_table_mcfg *)header;
> +
> +	/* how many config structures do we have */
> +	free_all_mmcfg();
> +	entries = 0;
> +	i = header->length - sizeof(struct acpi_table_mcfg);
> +	while (i >= sizeof(struct acpi_mcfg_allocation)) {
> +		entries++;
> +		i -= sizeof(struct acpi_mcfg_allocation);
> +	}
> +	if (entries == 0) {
> +		pr_err(PREFIX "MCFG table has no entries\n");
> +		return -ENODEV;
> +	}
> +
> +	cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
> +	for (i = 0; i < entries; i++) {
> +		cfg = &cfg_table[i];
> +		if (acpi_mcfg_check_entry(mcfg, cfg)) {
> +			free_all_mmcfg();
> +			return -ENODEV;
> +		}
> +
> +		if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
> +				   cfg->end_bus_number, cfg->address) == NULL) {
> +			pr_warn(PREFIX "no memory for MCFG entries\n");
> +			free_all_mmcfg();
> +			return -ENOMEM;
> +		}
> +	}
> +
> +	return 0;
> +}
> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> index 7a8f1c5..e2eb982 100644
> --- a/drivers/pci/Kconfig
> +++ b/drivers/pci/Kconfig
> @@ -22,6 +22,10 @@ config PCI_MSI_IRQ_DOMAIN
>  	depends on PCI_MSI
>  	select GENERIC_MSI_IRQ_DOMAIN
>  
> +config PCI_ECAM
> +	bool "Enhanced Configuration Access Mechanism (ECAM)"
> +	depends on PCI
> +
>  config PCI_DEBUG
>  	bool "PCI Debugging"
>  	depends on PCI && DEBUG_KERNEL
> diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
> index 73e4af4..ce7b630 100644
> --- a/drivers/pci/Makefile
> +++ b/drivers/pci/Makefile
> @@ -41,6 +41,11 @@ obj-$(CONFIG_SPARC_LEON) += setup-irq.o
>  obj-$(CONFIG_M68K) += setup-irq.o
>  
>  #
> +# Enhanced Configuration Access Mechanism (ECAM)
> +#
> +obj-$(CONFIG_PCI_ECAM)	+= ecam.o
> +
> +#
>  # ACPI Related PCI FW Functions
>  # ACPI _DSM provided firmware instance and string name
>  #
> diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
> new file mode 100644
> index 0000000..f540184
> --- /dev/null
> +++ b/drivers/pci/ecam.c
> @@ -0,0 +1,243 @@
> +/*
> + * Arch agnostic direct PCI config space access via
> + * ECAM (Enhanced Configuration Access Mechanism)
> + *
> + * Per-architecture code takes care of the mappings, region validation and
> + * accesses themselves.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/mutex.h>
> +#include <linux/rculist.h>
> +#include <linux/ecam.h>
> +
> +#define PREFIX "PCI: "
> +
> +static DEFINE_MUTEX(pci_mmcfg_lock);
> +
> +LIST_HEAD(pci_mmcfg_list);
> +
> +static u32
> +pci_mmconfig_generic_read(int len, void __iomem *addr)
> +{
> +	u32 data = 0;
> +
> +	switch (len) {
> +	case 1:
> +		data = readb(addr);
> +		break;
> +	case 2:
> +		data = readw(addr);
> +		break;
> +	case 4:
> +		data = readl(addr);
> +		break;
> +	}
> +
> +	return data;
> +}
> +
> +static void
> +pci_mmconfig_generic_write(int len, void __iomem *addr, u32 value)
> +{
> +	switch (len) {
> +	case 1:
> +		writeb(value, addr);
> +		break;
> +	case 2:
> +		writew(value, addr);
> +		break;
> +	case 4:
> +		writel(value, addr);
> +		break;
> +	}
> +}
> +
> +static struct pci_mmcfg_mmio_ops pci_mmcfg_mmio_default = {
> +	.read = pci_mmconfig_generic_read,
> +	.write = pci_mmconfig_generic_write,
> +};
> +
> +static struct pci_mmcfg_mmio_ops *pci_mmcfg_mmio = &pci_mmcfg_mmio_default;
> +
> +void
> +pci_mmconfig_register_mmio(struct pci_mmcfg_mmio_ops *ops)
> +{
> +	pci_mmcfg_mmio = ops;
> +}
> +
> +u32
> +pci_mmio_read(int len, void __iomem *addr)
> +{
> +	if (!pci_mmcfg_mmio) {
> +		pr_err("PCI config space has no accessors !");
> +		return 0;
> +	}
> +
> +	return pci_mmcfg_mmio->read(len, addr);
> +}
> +
> +void
> +pci_mmio_write(int len, void __iomem *addr, u32 value)
> +{
> +	if (!pci_mmcfg_mmio) {
> +		pr_err("PCI config space has no accessors !");
> +		return;
> +	}
> +
> +	pci_mmcfg_mmio->write(len, addr, value);
> +}
> +
> +static void __init pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
> +{
> +	if (cfg->res.parent)
> +		release_resource(&cfg->res);
> +	list_del(&cfg->list);
> +	kfree(cfg);
> +}
> +
> +void __init free_all_mmcfg(void)
> +{
> +	struct pci_mmcfg_region *cfg, *tmp;
> +
> +	pci_mmcfg_arch_free();
> +	list_for_each_entry_safe(cfg, tmp, &pci_mmcfg_list, list)
> +		pci_mmconfig_remove(cfg);
> +}
> +
> +void list_add_sorted(struct pci_mmcfg_region *new)
> +{
> +	struct pci_mmcfg_region *cfg;
> +
> +	/* keep list sorted by segment and starting bus number */
> +	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) {
> +		if (cfg->segment > new->segment ||
> +		    (cfg->segment == new->segment &&
> +		     cfg->start_bus >= new->start_bus)) {
> +			list_add_tail_rcu(&new->list, &cfg->list);
> +			return;
> +		}
> +	}
> +	list_add_tail_rcu(&new->list, &pci_mmcfg_list);
> +}
> +
> +struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
> +					    int end, u64 addr)
> +{
> +	struct pci_mmcfg_region *new;
> +	struct resource *res;
> +
> +	if (addr == 0)
> +		return NULL;
> +
> +	new = kzalloc(sizeof(*new), GFP_KERNEL);
> +	if (!new)
> +		return NULL;
> +
> +	new->address = addr;
> +	new->segment = segment;
> +	new->start_bus = start;
> +	new->end_bus = end;
> +
> +	res = &new->res;
> +	res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
> +	res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
> +	res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
> +	snprintf(new->name, PCI_MMCFG_RESOURCE_NAME_LEN,
> +		 "PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
> +	res->name = new->name;
> +
> +	return new;
> +}
> +
> +struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
> +					  int end, u64 addr)
> +{
> +	struct pci_mmcfg_region *new;
> +
> +	new = pci_mmconfig_alloc(segment, start, end, addr);
> +	if (new) {
> +		mutex_lock(&pci_mmcfg_lock);
> +		list_add_sorted(new);
> +		mutex_unlock(&pci_mmcfg_lock);
> +
> +		pr_info(PREFIX
> +		       "MMCONFIG for domain %04x [bus %02x-%02x] at %pR "
> +		       "(base %#lx)\n",
> +		       segment, start, end, &new->res, (unsigned long)addr);
> +	}
> +
> +	return new;
> +}
> +
> +struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
> +{
> +	struct pci_mmcfg_region *cfg;
> +
> +	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
> +		if (cfg->segment == segment &&
> +		    cfg->start_bus <= bus && bus <= cfg->end_bus)
> +			return cfg;
> +
> +	return NULL;
> +}
> +
> +/* Delete MMCFG information for host bridges */
> +int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
> +{
> +	struct pci_mmcfg_region *cfg;
> +
> +	mutex_lock(&pci_mmcfg_lock);
> +	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
> +		if (cfg->segment == seg && cfg->start_bus == start &&
> +		    cfg->end_bus == end) {
> +			list_del_rcu(&cfg->list);
> +			synchronize_rcu();
> +			pci_mmcfg_arch_unmap(cfg);
> +			if (cfg->res.parent)
> +				release_resource(&cfg->res);
> +			mutex_unlock(&pci_mmcfg_lock);
> +			kfree(cfg);
> +			return 0;
> +		}
> +	mutex_unlock(&pci_mmcfg_lock);
> +
> +	return -ENOENT;
> +}
> +
> +int pci_mmconfig_inject(struct pci_mmcfg_region *cfg)
> +{
> +	struct pci_mmcfg_region *cfg_conflict;
> +	int err = 0;
> +
> +	mutex_lock(&pci_mmcfg_lock);
> +	cfg_conflict = pci_mmconfig_lookup(cfg->segment, cfg->start_bus);
> +	if (cfg_conflict) {
> +		if (cfg_conflict->end_bus < cfg->end_bus)
> +			pr_info(FW_INFO "MMCONFIG for "
> +				"domain %04x [bus %02x-%02x] "
> +				"only partially covers this bridge\n",
> +				cfg_conflict->segment, cfg_conflict->start_bus,
> +				cfg_conflict->end_bus);
> +		err = -EEXIST;
> +		goto out;
> +	}
> +
> +	if (pci_mmcfg_arch_map(cfg)) {
> +		pr_warn("fail to map MMCONFIG %pR.\n", &cfg->res);
> +		err = -ENOMEM;
> +		goto out;
> +	} else {
> +		list_add_sorted(cfg);
> +		pr_info("MMCONFIG at %pR (base %#lx)\n",
> +			&cfg->res, (unsigned long)cfg->address);
> +
> +	}
> +out:
> +	mutex_unlock(&pci_mmcfg_lock);
> +	return err;
> +}
> diff --git a/include/linux/ecam.h b/include/linux/ecam.h
> new file mode 100644
> index 0000000..2387df5
> --- /dev/null
> +++ b/include/linux/ecam.h
> @@ -0,0 +1,51 @@
> +#ifndef __ECAM_H
> +#define __ECAM_H
> +#ifdef __KERNEL__
> +
> +#include <linux/types.h>
> +#include <linux/acpi.h>
> +
> +/* "PCI MMCONFIG %04x [bus %02x-%02x]" */
> +#define PCI_MMCFG_RESOURCE_NAME_LEN (22 + 4 + 2 + 2)
> +
> +struct pci_mmcfg_region {
> +	struct list_head list;
> +	struct resource res;
> +	u64 address;
> +	char __iomem *virt;
> +	u16 segment;
> +	u8 start_bus;
> +	u8 end_bus;
> +	char name[PCI_MMCFG_RESOURCE_NAME_LEN];
> +};
> +
> +struct pci_mmcfg_mmio_ops {
> +	u32 (*read)(int len, void __iomem *addr);
> +	void (*write)(int len, void __iomem *addr, u32 value);
> +};
> +
> +struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus);
> +struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
> +						   int end, u64 addr);
> +int pci_mmconfig_inject(struct pci_mmcfg_region *cfg);
> +struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
> +						 int end, u64 addr);
> +void list_add_sorted(struct pci_mmcfg_region *new);
> +void free_all_mmcfg(void);
> +int pci_mmconfig_delete(u16 seg, u8 start, u8 end);
> +
> +/* Arch specific calls */
> +int pci_mmcfg_arch_init(void);
> +void pci_mmcfg_arch_free(void);
> +int pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg);
> +void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg);
> +extern u32 pci_mmio_read(int len, void __iomem *addr);
> +extern void pci_mmio_write(int len, void __iomem *addr, u32 value);
> +extern void pci_mmconfig_register_mmio(struct pci_mmcfg_mmio_ops *ops);
> +
> +extern struct list_head pci_mmcfg_list;
> +
> +#define PCI_MMCFG_BUS_OFFSET(bus)      ((bus) << 20)
> +
> +#endif  /* __KERNEL__ */
> +#endif  /* __ECAM_H */





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