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Message-ID: <20160217110057.GA9794@red-moon>
Date: Wed, 17 Feb 2016 11:00:57 +0000
From: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
To: Tomasz Nowicki <tn@...ihalf.com>
Cc: helgaas@...nel.org, arnd@...db.de, will.deacon@....com,
catalin.marinas@....com, rafael@...nel.org, hanjun.guo@...aro.org,
okaya@...eaurora.org, jiang.liu@...ux.intel.com,
jchandra@...adcom.com, Stefano.Stabellini@...citrix.com,
robert.richter@...iumnetworks.com, mw@...ihalf.com,
Liviu.Dudau@....com, ddaney@...iumnetworks.com,
wangyijing@...wei.com, Suravee.Suthikulpanit@....com,
msalter@...hat.com, linux-pci@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, linux-acpi@...r.kernel.org,
linux-kernel@...r.kernel.org, linaro-acpi@...ts.linaro.org,
jcm@...hat.com
Subject: Re: [PATCH V5 01/15] ACPI: MCFG: Move mmcfg_list management to
drivers/acpi
On Tue, Feb 16, 2016 at 02:53:31PM +0100, Tomasz Nowicki wrote:
> From: Jayachandran C <jchandra@...adcom.com>
>
> Move pci_mmcfg_list handling to a drivers/acpi/pci_mcfg.c. This is
> to share the API and code with ARM64 later. The corresponding
> declarations are moved from asm/pci_x86.h to linux/pci-acpi.h
>
> As a part of this we introduce three functions that can be
> implemented by the arch code: pci_mmconfig_map_resource() to map a
> mcfg entry, pci_mmconfig_unmap_resource to do the corresponding
> unmap and pci_mmconfig_enabled to see if the arch setup of
> mcfg entries was successful. We also provide weak implementations
> of these, which will be used from ARM64. On x86, we retain the
> old logic by providing platform specific implementation.
>
> This patch is purely rearranging code, it should not have any
> impact on the logic of MCFG parsing or list handling.
>
> Signed-off-by: Jayachandran C <jchandra@...adcom.com>
> [Xen parts:]
> Acked-by: David Vrabel <david.vrabel@...rix.com>
> ---
> arch/x86/include/asm/pci_x86.h | 24 +---
> arch/x86/pci/mmconfig-shared.c | 269 +++++------------------------------
> 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/pci_mcfg.c | 312 +++++++++++++++++++++++++++++++++++++++++
> drivers/xen/pci.c | 5 +-
> include/linux/pci-acpi.h | 33 +++++
> 9 files changed, 386 insertions(+), 261 deletions(-)
> create mode 100644 drivers/acpi/pci_mcfg.c
This patch makes perfect sense to me and manages to move MCFG handling
to common code in a seamless manner, it is basically a code move with
weak functions to cater for X86 specific legacy bits which are otherwise
pretty complex to untangle, so (apart from a few nits below):
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
[...]
> diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
> new file mode 100644
> index 0000000..ea84365
> --- /dev/null
> +++ b/drivers/acpi/pci_mcfg.c
> @@ -0,0 +1,312 @@
> +/*
> + * pci_mcfg.c
> + *
> + * Common code to maintain the MCFG areas and mappings
> + *
> + * This has been extracted from arch/x86/pci/mmconfig-shared.c
> + * and moved here so that other architectures can use this code.
> + */
> +
> +#include <linux/pci.h>
> +#include <linux/init.h>
> +#include <linux/dmi.h>
> +#include <linux/pci-acpi.h>
> +#include <linux/sfi_acpi.h>
> +#include <linux/slab.h>
> +#include <linux/mutex.h>
> +#include <linux/rculist.h>
Nit: while at it order them alphabetically.
> +
> +#define PREFIX "ACPI: "
> +
> +static DEFINE_MUTEX(pci_mmcfg_lock);
> +LIST_HEAD(pci_mmcfg_list);
> +
> +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;
> +}
> +
> +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;
> +}
> +
> +/*
> + * Map a pci_mmcfg_region, can be overrriden by arch
s/overrriden/overridden/
[...]
> +static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
> + struct acpi_mcfg_allocation *cfg)
> +{
> + int year;
> +
> + if (!config_enabled(CONFIG_X86))
> + return 0;
This check in generic code may ruffle someone's feathers, I even think we
can run this function safely on ARM64 but to prevent surprises we'd better
keep the X86 check, alternatives like adding a weak function just for a
quirk do not make much sense to me.
Lorenzo
> +
> + 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;
> +}
> +
> +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 */
> + 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))
> + 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");
> + return -ENOMEM;
> + }
> + }
> +
> + return 0;
> +}
> +
> +int __init pci_mmconfig_parse_table(void)
> +{
> + return acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
> +}
> +
> +void __weak __init pci_mmcfg_late_init(void)
> +{
> + int err, n = 0;
> + struct pci_mmcfg_region *cfg;
> +
> + err = pci_mmconfig_parse_table();
> + if (err) {
> + pr_err(PREFIX " Failed to parse MCFG (%d)\n", err);
> + return;
> + }
> +
> + list_for_each_entry(cfg, &pci_mmcfg_list, list) {
> + pci_mmconfig_map_resource(NULL, cfg);
> + n++;
> + }
> +
> + pr_info(PREFIX " MCFG table loaded %d entries\n", n);
> +}
> diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
> index 7494dbe..97aa9d3 100644
> --- a/drivers/xen/pci.c
> +++ b/drivers/xen/pci.c
> @@ -27,9 +27,6 @@
> #include <asm/xen/hypervisor.h>
> #include <asm/xen/hypercall.h>
> #include "../pci/pci.h"
> -#ifdef CONFIG_PCI_MMCONFIG
> -#include <asm/pci_x86.h>
> -#endif
>
> static bool __read_mostly pci_seg_supported = true;
>
> @@ -221,7 +218,7 @@ static int __init xen_mcfg_late(void)
> if (!xen_initial_domain())
> return 0;
>
> - if ((pci_probe & PCI_PROBE_MMCONF) == 0)
> + if (!pci_mmconfig_enabled())
> return 0;
>
> if (list_empty(&pci_mmcfg_list))
> diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
> index 89ab057..e9450ef 100644
> --- a/include/linux/pci-acpi.h
> +++ b/include/linux/pci-acpi.h
> @@ -106,6 +106,39 @@ extern const u8 pci_acpi_dsm_uuid[];
> #define RESET_DELAY_DSM 0x08
> #define FUNCTION_DELAY_DSM 0x09
>
> +/* common API to maintain list of MCFG regions */
> +/* "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];
> +};
> +
> +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 struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
> + int end, u64 addr);
> +extern int pci_mmconfig_map_resource(struct device *dev,
> + struct pci_mmcfg_region *mcfg);
> +extern void pci_mmconfig_unmap_resource(struct pci_mmcfg_region *mcfg);
> +extern int pci_mmconfig_enabled(void);
> +extern int __init pci_mmconfig_parse_table(void);
> +
> +extern struct list_head pci_mmcfg_list;
> +
> +#define PCI_MMCFG_BUS_OFFSET(bus) ((bus) << 20)
> +#define PCI_MMCFG_OFFSET(bus, devfn) ((bus) << 20 | (devfn) << 12)
> +
> #else /* CONFIG_ACPI */
> static inline void acpi_pci_add_bus(struct pci_bus *bus) { }
> static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
> --
> 1.9.1
>
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