Re: [patch] PCI Express Enhanced Config Patch - 2.6.0-test11

From: Matthew Wilcox
Date: Thu Jan 29 2004 - 11:46:39 EST

On Thu, Jan 29, 2004 at 08:05:52AM -0800, Linus Torvalds wrote:
> The compiler _should_ entirely compile away "fix_to_virt(xxx)", so by
> creating a variable for the value, you're actually making code generation
> worse. You might as well have
>
> #define mmcfg_virt_addr (fix_to_virt(FIX_PCIE_MCFG))
>
> instead.

Ahh, I missed the comment towards the top of fixmap.h that this is a
constant address. You're so smart sometimes ;-)

> That said, this patch looks perfectly acceptable to me. With some testing,
> I'd take it through Greg or -mm.

Cool. Here's the final version for testing then.

diff -urpNX build-tools/dontdiff linus-2.6/arch/i386/Kconfig pciexp-2.6/arch/i386/Kconfig
--- linus-2.6/arch/i386/Kconfig 2004-01-27 21:05:17.000000000 -0500
+++ pciexp-2.6/arch/i386/Kconfig 2004-01-29 09:16:22.000000000 -0500
@@ -1030,12 +1030,16 @@ config PCI_GOBIOS
PCI-based systems don't have any BIOS at all. Linux can also try to
detect the PCI hardware directly without using the BIOS.

- With this option, you can specify how Linux should detect the PCI
- devices. If you choose "BIOS", the BIOS will be used, if you choose
- "Direct", the BIOS won't be used, and if you choose "Any", the
- kernel will try the direct access method and falls back to the BIOS
- if that doesn't work. If unsure, go with the default, which is
- "Any".
+ With this option, you can specify how Linux should detect the
+ PCI devices. If you choose "BIOS", the BIOS will be used,
+ if you choose "Direct", the BIOS won't be used, and if you
+ choose "MMConfig", then PCI Express MMCONFIG will be used.
+ If you choose "Any", the kernel will try MMCONFIG, then the
+ direct access method and falls back to the BIOS if that doesn't
+ work. If unsure, go with the default, which is "Any".
+
+config PCI_GOMMCONFIG
+ bool "MMConfig"

config PCI_GODIRECT
bool "Direct"
@@ -1055,6 +1059,12 @@ config PCI_DIRECT
depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
default y

+config PCI_MMCONFIG
+ bool
+ depends on PCI && (PCI_GOMMCONFIG || PCI_GOANY)
+ select ACPI_BOOT
+ default y
+
config PCI_USE_VECTOR
bool "Vector-based interrupt indexing"
depends on X86_LOCAL_APIC && X86_IO_APIC
diff -urpNX build-tools/dontdiff linus-2.6/arch/i386/kernel/acpi/boot.c pciexp-2.6/arch/i386/kernel/acpi/boot.c
--- linus-2.6/arch/i386/kernel/acpi/boot.c 2004-01-07 18:02:42.000000000 -0500
+++ pciexp-2.6/arch/i386/kernel/acpi/boot.c 2004-01-29 09:13:51.000000000 -0500
@@ -95,6 +95,27 @@ char *__acpi_map_table(unsigned long phy
}


+#ifdef CONFIG_PCI_MMCONFIG
+static int __init acpi_parse_mcfg(unsigned long phys_addr, unsigned long size)
+{
+ struct acpi_table_mcfg *mcfg;
+
+ if (!phys_addr || !size)
+ return -EINVAL;
+
+ mcfg = (struct acpi_table_mcfg *) __acpi_map_table(phys_addr, size);
+ if (!mcfg) {
+ printk(KERN_WARNING PREFIX "Unable to map MCFG\n");
+ return -ENODEV;
+ }
+
+ if (mcfg->base_address)
+ pci_mmcfg_base_addr = mcfg->base_address;
+
+ return 0;
+}
+#endif /* CONFIG_PCI_MMCONFIG */
+
#ifdef CONFIG_X86_LOCAL_APIC

static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
@@ -515,6 +536,19 @@ acpi_boot_init (void)

#endif /* CONFIG_X86_IO_APIC && CONFIG_ACPI_INTERPRETER */

+#ifdef CONFIG_PCI_MMCONFIG
+ result = acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg);
+ if (!result) {
+ printk(KERN_WARNING PREFIX "MCFG not present\n");
+ return 0;
+ } else if (result < 0) {
+ printk(KERN_ERR PREFIX "Error parsing MCFG\n");
+ return result;
+ } else if (result > 1) {
+ printk(KERN_WARNING PREFIX "Multiple MCFG tables exist\n");
+ }
+#endif /* CONFIG_PCI_MMCONFIG */
+
#ifdef CONFIG_X86_LOCAL_APIC
if (acpi_lapic && acpi_ioapic) {
smp_found_config = 1;
diff -urpNX build-tools/dontdiff linus-2.6/arch/i386/pci/Makefile pciexp-2.6/arch/i386/pci/Makefile
--- linus-2.6/arch/i386/pci/Makefile 2003-07-29 13:00:27.000000000 -0400
+++ pciexp-2.6/arch/i386/pci/Makefile 2004-01-29 08:11:28.000000000 -0500
@@ -1,6 +1,7 @@
obj-y := i386.o

obj-$(CONFIG_PCI_BIOS) += pcbios.o
+obj-$(CONFIG_PCI_MMCONFIG) += mmconfig.o
obj-$(CONFIG_PCI_DIRECT) += direct.o

pci-y := fixup.o
diff -urpNX build-tools/dontdiff linus-2.6/arch/i386/pci/common.c pciexp-2.6/arch/i386/pci/common.c
--- linus-2.6/arch/i386/pci/common.c 2003-09-08 17:41:32.000000000 -0400
+++ pciexp-2.6/arch/i386/pci/common.c 2004-01-29 08:11:19.000000000 -0500
@@ -19,7 +19,8 @@
extern void pcibios_sort(void);
#endif

-unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2;
+unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
+ PCI_PROBE_MMCONF;

int pcibios_last_bus = -1;
struct pci_bus *pci_root_bus = NULL;
@@ -197,6 +198,12 @@ char * __devinit pcibios_setup(char *st
return NULL;
}
#endif
+#ifdef CONFIG_PCI_MMCONFIG
+ else if (!strcmp(str, "nommconf")) {
+ pci_probe &= ~PCI_PROBE_MMCONF;
+ return NULL;
+ }
+#endif
#ifdef CONFIG_ACPI_PCI
else if (!strcmp(str, "noacpi")) {
pci_probe |= PCI_NO_ACPI_ROUTING;
diff -urpNX build-tools/dontdiff linus-2.6/arch/i386/pci/mmconfig.c pciexp-2.6/arch/i386/pci/mmconfig.c
--- linus-2.6/arch/i386/pci/mmconfig.c 1969-12-31 19:00:00.000000000 -0500
+++ pciexp-2.6/arch/i386/pci/mmconfig.c 2004-01-29 11:37:09.000000000 -0500
@@ -0,0 +1,115 @@
+/*
+ * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
+ */
+
+#include <linux/pci.h>
+#include <linux/init.h>
+#include "pci.h"
+
+/* The physical address of the MMCONFIG aperture. Set from ACPI tables. */
+u32 pci_mmcfg_base_addr;
+
+#define mmcfg_virt_addr (fix_to_virt(FIX_PCIE_MCFG))
+
+/* The base address of the last MMCONFIG device accessed */
+static u32 mmcfg_last_accessed_device;
+
+/*
+ * Functions for accessing PCI configuration space with MMCONFIG accesses
+ */
+
+static inline void pci_exp_set_dev_base(int bus, int devfn)
+{
+ u32 dev_base = pci_mmcfg_base_addr | (bus << 20) | (devfn << 12);
+ if (dev_base != mmcfg_last_accessed_device) {
+ mmcfg_last_accessed_device = dev_base;
+ set_fixmap(FIX_PCIE_MCFG, dev_base);
+ }
+}
+
+static int pci_mmcfg_read(int seg, int bus, int devfn, int reg, int len, u32 *value)
+{
+ unsigned long flags;
+
+ if (!value || (bus > 255) || (devfn > 255) || (reg > 4095))
+ return -EINVAL;
+
+ spin_lock_irqsave(&pci_config_lock, flags);
+
+ pci_exp_set_dev_base(bus, devfn);
+
+ switch (len) {
+ case 1:
+ *value = readb(mmcfg_virt_addr + reg);
+ break;
+ case 2:
+ *value = readw(mmcfg_virt_addr + reg);
+ break;
+ case 4:
+ *value = readl(mmcfg_virt_addr + reg);
+ break;
+ }
+
+ spin_unlock_irqrestore(&pci_config_lock, flags);
+
+ return 0;
+}
+
+static int pci_mmcfg_write(int seg, int bus, int devfn, int reg, int len, u32 value)
+{
+ unsigned long flags;
+
+ if ((bus > 255) || (devfn > 255) || (reg > 4095))
+ return -EINVAL;
+
+ spin_lock_irqsave(&pci_config_lock, flags);
+
+ pci_exp_set_dev_base(bus, devfn);
+
+ switch (len) {
+ case 1:
+ writeb(value, mmcfg_virt_addr + reg);
+ break;
+ case 2:
+ writew(value, mmcfg_virt_addr + reg);
+ break;
+ case 4:
+ writel(value, mmcfg_virt_addr + reg);
+ break;
+ }
+
+ /* Dummy read to flush PCI write */
+ readl(mmcfg_virt_addr);
+
+ spin_unlock_irqrestore(&pci_config_lock, flags);
+
+ return 0;
+}
+
+static struct pci_raw_ops pci_mmcfg = {
+ .read = pci_mmcfg_read,
+ .write = pci_mmcfg_write,
+};
+
+static int __init pci_mmcfg_init(void)
+{
+ struct resource *region;
+
+ if ((pci_probe & PCI_PROBE_MMCONF) == 0)
+ goto out;
+ if (!pci_mmcfg_base_addr)
+ goto out;
+ region = request_mem_region(pci_mmcfg_base_addr, 256 * 1024 * 1024,
+ "PCI MMCONFIG");
+ if (!region)
+ goto out;
+
+ printk(KERN_INFO "PCI: Using MMCONFIG\n");
+ raw_pci_ops = &pci_mmcfg;
+ pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
+
+ out:
+ return 0;
+}
+
+arch_initcall(pci_mmcfg_init);
diff -urpNX build-tools/dontdiff linus-2.6/arch/i386/pci/pci.h pciexp-2.6/arch/i386/pci/pci.h
--- linus-2.6/arch/i386/pci/pci.h 2003-07-29 13:00:27.000000000 -0400
+++ pciexp-2.6/arch/i386/pci/pci.h 2004-01-29 08:14:48.000000000 -0500
@@ -15,6 +15,9 @@
#define PCI_PROBE_BIOS 0x0001
#define PCI_PROBE_CONF1 0x0002
#define PCI_PROBE_CONF2 0x0004
+#define PCI_PROBE_MMCONF 0x0008
+#define PCI_PROBE_MASK 0x000f
+
#define PCI_NO_SORT 0x0100
#define PCI_BIOS_SORT 0x0200
#define PCI_NO_CHECKS 0x0400
diff -urpNX build-tools/dontdiff linus-2.6/drivers/acpi/tables.c pciexp-2.6/drivers/acpi/tables.c
--- linus-2.6/drivers/acpi/tables.c 2003-10-08 16:52:16.000000000 -0400
+++ pciexp-2.6/drivers/acpi/tables.c 2004-01-29 08:22:52.000000000 -0500
@@ -58,6 +58,7 @@ static char *acpi_table_signatures[ACPI_
[ACPI_SSDT] = "SSDT",
[ACPI_SPMI] = "SPMI",
[ACPI_HPET] = "HPET",
+ [ACPI_MCFG] = "MCFG",
};

/* System Description Table (RSDT/XSDT) */
diff -urpNX build-tools/dontdiff linus-2.6/drivers/pci/pci-sysfs.c pciexp-2.6/drivers/pci/pci-sysfs.c
--- linus-2.6/drivers/pci/pci-sysfs.c 2003-08-22 22:46:57.000000000 -0400
+++ pciexp-2.6/drivers/pci/pci-sysfs.c 2004-01-29 09:30:43.000000000 -0500
@@ -71,7 +71,7 @@ pci_read_config(struct kobject *kobj, ch

/* Several chips lock up trying to read undefined config space */
if (capable(CAP_SYS_ADMIN)) {
- size = 256;
+ size = dev->cfg_size;
} else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
size = 128;
}
@@ -123,10 +123,10 @@ pci_write_config(struct kobject *kobj, c
unsigned int size = count;
loff_t init_off = off;

- if (off > 256)
+ if (off > dev->cfg_size)
return 0;
- if (off + count > 256) {
- size = 256 - off;
+ if (off + count > dev->cfg_size) {
+ size = dev->cfg_size - off;
count = size;
}

@@ -166,6 +166,16 @@ static struct bin_attribute pci_config_a
.write = pci_write_config,
};

+static struct bin_attribute pcie_config_attr = {
+ .attr = {
+ .name = "config",
+ .mode = S_IRUGO | S_IWUSR,
+ },
+ .size = 4096,
+ .read = pci_read_config,
+ .write = pci_write_config,
+};
+
void pci_create_sysfs_dev_files (struct pci_dev *pdev)
{
struct device *dev = &pdev->dev;
@@ -178,5 +188,9 @@ void pci_create_sysfs_dev_files (struct
device_create_file (dev, &dev_attr_class);
device_create_file (dev, &dev_attr_irq);
device_create_file (dev, &dev_attr_resource);
- sysfs_create_bin_file(&dev->kobj, &pci_config_attr);
+ if (pdev->cfg_size < 4096) {
+ sysfs_create_bin_file(&dev->kobj, &pci_config_attr);
+ } else {
+ sysfs_create_bin_file(&dev->kobj, &pcie_config_attr);
+ }
}
diff -urpNX build-tools/dontdiff linus-2.6/drivers/pci/pci.c pciexp-2.6/drivers/pci/pci.c
--- linus-2.6/drivers/pci/pci.c 2003-10-08 16:52:35.000000000 -0400
+++ pciexp-2.6/drivers/pci/pci.c 2004-01-29 08:23:57.000000000 -0500
@@ -90,6 +90,8 @@ pci_max_busnr(void)
* %PCI_CAP_ID_CHSWP CompactPCI HotSwap
*
* %PCI_CAP_ID_PCIX PCI-X
+ *
+ * %PCI_CAP_ID_EXP PCI Express
*/
int
pci_find_capability(struct pci_dev *dev, int cap)
diff -urpNX build-tools/dontdiff linus-2.6/drivers/pci/probe.c pciexp-2.6/drivers/pci/probe.c
--- linus-2.6/drivers/pci/probe.c 2004-01-07 18:02:53.000000000 -0500
+++ pciexp-2.6/drivers/pci/probe.c 2004-01-29 08:59:46.000000000 -0500
@@ -17,6 +17,8 @@

#define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
#define CARDBUS_RESERVE_BUSNR 3
+#define PCI_CFG_SPACE_SIZE 256
+#define PCI_CFG_SPACE_EXP_SIZE 4096

/* Ugh. Need to stop exporting this to modules. */
LIST_HEAD(pci_root_buses);
@@ -479,6 +481,20 @@ static void pci_release_dev(struct devic
kfree(pci_dev);
}

+/**
+ * pci_cfg_space_size - get the configuration space size of the PCI device
+ */
+static int pci_cfg_space_size(struct pci_dev *dev)
+{
+#ifdef CONFIG_PCI_MMCONFIG
+ /* Find whether the device is PCI Express */
+ int is_pci_express_dev = pci_find_capability(dev, PCI_CAP_ID_EXP);
+ if (is_pci_express_dev)
+ return PCI_CFG_SPACE_EXP_SIZE;
+#endif
+ return PCI_CFG_SPACE_SIZE;
+}
+
/*
* Read the config data for a PCI device, sanity-check it
* and fill in the dev structure...
@@ -515,6 +531,7 @@ pci_scan_device(struct pci_bus *bus, int
dev->multifunction = !!(hdr_type & 0x80);
dev->vendor = l & 0xffff;
dev->device = (l >> 16) & 0xffff;
+ dev->cfg_size = pci_cfg_space_size(dev);

/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
set this higher, assuming the system even supports it. */
diff -urpNX build-tools/dontdiff linus-2.6/drivers/pci/proc.c pciexp-2.6/drivers/pci/proc.c
--- linus-2.6/drivers/pci/proc.c 2004-01-07 18:02:53.000000000 -0500
+++ pciexp-2.6/drivers/pci/proc.c 2004-01-29 08:38:49.000000000 -0500
@@ -16,16 +16,15 @@
#include <asm/uaccess.h>
#include <asm/byteorder.h>

-#define PCI_CFG_SPACE_SIZE 256
-
static int proc_initialized; /* = 0 */

static loff_t
proc_bus_pci_lseek(struct file *file, loff_t off, int whence)
{
loff_t new = -1;
+ struct inode *inode = file->f_dentry->d_inode;

- down(&file->f_dentry->d_inode->i_sem);
+ down(&inode->i_sem);
switch (whence) {
case 0:
new = off;
@@ -34,14 +33,14 @@ proc_bus_pci_lseek(struct file *file, lo
new = file->f_pos + off;
break;
case 2:
- new = PCI_CFG_SPACE_SIZE + off;
+ new = inode->i_size + off;
break;
}
- if (new < 0 || new > PCI_CFG_SPACE_SIZE)
+ if (new < 0 || new > inode->i_size)
new = -EINVAL;
else
file->f_pos = new;
- up(&file->f_dentry->d_inode->i_sem);
+ up(&inode->i_sem);
return new;
}

@@ -61,7 +60,7 @@ proc_bus_pci_read(struct file *file, cha
*/

if (capable(CAP_SYS_ADMIN))
- size = PCI_CFG_SPACE_SIZE;
+ size = dev->cfg_size;
else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
size = 128;
else
@@ -134,14 +133,15 @@ proc_bus_pci_write(struct file *file, co
const struct proc_dir_entry *dp = PDE(ino);
struct pci_dev *dev = dp->data;
int pos = *ppos;
+ int size = dev->cfg_size;
int cnt;

- if (pos >= PCI_CFG_SPACE_SIZE)
+ if (pos >= size)
return 0;
- if (nbytes >= PCI_CFG_SPACE_SIZE)
- nbytes = PCI_CFG_SPACE_SIZE;
- if (pos + nbytes > PCI_CFG_SPACE_SIZE)
- nbytes = PCI_CFG_SPACE_SIZE - pos;
+ if (nbytes >= size)
+ nbytes = size;
+ if (pos + nbytes > size)
+ nbytes = size - pos;
cnt = nbytes;

if (!access_ok(VERIFY_READ, buf, cnt))
@@ -403,7 +403,7 @@ int pci_proc_attach_device(struct pci_de
return -ENOMEM;
e->proc_fops = &proc_bus_pci_operations;
e->data = dev;
- e->size = PCI_CFG_SPACE_SIZE;
+ e->size = dev->cfg_size;

return 0;
}
diff -urpNX build-tools/dontdiff linus-2.6/include/asm-i386/fixmap.h pciexp-2.6/include/asm-i386/fixmap.h
--- linus-2.6/include/asm-i386/fixmap.h 2003-07-29 13:01:54.000000000 -0400
+++ pciexp-2.6/include/asm-i386/fixmap.h 2004-01-29 08:40:21.000000000 -0500
@@ -71,6 +71,9 @@ enum fixed_addresses {
FIX_ACPI_BEGIN,
FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1,
#endif
+#ifdef CONFIG_PCI_MMCONFIG
+ FIX_PCIE_MCFG,
+#endif
__end_of_permanent_fixed_addresses,
/* temporary boot-time mappings, used before ioremap() is functional */
#define NR_FIX_BTMAPS 16
diff -urpNX build-tools/dontdiff linus-2.6/include/linux/acpi.h pciexp-2.6/include/linux/acpi.h
--- linus-2.6/include/linux/acpi.h 2003-10-08 16:53:03.000000000 -0400
+++ pciexp-2.6/include/linux/acpi.h 2004-01-29 08:46:48.000000000 -0500
@@ -317,6 +317,15 @@ struct acpi_table_ecdt {
char ec_id[0];
} __attribute__ ((packed));

+/* PCI MMCONFIG */
+
+struct acpi_table_mcfg {
+ struct acpi_table_header header;
+ u8 reserved[8];
+ u32 base_address;
+ u32 base_reserved;
+} __attribute__ ((packed));
+
/* Table Handlers */

enum acpi_table_id {
@@ -338,6 +347,7 @@ enum acpi_table_id {
ACPI_SSDT,
ACPI_SPMI,
ACPI_HPET,
+ ACPI_MCFG,
ACPI_TABLE_COUNT
};

@@ -369,6 +379,8 @@ void acpi_numa_arch_fixup(void);

extern int acpi_mp_config;

+extern u32 pci_mmcfg_base_addr;
+
#else /*!CONFIG_ACPI_BOOT*/

#define acpi_mp_config 0
diff -urpNX build-tools/dontdiff linus-2.6/include/linux/pci.h pciexp-2.6/include/linux/pci.h
--- linus-2.6/include/linux/pci.h 2004-01-27 21:05:48.000000000 -0500
+++ pciexp-2.6/include/linux/pci.h 2004-01-29 09:13:20.000000000 -0500
@@ -410,6 +410,8 @@ struct pci_dev {
unsigned short vendor_compatible[DEVICE_COUNT_COMPATIBLE];
unsigned short device_compatible[DEVICE_COUNT_COMPATIBLE];

+ int cfg_size; /* Size of configuration space */
+
/*
* Instead of touching interrupt line and base address registers
* directly, use the values stored here. They might be different!

--
"Next the statesmen will invent cheap lies, putting the blame upon
the nation that is attacked, and every man will be glad of those
conscience-soothing falsities, and will diligently study them, and refuse
to examine any refutations of them; and thus he will by and by convince
himself that the war is just, and will thank God for the better sleep
he enjoys after this process of grotesque self-deception." -- Mark Twain
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/