[PATCH] PCI: add proper MCFG table parsing to ACPI core.

[PATCH] PCI: add proper MCFG table parsing to ACPI core.

[Greg KH]

In order to handle the MCFG ACPI table properly, we need to at least
parse the thing properly :)  So, here's a patch that adds support for
this.  It's against my latest PCI tree (which is included in -mm) but
will apply with a bit of fuzz against 2.6.12-rc6.

I've tested this out on boxes that only have 1 MCFG config table, if
anyone has access to ones that have more than this, I'd be interested to
see how well it works.  Based on the comments in the mmconfig.c file,
I'm guessing that various AMD boxes are like this...

Anyone have any objections to this patch?

thanks,

greg k-h

-----------------------

Subject: PCI: add proper MCFG table parsing to ACPI core.
From: Greg Kroah-Hartman <gregkh-l3A5Bk7waGM@public.gmane.org>

This patch is the first step in properly handling the MCFG PCI table.
It defines the structures properly, and saves off the table so that the
pci mmconfig code can access it.  It moves the parsing of the table a
little later in the boot process, but still before the information is
needed.


Signed-off-by: Greg Kroah-Hartman <gregkh-l3A5Bk7waGM@public.gmane.org>

---
     
 arch/i386/kernel/acpi/boot.c |   33 +++++++++++++++++++++++++--------
 arch/i386/pci/mmconfig.c     |   12 +++++++++---
 arch/x86_64/pci/mmconfig.c   |   18 ++++++++++++------
 include/linux/acpi.h         |   16 +++++++++++++---
 4 files changed, 59 insertions(+), 20 deletions(-)

--- gregkh-2.6.orig/arch/i386/kernel/acpi/boot.c	2005-06-10 23:47:32.000000000 -0700
+++ gregkh-2.6/arch/i386/kernel/acpi/boot.c	2005-06-13 23:25:39.000000000 -0700
@@ -158,9 +158,10 @@
 #endif
 
 #ifdef CONFIG_PCI_MMCONFIG
-static int __init acpi_parse_mcfg(unsigned long phys_addr, unsigned long size)
+int __init acpi_parse_mcfg(unsigned long phys_addr, unsigned long size)
 {
 	struct acpi_table_mcfg *mcfg;
+	unsigned long i;
 
 	if (!phys_addr || !size)
 		return -EINVAL;
@@ -171,18 +172,35 @@
 		return -ENODEV;
 	}
 
-	if (mcfg->base_reserved) {
-		printk(KERN_ERR PREFIX "MMCONFIG not in low 4GB of memory\n");
+	/* how many config structures do we have */
+	pci_mmcfg_config_num = 0;
+	i = size - sizeof(struct acpi_table_mcfg);
+	while (i >= sizeof(struct acpi_table_mcfg_config)) {
+		++pci_mmcfg_config_num;
+		i -= sizeof(struct acpi_table_mcfg_config);
+	};
+	if (pci_mmcfg_config_num == 0) {
+		printk(KERN_ERR PREFIX "MMCONFIG has no entries\n");
 		return -ENODEV;
 	}
 
-	pci_mmcfg_base_addr = mcfg->base_address;
+	pci_mmcfg_config = kmalloc(pci_mmcfg_config_num * sizeof(*pci_mmcfg_config), GFP_KERNEL);
+	if (!pci_mmcfg_config) {
+		printk(KERN_WARNING PREFIX "No memory for MCFG config tables\n");
+		return -ENOMEM;
+	}
+
+	memcpy(pci_mmcfg_config, &mcfg->config, pci_mmcfg_config_num * sizeof(*pci_mmcfg_config));
+	for (i = 0; i < pci_mmcfg_config_num; ++i) {
+		if (mcfg->config[i].base_reserved) {
+			printk(KERN_ERR PREFIX "MMCONFIG not in low 4GB of memory\n");
+			return -ENODEV;
+		}
+	}
 
 	return 0;
 }
-#else
-#define	acpi_parse_mcfg NULL
-#endif /* !CONFIG_PCI_MMCONFIG */
+#endif /* CONFIG_PCI_MMCONFIG */
 
 #ifdef CONFIG_X86_LOCAL_APIC
 static int __init
@@ -923,7 +941,6 @@
 	acpi_process_madt();
 
 	acpi_table_parse(ACPI_HPET, acpi_parse_hpet);
-	acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg);
 
 	return 0;
 }
--- gregkh-2.6.orig/include/linux/acpi.h	2005-06-10 23:47:32.000000000 -0700
+++ gregkh-2.6/include/linux/acpi.h	2005-06-13 23:25:39.000000000 -0700
@@ -342,11 +342,19 @@
 
 /* PCI MMCONFIG */
 
+/* Defined in PCI Firmware Specification 3.0 */
+struct acpi_table_mcfg_config {
+	u32				base_address;
+	u32				base_reserved;
+	u16				pci_segment_group_number;
+	u8				start_bus_number;
+	u8				end_bus_number;
+	u8				reserved[4];
+} __attribute__ ((packed));
 struct acpi_table_mcfg {
 	struct acpi_table_header	header;
 	u8				reserved[8];
-	u32				base_address;
-	u32				base_reserved;
+	struct acpi_table_mcfg_config	config[0];
 } __attribute__ ((packed));
 
 /* Table Handlers */
@@ -391,6 +399,7 @@
 int acpi_get_table_header_early (enum acpi_table_id id, struct acpi_table_header **header);
 int acpi_table_parse_madt (enum acpi_madt_entry_id id, acpi_madt_entry_handler handler, unsigned int max_entries);
 int acpi_table_parse_srat (enum acpi_srat_entry_id id, acpi_madt_entry_handler handler, unsigned int max_entries);
+int acpi_parse_mcfg (unsigned long phys_addr, unsigned long size);
 void acpi_table_print (struct acpi_table_header *header, unsigned long phys_addr);
 void acpi_table_print_madt_entry (acpi_table_entry_header *madt);
 void acpi_table_print_srat_entry (acpi_table_entry_header *srat);
@@ -412,7 +421,8 @@
 
 extern int acpi_mp_config;
 
-extern u32 pci_mmcfg_base_addr;
+extern struct acpi_table_mcfg_config *pci_mmcfg_config;
+extern int pci_mmcfg_config_num;
 
 extern int sbf_port ;
 
--- gregkh-2.6.orig/arch/i386/pci/mmconfig.c	2005-06-06 12:08:31.000000000 -0700
+++ gregkh-2.6/arch/i386/pci/mmconfig.c	2005-06-13 23:25:39.000000000 -0700
@@ -11,10 +11,12 @@
 
 #include <linux/pci.h>
 #include <linux/init.h>
+#include <linux/acpi.h>
 #include "pci.h"
 
 /* The physical address of the MMCONFIG aperture.  Set from ACPI tables. */
-u32 pci_mmcfg_base_addr;
+struct acpi_table_mcfg_config *pci_mmcfg_config;
+int pci_mmcfg_config_num;
 
 #define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG))
 
@@ -27,7 +29,7 @@
 
 static inline void pci_exp_set_dev_base(int bus, int devfn)
 {
-	u32 dev_base = pci_mmcfg_base_addr | (bus << 20) | (devfn << 12);
+	u32 dev_base = pci_mmcfg_config[0].base_address | (bus << 20) | (devfn << 12);
 	if (dev_base != mmcfg_last_accessed_device) {
 		mmcfg_last_accessed_device = dev_base;
 		set_fixmap_nocache(FIX_PCIE_MCFG, dev_base);
@@ -101,7 +103,11 @@
 {
 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
 		goto out;
-	if (!pci_mmcfg_base_addr)
+
+	acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg);
+	if ((pci_mmcfg_config_num == 0) ||
+	    (pci_mmcfg_config == NULL) ||
+	    (pci_mmcfg_config[0].base_address == 0))
 		goto out;
 
 	/* Kludge for now. Don't use mmconfig on AMD systems because
--- gregkh-2.6.orig/arch/x86_64/pci/mmconfig.c	2005-06-06 12:08:36.000000000 -0700
+++ gregkh-2.6/arch/x86_64/pci/mmconfig.c	2005-06-13 23:25:39.000000000 -0700
@@ -7,15 +7,17 @@
 
 #include <linux/pci.h>
 #include <linux/init.h>
+#include <linux/acpi.h>
 #include "pci.h"
 
 #define MMCONFIG_APER_SIZE (256*1024*1024)
 
 /* The physical address of the MMCONFIG aperture.  Set from ACPI tables. */
-u32 pci_mmcfg_base_addr;
+struct acpi_table_mcfg_config *pci_mmcfg_config;
+int pci_mmcfg_config_num;
 
 /* Static virtual mapping of the MMCONFIG aperture */
-char *pci_mmcfg_virt;
+static char *pci_mmcfg_virt;
 
 static inline char *pci_dev_base(unsigned int bus, unsigned int devfn)
 {
@@ -77,8 +79,12 @@
 {
 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
 		return 0;
-	if (!pci_mmcfg_base_addr)
-		return 0;
+
+	acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg);
+	if ((pci_mmcfg_config_num == 0) ||
+	    (pci_mmcfg_config == NULL) ||
+	    (pci_mmcfg_config[0].base_address == 0))
+		goto out;
 
 	/* Kludge for now. Don't use mmconfig on AMD systems because
 	   those have some busses where mmconfig doesn't work,
@@ -88,13 +94,13 @@
 		return 0; 
 
 	/* RED-PEN i386 doesn't do _nocache right now */
-	pci_mmcfg_virt = ioremap_nocache(pci_mmcfg_base_addr, MMCONFIG_APER_SIZE);
+	pci_mmcfg_virt = ioremap_nocache(pci_mmcfg_config[0].base_address, MMCONFIG_APER_SIZE);
 	if (!pci_mmcfg_virt) { 
 		printk("PCI: Cannot map mmconfig aperture\n");
 		return 0;
 	}	
 
-	printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_base_addr);
+	printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_config[0].base_address);
 	raw_pci_ops = &pci_mmcfg;
 	pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
 


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Re: [PATCH] PCI: add proper MCFG table parsing to ACPI core.

[Andi Kleen]

On Mon, Jun 13, 2005 at 11:37:46PM -0700, Greg KH wrote:
> In order to handle the MCFG ACPI table properly, we need to at least
> parse the thing properly :)  So, here's a patch that adds support for
> this.  It's against my latest PCI tree (which is included in -mm) but
> will apply with a bit of fuzz against 2.6.12-rc6.
> 
> I've tested this out on boxes that only have 1 MCFG config table, if
> anyone has access to ones that have more than this, I'd be interested to
> see how well it works.  Based on the comments in the mmconfig.c file,
> I'm guessing that various AMD boxes are like this...

All the AMD boxes with PCI-Express. The internal busses of the
Northbridge don't support MMCONFIG, but the PCI-Express busses
do. 

> 
> Anyone have any objections to this patch?

Looks good as a first step. Next step will be to query the
PCI segment group numbers and then assign different pci ops to the different 
busses based on that.

-Andi


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This SF.Net email is sponsored by: NEC IT Guy Games.  How far can you shotput
a projector? How fast can you ride your desk chair down the office luge track?
If you want to score the big prize, get to know the little guy.  
Play to win an NEC 61" plasma display: http://www.necitguy.com/?r=20