Re: [Intel-IOMMU 01/10] DMAR detection and parsing logic

[Jeff Garzik]

On Mon, Jun 04, 2007 at 02:02:43PM -0700, anil.s.keshavamurthy@xxxxxxxxx wrote:
> --- linux-2.6.22-rc3.orig/drivers/pci/Makefile	2007-06-04 12:28:13.000000000 -0700
> +++ linux-2.6.22-rc3/drivers/pci/Makefile	2007-06-04 12:33:15.000000000 -0700
> @@ -20,6 +20,9 @@
>  # Build the Hypertransport interrupt support
>  obj-$(CONFIG_HT_IRQ) += htirq.o
>  
> +# Build Intel IOMMU support
> +obj-$(CONFIG_DMAR) += dmar.o

It's not Intel IOMMU support though, is it?

It's x86 PCI IOMMU support (as opposed to x86 GART IOMMU).

I just want to avoid Intel branding on something that will not be
specific to Intel-manufacured products in the long term.



> Index: linux-2.6.22-rc3/drivers/pci/dmar.c
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6.22-rc3/drivers/pci/dmar.c	2007-06-04 12:33:15.000000000 -0700
> @@ -0,0 +1,318 @@
> +/*
> + * Copyright (c) 2006, Intel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> + * Place - Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * 	Copyright (C) Ashok Raj <ashok.raj@xxxxxxxxx>
> + *	Copyright (C) Shaohua Li <shaohua.li@xxxxxxxxx>
> + *
> + * 	This file implements early detection/parsing of DMA Remapping Devices
> + * reported to OS through BIOS via DMA remapping reporting (DMAR) ACPI
> + * tables.
> + */
> +
> +#include <linux/pci.h>
> +#include <linux/dmar.h>
> +
> +#undef PREFIX
> +#define PREFIX "DMAR:"
> +
> +/* No locks are needed as DMA remapping hardware unit
> + * list is constructed at boot time and hotplug of
> + * these units are not supported by the architecture.
> + */
> +LIST_HEAD(dmar_drhd_units);
> +LIST_HEAD(dmar_rmrr_units);
> +
> +static struct acpi_table_header * __initdata dmar_tbl;
> +
> +static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
> +{
> +	/*
> +	 * add INCLUDE_ALL at the tail, so scan the list will find it at
> +	 * the very end.
> +	 */
> +	if (drhd->include_all)
> +		list_add_tail(&drhd->list, &dmar_drhd_units);
> +	else
> +		list_add(&drhd->list, &dmar_drhd_units);
> +}
> +
> +static void __init dmar_register_rmrr_unit(struct dmar_rmrr_unit *rmrr)
> +{
> +	list_add(&rmrr->list, &dmar_rmrr_units);
> +}
> +
> +static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
> +					   struct pci_dev **dev, u16 segment)
> +{
> +	struct pci_bus *bus;
> +	struct pci_dev *pdev = NULL;
> +	struct acpi_dmar_pci_path *path;
> +	int count;
> +
> +	bus = pci_find_bus(segment, scope->bus);
> +	path = (struct acpi_dmar_pci_path *)(scope + 1);
> +	count = (scope->length - sizeof(struct acpi_dmar_device_scope))
> +		/sizeof(struct acpi_dmar_pci_path);

add a space.

But overall this casting and typed-struct pointer addition is a bit
fragile.  No comment (I haven't read enough yet) whether it is needed or
not.




> +
> +	while (count) {
> +		if (pdev)
> +			pci_dev_put(pdev);
> +		/*
> +		 * Some BIOSes list non-exist devices in DMAR table, just
> +		 * ignore it
> +		 */
> +		if (!bus) {
> +			printk(KERN_WARNING
> +			PREFIX "Device scope bus [%d] not found\n",
> +			scope->bus);
> +			break;
> +		}
> +		pdev = pci_get_slot(bus, PCI_DEVFN(path->dev, path->fn));
> +		if (!pdev) {
> +			printk(KERN_WARNING PREFIX
> +			"Device scope device [%04x:%02x:%02x.%02x] not found\n",
> +				segment, bus->number, path->dev, path->fn);
> +			break;
> +		}
> +		path ++;
> +		count --;
> +		bus = pdev->subordinate;
> +	}
> +	if (!pdev) {
> +		printk(KERN_WARNING PREFIX
> +		"Device scope device [%04x:%02x:%02x.%02x] not found\n",
> +		segment, scope->bus, path->dev, path->fn);
> +		*dev = NULL;
> +		return 0;
> +	}
> +	if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT && pdev->subordinate)
> +	   || (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE && !pdev->subordinate)) {
> +		pci_dev_put(pdev);
> +		printk(KERN_WARNING PREFIX "Device scope type does not match for %s\n", pci_name(pdev));
> +		return -EINVAL;
> +	}
> +	*dev = pdev;
> +	return 0;
> +}
> +
> +static int __init dmar_parse_dev_scope(void *start, void *end, int *cnt,
> +				       struct pci_dev ***devices, u16 segment)
> +{
> +	struct acpi_dmar_device_scope *scope;
> +	void * tmp = start;
> +	int index;
> +	int ret;
> +
> +	*cnt = 0;
> +	while (start < end) {
> +		scope = start;
> +		if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
> +		    scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
> +			(*cnt)++;
> +		else
> +			printk(KERN_WARNING PREFIX "Unsupported device scope\n");
> +		start += scope->length;
> +	}
> +	if (*cnt == 0)
> +		return 0;
> +
> +	*devices = kcalloc(*cnt, sizeof(struct pci_dev *), GFP_KERNEL);
> +	if (!*devices)
> +		return -ENOMEM;
> +
> +	start = tmp;
> +	index = 0;
> +	while (start < end) {
> +		scope = start;
> +		if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
> +		    scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE) {
> +			ret = dmar_parse_one_dev_scope(scope,
> +				&(*devices)[index], segment);
> +			if (ret) {
> +				kfree(*devices);
> +				return ret;
> +			}
> +			index ++;
> +		}
> +		start += scope->length;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
> + * structure which uniquely represent one DMA remapping hardware unit
> + * present in the platform
> + */
> +static int __init
> +dmar_parse_one_drhd(struct acpi_dmar_header *header)
> +{
> +	struct acpi_dmar_hardware_unit * drhd = (struct acpi_dmar_hardware_unit *)header;
> +	struct dmar_drhd_unit *dmaru;
> +	int ret = 0;
> +	static int include_all;
> +
> +	dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
> +	if (!dmaru)
> +		return -ENOMEM;
> +
> +	dmaru->reg_base_addr = drhd->address;
> +	dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
> +
> +	if (!dmaru->include_all)
> +		ret = dmar_parse_dev_scope((void *)(drhd + 1),
> +				((void *)drhd) + header->length,
> +				&dmaru->devices_cnt, &dmaru->devices,
> +				drhd->segment);
> +	else {
> +		/* Only allow one INCLUDE_ALL */
> +		if (include_all) {
> +			printk(KERN_WARNING PREFIX "Only one INCLUDE_ALL "
> +				"device scope is allowed\n");
> +			ret = -EINVAL;
> +		}
> +		include_all = 1;
> +	}
> +
> +	if (ret || (dmaru->devices_cnt == 0 && !dmaru->include_all))
> +		kfree(dmaru);
> +	else
> +		dmar_register_drhd_unit(dmaru);
> +	return ret;
> +}
> +
> +static int __init
> +dmar_parse_one_rmrr(struct acpi_dmar_header *header)
> +{
> +	struct acpi_dmar_reserved_memory *rmrr = (struct acpi_dmar_reserved_memory *)header;
> +	struct dmar_rmrr_unit *rmrru;
> +	int ret = 0;
> +
> +	rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
> +	if (!rmrru)
> +		return -ENOMEM;
> +
> +	rmrru->base_address = rmrr->base_address;
> +	rmrru->end_address = rmrr->end_address;
> +	ret = dmar_parse_dev_scope((void *)(rmrr + 1),
> +		((void*)rmrr) + header->length,
> +		&rmrru->devices_cnt, &rmrru->devices, rmrr->segment);
> +
> +	if (ret || (rmrru->devices_cnt == 0))
> +		kfree(rmrru);
> +	else
> +		dmar_register_rmrr_unit(rmrru);
> +	return ret;
> +}
> +
> +static void __init
> +dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
> +{
> +	struct acpi_dmar_hardware_unit *drhd;
> +	struct acpi_dmar_reserved_memory *rmrr;
> +
> +	switch (header->type) {
> +	case ACPI_DMAR_TYPE_HARDWARE_UNIT:
> +		drhd = (struct acpi_dmar_hardware_unit *)header;
> +		printk (KERN_INFO PREFIX
> +			"DRHD (flags: 0x%08x)base: 0x%016Lx\n",
> +			drhd->flags, drhd->address);
> +		break;
> +	case ACPI_DMAR_TYPE_RESERVED_MEMORY:
> +		rmrr = (struct acpi_dmar_reserved_memory *)header;
> +
> +		printk (KERN_INFO PREFIX
> +			"RMRR base: 0x%016Lx end: 0x%016Lx\n",
> +			rmrr->base_address, rmrr->end_address);
> +		break;
> +	}
> +}
> +
> +/**
> + * parse_dmar_table - parses the DMA reporting table
> + */
> +static int __init
> +parse_dmar_table(void)
> +{
> +	struct acpi_table_dmar *dmar;
> +	struct acpi_dmar_header *entry_header;
> +	int ret = 0;
> +
> +	dmar = (struct acpi_table_dmar *)dmar_tbl;
> +
> +	if (!dmar->width) {
> +		printk (KERN_WARNING PREFIX "Zero: Invalid DMAR haw\n");
> +		return -EINVAL;
> +	}
> +
> +	printk (KERN_INFO PREFIX "Host address width %d\n",
> +		dmar->width + 1);
> +
> +	entry_header = (struct acpi_dmar_header *)(dmar + 1);
> +	while (((unsigned long)entry_header) < (((unsigned long)dmar) + dmar_tbl->length)) {
> +		dmar_table_print_dmar_entry(entry_header);
> +
> +		switch (entry_header->type) {
> +		case ACPI_DMAR_TYPE_HARDWARE_UNIT:
> +			ret = dmar_parse_one_drhd(entry_header);
> +			break;
> +		case ACPI_DMAR_TYPE_RESERVED_MEMORY:
> +			ret = dmar_parse_one_rmrr(entry_header);
> +			break;
> +		default:
> +			printk(KERN_WARNING PREFIX "Unknown DMAR structure type\n");
> +			ret = 0; /* for forward compatibility */
> +			break;
> +		}
> +		if (ret)
> +			break;
> +
> +		entry_header = ((void *)entry_header + entry_header->length);
> +	}
> +	return ret;
> +}
> +
> +
> +int __init dmar_table_init(void)
> +{
> +
> +	parse_dmar_table();
> +	if (list_empty(&dmar_drhd_units)) {
> +		printk(KERN_ERR PREFIX "No DMAR devices found\n");
> +		return -ENODEV;
> +	}
> +	return 0;
> +}
> +
> +/**
> + * early_dmar_detect - checks to see if the platform supports DMAR devices
> + */
> +int __init early_dmar_detect(void)
> +{
> +	acpi_status status = AE_OK;
> +
> +	/* if we could find DMAR table, then there are DMAR devices */
> +	status = acpi_get_table(ACPI_SIG_DMAR, 0,
> +				(struct acpi_table_header **)&dmar_tbl);
> +
> +	if (ACPI_SUCCESS(status) && !dmar_tbl) {
> +		printk (KERN_WARNING PREFIX "Unable to map DMAR\n");
> +		status = AE_NOT_FOUND;
> +	}
> +
> +	return (ACPI_SUCCESS(status) ? 1 : 0);
> +}
> Index: linux-2.6.22-rc3/include/acpi/actbl1.h
> ===================================================================
> --- linux-2.6.22-rc3.orig/include/acpi/actbl1.h	2007-06-04 12:28:13.000000000 -0700
> +++ linux-2.6.22-rc3/include/acpi/actbl1.h	2007-06-04 12:33:15.000000000 -0700
> @@ -257,7 +257,8 @@
>  struct acpi_table_dmar {
>  	struct acpi_table_header header;	/* Common ACPI table header */
>  	u8 width;		/* Host Address Width */
> -	u8 reserved[11];
> +	u8 flags;
> +	u8 reserved[10];
>  };
>  
>  /* DMAR subtable header */
> @@ -265,8 +266,6 @@
>  struct acpi_dmar_header {
>  	u16 type;
>  	u16 length;
> -	u8 flags;
> -	u8 reserved[3];
>  };
>  
>  /* Values for subtable type in struct acpi_dmar_header */
> @@ -274,13 +273,15 @@
>  enum acpi_dmar_type {
>  	ACPI_DMAR_TYPE_HARDWARE_UNIT = 0,
>  	ACPI_DMAR_TYPE_RESERVED_MEMORY = 1,
> -	ACPI_DMAR_TYPE_RESERVED = 2	/* 2 and greater are reserved */
> +	ACPI_DMAR_TYPE_ATSR = 2,
> +	ACPI_DMAR_TYPE_RESERVED = 3	/* 3 and greater are reserved */
>  };
>  
>  struct acpi_dmar_device_scope {
>  	u8 entry_type;
>  	u8 length;
> -	u8 segment;
> +	u16 reserved;
> +	u8 enumeration_id;
>  	u8 bus;
>  };
>  
> @@ -290,7 +291,14 @@
>  	ACPI_DMAR_SCOPE_TYPE_NOT_USED = 0,
>  	ACPI_DMAR_SCOPE_TYPE_ENDPOINT = 1,
>  	ACPI_DMAR_SCOPE_TYPE_BRIDGE = 2,
> -	ACPI_DMAR_SCOPE_TYPE_RESERVED = 3	/* 3 and greater are reserved */
> +	ACPI_DMAR_SCOPE_TYPE_IOAPIC = 3,
> +	ACPI_DMAR_SCOPE_TYPE_HPET = 4,
> +	ACPI_DMAR_SCOPE_TYPE_RESERVED = 5	/* 5 and greater are reserved */
> +};
> +
> +struct acpi_dmar_pci_path {
> +	u8 dev;
> +	u8 fn;
>  };
>  
>  /*
> @@ -301,6 +309,9 @@
>  
>  struct acpi_dmar_hardware_unit {
>  	struct acpi_dmar_header header;
> +	u8 flags;
> +	u8 reserved;
> +	u16 segment;
>  	u64 address;		/* Register Base Address */
>  };
>  
> @@ -312,7 +323,9 @@
>  
>  struct acpi_dmar_reserved_memory {
>  	struct acpi_dmar_header header;
> -	u64 address;		/* 4_k aligned base address */
> +	u16 reserved;
> +	u16 segment;
> +	u64 base_address;		/* 4_k aligned base address */
>  	u64 end_address;	/* 4_k aligned limit address */
>  };
>  
> Index: linux-2.6.22-rc3/include/linux/dmar.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6.22-rc3/include/linux/dmar.h	2007-06-04 12:33:15.000000000 -0700
> @@ -0,0 +1,52 @@
> +/*
> + * Copyright (c) 2006, Intel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> + * Place - Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * Copyright (C) Ashok Raj <ashok.raj@xxxxxxxxx>
> + * Copyright (C) Shaohua Li <shaohua.li@xxxxxxxxx>
> + */
> +
> +#ifndef __DMAR_H__
> +#define __DMAR_H__
> +
> +#include <linux/acpi.h>
> +#include <linux/types.h>
> +
> +
> +extern int dmar_table_init(void);
> +extern int early_dmar_detect(void);
> +
> +extern struct list_head dmar_drhd_units;
> +extern struct list_head dmar_rmrr_units;
> +
> +struct dmar_drhd_unit {
> +	struct list_head list;		/* list of drhd units	*/
> +	u64	reg_base_addr;		/* register base address*/
> +	struct	pci_dev **devices; 	/* target device array	*/
> +	int	devices_cnt;		/* target device count	*/
> +	u8	ignored:1; 		/* ignore drhd		*/
> +	u8	include_all:1;
> +	struct intel_iommu *iommu;
> +};
> +
> +struct dmar_rmrr_unit {
> +	struct list_head list;		/* list of rmrr units	*/
> +	u64	base_address;		/* reserved base address*/
> +	u64	end_address;		/* reserved end address */
> +	struct pci_dev **devices;	/* target devices */
> +	int	devices_cnt;		/* target device count */
> +};
> +
> +#endif /* __DMAR_H__ */
> 
> -- 
> -
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