[GIT PULL] x86/iommu for v2.6.37

From: Ingo Molnar
Date: Thu Oct 21 2010 - 09:51:00 EST

Linus,

Please pull the latest x86-iommu-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-iommu-for-linus


out-of-topic modifications in x86-iommu-for-linus:
--------------------------------------------------
arch/ia64/include/asm/iommu_table.h# fc6a2f3: ia64, iommu: Add a dummy iommu_ta
drivers/pci/dmar.c # 4db77ff: x86, VT-d: Make Intel VT-d IOMMU
# 480125b: x86, iommu: Make all IOMMU's dete
include/linux/dmar.h # 480125b: x86, iommu: Make all IOMMU's dete

Thanks,

Ingo

------------------>
Konrad Rzeszutek Wilk (14):
x86, iommu: Add IOMMU_INIT macros, .iommu_table section, and iommu_table_entry structure
x86, iommu: Make all IOMMU's detection routines return a value.
x86, iommu: Add proper dependency sort routine (and sanity check).
x86, swiotlb: Simplify SWIOTLB pci_swiotlb_detect routine.
x86, swiotlb: Make SWIOTLB use IOMMU_INIT_* macros.
x86, xen-swiotlb: Make Xen-SWIOTLB use IOMMU_INIT_* macros.
x86, calgary: Make Calgary IOMMU use IOMMU_INIT_* macros.
x86, GART/AMD-VI: Make AMD GART and IOMMU use IOMMU_INIT_* macros.
x86, VT-d: Make Intel VT-d IOMMU use IOMMU_INIT_* macros.
x86, iommu: Utilize the IOMMU_INIT macros functionality.
x86, doc: Adding comments about .iommu_table and its neighbors.
x86, iommu: Fix IOMMU_INIT alignment rules
ia64, iommu: Add a dummy iommu_table.h file in IA64.
x86, iommu: Update header comments with appropriate naming


arch/ia64/include/asm/iommu_table.h | 6 ++
arch/x86/include/asm/amd_iommu.h | 4 +-
arch/x86/include/asm/calgary.h | 4 +-
arch/x86/include/asm/gart.h | 5 +-
arch/x86/include/asm/iommu_table.h | 100 +++++++++++++++++++++++++++++++++++
arch/x86/include/asm/swiotlb.h | 13 ++++-
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/amd_iommu_init.c | 15 ++++--
arch/x86/kernel/aperture_64.c | 11 +++--
arch/x86/kernel/pci-calgary_64.c | 18 ++++---
arch/x86/kernel/pci-dma.c | 44 +++++++--------
arch/x86/kernel/pci-gart_64.c | 2 +
arch/x86/kernel/pci-iommu_table.c | 89 +++++++++++++++++++++++++++++++
arch/x86/kernel/pci-swiotlb.c | 44 +++++++++++++---
arch/x86/kernel/vmlinux.lds.S | 28 ++++++++++
arch/x86/xen/pci-swiotlb-xen.c | 5 ++
drivers/pci/dmar.c | 6 ++-
include/linux/dmar.h | 6 +-
18 files changed, 344 insertions(+), 57 deletions(-)
create mode 100644 arch/ia64/include/asm/iommu_table.h
create mode 100644 arch/x86/include/asm/iommu_table.h
create mode 100644 arch/x86/kernel/pci-iommu_table.c

diff --git a/arch/ia64/include/asm/iommu_table.h b/arch/ia64/include/asm/iommu_table.h
new file mode 100644
index 0000000..92c8d36
--- /dev/null
+++ b/arch/ia64/include/asm/iommu_table.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_IA64_IOMMU_TABLE_H
+#define _ASM_IA64_IOMMU_TABLE_H
+
+#define IOMMU_INIT_POST(_detect)
+
+#endif /* _ASM_IA64_IOMMU_TABLE_H */
diff --git a/arch/x86/include/asm/amd_iommu.h b/arch/x86/include/asm/amd_iommu.h
index 5af2982..2798142 100644
--- a/arch/x86/include/asm/amd_iommu.h
+++ b/arch/x86/include/asm/amd_iommu.h
@@ -24,11 +24,11 @@

#ifdef CONFIG_AMD_IOMMU

-extern void amd_iommu_detect(void);
+extern int amd_iommu_detect(void);

#else

-static inline void amd_iommu_detect(void) { }
+static inline int amd_iommu_detect(void) { return -ENODEV; }

#endif

diff --git a/arch/x86/include/asm/calgary.h b/arch/x86/include/asm/calgary.h
index 0918654..0d467b3 100644
--- a/arch/x86/include/asm/calgary.h
+++ b/arch/x86/include/asm/calgary.h
@@ -62,9 +62,9 @@ struct cal_chipset_ops {
extern int use_calgary;

#ifdef CONFIG_CALGARY_IOMMU
-extern void detect_calgary(void);
+extern int detect_calgary(void);
#else
-static inline void detect_calgary(void) { return; }
+static inline int detect_calgary(void) { return -ENODEV; }
#endif

#endif /* _ASM_X86_CALGARY_H */
diff --git a/arch/x86/include/asm/gart.h b/arch/x86/include/asm/gart.h
index 4ac5b0f..d7d1d4c 100644
--- a/arch/x86/include/asm/gart.h
+++ b/arch/x86/include/asm/gart.h
@@ -37,7 +37,7 @@ extern int gart_iommu_aperture_disabled;
extern void early_gart_iommu_check(void);
extern int gart_iommu_init(void);
extern void __init gart_parse_options(char *);
-extern void gart_iommu_hole_init(void);
+extern int gart_iommu_hole_init(void);

#else
#define gart_iommu_aperture 0
@@ -50,8 +50,9 @@ static inline void early_gart_iommu_check(void)
static inline void gart_parse_options(char *options)
{
}
-static inline void gart_iommu_hole_init(void)
+static inline int gart_iommu_hole_init(void)
{
+ return -ENODEV;
}
#endif

diff --git a/arch/x86/include/asm/iommu_table.h b/arch/x86/include/asm/iommu_table.h
new file mode 100644
index 0000000..f229b13
--- /dev/null
+++ b/arch/x86/include/asm/iommu_table.h
@@ -0,0 +1,100 @@
+#ifndef _ASM_X86_IOMMU_TABLE_H
+#define _ASM_X86_IOMMU_TABLE_H
+
+#include <asm/swiotlb.h>
+
+/*
+ * History lesson:
+ * The execution chain of IOMMUs in 2.6.36 looks as so:
+ *
+ * [xen-swiotlb]
+ * |
+ * +----[swiotlb *]--+
+ * / | \
+ * / | \
+ * [GART] [Calgary] [Intel VT-d]
+ * /
+ * /
+ * [AMD-Vi]
+ *
+ * *: if SWIOTLB detected 'iommu=soft'/'swiotlb=force' it would skip
+ * over the rest of IOMMUs and unconditionally initialize the SWIOTLB.
+ * Also it would surreptitiously initialize set the swiotlb=1 if there were
+ * more than 4GB and if the user did not pass in 'iommu=off'. The swiotlb
+ * flag would be turned off by all IOMMUs except the Calgary one.
+ *
+ * The IOMMU_INIT* macros allow a similar tree (or more complex if desired)
+ * to be built by defining who we depend on.
+ *
+ * And all that needs to be done is to use one of the macros in the IOMMU
+ * and the pci-dma.c will take care of the rest.
+ */
+
+struct iommu_table_entry {
+ initcall_t detect;
+ initcall_t depend;
+ void (*early_init)(void); /* No memory allocate available. */
+ void (*late_init)(void); /* Yes, can allocate memory. */
+#define IOMMU_FINISH_IF_DETECTED (1<<0)
+#define IOMMU_DETECTED (1<<1)
+ int flags;
+};
+/*
+ * Macro fills out an entry in the .iommu_table that is equivalent
+ * to the fields that 'struct iommu_table_entry' has. The entries
+ * that are put in the .iommu_table section are not put in any order
+ * hence during boot-time we will have to resort them based on
+ * dependency. */
+
+
+#define __IOMMU_INIT(_detect, _depend, _early_init, _late_init, _finish)\
+ static const struct iommu_table_entry const \
+ __iommu_entry_##_detect __used \
+ __attribute__ ((unused, __section__(".iommu_table"), \
+ aligned((sizeof(void *))))) \
+ = {_detect, _depend, _early_init, _late_init, \
+ _finish ? IOMMU_FINISH_IF_DETECTED : 0}
+/*
+ * The simplest IOMMU definition. Provide the detection routine
+ * and it will be run after the SWIOTLB and the other IOMMUs
+ * that utilize this macro. If the IOMMU is detected (ie, the
+ * detect routine returns a positive value), the other IOMMUs
+ * are also checked. You can use IOMMU_INIT_POST_FINISH if you prefer
+ * to stop detecting the other IOMMUs after yours has been detected.
+ */
+#define IOMMU_INIT_POST(_detect) \
+ __IOMMU_INIT(_detect, pci_swiotlb_detect_4gb, 0, 0, 0)
+
+#define IOMMU_INIT_POST_FINISH(detect) \
+ __IOMMU_INIT(_detect, pci_swiotlb_detect_4gb, 0, 0, 1)
+
+/*
+ * A more sophisticated version of IOMMU_INIT. This variant requires:
+ * a). A detection routine function.
+ * b). The name of the detection routine we depend on to get called
+ * before us.
+ * c). The init routine which gets called if the detection routine
+ * returns a positive value from the pci_iommu_alloc. This means
+ * no presence of a memory allocator.
+ * d). Similar to the 'init', except that this gets called from pci_iommu_init
+ * where we do have a memory allocator.
+ *
+ * The standard vs the _FINISH differs in that the _FINISH variant will
+ * continue detecting other IOMMUs in the call list after the
+ * the detection routine returns a positive number. The _FINISH will
+ * stop the execution chain. Both will still call the 'init' and
+ * 'late_init' functions if they are set.
+ */
+#define IOMMU_INIT_FINISH(_detect, _depend, _init, _late_init) \
+ __IOMMU_INIT(_detect, _depend, _init, _late_init, 1)
+
+#define IOMMU_INIT(_detect, _depend, _init, _late_init) \
+ __IOMMU_INIT(_detect, _depend, _init, _late_init, 0)
+
+void sort_iommu_table(struct iommu_table_entry *start,
+ struct iommu_table_entry *finish);
+
+void check_iommu_entries(struct iommu_table_entry *start,
+ struct iommu_table_entry *finish);
+
+#endif /* _ASM_X86_IOMMU_TABLE_H */
diff --git a/arch/x86/include/asm/swiotlb.h b/arch/x86/include/asm/swiotlb.h
index 8085277..977f176 100644
--- a/arch/x86/include/asm/swiotlb.h
+++ b/arch/x86/include/asm/swiotlb.h
@@ -5,17 +5,26 @@

#ifdef CONFIG_SWIOTLB
extern int swiotlb;
-extern int __init pci_swiotlb_detect(void);
+extern int __init pci_swiotlb_detect_override(void);
+extern int __init pci_swiotlb_detect_4gb(void);
extern void __init pci_swiotlb_init(void);
+extern void __init pci_swiotlb_late_init(void);
#else
#define swiotlb 0
-static inline int pci_swiotlb_detect(void)
+static inline int pci_swiotlb_detect_override(void)
+{
+ return 0;
+}
+static inline int pci_swiotlb_detect_4gb(void)
{
return 0;
}
static inline void pci_swiotlb_init(void)
{
}
+static inline void pci_swiotlb_late_init(void)
+{
+}
#endif

static inline void dma_mark_clean(void *addr, size_t size) {}
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 0925676..6817546 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -42,6 +42,7 @@ obj-y += bootflag.o e820.o
obj-y += pci-dma.o quirks.o i8237.o topology.o kdebugfs.o
obj-y += alternative.o i8253.o pci-nommu.o hw_breakpoint.o
obj-y += tsc.o io_delay.o rtc.o
+obj-y += pci-iommu_table.o

obj-$(CONFIG_X86_TRAMPOLINE) += trampoline.o
obj-y += process.o
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 3cc63e2..26a5e43 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -31,7 +31,7 @@
#include <asm/iommu.h>
#include <asm/gart.h>
#include <asm/x86_init.h>
-
+#include <asm/iommu_table.h>
/*
* definitions for the ACPI scanning code
*/
@@ -1382,13 +1382,13 @@ static int __init early_amd_iommu_detect(struct acpi_table_header *table)
return 0;
}

-void __init amd_iommu_detect(void)
+int __init amd_iommu_detect(void)
{
if (no_iommu || (iommu_detected && !gart_iommu_aperture))
- return;
+ return -ENODEV;

if (amd_iommu_disabled)
- return;
+ return -ENODEV;

if (acpi_table_parse("IVRS", early_amd_iommu_detect) == 0) {
iommu_detected = 1;
@@ -1397,7 +1397,9 @@ void __init amd_iommu_detect(void)

/* Make sure ACS will be enabled */
pci_request_acs();
+ return 1;
}
+ return -ENODEV;
}

/****************************************************************************
@@ -1428,3 +1430,8 @@ static int __init parse_amd_iommu_options(char *str)

__setup("amd_iommu_dump", parse_amd_iommu_dump);
__setup("amd_iommu=", parse_amd_iommu_options);
+
+IOMMU_INIT_FINISH(amd_iommu_detect,
+ gart_iommu_hole_init,
+ 0,
+ 0);
diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index a2e0caf..afa0dab 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -371,7 +371,7 @@ void __init early_gart_iommu_check(void)

static int __initdata printed_gart_size_msg;

-void __init gart_iommu_hole_init(void)
+int __init gart_iommu_hole_init(void)
{
u32 agp_aper_base = 0, agp_aper_order = 0;
u32 aper_size, aper_alloc = 0, aper_order = 0, last_aper_order = 0;
@@ -381,7 +381,7 @@ void __init gart_iommu_hole_init(void)

if (gart_iommu_aperture_disabled || !fix_aperture ||
!early_pci_allowed())
- return;
+ return -ENODEV;

printk(KERN_INFO "Checking aperture...\n");

@@ -463,8 +463,9 @@ out:
unsigned long n = (32 * 1024 * 1024) << last_aper_order;

insert_aperture_resource((u32)last_aper_base, n);
+ return 1;
}
- return;
+ return 0;
}

if (!fallback_aper_force) {
@@ -500,7 +501,7 @@ out:
panic("Not enough memory for aperture");
}
} else {
- return;
+ return 0;
}

/* Fix up the north bridges */
@@ -524,4 +525,6 @@ out:
}

set_up_gart_resume(aper_order, aper_alloc);
+
+ return 1;
}
diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index 078d4ec..f56a117 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -47,6 +47,7 @@
#include <asm/rio.h>
#include <asm/bios_ebda.h>
#include <asm/x86_init.h>
+#include <asm/iommu_table.h>

#ifdef CONFIG_CALGARY_IOMMU_ENABLED_BY_DEFAULT
int use_calgary __read_mostly = 1;
@@ -1364,7 +1365,7 @@ static int __init calgary_iommu_init(void)
return 0;
}

-void __init detect_calgary(void)
+int __init detect_calgary(void)
{
int bus;
void *tbl;
@@ -1378,13 +1379,13 @@ void __init detect_calgary(void)
* another HW IOMMU already, bail out.
*/
if (no_iommu || iommu_detected)
- return;
+ return -ENODEV;

if (!use_calgary)
- return;
+ return -ENODEV;

if (!early_pci_allowed())
- return;
+ return -ENODEV;

printk(KERN_DEBUG "Calgary: detecting Calgary via BIOS EBDA area\n");

@@ -1410,13 +1411,13 @@ void __init detect_calgary(void)
if (!rio_table_hdr) {
printk(KERN_DEBUG "Calgary: Unable to locate Rio Grande table "
"in EBDA - bailing!\n");
- return;
+ return -ENODEV;
}

ret = build_detail_arrays();
if (ret) {
printk(KERN_DEBUG "Calgary: build_detail_arrays ret %d\n", ret);
- return;
+ return -ENOMEM;
}

specified_table_size = determine_tce_table_size((is_kdump_kernel() ?
@@ -1464,7 +1465,7 @@ void __init detect_calgary(void)

x86_init.iommu.iommu_init = calgary_iommu_init;
}
- return;
+ return calgary_found;

cleanup:
for (--bus; bus >= 0; --bus) {
@@ -1473,6 +1474,7 @@ cleanup:
if (info->tce_space)
free_tce_table(info->tce_space);
}
+ return -ENOMEM;
}

static int __init calgary_parse_options(char *p)
@@ -1594,3 +1596,5 @@ static int __init calgary_fixup_tce_spaces(void)
* and before device_initcall.
*/
rootfs_initcall(calgary_fixup_tce_spaces);
+
+IOMMU_INIT_POST(detect_calgary);
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 9f07cfc..9ea999a 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -11,9 +11,8 @@
#include <asm/iommu.h>
#include <asm/gart.h>
#include <asm/calgary.h>
-#include <asm/amd_iommu.h>
#include <asm/x86_init.h>
-#include <asm/xen/swiotlb-xen.h>
+#include <asm/iommu_table.h>

static int forbid_dac __read_mostly;

@@ -45,6 +44,8 @@ int iommu_detected __read_mostly = 0;
*/
int iommu_pass_through __read_mostly;

+extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];
+
/* Dummy device used for NULL arguments (normally ISA). */
struct device x86_dma_fallback_dev = {
.init_name = "fallback device",
@@ -130,26 +131,24 @@ static void __init dma32_free_bootmem(void)

void __init pci_iommu_alloc(void)
{
+ struct iommu_table_entry *p;
+
/* free the range so iommu could get some range less than 4G */
dma32_free_bootmem();

- if (pci_xen_swiotlb_detect() || pci_swiotlb_detect())
- goto out;
-
- gart_iommu_hole_init();
-
- detect_calgary();
-
- detect_intel_iommu();
+ sort_iommu_table(__iommu_table, __iommu_table_end);
+ check_iommu_entries(__iommu_table, __iommu_table_end);

- /* needs to be called after gart_iommu_hole_init */
- amd_iommu_detect();
-out:
- pci_xen_swiotlb_init();
-
- pci_swiotlb_init();
+ for (p = __iommu_table; p < __iommu_table_end; p++) {
+ if (p && p->detect && p->detect() > 0) {
+ p->flags |= IOMMU_DETECTED;
+ if (p->early_init)
+ p->early_init();
+ if (p->flags & IOMMU_FINISH_IF_DETECTED)
+ break;
+ }
+ }
}
-
void *dma_generic_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_addr, gfp_t flag)
{
@@ -292,6 +291,7 @@ EXPORT_SYMBOL(dma_supported);

static int __init pci_iommu_init(void)
{
+ struct iommu_table_entry *p;
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);

#ifdef CONFIG_PCI
@@ -299,12 +299,10 @@ static int __init pci_iommu_init(void)
#endif
x86_init.iommu.iommu_init();

- if (swiotlb || xen_swiotlb) {
- printk(KERN_INFO "PCI-DMA: "
- "Using software bounce buffering for IO (SWIOTLB)\n");
- swiotlb_print_info();
- } else
- swiotlb_free();
+ for (p = __iommu_table; p < __iommu_table_end; p++) {
+ if (p && (p->flags & IOMMU_DETECTED) && p->late_init)
+ p->late_init();
+ }

return 0;
}
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 0f7f130..de9734b 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -41,6 +41,7 @@
#include <asm/dma.h>
#include <asm/k8.h>
#include <asm/x86_init.h>
+#include <asm/iommu_table.h>

static unsigned long iommu_bus_base; /* GART remapping area (physical) */
static unsigned long iommu_size; /* size of remapping area bytes */
@@ -896,3 +897,4 @@ void __init gart_parse_options(char *p)
}
}
}
+IOMMU_INIT_POST(gart_iommu_hole_init);
diff --git a/arch/x86/kernel/pci-iommu_table.c b/arch/x86/kernel/pci-iommu_table.c
new file mode 100644
index 0000000..55d745e
--- /dev/null
+++ b/arch/x86/kernel/pci-iommu_table.c
@@ -0,0 +1,89 @@
+#include <linux/dma-mapping.h>
+#include <asm/iommu_table.h>
+#include <linux/string.h>
+#include <linux/kallsyms.h>
+
+
+#define DEBUG 1
+
+static struct iommu_table_entry * __init
+find_dependents_of(struct iommu_table_entry *start,
+ struct iommu_table_entry *finish,
+ struct iommu_table_entry *q)
+{
+ struct iommu_table_entry *p;
+
+ if (!q)
+ return NULL;
+
+ for (p = start; p < finish; p++)
+ if (p->detect == q->depend)
+ return p;
+
+ return NULL;
+}
+
+
+void __init sort_iommu_table(struct iommu_table_entry *start,
+ struct iommu_table_entry *finish) {
+
+ struct iommu_table_entry *p, *q, tmp;
+
+ for (p = start; p < finish; p++) {
+again:
+ q = find_dependents_of(start, finish, p);
+ /* We are bit sneaky here. We use the memory address to figure
+ * out if the node we depend on is past our point, if so, swap.
+ */
+ if (q > p) {
+ tmp = *p;
+ memmove(p, q, sizeof(*p));
+ *q = tmp;
+ goto again;
+ }
+ }
+
+}
+
+#ifdef DEBUG
+void __init check_iommu_entries(struct iommu_table_entry *start,
+ struct iommu_table_entry *finish)
+{
+ struct iommu_table_entry *p, *q, *x;
+ char sym_p[KSYM_SYMBOL_LEN];
+ char sym_q[KSYM_SYMBOL_LEN];
+
+ /* Simple cyclic dependency checker. */
+ for (p = start; p < finish; p++) {
+ q = find_dependents_of(start, finish, p);
+ x = find_dependents_of(start, finish, q);
+ if (p == x) {
+ sprint_symbol(sym_p, (unsigned long)p->detect);
+ sprint_symbol(sym_q, (unsigned long)q->detect);
+
+ printk(KERN_ERR "CYCLIC DEPENDENCY FOUND! %s depends" \
+ " on %s and vice-versa. BREAKING IT.\n",
+ sym_p, sym_q);
+ /* Heavy handed way..*/
+ x->depend = 0;
+ }
+ }
+
+ for (p = start; p < finish; p++) {
+ q = find_dependents_of(p, finish, p);
+ if (q && q > p) {
+ sprint_symbol(sym_p, (unsigned long)p->detect);
+ sprint_symbol(sym_q, (unsigned long)q->detect);
+
+ printk(KERN_ERR "EXECUTION ORDER INVALID! %s "\
+ "should be called before %s!\n",
+ sym_p, sym_q);
+ }
+ }
+}
+#else
+inline void check_iommu_entries(struct iommu_table_entry *start,
+ struct iommu_table_entry *finish)
+{
+}
+#endif
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index a5bc528..8f972cb 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -10,7 +10,8 @@
#include <asm/iommu.h>
#include <asm/swiotlb.h>
#include <asm/dma.h>
-
+#include <asm/xen/swiotlb-xen.h>
+#include <asm/iommu_table.h>
int swiotlb __read_mostly;

static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
@@ -41,25 +42,42 @@ static struct dma_map_ops swiotlb_dma_ops = {
};

/*
- * pci_swiotlb_detect - set swiotlb to 1 if necessary
+ * pci_swiotlb_detect_override - set swiotlb to 1 if necessary
*
* This returns non-zero if we are forced to use swiotlb (by the boot
* option).
*/
-int __init pci_swiotlb_detect(void)
+int __init pci_swiotlb_detect_override(void)
{
int use_swiotlb = swiotlb | swiotlb_force;

+ if (swiotlb_force)
+ swiotlb = 1;
+
+ return use_swiotlb;
+}
+IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
+ pci_xen_swiotlb_detect,
+ pci_swiotlb_init,
+ pci_swiotlb_late_init);
+
+/*
+ * if 4GB or more detected (and iommu=off not set) return 1
+ * and set swiotlb to 1.
+ */
+int __init pci_swiotlb_detect_4gb(void)
+{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
#ifdef CONFIG_X86_64
if (!no_iommu && max_pfn > MAX_DMA32_PFN)
swiotlb = 1;
#endif
- if (swiotlb_force)
- swiotlb = 1;
-
- return use_swiotlb;
+ return swiotlb;
}
+IOMMU_INIT(pci_swiotlb_detect_4gb,
+ pci_swiotlb_detect_override,
+ pci_swiotlb_init,
+ pci_swiotlb_late_init);

void __init pci_swiotlb_init(void)
{
@@ -68,3 +86,15 @@ void __init pci_swiotlb_init(void)
dma_ops = &swiotlb_dma_ops;
}
}
+
+void __init pci_swiotlb_late_init(void)
+{
+ /* An IOMMU turned us off. */
+ if (!swiotlb)
+ swiotlb_free();
+ else {
+ printk(KERN_INFO "PCI-DMA: "
+ "Using software bounce buffering for IO (SWIOTLB)\n");
+ swiotlb_print_info();
+ }
+}
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index d0bb522..38e2b67 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -242,6 +242,12 @@ SECTIONS
__x86_cpu_dev_end = .;
}

+ /*
+ * start address and size of operations which during runtime
+ * can be patched with virtualization friendly instructions or
+ * baremetal native ones. Think page table operations.
+ * Details in paravirt_types.h
+ */
. = ALIGN(8);
.parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
__parainstructions = .;
@@ -249,6 +255,11 @@ SECTIONS
__parainstructions_end = .;
}

+ /*
+ * struct alt_inst entries. From the header (alternative.h):
+ * "Alternative instructions for different CPU types or capabilities"
+ * Think locking instructions on spinlocks.
+ */
. = ALIGN(8);
.altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
__alt_instructions = .;
@@ -256,11 +267,28 @@ SECTIONS
__alt_instructions_end = .;
}

+ /*
+ * And here are the replacement instructions. The linker sticks
+ * them as binary blobs. The .altinstructions has enough data to
+ * get the address and the length of them to patch the kernel safely.
+ */
.altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
*(.altinstr_replacement)
}

/*
+ * struct iommu_table_entry entries are injected in this section.
+ * It is an array of IOMMUs which during run time gets sorted depending
+ * on its dependency order. After rootfs_initcall is complete
+ * this section can be safely removed.
+ */
+ .iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) {
+ __iommu_table = .;
+ *(.iommu_table)
+ __iommu_table_end = .;
+ }
+ . = ALIGN(8);
+ /*
* .exit.text is discard at runtime, not link time, to deal with
* references from .altinstructions and .eh_frame
*/
diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
index a013ec9..2247100 100644
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ b/arch/x86/xen/pci-swiotlb-xen.c
@@ -5,6 +5,7 @@

#include <asm/xen/hypervisor.h>
#include <xen/xen.h>
+#include <asm/iommu_table.h>

int xen_swiotlb __read_mostly;

@@ -56,3 +57,7 @@ void __init pci_xen_swiotlb_init(void)
dma_ops = &xen_swiotlb_dma_ops;
}
}
+IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
+ 0,
+ pci_xen_swiotlb_init,
+ 0);
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index 0a19708..4ef56a0 100644
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -36,6 +36,7 @@
#include <linux/tboot.h>
#include <linux/dmi.h>
#include <linux/slab.h>
+#include <asm/iommu_table.h>

#define PREFIX "DMAR: "

@@ -687,7 +688,7 @@ failed:
return 0;
}

-void __init detect_intel_iommu(void)
+int __init detect_intel_iommu(void)
{
int ret;

@@ -723,6 +724,8 @@ void __init detect_intel_iommu(void)
}
early_acpi_os_unmap_memory(dmar_tbl, dmar_tbl_size);
dmar_tbl = NULL;
+
+ return ret ? 1 : -ENODEV;
}


@@ -1455,3 +1458,4 @@ int __init dmar_ir_support(void)
return 0;
return dmar->flags & 0x1;
}
+IOMMU_INIT_POST(detect_intel_iommu);
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index d7cecc9..a206020 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -57,15 +57,15 @@ extern int dmar_table_init(void);
extern int dmar_dev_scope_init(void);

/* Intel IOMMU detection */
-extern void detect_intel_iommu(void);
+extern int detect_intel_iommu(void);
extern int enable_drhd_fault_handling(void);

extern int parse_ioapics_under_ir(void);
extern int alloc_iommu(struct dmar_drhd_unit *);
#else
-static inline void detect_intel_iommu(void)
+static inline int detect_intel_iommu(void)
{
- return;
+ return -ENODEV;
}

static inline int dmar_table_init(void)
--
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