Commit Graph

536 Commits

Author SHA1 Message Date
Konstantin Belousov
0df87548b9 Type of the interrupt handlers on x86 cannot be expressed in C.
Simplify and unify placeholder type definitions.

Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D5771
2016-03-29 19:56:48 +00:00
Konstantin Belousov
d317106ce2 Fix several bugs in r297374:
- fix UP build [1]
- do not obliterate initial reading of rdtsc by the loop counter [2]
- restore the meaning of the argument -1 to native_lapic_ipi_wait()
  as wait until LAPIC acknowledge without timeout
- correct formula for calculating loop iteration count for 1us, it was
  inverted, and ensure that even on unlikely slow CPUs at least one
  check for ack is performed.

Reported by:	Michael Butler <imb@protected-networks.net> [1], rpokala[2],
	jhb[3]
Tested by:	Michael Butler
Pointy hat to:	kib
Sponsored by:	The FreeBSD Foundation
2016-03-29 19:54:13 +00:00
Konstantin Belousov
998e1ef11f Calibrate the frequency of the of the native_lapic_ipi_wait() loop,
and avoid a delay while waiting for IPI delivery acknowledgement in
xAPIC mode.  This makes the loop exit immediately after the delivery
bit in APIC_ICR register is set, instead of waiting for some
microseconds.

We only need to ensure that some amount of time is allowed for the
LAPIC to react to the command, and we need that the wait time is
finite and reasonable.  For that reasons, it is irrelevant if the CPU
frequency or throttling decrease the speed and make the loop,
calibrated for full CPU speed at boot time, execute somewhat slower.

Discussed with:	bde, jhb
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2016-03-29 08:44:56 +00:00
Konstantin Belousov
d58c003a8a Use ANSI function definition.
Sponsored by:	The FreeBSD Foundation
2016-03-29 08:31:34 +00:00
Konstantin Belousov
841d5e0151 Do not load LAPIC_DCR_TIMER with an undefined value. If we are in the
deadline mode the divide configuration is not used and
lapic_timer_divisor is not set.

Reported by:	dhw, mav
Tested by:	mav
Sponsored by:	The FreeBSD Foundation
2016-03-28 15:05:00 +00:00
Konstantin Belousov
ecabd74728 Use TSC deadline mode for LAPIC timer, when available. The mode fires
LAPIC timer iinterrupt when TSC reaches the value written to the
IA32_TSC_DEADLINE MSR.  To arm or reset the timer in deadline mode, a
single non-serializing MSR write is enough.  This is an advance from
the one-shot mode of LAPIC, where timer operated with the FSB
frequency and required two (serialized in case of xAPIC) writes to the
APIC registers.

The LVT_TIMER register value is cached to avoid unneeded writes in the
deadline mode.  Unused arguments to specify period (which is passed in
struct lapic as la_timer_period) and interrupt enable (which is always
enabled) are removed from lapic_timer_{oneshot,periodic,deadline}
functions.  Instead, special lapic_timer_oneshot_nointr() function for
interrupt-less one-shot calibration is added.

Reviewed by:	mav (previous version)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D5738
2016-03-28 09:52:44 +00:00
Konstantin Belousov
7c4e76935e Add defines for the LAPIC TSC deadline timer mode. The LVT timer mode
field is two-bit, extend the mask.

Also add comments about all MSRs writes to which are not serializing.

Sponsored by:	The FreeBSD Foundation
2016-03-28 09:43:40 +00:00
John Baldwin
7a2c1d8c60 Enable interrupts on the BSP once all PICs are initialized.
This moves the enabling of interrupts slightly earlier (the old location
was still before devices were enumerated and probed) and does it in the
interrupt code (rather than in the device configuration code).  This
also avoids tripping over an assertion on the first TLB shootdown with
earlier AP startup.

Reviewed by:	kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D5710
2016-03-24 00:24:07 +00:00
Justin Hibbits
f8fd3fb518 Fix the resource_list_print_type() calls to use uintmax_t.
Missed a bunch from r297000.
2016-03-22 22:25:08 +00:00
John Baldwin
4a5202f9c4 Check IPI status more frequently when waiting.
An IPI cannot be sent via the local APIC if a previous IPI is still
being delivered.  Attempts to send an IPI will wait for a pending IPI
to clear.  Prior to r278325 these checks used a spin loop with a
hardcoded maximum count which broke AP startup on some systems.
However, r278325 also enforced a minimum latency of 5 microseconds if an
IPI was still pending which resulted in a measurable performance hit.
This change reduces that minimum latency to 1 microsecond.

Tested by:	stas
MFC after:	3 days
2016-03-18 19:48:49 +00:00
Justin Hibbits
da1b038af9 Use uintmax_t (typedef'd to rman_res_t type) for rman ranges.
On some architectures, u_long isn't large enough for resource definitions.
Particularly, powerpc and arm allow 36-bit (or larger) physical addresses, but
type `long' is only 32-bit.  This extends rman's resources to uintmax_t.  With
this change, any resource can feasibly be placed anywhere in physical memory
(within the constraints of the driver).

Why uintmax_t and not something machine dependent, or uint64_t?  Though it's
possible for uintmax_t to grow, it's highly unlikely it will become 128-bit on
32-bit architectures.  64-bit architectures should have plenty of RAM to absorb
the increase on resource sizes if and when this occurs, and the number of
resources on memory-constrained systems should be sufficiently small as to not
pose a drastic overhead.  That being said, uintmax_t was chosen for source
clarity.  If it's specified as uint64_t, all printf()-like calls would either
need casts to uintmax_t, or be littered with PRI*64 macros.  Casts to uintmax_t
aren't horrible, but it would also bake into the API for
resource_list_print_type() either a hidden assumption that entries get cast to
uintmax_t for printing, or these calls would need the PRI*64 macros.  Since
source code is meant to be read more often than written, I chose the clearest
path of simply using uintmax_t.

Tested on a PowerPC p5020-based board, which places all device resources in
0xfxxxxxxxx, and has 8GB RAM.
Regression tested on qemu-system-i386
Regression tested on qemu-system-mips (malta profile)

Tested PAE and devinfo on virtualbox (live CD)

Special thanks to bz for his testing on ARM.

Reviewed By: bz, jhb (previous)
Relnotes:	Yes
Sponsored by:	Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D4544
2016-03-18 01:28:41 +00:00
Justin Hibbits
534ccd7bbf Replace all resource occurrences of '0UL/~0UL' with '0/~0'.
Summary:
The idea behind this is '~0ul' is well-defined, and casting to uintmax_t, on a
32-bit platform, will leave the upper 32 bits as 0.  The maximum range of a
resource is 0xFFF.... (all bits of the full type set).  By dropping the 'ul'
suffix, C type promotion rules apply, and the sign extension of ~0 on 32 bit
platforms gets it to a type-independent 'unsigned max'.

Reviewed By: cem
Sponsored by:	Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D5255
2016-03-03 05:07:35 +00:00
John Baldwin
cbc4d2db75 Remove taskqueue_enqueue_fast().
taskqueue_enqueue() was changed to support both fast and non-fast
taskqueues 10 years ago in r154167.  It has been a compat shim ever
since.  It's time for the compat shim to go.

Submitted by:	Howard Su <howard0su@gmail.com>
Reviewed by:	sephe
Differential Revision:	https://reviews.freebsd.org/D5131
2016-03-01 17:47:32 +00:00
Justin Hibbits
e665eafb25 Correct the memory rman ranges to be to BUS_SPACE_MAXADDR
Summary:
As part of the migration of rman_res_t to be typed to uintmax_t, memory ranges
must be clamped appropriately for the bus, to prevent completely bogus addresses
from being used.

This is extracted from D4544.

Reviewed By: cem
Sponsored by:	Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D5134
2016-03-01 02:59:06 +00:00
Jung-uk Kim
0eda5b3f23 Silence PVS-Studio warning (V595). It can never be NULL here. 2016-02-23 23:57:24 +00:00
Svatopluk Kraus
a1e1814d76 As <machine/pmap.h> is included from <vm/pmap.h>, there is no need to
include it explicitly when <vm/pmap.h> is already included.

Reviewed by:	alc, kib
Differential Revision:	https://reviews.freebsd.org/D5373
2016-02-22 09:02:20 +00:00
Konstantin Belousov
2fe1339ea2 Some BIOSes ACPI bytecode needs to take (sleepable) acpi mutex for
acpi_GetInteger() execution.  Intel DMAR interrupt remapping code
needs to know UID of the HPET to properly route the FSB interrupts
from the HPET, even when interrupt remapping is disabled, and the code
is executed under some non-sleepable mutexes.

Cache HPET UIDs in the device softc at the attach time and provide
lock-less method to get UID, use the method from the dmar hpet
handling code instead of calling GetInteger().

Reported and tested by:	Larry Rosenman <ler@lerctr.org>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2016-02-20 13:37:04 +00:00
Justin Hibbits
7915adb560 Introduce a RMAN_IS_DEFAULT_RANGE() macro, and use it.
This simplifies checking for default resource range for bus_alloc_resource(),
and improves readability.

This is part of, and related to, the migration of rman_res_t from u_long to
uintmax_t.

Discussed with:	jhb
Suggested by:	marcel
2016-02-20 01:32:58 +00:00
Konstantin Belousov
90edf67ecf POSIX states that #include <signal.h> shall make both mcontext_t and
ucontext_t available.  Our code even has XXX comment about this.

Add a bit of compliance by moving struct __ucontext definition into
sys/_ucontext.h and including it into signal.h and sys/ucontext.h.

Several machine/ucontext.h headers were changed to use namespace-safe
types (like uint64_t->__uint64_t) to not depend on sys/types.h.
struct __stack_t from sys/signal.h is made always visible in private
namespace to satisfy sys/_ucontext.h requirements.

Apparently mips _types.h pollutes global namespace with f_register_t
type definition.  This commit does not try to fix the issue.

PR:	207079
Reported and tested by:	Ting-Wei Lan <lantw44@gmail.com>
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-02-12 07:38:19 +00:00
Justin Hibbits
2dd1bdf183 Convert rman to use rman_res_t instead of u_long
Summary:
Migrate to using the semi-opaque type rman_res_t to specify rman resources.  For
now, this is still compatible with u_long.

This is step one in migrating rman to use uintmax_t for resources instead of
u_long.

Going forward, this could feasibly be used to specify architecture-specific
definitions of resource ranges, rather than baking a specific integer type into
the API.

This change has been broken out to facilitate MFC'ing drivers back to 10 without
breaking ABI.

Reviewed By: jhb
Sponsored by:	Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D5075
2016-01-27 02:23:54 +00:00
Sepherosa Ziehau
69a53a7a3a hyperv: use x86 generic code to do the hypervisor detection
This is first step to move the generic part of HV code into kernel instead
of module, so that it is possible to use hypercall to implement some other
paravirtualization code in the kernel.

Submitted by:		Howard Su <howard0su@gmail.com>
Reviewed by:		royger, delphij, adrian
Approved by:		adrian (mentor)
Sponsored by:		Microsoft OSTC
Differential Revision:	https://reviews.freebsd.org/D3072
2016-01-14 02:50:13 +00:00
Ed Maste
0e42ee5dd8 Move amd64 metadata.h to x86 and share with i386
MFC after:	1 week
2016-01-07 19:47:26 +00:00
Ian Lepore
69dcb7e771 Make the 'env' directive described in config(5) work on all architectures,
providing compiled-in static environment data that is used instead of any
data passed in from a boot loader.

Previously 'env' worked only on i386 and arm xscale systems, because it
required the MD startup code to examine the global envmode variable and
decide whether to use static_env or an environment obtained from the boot
loader, and set the global kern_envp accordingly.  Most startup code wasn't
doing so.  Making things even more complex, some mips startup code uses an
alternate scheme that involves calling init_static_kenv() to pass an empty
buffer and its size, then uses a series of kern_setenv() calls to populate
that buffer.

Now all MD startup code calls init_static_kenv(), and that routine provides
a single point where envmode is checked and the decision is made whether to
use the compiled-in static_kenv or the values provided by the MD code.

The routine also continues to serve its original purpose for mips; if a
non-zero buffer size is passed the routine installs the empty buffer ready
to accept kern_setenv() values.  Now if the size is zero, the provided buffer
full of existing env data is installed.  A NULL pointer can be passed if the
boot loader provides no env data; this allows the static env to be installed
if envmode is set to do so.

Most of the work here is a near-mechanical change to call the init function
instead of directly setting kern_envp.  A notable exception is in xen/pv.c;
that code was originally installing a buffer full of preformatted env data
along with its non-zero size (like mips code does), which would have allowed
kern_setenv() calls to wipe out the preformatted data.  Now it passes a zero
for the size so that the buffer of data it installs is treated as
non-writeable.
2016-01-02 02:53:48 +00:00
Konstantin Belousov
6b247f858e Add standard extended feature bit 6 from the Intel SDM rev. 57, which
indicates that data-pointer in the saved x87 FPU state is only updated
on FPU exceptions.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-12-29 22:14:21 +00:00
John Baldwin
9e8d8b4b0c Move shared variables from {amd64,i386}/initcpu.c to x86/identcpu.c.
While here, move the common bits of <machine/cputypes.h> to
<x86/cputypes.h> as well.

Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D4670
2015-12-23 21:41:42 +00:00
Enji Cooper
b59f7a7ad8 Remove redundant declarations in sys/x86/xen which are now handled in other sys/x86
headers

Differential Revision: https://reviews.freebsd.org/D4685
X-MFC with: r291949
Sponsored by: EMC / Isilon Storage Division
2015-12-23 17:43:55 +00:00
Conrad Meyer
986fd63b46 x86: Add CPUID_STDEXT_* macros for CPU feature bits
A follow-up to r292478 and r292488.

Sponsored by:	EMC / Isilon Storage Division
2015-12-21 04:42:58 +00:00
Conrad Meyer
ce43b54ab2 x86: Detect feature flags "AVX512DQ", "AVX512IFMA", "AVX512BW", "AVX512VBMI"
Documented in Intel Architecture Set Extensions Programming Reference
(319433-023).

Sponsored by:	EMC / Isilon Storage Division
2015-12-20 03:34:30 +00:00
Conrad Meyer
f750a7edaa x86: Detect feature flags "CLWB" and "PCOMMIT"
"The availability of CLWB instruction is indicated by the presence of
the CPUID feature flag CLWB (bit 24 of the EBX register)."

CLWB is similar to CLFLUSHOPT, except that it is not required to discard
cacheline contents.

"On processors that supports PCOMMIT, PCOMMIT is enumerated through
CPUID (CPUID.7.0.EBX[22]) only when the feature is enabled by BIOS."

PCOMMIT is used to cause store-to-memory operations to become persistent
(protected from power failure).

Sponsored by:	EMC / Isilon Storage Division
2015-12-19 20:47:15 +00:00
Roger Pau Monné
a7285da666 x86/bounce: try to always completely fill bounce pages
Current code doesn't try to make use of the full page when bouncing because
the size is only expanded to be a multiple of the alignment. Instead try to
always create segments of PAGE_SIZE when using bounce pages.

This allows us to remove the specific casing done for
BUS_DMA_KEEP_PG_OFFSET, since the requirement is to make sure the offsets
into contiguous segments are aligned, and now this is done by default.

Sponsored by:		Citrix Systems R&D
Reviewed by:		hps, kib
Differential revision:	https://reviews.freebsd.org/D4119
2015-12-15 10:07:03 +00:00
Konstantin Belousov
7c958a41fe Merge common parts of i386 and amd64 md_var.h and smp.h into
new headers x86/include x86_var.h and x86_smp.h.

Reviewed by:	emaste, jhb
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D4358
2015-12-07 17:41:20 +00:00
Konstantin Belousov
9a5d210cb4 It seems that at least some KVM versions advertise support for EIO
suppression but the version of the IOAPIC reported is 0x11 and neither
IOAPIC EOIR nor the Linux trick of temporal reprogramming of the pin
to edge-trigger mode to issue EOI work.

Disable eoi suppression if KVM is detected.  The mode can still be
forced with the tunable.

Reported and tested by:	Roman Mamontov <mr.xanto@gmail.com>
Sponsored by:	The FreeBSD Foundation
2015-12-05 08:52:37 +00:00
Konstantin Belousov
27691a24ab For amd64 non-PCID machines, and for i386 machines with support for
the PG_G global pte flag, pmap_invalidate_all() fails to flush global
TLB entries [*].  This is because TLB shootdown handler for such
configs reloads CR3, and on i386 pmap_invalidate_all() does the same
for the initiating CPU.  Note that current code does not issue total
invalidation requests for the kernel_pmap.

Rename amd64 function invltlb_globpcid() to invltlb_glob(), it is not
specific for PCID for quite some time, and implement the same
functionality for i386.  Use the function instead of invltlb() in
shootdown handlers and in i386 pmap_invalidate_all(), but only for the
kernel pmap (which maps pages with the PG_G attribute set), which
takes care of PG_G TLB entries on flush.

To detect the affected pmap in i386 TLB shootdown handler, pmap should
be passed to the smp_masked_invltlb() function, which makes amd64 and
i386 TLB shootdown code almost identical.  Merge the code under x86/.

Noted by:	jhb [*]
Reviewed by:	cem, jhb, pho
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D4346
2015-12-03 11:14:14 +00:00
Konstantin Belousov
906430e4f0 In the SandyBridge x2APIC workaround detection code, only fetch the
environment variable when SandyBridge CPU is detected.  Reduce code
duplication.

Sponsored by:	The FreeBSD Foundation
2015-12-03 10:59:10 +00:00
Konstantin Belousov
2a8a46b161 Correct the number of DTLB entries reported for the CPUID Leaf 2
descriptor 0x6c.

Confirmed by:	Intel
MFC after:	3 days
2015-11-24 19:55:11 +00:00
Svatopluk Kraus
eae22c4430 Revert r291142.
The not quite consistent logic for bounce pages allocation is utilizited
by re(4) interface which can hang now.

Approved by:	kib (mentor)
2015-11-23 11:19:00 +00:00
Svatopluk Kraus
6fa7734d6f Fix BUS_DMA_MIN_ALLOC_COMP flag logic. When bus_dmamap_t map is being
created for bus_dma_tag_t tag, bounce pages should be allocated
only if needed.

Before the fix, they were allocated always if BUS_DMA_COULD_BOUNCE flag
was set but BUS_DMA_MIN_ALLOC_COMP not. As bounce pages are never freed,
it could cause memory exhaustion when a lot of such tags together with
their maps were created.

Note that there could be more maps in one tag by current design.
However BUS_DMA_MIN_ALLOC_COMP flag is tag's flag. It's set after
bounce pages are allocated. Thus, they are allocated only for first
tag's map which needs them.

Approved by:	kib (mentor)
2015-11-21 19:55:01 +00:00
Marius Strobl
ec2fbee752 Avoid a NULL pointer dereference in bounce_bus_dmamap_unload() when
the map has been created via bounce_bus_dmamem_alloc(). In that case
bus_dmamap_unload(9) typically isn't called during normal operation
but still should be during detach, cleanup from failed attach etc.

Submitted by:	yongari
MFC after:	3 days
2015-11-21 02:08:47 +00:00
Marius Strobl
8fd47ac11c Avoid a NULL pointer dereference in bounce_bus_dmamap_sync() when the
map has been created via bounce_bus_dmamem_alloc(). Even for coherent
DMA - which bus_dmamem_alloc(9) typically is used for -, calling of
bus_dmamap_sync(9) isn't optional.

PR:		188899 (non-original problem)
MFC after:	3 days
2015-11-20 02:23:35 +00:00
Roger Pau Monné
1522652230 xen: fix dropping bitmap IPIs during resume
Current Xen resume code clears all pending bitmap IPIs on resume, which is
not correct. Instead re-inject bitmap IPI vectors on resume to all CPUs in
order to acknowledge any pending bitmap IPIs.

Sponsored by:		Citrix Systems R&D
MFC after:		2 weeks
2015-11-18 18:11:19 +00:00
Roger Pau Monné
ea64b86f94 xen/intr: properly dispose event channels on resume
All event channels are torn down when performing a migration on Xen, make
sure all handlers are also removed and the event channel structure is
properly disposed so it can be reused.

Sponsored by:		Citrix Systems R&D
MFC after:		2 weeks
2015-11-18 18:10:28 +00:00
Roger Pau Monné
531cfe55e2 x86/intr: allow mutex recursion in intr_remove_handler
This is needed so interrupt handlers can be removed while the PIC is
resuming, it was previously not possible due to intr_resume holding the
intr_table_lock and intr_remove_handler recursing on it.

Sponsored by:		Citrix Systems R&D
Reviewed by:		kib (previous version)
MFC after:		2 weeks
Differential Revision:	https://reviews.freebsd.org/D4114
2015-11-18 18:09:49 +00:00
Roger Pau Monné
5c4133b1b5 x86/dma_bounce: rework _bus_dmamap_load_ma implementation
The implementation of bus_dmamap_load_ma_triv currently calls
_bus_dmamap_load_phys on each page that is part of the passed in buffer.
Since each page is treated as an individual buffer, the resulting behaviour
is different from the behaviour of _bus_dmamap_load_buffer. This breaks
certain drivers, like Xen blkfront.

If an unmapped buffer of size 4096 that starts at offset 13 into the first
page is passed to the current _bus_dmamap_load_ma implementation (so the ma
array contains two pages), the result is that two segments are created, one
with a size of 4083 and the other with size 13 (because two independant
calls to _bus_dmamap_load_phys are performed, one for each physical page).
If the same is done with a mapped buffer and calling _bus_dmamap_load_buffer
the result is that only one segment is created, with a size of 4096.

This patch relegates the usage of bus_dmamap_load_ma_triv in x86 bounce
buffer code to drivers requesting BUS_DMA_KEEP_PG_OFFSET and implements
_bus_dmamap_load_ma so that it's behaviour is the same as the mapped version
(_bus_dmamap_load_buffer). This patch only modifies the x86 bounce buffer
code, other arches are left untouched.

Sponsored by:		Citrix Systems R&D
Reviewed by:		kib, jah (previous version)
MFC after:		2 weeks
Differential Revision:	https://reviews.freebsd.org/D888
2015-11-09 12:19:58 +00:00
Tijl Coosemans
27f38a8d69 Since r289279 bufinit() uses mp_ncpus, but some architectures set this
variable during mp_start() which is too late.  Move this to mp_setmaxid()
where other architectures set it and move x86 assertions to MI code.

Reviewed by:	kib (x86 part)
2015-11-08 14:26:50 +00:00
Roger Pau Monné
f186ed526a xen/intr: fix the event channel enabled per-cpu mask
Fix two issues with the current event channel code, first ENABLED_SETSIZE is
not correctly defined and then using a BITSET to store the per-cpu masks is
not portable to other arches, since on arm32 the event channel arrays shared
with the hypervisor are of type uint64_t and not long. Partially restore the
previous code but switch the bit operations to use the recently introduced
xen_{set/clear/test}_bit versions.

Reviewed by:		Julien Grall <julien.grall@citrix.com>
Sponsored by:		Citrix Systems R&D
Differential Revision:	https://reviews.freebsd.org/D4080
2015-11-05 14:33:46 +00:00
Ian Lepore
53f93ed3ff Fix an alignment check that is wrong in half the busdma implementations.
This will enable the elimination of a workaround in the USB driver that
artifically allocates buffers twice as big as they need to be (which
actually saves memory for very small buffers on the buggy platforms).

When deciding how to allocate a dma buffer, armv4, armv6, mips, and
x86/iommu all correctly check for the tag alignment <= maxsize as enabling
simple uma/malloc based allocation.  Powerpc, sparc64, x86/bounce, and
arm64/bounce were all checking for alignment < maxsize; on those platforms
when alignment was equal to the max size it would fall back to page-based
allocators even for very small buffers.

This change makes all platforms use the <= check.  It should be noted that
on all platforms other than arm[v6] and mips, this check is relying on
undocumented behavior in malloc(9) that if you allocate a block of a given
size it will be aligned to the next larger power-of-2 boundary.  There is
nothing in the malloc(9) man page that makes that explicit promise (but the
busdma code has been relying on this behavior all along so I guess it works).

Arm and mips code uses the allocator in kern/subr_busdma_buffalloc.c, which
does explicitly implement this promise about size and alignment.  Other
platforms probably should switch to the aligned allocator.
2015-11-02 23:37:19 +00:00
Roger Pau Monné
f4576dd975 x86/dma_bounce: revert r289834 and r289836
The new load_ma implementation can cause dereferences when used with
certain drivers, back it out until the reason is found:

Fatal trap 12: page fault while in kernel mode
cpuid = 11; apic id = 03
fault virtual address   = 0x30
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff808a2d22
stack pointer           = 0x28:0xfffffe07cc737710
frame pointer           = 0x28:0xfffffe07cc737790
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 13 (g_down)
trap number             = 12
panic: page fault
cpuid = 11
KDB: stack backtrace:
#0 0xffffffff80641647 at kdb_backtrace+0x67
#1 0xffffffff80606762 at vpanic+0x182
#2 0xffffffff806067e3 at panic+0x43
#3 0xffffffff8084eef1 at trap_fatal+0x351
#4 0xffffffff8084f0e4 at trap_pfault+0x1e4
#5 0xffffffff8084e82f at trap+0x4bf
#6 0xffffffff80830d57 at calltrap+0x8
#7 0xffffffff8063beab at _bus_dmamap_load_ccb+0x1fb
#8 0xffffffff8063bc51 at bus_dmamap_load_ccb+0x91
#9 0xffffffff8042dcad at ata_dmaload+0x11d
#10 0xffffffff8042df7e at ata_begin_transaction+0x7e
#11 0xffffffff8042c18e at ataaction+0x9ce
#12 0xffffffff802a220f at xpt_run_devq+0x5bf
#13 0xffffffff802a17ad at xpt_action_default+0x94d
#14 0xffffffff802c0024 at adastart+0x8b4
#15 0xffffffff802a2e93 at xpt_run_allocq+0x193
#16 0xffffffff802c0735 at adastrategy+0xf5
#17 0xffffffff80554206 at g_disk_start+0x426
Uptime: 2m29s
2015-10-26 14:50:35 +00:00
Conrad Meyer
ce7543042c xen: Add missing semi-colon for BITSET_DEFINE()
Broken when it was removed from the macro in r289867.

Pointy-hat:	markj
Sponsored by:	EMC / Isilon Storage Division
2015-10-24 19:04:55 +00:00
Roger Pau Monné
59cd0f10b3 x86/dma_bounce: rework _bus_dmamap_load_ma implementation
The implementation of bus_dmamap_load_ma_triv currently calls
_bus_dmamap_load_phys on each page that is part of the passed in buffer.
Since each page is treated as an individual buffer, the resulting behaviour
is different from the behaviour of _bus_dmamap_load_buffer. This breaks
certain drivers, like Xen blkfront.

If an unmapped buffer of size 4096 that starts at offset 13 into the first
page is passed to the current _bus_dmamap_load_ma implementation (so the ma
array contains two pages), the result is that two segments are created, one
with a size of 4083 and the other with size 13 (because two independant
calls to _bus_dmamap_load_phys are performed, one for each physical page).
If the same is done with a mapped buffer and calling _bus_dmamap_load_buffer
the result is that only one segment is created, with a size of 4096.

This patch relegates the usage of bus_dmamap_load_ma_triv in x86 bounce
buffer code to drivers requesting BUS_DMA_KEEP_PG_OFFSET and implements
_bus_dmamap_load_ma so that it's behaviour is the same as the mapped version
(_bus_dmamap_load_buffer). This patch only modifies the x86 bounce buffer
code, other arches are left untouched.

Reviewed by:		kib, jah
Differential Revision:	https://reviews.freebsd.org/D888
Sponsored by:		Citrix Systems R&D
2015-10-23 15:39:59 +00:00
Jason A. Harmening
a50730587b Remove unclear comment about address truncation in busdma. Add (hopefully much clearer) comment at declaration of PHYS_TO_VM_PAGE().
Noted by:	avg
2015-10-23 12:03:25 +00:00