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-rw-r--r--Documentation/kernel-parameters.txt3
-rw-r--r--Documentation/x86_64/boot-options.txt109
-rw-r--r--arch/x86_64/Kconfig10
-rw-r--r--arch/x86_64/kernel/pci-dma.c28
4 files changed, 90 insertions, 60 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d25acd51e181..733a736bc6c8 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -104,6 +104,9 @@ loader, and have no meaning to the kernel directly.
104Do not modify the syntax of boot loader parameters without extreme 104Do not modify the syntax of boot loader parameters without extreme
105need or coordination with <Documentation/i386/boot.txt>. 105need or coordination with <Documentation/i386/boot.txt>.
106 106
107There are also arch-specific kernel-parameters not documented here.
108See for example <Documentation/x86_64/boot-options.txt>.
109
107Note that ALL kernel parameters listed below are CASE SENSITIVE, and that 110Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
108a trailing = on the name of any parameter states that that parameter will 111a trailing = on the name of any parameter states that that parameter will
109be entered as an environment variable, whereas its absence indicates that 112be entered as an environment variable, whereas its absence indicates that
diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
index 5c86ed6f0448..0d653993f361 100644
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -180,40 +180,81 @@ PCI
180 pci=lastbus=NUMBER Scan upto NUMBER busses, no matter what the mptable says. 180 pci=lastbus=NUMBER Scan upto NUMBER busses, no matter what the mptable says.
181 pci=noacpi Don't use ACPI to set up PCI interrupt routing. 181 pci=noacpi Don't use ACPI to set up PCI interrupt routing.
182 182
183IOMMU 183IOMMU (input/output memory management unit)
184 184
185 iommu=[size][,noagp][,off][,force][,noforce][,leak][,memaper[=order]][,merge] 185 Currently four x86-64 PCI-DMA mapping implementations exist:
186 [,forcesac][,fullflush][,nomerge][,noaperture][,calgary] 186
187 size set size of iommu (in bytes) 187 1. <arch/x86_64/kernel/pci-nommu.c>: use no hardware/software IOMMU at all
188 noagp don't initialize the AGP driver and use full aperture. 188 (e.g. because you have < 3 GB memory).
189 off don't use the IOMMU 189 Kernel boot message: "PCI-DMA: Disabling IOMMU"
190 leak turn on simple iommu leak tracing (only when CONFIG_IOMMU_LEAK is on) 190
191 memaper[=order] allocate an own aperture over RAM with size 32MB^order. 191 2. <arch/x86_64/kernel/pci-gart.c>: AMD GART based hardware IOMMU.
192 noforce don't force IOMMU usage. Default. 192 Kernel boot message: "PCI-DMA: using GART IOMMU"
193 force Force IOMMU. 193
194 merge Do SG merging. Implies force (experimental) 194 3. <arch/x86_64/kernel/pci-swiotlb.c> : Software IOMMU implementation. Used
195 nomerge Don't do SG merging. 195 e.g. if there is no hardware IOMMU in the system and it is need because
196 forcesac For SAC mode for masks <40bits (experimental) 196 you have >3GB memory or told the kernel to us it (iommu=soft))
197 fullflush Flush IOMMU on each allocation (default) 197 Kernel boot message: "PCI-DMA: Using software bounce buffering
198 nofullflush Don't use IOMMU fullflush 198 for IO (SWIOTLB)"
199 allowed overwrite iommu off workarounds for specific chipsets. 199
200 soft Use software bounce buffering (default for Intel machines) 200 4. <arch/x86_64/pci-calgary.c> : IBM Calgary hardware IOMMU. Used in IBM
201 noaperture Don't touch the aperture for AGP. 201 pSeries and xSeries servers. This hardware IOMMU supports DMA address
202 allowdac Allow DMA >4GB 202 mapping with memory protection, etc.
203 When off all DMA over >4GB is forced through an IOMMU or bounce 203 Kernel boot message: "PCI-DMA: Using Calgary IOMMU"
204 buffering. 204
205 nodac Forbid DMA >4GB 205 iommu=[<size>][,noagp][,off][,force][,noforce][,leak[=<nr_of_leak_pages>]
206 panic Always panic when IOMMU overflows 206 [,memaper[=<order>]][,merge][,forcesac][,fullflush][,nomerge]
207 calgary Use the Calgary IOMMU if it is available 207 [,noaperture][,calgary]
208 208
209 swiotlb=pages[,force] 209 General iommu options:
210 210 off Don't initialize and use any kind of IOMMU.
211 pages Prereserve that many 128K pages for the software IO bounce buffering. 211 noforce Don't force hardware IOMMU usage when it is not needed.
212 force Force all IO through the software TLB. 212 (default).
213 213 force Force the use of the hardware IOMMU even when it is
214 calgary=[64k,128k,256k,512k,1M,2M,4M,8M] 214 not actually needed (e.g. because < 3 GB memory).
215 calgary=[translate_empty_slots] 215 soft Use software bounce buffering (SWIOTLB) (default for
216 calgary=[disable=<PCI bus number>] 216 Intel machines). This can be used to prevent the usage
217 of an available hardware IOMMU.
218
219 iommu options only relevant to the AMD GART hardware IOMMU:
220 <size> Set the size of the remapping area in bytes.
221 allowed Overwrite iommu off workarounds for specific chipsets.
222 fullflush Flush IOMMU on each allocation (default).
223 nofullflush Don't use IOMMU fullflush.
224 leak Turn on simple iommu leak tracing (only when
225 CONFIG_IOMMU_LEAK is on). Default number of leak pages
226 is 20.
227 memaper[=<order>] Allocate an own aperture over RAM with size 32MB<<order.
228 (default: order=1, i.e. 64MB)
229 merge Do scather-gather (SG) merging. Implies "force"
230 (experimental).
231 nomerge Don't do scather-gather (SG) merging.
232 noaperture Ask the IOMMU not to touch the aperture for AGP.
233 forcesac Force single-address cycle (SAC) mode for masks <40bits
234 (experimental).
235 noagp Don't initialize the AGP driver and use full aperture.
236 allowdac Allow double-address cycle (DAC) mode, i.e. DMA >4GB.
237 DAC is used with 32-bit PCI to push a 64-bit address in
238 two cycles. When off all DMA over >4GB is forced through
239 an IOMMU or software bounce buffering.
240 nodac Forbid DAC mode, i.e. DMA >4GB.
241 panic Always panic when IOMMU overflows.
242 calgary Use the Calgary IOMMU if it is available
243
244 iommu options only relevant to the software bounce buffering (SWIOTLB) IOMMU
245 implementation:
246 swiotlb=<pages>[,force]
247 <pages> Prereserve that many 128K pages for the software IO
248 bounce buffering.
249 force Force all IO through the software TLB.
250
251 Settings for the IBM Calgary hardware IOMMU currently found in IBM
252 pSeries and xSeries machines:
253
254 calgary=[64k,128k,256k,512k,1M,2M,4M,8M]
255 calgary=[translate_empty_slots]
256 calgary=[disable=<PCI bus number>]
257 panic Always panic when IOMMU overflows
217 258
218 64k,...,8M - Set the size of each PCI slot's translation table 259 64k,...,8M - Set the size of each PCI slot's translation table
219 when using the Calgary IOMMU. This is the size of the translation 260 when using the Calgary IOMMU. This is the size of the translation
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 02dd39457bcf..a55382a1bb46 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -458,8 +458,8 @@ config IOMMU
458 on systems with more than 3GB. This is usually needed for USB, 458 on systems with more than 3GB. This is usually needed for USB,
459 sound, many IDE/SATA chipsets and some other devices. 459 sound, many IDE/SATA chipsets and some other devices.
460 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART 460 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
461 based IOMMU and a software bounce buffer based IOMMU used on Intel 461 based hardware IOMMU and a software bounce buffer based IOMMU used
462 systems and as fallback. 462 on Intel systems and as fallback.
463 The code is only active when needed (enough memory and limited 463 The code is only active when needed (enough memory and limited
464 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified 464 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
465 too. 465 too.
@@ -496,6 +496,12 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT
496# need this always selected by IOMMU for the VIA workaround 496# need this always selected by IOMMU for the VIA workaround
497config SWIOTLB 497config SWIOTLB
498 bool 498 bool
499 help
500 Support for software bounce buffers used on x86-64 systems
501 which don't have a hardware IOMMU (e.g. the current generation
502 of Intel's x86-64 CPUs). Using this PCI devices which can only
503 access 32-bits of memory can be used on systems with more than
504 3 GB of memory. If unsure, say Y.
499 505
500config X86_MCE 506config X86_MCE
501 bool "Machine check support" if EMBEDDED 507 bool "Machine check support" if EMBEDDED
diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c
index 683b7a5c1ab3..651ccfb06697 100644
--- a/arch/x86_64/kernel/pci-dma.c
+++ b/arch/x86_64/kernel/pci-dma.c
@@ -223,30 +223,10 @@ int dma_set_mask(struct device *dev, u64 mask)
223} 223}
224EXPORT_SYMBOL(dma_set_mask); 224EXPORT_SYMBOL(dma_set_mask);
225 225
226/* iommu=[size][,noagp][,off][,force][,noforce][,leak][,memaper[=order]][,merge] 226/*
227 [,forcesac][,fullflush][,nomerge][,biomerge] 227 * See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter
228 size set size of iommu (in bytes) 228 * documentation.
229 noagp don't initialize the AGP driver and use full aperture. 229 */
230 off don't use the IOMMU
231 leak turn on simple iommu leak tracing (only when CONFIG_IOMMU_LEAK is on)
232 memaper[=order] allocate an own aperture over RAM with size 32MB^order.
233 noforce don't force IOMMU usage. Default.
234 force Force IOMMU.
235 merge Do lazy merging. This may improve performance on some block devices.
236 Implies force (experimental)
237 biomerge Do merging at the BIO layer. This is more efficient than merge,
238 but should be only done with very big IOMMUs. Implies merge,force.
239 nomerge Don't do SG merging.
240 forcesac For SAC mode for masks <40bits (experimental)
241 fullflush Flush IOMMU on each allocation (default)
242 nofullflush Don't use IOMMU fullflush
243 allowed overwrite iommu off workarounds for specific chipsets.
244 soft Use software bounce buffering (default for Intel machines)
245 noaperture Don't touch the aperture for AGP.
246 allowdac Allow DMA >4GB
247 nodac Forbid DMA >4GB
248 panic Force panic when IOMMU overflows
249*/
250__init int iommu_setup(char *p) 230__init int iommu_setup(char *p)
251{ 231{
252 iommu_merge = 1; 232 iommu_merge = 1;