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2005-11-16[ARM] sa1111.c needs asm/sizes.hRussell King
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-16[ARM] Move zone adjustment for SA1111 on SA11x0 platformsRussell King
Unfortunately, using PAGE_SHIFT in asm/arch/memory.h is unsafe, and we can't include asm/page.h into this file because then we have a circular dependency. Move the offending code to arch/arm/common/sa1111.c instead. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-16[ARM] 3162/1: S3C2410 - updated defconfigBen Dooks
Patch from Ben Dooks Minor changes, including add SysRq, selecting the DM9000 as a built-in driver, not as a module, and selecting the framebuffer. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-16[ARM] 3161/1: BAST - fix commas on end of structsBen Dooks
Patch from Ben Dooks Make the use of , on the lsat entry structs consistenent through arch/arm/mach-s3c2410/mach-bast.c Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-16[ARM] compressed/head.S debugging defaults to asm/arch/debug-macro.SRussell King
Since we want new platforms to use debug-macro.S, make the decompressor debugging method default to using this include file rather than having new platforms add to an #if defined(). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-16[ARM] Include asm/hardware.h instead of asm/arch/hardware.hRussell King
Rationalise hardware.h include. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-16[ARM] Fix arch-realview/system.h to use __io_address()Russell King
Move __io_address to arch-realview/hardware.h, drop core.h from platsmp.c and localtimer.c, and include asm/io.h where required. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-16[PATCH] powerpc: Fix sparsemem with memory holes [was Re: ppc64 oops..]Paul Mackerras
This patch should fix the crashes we have been seeing on 64-bit powerpc systems with a memory hole when sparsemem is enabled. I'd appreciate it if people who know more about NUMA and sparsemem than me could look over it. There were two bugs. The first was that if NUMA was enabled but there was no NUMA information for the machine, the setup_nonnuma() function was adding a single region, assuming memory was contiguous. The second was that the loops in mem_init() and show_mem() assumed that all pages within the span of a pgdat were valid (had a valid struct page). I also fixed the incorrect setting of num_physpages that Mike Kravetz pointed out. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] ia64: cpu_idle performance bug fixChen, Kenneth W
Our performance validation on 2.6.15-rc1 caught a disastrous performance regression on ia64 with netperf (-98%) and volanomark (-58%) compares to previous kernel version 2.6.14-git7. See the following chart (result group 1 & 2). http://kernel-perf.sourceforge.net/results.machine_id=26.html We have root caused it to commit 64c7c8f88559624abdbe12b5da6502e8879f8d28 This changeset broke the ia64 task resched notification. In sched.c:resched_task(), a reschedule IPI is conditioned upon TIF_POLLING_NRFLAG. However, the above changeset unconditionally set the polling thread flag for idle tasks regardless whether pal_halt_light is in use or not. As a result, resched IPI is not sent from resched_task(). And since the default behavior on ia64 is to use pal_halt_light, we end up delaying the rescheduling task until next timer tick, and thus cause the performance regression. This fixes the performance bug. I'm glad our performance suite is turning up bad performance bug like this in time. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15Merge master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
2005-11-15[ARM] Initialise SA1111 core before SA1111 PCMCIARussell King
This avoids a BUG_ON with kref.c when SA1111 tries to register a driver with an unregistered bus type. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-15[PATCH] v850: use generic hardirq codeChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Miles Bader <miles@gnu.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] v850: Fix show_interruptsMiles Bader
A variable was being used in multiple conflicting ways. I also restructured the code a bit for clarity. Signed-off-by: Miles Bader <miles@gnu.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] Add missing EXPORT_SYMBOLS() for __ide_mm_* functions on powerpcBen Collins
These exported symbols are in arch/ppc/ but missing from arch/powerpc/ for ppc32 builds. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] drop "[PATCH] i386 kexec-on-panic: Don't shutdown the apics"Vivek Goyal
A patch by Eric was merged (f2b36db692b7ff6972320ad9839ae656a3b0ee3e) and later on reverted back (1e4c85f97fe26fbd70da12148b3992c0e00361fd). Along with above patch, another patch was posted and has been merged (3d1675b41b02d64bd1185903ea0d25a8c0bb6dea). That patch was dependent on the above patch and now it should also be reverted. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[ARM] Use kernel/power/KconfigRussell King
Rather than defining our own PM option, use kernel/power/Kconfig. This fixes build errors introduced by bca73e4bf8563d83f7856164caa44d5f42e44cca Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-15Merge x86-64 update from AndiLinus Torvalds
2005-11-15[PATCH] x86_64: Fix sparse memBob Picco
Fix up booting with sparse mem enabled. Otherwise it would just cause an early PANIC at boot. Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Increase the maximum number of local APICs to the maximumAndi Kleen
This is needed for large multinode IBM systems which have a sparse APIC space in clustered mode, fully covering the available 8 bits. The previous kernels would limit the local APIC number to 127, which caused it to reject some of the CPUs at boot. I increased the maximum and shrunk the apic_version array a bit to make up for that (the version is only 8 bit, so don't need an full int to store) Cc: Chris McDermott <lcm@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Remove CONFIG_CHECKING and add command line option for ↵Andi Kleen
pagefault tracing CONFIG_CHECKING covered some debugging code used in the early times of the port. But it wasn't even SMP safe for quite some time and the bugs it checked for seem to be gone. This patch removes all the code to verify GS at kernel entry. There haven't been any new bugs in this area for a long time. Previously it also covered the sysctl for the page fault tracing. That didn't make much sense because that code was unconditionally compiled in. I made that a boot option now because it is typically only useful at boot. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Make node boundaries consistentMagnus Damm
The current x86_64 NUMA memory code is inconsequent when it comes to node memory ranges. The exact behaviour varies depending on which config option that is used. setup_node_bootmem() has start and end as arguments and these are used to calculate the size of the node like this: (end - start). This is all fine if end is pointing to the first non-available byte. The problem is that the current x86_64 code sometimes treats it as the last present byte and sometimes as the first non-available byte. The result is that some configurations might lose a page at the end of the range. This patch tries to fix CONFIG_ACPI_NUMA, CONFIG_K8_NUMA and CONFIG_NUMA_EMU so they all treat the end variable as the first non-available byte. This is the same way as the single node code. The patch is boot tested on dual x86_64 hardware with the above configurations, but maybe the removed code is needed as some workaround? Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Log machine checks from boot on Intel systemsAndi Kleen
The logging for boot errors was turned off because it was broken on some AMD systems. But give Intel EM64T systems a chance because they are supposed to be correct there. The advantage is that there is a chance to actually log uncorrected machine checks after the reset. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Make ACPI NUMA and NUMA emulation peers of K8_NUMA in KconfigRavikiran G Thirumalai
On x86_64 arches, there is no way to choose ACPI_NUMA without having to choose K8_NUMA. CONFIG_K8_NUMA is not needed for Intel EM64T NUMA boxes. It also looks odd if you have to select ACPI_NUMA from the power management menu. This patch fixes those oddities. Patch does the following: 1. Makes NUMA a config option like other arches 2. Makes topology detection options like K8_NUMA dependent on NUMA 3. Choosing ACPI NUMA detection can be done from the standard "Processor type and features" menu AK: I fixed up the dependencies and changed the help texts a bit on top of Kiran's patch. Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Use common sys_time64Paolo 'Blaisorblade' Giarrusso
Keeping this function does not makes sense because it's a copied (and buggy) copy of sys_time. The only difference is that now.tv_sec (which is a time_t, i.e. a 64-bit long) is copied (and truncated) into a int (32-bit). The prototype is the same (they both take a long __user *), so let's drop this and redirect it to sys_time (and make sure it exists by defining __ARCH_WANT_SYS_TIME). Only disadvantage is that the sys_stime definition is also compiled (may be fixed if needed by adding a separate __ARCH_WANT_SYS_STIME macro, and defining it for all arch's defining __ARCH_WANT_SYS_TIME except x86_64). Acked-by: Andi Kleen <ak@suse.de> Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Remove optimization for B stepping AMD K8Andi Kleen
B stepping were the first shipping Opterons. memcpy/memset/copy_page/ clear_page had special optimized version for them. These are really old and in the minority now and the difference to the generic versions (using rep microcode) is not that big anyways. So just remove them. TODO: figure out optimized versions for Intel Netburst based EM64T Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Reduce number of retries for reset through keyboard controllerAndi Kleen
Old code could retry for 10 seconds worst time. Only try it for one second now. Suggested by Yinghai Lu Cc: Yinghai.Lu@amd.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: x86_64/i386 fix Intel cache detection code assumption about ↵Siddha, Suresh B
threads sharing Fix the Intel cache detection code assumption that number of threads sharing the cache will either be equal to number of HT or core siblings. This also cleans up the code in general a bit. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86-64/i386: Intel HT, Multi core detection fixesSiddha, Suresh B
Fields obtained through cpuid vector 0x1(ebx[16:23]) and vector 0x4(eax[14:25], eax[26:31]) indicate the maximum values and might not always be the same as what is available and what OS sees. So make sure "siblings" and "cpu cores" values in /proc/cpuinfo reflect the values as seen by OS instead of what cpuid instruction says. This will also fix the buggy BIOS cases (for example where cpuid on a single core cpu says there are "2" siblings, even when HT is disabled in the BIOS. http://bugzilla.kernel.org/show_bug.cgi?id=4359) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Don't enable interrupt unconditionally in reboot pathAndi Kleen
When they were disabled before (e.g. after a panic) it's better to keep them off, otherwise followon panics can happen from timer interrupt handlers etc. Drawback is that pageup in the console won't work anymore though. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Formatting fixes for arch/x86_64/kernel/process.cAndi Kleen
No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Allow modular build of ia32 aout loaderAndi Kleen
Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Force correct address space size for MTRR on some 64bit ↵Shaohua Li
Intel Xeons They report 40bit, but only have 36bits of physical address space. This caused problems with setting up the correct masks for MTRR. CPUID workaround for steppings 0F33h(supporting x86) and 0F34h(supporting x86 and EM64T). Detail info can be found at: http://download.intel.com/design/Xeon/specupdt/30240216.pdf http://download.intel.com/design/Pentium4/specupdt/30235221.pdf Signed-off-by: Shaohua Li<shaohua.li@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Optimize NUMA node hash functionEric Dumazet
Compute the highest possible value for memnode_shift, in order to reduce footprint of memnodemap[] to the minimum, thus making all users (phys_to_nid(), kfree()), more cache friendly. Before the patch : Node 0 MemBase 0000000000000000 Limit 00000001ffffffff Node 1 MemBase 0000000200000000 Limit 00000003ffffffff Using 23 for the hash shift. Max adder is 3ffffffff After the patch : Node 0 MemBase 0000000000000000 Limit 00000001ffffffff Node 1 MemBase 0000000200000000 Limit 00000003ffffffff Using 33 for the hash shift. In this case, only 2 bytes of memnodemap[] are used, instead of 2048 Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Save/restore CS in 64bit signal handlers and force __USER_CS ↵Bryan Ford
for CS This allows to run 64bit signal handlers in 64bit processes that run small code snippets in compat mode. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: New heuristics to find out hotpluggable CPUs.Andi Kleen
With a NR_CPUS==128 kernel with CPU hotplug enabled we would waste 4MB on per CPU data of all possible CPUs. The reason was that HOTPLUG always set up possible map to NR_CPUS cpus and then we need to allocate that much (each per CPU data is roughly ~32k now) The underlying problem is that ACPI didn't tell us how many hotplug CPUs the platform supports. So the old code just assumed all, which would lead to this memory wastage. This implements some new heuristics: - If the BIOS specified disabled CPUs in the ACPI/mptables assume they can be enabled later (this is bending the ACPI specification a bit, but seems like a obvious extension) - The user can overwrite it with a new additionals_cpus=NUM option - Otherwise use half of the available CPUs or 2, whatever is more. Cc: ashok.raj@intel.com Cc: len.brown@intel.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Replace swiotlb extern with includeAndi Kleen
Minor victory on the continuous quest against all stray extern. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Replace cpu_pda extern with includeAndi Kleen
Minor cleanup - remove obsolete extern Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Only use asm/sections.h to declare section symbolsAndi Kleen
Adding __initdata_* to asm-generic/sections.h Replaces a lot of open coded externs in arch/x86_64/* I had to change __bss_end to __bss_stop to match the other architectures. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Unmap NULL during early bootupSiddha, Suresh B
We should zap the low mappings, as soon as possible, so that we can catch kernel bugs more effectively. Previously early boot had NULL mapped and didn't trap on NULL references. This patch introduces boot_level4_pgt, which will always have low identity addresses mapped. Druing boot, all the processors will use this as their level4 pgt. On BP, we will switch to init_level4_pgt as soon as we enter C code and zap the low mappings as soon as we are done with the usage of identity low mapped addresses. On AP's we will zap the low mappings as soon as we jump to C code. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Speed up numa_node_id by putting it directly into the PDAAndi Kleen
Not go from the CPU number to an mapping array. Mode number is often used now in fast paths. This also adds a generic numa_node_id to all the topology includes Suggested by Eric Dumazet Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Fix gcc 4 warning in aperture.cAndi Kleen
Fix arch/x86_64/kernel/aperture.c: In function #iommu_hole_init#: arch/x86_64/kernel/aperture.c:199: warning: #aper_order# may be used uninitialized in this function Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86-64/i386: Fix CPU model for family 6Suresh Siddha
According to cpuid instruction in IA32 SDM-Vol2, when computing cpu model, we need to consider extended model ID for family 0x6 also. AK: Also added fixes/simplifcation from Petr Vandrovec Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Remove duplicate __cpuinit defineAshok Raj
Remove duplicate __cpuinit in smp.c. Already defined in init.h which is already included. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Use the DMA32 zone for dma_alloc_coherent()/pci_alloc_consistentAndi Kleen
Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] i386/x86-64: Share interrupt vectors when there is a large number of ↵James Cleverdon
interrupt sources Here's a patch that builds on Natalie Protasevich's IRQ compression patch and tries to work for MPS boots as well as ACPI. It is meant for a 4-node IBM x460 NUMA box, which was dying because it had interrupt pins with GSI numbers > NR_IRQS and thus overflowed irq_desc. The problem is that this system has 270 GSIs (which are 1:1 mapped with I/O APIC RTEs) and an 8-node box would have 540. This is much bigger than NR_IRQS (224 for both i386 and x86_64). Also, there aren't enough vectors to go around. There are about 190 usable vectors, not counting the reserved ones and the unused vectors at 0x20 to 0x2F. So, my patch attempts to compress the GSI range and share vectors by sharing IRQs. Cc: "Protasevich, Natalie" <Natalie.Protasevich@unisys.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Support for AMD specific MCE Threshold.Jacob Shin
MC4_MISC - DRAM Errors Threshold Register realized under AMD K8 Rev F. This register is used to count correctable and uncorrectable ECC errors that occur during DRAM read operations. The user may interface through sysfs files in order to change the threshold configuration. bank%d/error_count - reads current error count, write to clear. bank%d/interrupt_enable - set/clear interrupt enable. bank%d/threshold_limit - read/write the threshold limit. APIC vector 0xF9 in hw_irq.h. 5 software defined bank ids in mce.h. new apic.c function to setup threshold apic lvt. defaults to interrupt off, count enabled, and threshold limit max. sysfs interface created on /sys/devices/system/threshold. AK: added some ifdefs to make it compile on UP Signed-off-by: Jacob Shin <jacob.shin@amd.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Account mem_map in VM holes accountingAndi Kleen
The VM needs to know about lost memory in zones to accurately balance dirty pages. This patch accounts mem_map in there too, which fixes a constant errror of a few percent. Also some other misc mappings and the kernel text itself are accounted too. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Make i386 compile again with fourth DMA32 zoneAndi Kleen
The code should deal with an additional empty zone, so fix up the #error. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Set compatibility flag for 4GB zone on IA64Andi Kleen
IA64 traditionally had a 4GB DMA32 zone. Set the compatibility flag to keep old drivers working. For new drivers it would be better to use ZONE_DMA32 now. Cc: tony.luck@intel.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15[PATCH] x86_64: Add 4GB DMA32 zoneAndi Kleen
Add a new 4GB GFP_DMA32 zone between the GFP_DMA and GFP_NORMAL zones. As a bit of historical background: when the x86-64 port was originally designed we had some discussion if we should use a 16MB DMA zone like i386 or a 4GB DMA zone like IA64 or both. Both was ruled out at this point because it was in early 2.4 when VM is still quite shakey and had bad troubles even dealing with one DMA zone. We settled on the 16MB DMA zone mainly because we worried about older soundcards and the floppy. But this has always caused problems since then because device drivers had trouble getting enough DMA able memory. These days the VM works much better and the wide use of NUMA has proven it can deal with many zones successfully. So this patch adds both zones. This helps drivers who need a lot of memory below 4GB because their hardware is not accessing more (graphic drivers - proprietary and free ones, video frame buffer drivers, sound drivers etc.). Previously they could only use IOMMU+16MB GFP_DMA, which was not enough memory. Another common problem is that hardware who has full memory addressing for >4GB misses it for some control structures in memory (like transmit rings or other metadata). They tended to allocate memory in the 16MB GFP_DMA or the IOMMU/swiotlb then using pci_alloc_consistent, but that can tie up a lot of precious 16MB GFPDMA/IOMMU/swiotlb memory (even on AMD systems the IOMMU tends to be quite small) especially if you have many devices. With the new zone pci_alloc_consistent can just put this stuff into memory below 4GB which works better. One argument was still if the zone should be 4GB or 2GB. The main motivation for 2GB would be an unnamed not so unpopular hardware raid controller (mostly found in older machines from a particular four letter company) who has a strange 2GB restriction in firmware. But that one works ok with swiotlb/IOMMU anyways, so it doesn't really need GFP_DMA32. I chose 4GB to be compatible with IA64 and because it seems to be the most common restriction. The new zone is so far added only for x86-64. For other architectures who don't set up this new zone nothing changes. Architectures can set a compatibility define in Kconfig CONFIG_DMA_IS_DMA32 that will define GFP_DMA32 as GFP_DMA. Otherwise it's a nop because on 32bit architectures it's normally not needed because GFP_NORMAL (=0) is DMA able enough. One problem is still that GFP_DMA means different things on different architectures. e.g. some drivers used to have #ifdef ia64 use GFP_DMA (trusting it to be 4GB) #elif __x86_64__ (use other hacks like the swiotlb because 16MB is not enough) ... . This was quite ugly and is now obsolete. These should be now converted to use GFP_DMA32 unconditionally. I haven't done this yet. Or best only use pci_alloc_consistent/dma_alloc_coherent which will use GFP_DMA32 transparently. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>