kernel.git/arch/powerpc/kernel/iommu.c, branch linux-3.8.y

powerpc/iommu: Use bitmap library

2012-11-15T02:01:04Z

- Caluculate the bitmap size with BITS_TO_LONGS() - Use bitmap_empty() to verify that all bits are cleared This also includes a printk to pr_warn() conversion. Signed-off-by: Akinobu Mita Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Benjamin Herrenschmidt

powerpc/iommu: Fix multiple issues with IOMMU pools code

2012-10-04T08:03:20Z

There are a number of issues in the recent IOMMU pools code: - On a preempt kernel we might switch CPUs in the middle of building a scatter gather list. When this happens the handle hint passed in no longer falls within the local CPU's pool. Check for this and fall back to the pool hint. - We were missing a spin_unlock/spin_lock in one spot where we switch pools. - We need to provide locking around dart_tlb_invalidate_all and dart_tlb_invalidate_one now that the global lock is gone. Reported-by: Alexander Graf Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt CC: [v3.6]

powerpc/iommu: Fix iommu pool initialization

2012-07-13T07:45:49Z

The iommu pool patch has a bug where it would cause a crash when using only one pool (based on the size of the DMA window). Signed-off-by: Benjamin Herrenschmidt

powerpc: IOMMU fault injection

2012-07-10T09:18:59Z

Add the ability to inject IOMMU faults. We enable this per device via a fail_iommu sysfs property, similar to fault injection on other subsystems. An example: ... 0003:01:00.1 Ethernet controller: Emulex Corporation OneConnect 10Gb NIC (be3) (rev 02) To inject one error to this device: echo 1 > /sys/bus/pci/devices/0003:01:00.1/fail_iommu echo 1 > /sys/kernel/debug/fail_iommu/probability echo 1 > /sys/kernel/debug/fail_iommu/times As feared, the first failure injected on the be3 results in an unrecoverable error, taking down both functions of the card permanently: be2net 0003:01:00.1: Unrecoverable error in the card Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc/iommu: Implement IOMMU pools to improve multiqueue adapter performance

2012-07-03T04:14:48Z

At the moment all queues in a multiqueue adapter will serialise against the IOMMU table lock. This is proving to be a big issue, especially with 10Gbit ethernet. This patch creates 4 pools and tries to spread the load across them. If the table is under 1GB in size we revert back to the original behaviour of 1 pool and 1 largealloc pool. We create a hash to map CPUs to pools. Since we prefer interrupts to be affinitised to primary CPUs, without some form of hashing we are very likely to end up using the same pool. As an example, POWER7 has 4 way SMT and with 4 pools all primary threads will map to the same pool. The largealloc pool is reduced from 1/2 to 1/4 of the space to partially offset the overhead of breaking the table up into pools. Some performance numbers were obtained with a Chelsio T3 adapter on two POWER7 boxes, running a 100 session TCP round robin test. Performance improved 69% with this patch applied. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc/iommu: Push spinlock into iommu_range_alloc and __iommu_free

2012-07-03T04:14:47Z

In preparation for IOMMU pools, push the spinlock into iommu_range_alloc and __iommu_free. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc/iommu: Reduce spinlock coverage in iommu_free

2012-07-03T04:14:47Z

This patch moves tce_free outside of the lock in iommu_free. Some performance numbers were obtained with a Chelsio T3 adapter on two POWER7 boxes, running a 100 session TCP round robin test. Performance improved 25% with this patch applied. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc/iommu: Reduce spinlock coverage in iommu_alloc and iommu_free

2012-07-03T04:14:47Z

We currently hold the IOMMU spinlock around tce_build and tce_flush. This causes our spinlock hold times to be much higher than required and can impact multiqueue adapters. This patch moves tce_build and tce_flush outside of the lock in iommu_alloc, and tce_flush outside of the lock in iommu_free. Some performance numbers were obtained with a Chelsio T3 adapter on two POWER7 boxes, running a 100 session TCP round robin test. Performance improved 32% with this patch applied. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

fadump: Register for firmware assisted dump.

2012-02-22T23:50:01Z

On 2012-02-20 11:02:51 Mon, Paul Mackerras wrote: > On Thu, Feb 16, 2012 at 04:44:30PM +0530, Mahesh J Salgaonkar wrote: > > If I have read the code correctly, we are going to get this printk on > non-pSeries machines or on older pSeries machines, even if the user > has not put the fadump=on option on the kernel command line. The > printk will be annoying since there is no actual error condition. It > seems to me that the condition for the printk should include > fw_dump.fadump_enabled. In other words you should probably add > > if (!fw_dump.fadump_enabled) > return 0; > > at the beginning of the function. Hi Paul, Thanks for pointing it out. Please find the updated patch below. The existing patches above this (4/10 through 10/10) cleanly applies on this update. Thanks, -Mahesh. Signed-off-by: Benjamin Herrenschmidt

powerpc: Reserve iommu page 0

2011-09-23T00:27:03Z

Some devices have a dma-window that starts at the address 0. This allows DMA addresses to be mapped to this address and returned to drivers as a valid DMA address. Some drivers may not behave well in this case, since the address 0 is considered an error or not allocated. The solution to avoid this kind of error from happening is reserve the page addressed as 0 so it cannot be allocated for a DMA mapping. Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Benjamin Herrenschmidt