From: Alexey Kardashevskiy <aik@ozlabs.ru>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: "Alex Williamson" <alex.williamson@redhat.com>,
"Jose Ricardo Ziviani" <joserz@linux.ibm.com>,
"Sam Bobroff" <sbobroff@linux.ibm.com>,
"Alistair Popple" <alistair@popple.id.au>,
linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org,
"Piotr Jaroszynski" <pjaroszynski@nvidia.com>,
"Oliver O'Halloran" <oohall@gmail.com>,
"Andrew Donnellan" <andrew.donnellan@au1.ibm.com>,
"Leonardo Augusto Guimarães Garcia" <lagarcia@br.ibm.com>,
"Reza Arbab" <arbab@linux.ibm.com>
Subject: Re: [PATCH kernel v3 10/22] powerpc/pseries/iommu: Use memory@ nodes in max RAM address calculation
Date: Mon, 19 Nov 2018 18:43:36 +1100 [thread overview]
Message-ID: <41aaf5c0-4f30-0e87-a58b-31cde2f9b86c@ozlabs.ru> (raw)
In-Reply-To: <20181116052351.GC23632@umbus>
On 16/11/2018 16:23, David Gibson wrote:
> On Tue, Nov 13, 2018 at 07:28:11PM +1100, Alexey Kardashevskiy wrote:
>> We might have memory@ nodes with "linux,usable-memory" set to zero
>> (for example, to replicate powernv's behaviour for GPU coherent memory)
>> which means that the memory needs an extra initialization but since
>> it can be used afterwards, the pseries platform will try mapping it
>> for DMA so the DMA window needs to cover those memory regions too.
>>
>> This walks through the memory nodes to find the highest RAM address to
>> let a huge DMA window cover that too in case this memory gets onlined
>> later.
>>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> ---
>> arch/powerpc/platforms/pseries/iommu.c | 43 +++++++++++++++++++++++++-
>> 1 file changed, 42 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
>> index 78473ac..f818737 100644
>> --- a/arch/powerpc/platforms/pseries/iommu.c
>> +++ b/arch/powerpc/platforms/pseries/iommu.c
>> @@ -967,6 +967,47 @@ struct failed_ddw_pdn {
>>
>> static LIST_HEAD(failed_ddw_pdn_list);
>>
>> +static unsigned long read_n_cells(int n, const __be32 **buf)
>> +{
>> + unsigned long result = 0;
>> +
>> + while (n--) {
>> + result = (result << 32) | of_read_number(*buf, 1);
>> + (*buf)++;
>> + }
>> + return result;
>> +}
>
> Um.. this appears to be re-implementing of_read_number() in terms of
> of_read_number(). Wat!?
This is a cut-n-paste from arch/powerpc/mm/numa.c :) My bad, I did not
think much when I did this.
>
>> +static phys_addr_t ddw_memory_hotplug_max(void)
>> +{
>> + phys_addr_t max_addr = memory_hotplug_max();
>> + struct device_node *memory;
>> +
>> + for_each_node_by_type(memory, "memory") {
>> + unsigned long start, size;
>> + int ranges, n_mem_addr_cells, n_mem_size_cells, len;
>> + const __be32 *memcell_buf;
>> +
>> + memcell_buf = of_get_property(memory, "reg", &len);
>> + if (!memcell_buf || len <= 0)
>> + continue;
>> +
>> + n_mem_addr_cells = of_n_addr_cells(memory);
>> + n_mem_size_cells = of_n_size_cells(memory);
>> +
>> + /* ranges in cell */
>> + ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
>> +
>> + /* these are order-sensitive, and modify the buffer pointer */
>> + start = read_n_cells(n_mem_addr_cells, &memcell_buf);
>> + size = read_n_cells(n_mem_size_cells, &memcell_buf);
>> +
>> + max_addr = max_t(phys_addr_t, max_addr, start + size);
>> + }
>> +
>> + return max_addr;
>> +}
>
> Is there really no existing place we keep track of maxmimum possible
> memory address?
There are:
1. memblocks from mm/memblock.c - populated at the boot time from
"usable" memory@ nodes and mine are not "usable";
2. drmem from mm/drmem.c - populated from ibm,dynamic-memory-v2 - these
things do not support sparse regions so when I tried these with a GPU
RAM region mapped at 0x244000000000 - the device tree became quickly
over 1 MB and then qemu crashed, I did not debug any further as this
memory is not hotpluggable anyway from the rtas/qemu prospective, in
other words it is not something the user can hotplug or unplug.
And that is it afaict.
>
>> /*
>> * If the PE supports dynamic dma windows, and there is space for a table
>> * that can map all pages in a linear offset, then setup such a table,
>> @@ -1067,7 +1108,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn,
>> }
>> /* verify the window * number of ptes will map the partition */
>> /* check largest block * page size > max memory hotplug addr */
>> - max_addr = memory_hotplug_max();
>> + max_addr = ddw_memory_hotplug_max();
>> if (query.largest_available_block < (max_addr >> page_shift)) {
>> dev_dbg(&dev->dev, "can't map partition max 0x%llx with %u "
>> "%llu-sized pages\n", max_addr, query.largest_available_block,
>
--
Alexey
next prev parent reply other threads:[~2018-11-19 7:46 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 8:28 [PATCH kernel v3 00/22] powerpc/powernv/npu, vfio: NVIDIA V100 + P9 passthrough Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 01/22] powerpc/ioda/npu: Call skiboot's hot reset hook when disabling NPU2 Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 02/22] powerpc/mm/iommu/vfio_spapr_tce: Change mm_iommu_get to reference a region Alexey Kardashevskiy
2018-11-15 5:32 ` David Gibson
2018-11-13 8:28 ` [PATCH kernel v3 03/22] powerpc/mm/iommu: Make mm_iommu_new() fail on existing regions Alexey Kardashevskiy
2018-11-15 5:38 ` David Gibson
2018-11-13 8:28 ` [PATCH kernel v3 04/22] powerpc/vfio/iommu/kvm: Do not pin device memory Alexey Kardashevskiy
2018-11-16 3:11 ` David Gibson
2018-11-13 8:28 ` [PATCH kernel v3 05/22] powerpc/powernv/npu: Add helper to access struct npu for NPU device Alexey Kardashevskiy
2018-11-14 3:42 ` Alistair Popple
2018-11-13 8:28 ` [PATCH kernel v3 06/22] powerpc/powernv: Detach npu struct from pnv_phb Alexey Kardashevskiy
2018-11-14 4:28 ` Alistair Popple
2018-11-19 7:18 ` Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 07/22] powerpc/powernv/npu: Move OPAL calls away from context manipulation Alexey Kardashevskiy
2018-11-14 4:57 ` Alistair Popple
2018-11-13 8:28 ` [PATCH kernel v3 08/22] powerpc/pseries/iommu: Allow dynamic window to start from zero Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 09/22] powerpc/pseries/iommu: Force default DMA window removal Alexey Kardashevskiy
2018-11-16 4:54 ` David Gibson
2018-11-19 7:28 ` Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 10/22] powerpc/pseries/iommu: Use memory@ nodes in max RAM address calculation Alexey Kardashevskiy
2018-11-16 5:23 ` David Gibson
2018-11-19 7:43 ` Alexey Kardashevskiy [this message]
2018-11-13 8:28 ` [PATCH kernel v3 11/22] powerpc/pseries/npu: Enable platform support Alexey Kardashevskiy
2018-11-16 5:25 ` David Gibson
2018-11-19 7:50 ` Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 12/22] powerpc/pseries: Remove IOMMU API support for non-LPAR systems Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 13/22] powerpc/powernv/pseries: Rework device adding to IOMMU groups Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 14/22] powerpc/iommu_api: Move IOMMU groups setup to a single place Alexey Kardashevskiy
2018-11-19 0:15 ` David Gibson
2018-11-13 8:28 ` [PATCH kernel v3 15/22] powerpc/powernv: Reference iommu_table while it is linked to a group Alexey Kardashevskiy
2018-11-19 0:20 ` David Gibson
2018-11-13 8:28 ` [PATCH kernel v3 16/22] powerpc/powernv: Add purge cache OPAL call Alexey Kardashevskiy
2018-11-19 0:21 ` David Gibson
2018-11-13 8:28 ` [PATCH kernel v3 17/22] powerpc/powernv/npu: Convert NPU IOMMU helpers to iommu_table_group_ops Alexey Kardashevskiy
2018-11-19 0:24 ` David Gibson
2018-11-13 8:28 ` [PATCH kernel v3 18/22] powerpc/powernv/npu: Add compound IOMMU groups Alexey Kardashevskiy
2018-11-19 1:12 ` David Gibson
2018-11-19 2:29 ` Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 19/22] powerpc/powernv/npu: Add release_ownership hook Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 20/22] vfio_pci: Allow mapping extra regions Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 21/22] vfio_pci: Allow regions to add own capabilities Alexey Kardashevskiy
2018-11-13 8:28 ` [PATCH kernel v3 22/22] vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] [10de:1db1] subdriver Alexey Kardashevskiy
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