* [PATCH kernel v5 3/4] powerpc/powernv/ioda2: Allocate TCE table levels on demand for default DMA window
2019-07-18 5:11 [PATCH kernel v5 0/4] powerpc/ioda2: Yet another attempt to allow DMA masks between 32 and 59 Alexey Kardashevskiy
2019-07-18 5:11 ` [PATCH kernel v5 1/4] powerpc/powernv/ioda: Fix race in TCE level allocation Alexey Kardashevskiy
2019-07-18 5:11 ` [PATCH kernel v5 2/4] powerpc/iommu: Allow bypass-only for DMA Alexey Kardashevskiy
@ 2019-07-18 5:11 ` Alexey Kardashevskiy
2019-07-18 5:11 ` [PATCH kernel v5 4/4] powerpc/powernv/ioda2: Create bigger default window with 64k IOMMU pages Alexey Kardashevskiy
3 siblings, 0 replies; 6+ messages in thread
From: Alexey Kardashevskiy @ 2019-07-18 5:11 UTC (permalink / raw)
To: linuxppc-dev
Cc: Sam Bobroff, Alistair Popple, Oliver O'Halloran,
Alexey Kardashevskiy, David Gibson
We allocate only the first level of multilevel TCE tables for KVM
already (alloc_userspace_copy==true), and the rest is allocated on demand.
This is not enabled though for bare metal.
This removes the KVM limitation (implicit, via the alloc_userspace_copy
parameter) and always allocates just the first level. The on-demand
allocation of missing levels is already implemented.
As from now on DMA map might happen with disabled interrupts, this
allocates TCEs with GFP_ATOMIC; otherwise lockdep reports errors 1].
In practice just a single page is allocated there so chances for failure
are quite low.
To save time when creating a new clean table, this skips non-allocated
indirect TCE entries in pnv_tce_free just like we already do in
the VFIO IOMMU TCE driver.
This changes the default level number from 1 to 2 to reduce the amount
of memory required for the default 32bit DMA window at the boot time.
The default window size is up to 2GB which requires 4MB of TCEs which is
unlikely to be used entirely or at all as most devices these days are
64bit capable so by switching to 2 levels by default we save 4032KB of
RAM per a device.
While at this, add __GFP_NOWARN to alloc_pages_node() as the userspace
can trigger this path via VFIO, see the failure and try creating a table
again with different parameters which might succeed.
[1]:
===
BUG: sleeping function called from invalid context at mm/page_alloc.c:4596
in_atomic(): 1, irqs_disabled(): 1, pid: 1038, name: scsi_eh_1
2 locks held by scsi_eh_1/1038:
#0: 000000005efd659a (&host->eh_mutex){+.+.}, at: ata_eh_acquire+0x34/0x80
#1: 0000000006cf56a6 (&(&host->lock)->rlock){....}, at: ata_exec_internal_sg+0xb0/0x5c0
irq event stamp: 500
hardirqs last enabled at (499): [<c000000000cb8a74>] _raw_spin_unlock_irqrestore+0x94/0xd0
hardirqs last disabled at (500): [<c000000000cb85c4>] _raw_spin_lock_irqsave+0x44/0x120
softirqs last enabled at (0): [<c000000000101120>] copy_process.isra.4.part.5+0x640/0x1a80
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 73 PID: 1038 Comm: scsi_eh_1 Not tainted 5.2.0-rc6-le_nv2_aikATfstn1-p1 #634
Call Trace:
[c000003d064cef50] [c000000000c8e6c4] dump_stack+0xe8/0x164 (unreliable)
[c000003d064cefa0] [c00000000014ed78] ___might_sleep+0x2f8/0x310
[c000003d064cf020] [c0000000003ca084] __alloc_pages_nodemask+0x2a4/0x1560
[c000003d064cf220] [c0000000000c2530] pnv_alloc_tce_level.isra.0+0x90/0x130
[c000003d064cf290] [c0000000000c2888] pnv_tce+0x128/0x3b0
[c000003d064cf360] [c0000000000c2c00] pnv_tce_build+0xb0/0xf0
[c000003d064cf3c0] [c0000000000bbd9c] pnv_ioda2_tce_build+0x3c/0xb0
[c000003d064cf400] [c00000000004cfe0] ppc_iommu_map_sg+0x210/0x550
[c000003d064cf510] [c00000000004b7a4] dma_iommu_map_sg+0x74/0xb0
[c000003d064cf530] [c000000000863944] ata_qc_issue+0x134/0x470
[c000003d064cf5b0] [c000000000863ec4] ata_exec_internal_sg+0x244/0x5c0
[c000003d064cf700] [c0000000008642d0] ata_exec_internal+0x90/0xe0
[c000003d064cf780] [c0000000008650ac] ata_dev_read_id+0x2ec/0x640
[c000003d064cf8d0] [c000000000878e28] ata_eh_recover+0x948/0x16d0
[c000003d064cfa10] [c00000000087d760] sata_pmp_error_handler+0x480/0xbf0
[c000003d064cfbc0] [c000000000884624] ahci_error_handler+0x74/0xe0
[c000003d064cfbf0] [c000000000879fa8] ata_scsi_port_error_handler+0x2d8/0x7c0
[c000003d064cfca0] [c00000000087a544] ata_scsi_error+0xb4/0x100
[c000003d064cfd00] [c000000000802450] scsi_error_handler+0x120/0x510
[c000003d064cfdb0] [c000000000140c48] kthread+0x1b8/0x1c0
[c000003d064cfe20] [c00000000000bd8c] ret_from_kernel_thread+0x5c/0x70
ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
irq event stamp: 2305
========================================================
hardirqs last enabled at (2305): [<c00000000000e4c8>] fast_exc_return_irq+0x28/0x34
hardirqs last disabled at (2303): [<c000000000cb9fd0>] __do_softirq+0x4a0/0x654
WARNING: possible irq lock inversion dependency detected
5.2.0-rc6-le_nv2_aikATfstn1-p1 #634 Tainted: G W
softirqs last enabled at (2304): [<c000000000cba054>] __do_softirq+0x524/0x654
softirqs last disabled at (2297): [<c00000000010f278>] irq_exit+0x128/0x180
--------------------------------------------------------
swapper/0/0 just changed the state of lock:
0000000006cf56a6 (&(&host->lock)->rlock){-...}, at: ahci_single_level_irq_intr+0xac/0x120
but this lock took another, HARDIRQ-unsafe lock in the past:
(fs_reclaim){+.+.}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
local_irq_disable();
lock(&(&host->lock)->rlock);
lock(fs_reclaim);
<Interrupt>
lock(&(&host->lock)->rlock);
*** DEADLOCK ***
no locks held by swapper/0/0.
the shortest dependencies between 2nd lock and 1st lock:
-> (fs_reclaim){+.+.} ops: 167579 {
HARDIRQ-ON-W at:
lock_acquire+0xf8/0x2a0
fs_reclaim_acquire.part.23+0x44/0x60
kmem_cache_alloc_node_trace+0x80/0x590
alloc_desc+0x64/0x270
__irq_alloc_descs+0x2e4/0x3a0
irq_domain_alloc_descs+0xb0/0x150
irq_create_mapping+0x168/0x2c0
xics_smp_probe+0x2c/0x98
pnv_smp_probe+0x40/0x9c
smp_prepare_cpus+0x524/0x6c4
kernel_init_freeable+0x1b4/0x650
kernel_init+0x2c/0x148
ret_from_kernel_thread+0x5c/0x70
SOFTIRQ-ON-W at:
lock_acquire+0xf8/0x2a0
fs_reclaim_acquire.part.23+0x44/0x60
kmem_cache_alloc_node_trace+0x80/0x590
alloc_desc+0x64/0x270
__irq_alloc_descs+0x2e4/0x3a0
irq_domain_alloc_descs+0xb0/0x150
irq_create_mapping+0x168/0x2c0
xics_smp_probe+0x2c/0x98
pnv_smp_probe+0x40/0x9c
smp_prepare_cpus+0x524/0x6c4
kernel_init_freeable+0x1b4/0x650
kernel_init+0x2c/0x148
ret_from_kernel_thread+0x5c/0x70
INITIAL USE at:
lock_acquire+0xf8/0x2a0
fs_reclaim_acquire.part.23+0x44/0x60
kmem_cache_alloc_node_trace+0x80/0x590
alloc_desc+0x64/0x270
__irq_alloc_descs+0x2e4/0x3a0
irq_domain_alloc_descs+0xb0/0x150
irq_create_mapping+0x168/0x2c0
xics_smp_probe+0x2c/0x98
pnv_smp_probe+0x40/0x9c
smp_prepare_cpus+0x524/0x6c4
kernel_init_freeable+0x1b4/0x650
kernel_init+0x2c/0x148
ret_from_kernel_thread+0x5c/0x70
}
===
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
---
Changes:
v4:
* added lockdep output to the commit log to justify ATOMIC in alloc_pages_node
v2:
* added __GFP_NOWARN to alloc_pages_node
---
arch/powerpc/platforms/powernv/pci.h | 2 +-
arch/powerpc/platforms/powernv/pci-ioda-tce.c | 20 +++++++++----------
2 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 469c24463247..f914f0b14e4e 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -219,7 +219,7 @@ extern struct iommu_table_group *pnv_npu_compound_attach(
struct pnv_ioda_pe *pe);
/* pci-ioda-tce.c */
-#define POWERNV_IOMMU_DEFAULT_LEVELS 1
+#define POWERNV_IOMMU_DEFAULT_LEVELS 2
#define POWERNV_IOMMU_MAX_LEVELS 5
extern int pnv_tce_build(struct iommu_table *tbl, long index, long npages,
diff --git a/arch/powerpc/platforms/powernv/pci-ioda-tce.c b/arch/powerpc/platforms/powernv/pci-ioda-tce.c
index 8d6569590161..a0b9c0c23ed2 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda-tce.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda-tce.c
@@ -36,7 +36,8 @@ static __be64 *pnv_alloc_tce_level(int nid, unsigned int shift)
struct page *tce_mem = NULL;
__be64 *addr;
- tce_mem = alloc_pages_node(nid, GFP_KERNEL, shift - PAGE_SHIFT);
+ tce_mem = alloc_pages_node(nid, GFP_ATOMIC | __GFP_NOWARN,
+ shift - PAGE_SHIFT);
if (!tce_mem) {
pr_err("Failed to allocate a TCE memory, level shift=%d\n",
shift);
@@ -169,6 +170,9 @@ void pnv_tce_free(struct iommu_table *tbl, long index, long npages)
if (ptce)
*ptce = cpu_to_be64(0);
+ else
+ /* Skip the rest of the level */
+ i |= tbl->it_level_size - 1;
}
}
@@ -268,7 +272,6 @@ long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
unsigned int table_shift = max_t(unsigned int, entries_shift + 3,
PAGE_SHIFT);
const unsigned long tce_table_size = 1UL << table_shift;
- unsigned int tmplevels = levels;
if (!levels || (levels > POWERNV_IOMMU_MAX_LEVELS))
return -EINVAL;
@@ -276,9 +279,6 @@ long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
if (!is_power_of_2(window_size))
return -EINVAL;
- if (alloc_userspace_copy && (window_size > (1ULL << 32)))
- tmplevels = 1;
-
/* Adjust direct table size from window_size and levels */
entries_shift = (entries_shift + levels - 1) / levels;
level_shift = entries_shift + 3;
@@ -289,7 +289,7 @@ long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
/* Allocate TCE table */
addr = pnv_pci_ioda2_table_do_alloc_pages(nid, level_shift,
- tmplevels, tce_table_size, &offset, &total_allocated);
+ 1, tce_table_size, &offset, &total_allocated);
/* addr==NULL means that the first level allocation failed */
if (!addr)
@@ -300,18 +300,18 @@ long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
* we did not allocate as much as we wanted,
* release partially allocated table.
*/
- if (tmplevels == levels && offset < tce_table_size)
+ if (levels == 1 && offset < tce_table_size)
goto free_tces_exit;
/* Allocate userspace view of the TCE table */
if (alloc_userspace_copy) {
offset = 0;
uas = pnv_pci_ioda2_table_do_alloc_pages(nid, level_shift,
- tmplevels, tce_table_size, &offset,
+ 1, tce_table_size, &offset,
&total_allocated_uas);
if (!uas)
goto free_tces_exit;
- if (tmplevels == levels && (offset < tce_table_size ||
+ if (levels == 1 && (offset < tce_table_size ||
total_allocated_uas != total_allocated))
goto free_uas_exit;
}
@@ -326,7 +326,7 @@ long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
pr_debug("Created TCE table: ws=%08llx ts=%lx @%08llx base=%lx uas=%p levels=%d/%d\n",
window_size, tce_table_size, bus_offset, tbl->it_base,
- tbl->it_userspace, tmplevels, levels);
+ tbl->it_userspace, 1, levels);
return 0;
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH kernel v5 4/4] powerpc/powernv/ioda2: Create bigger default window with 64k IOMMU pages
2019-07-18 5:11 [PATCH kernel v5 0/4] powerpc/ioda2: Yet another attempt to allow DMA masks between 32 and 59 Alexey Kardashevskiy
` (2 preceding siblings ...)
2019-07-18 5:11 ` [PATCH kernel v5 3/4] powerpc/powernv/ioda2: Allocate TCE table levels on demand for default DMA window Alexey Kardashevskiy
@ 2019-07-18 5:11 ` Alexey Kardashevskiy
3 siblings, 0 replies; 6+ messages in thread
From: Alexey Kardashevskiy @ 2019-07-18 5:11 UTC (permalink / raw)
To: linuxppc-dev
Cc: Sam Bobroff, Alistair Popple, Oliver O'Halloran,
Alexey Kardashevskiy, David Gibson
At the moment we create a small window only for 32bit devices, the window
maps 0..2GB of the PCI space only. For other devices we either use
a sketchy bypass or hardware bypass but the former can only work if
the amount of RAM is no bigger than the device's DMA mask and the latter
requires devices to support at least 59bit DMA.
This extends the default DMA window to the maximum size possible to allow
a wider DMA mask than just 32bit. The default window size is now limited
by the the iommu_table::it_map allocation bitmap which is a contiguous
array, 1 bit per an IOMMU page.
This increases the default IOMMU page size from hard coded 4K to
the system page size to allow wider DMA masks.
This increases the level number to not exceed the max order allocation
limit per TCE level. By the same time, this keeps minimal levels number
as 2 in order to save memory.
As the extended window now overlaps the 32bit MMIO region, this adds
an area reservation to iommu_init_table().
After this change the default window size is 0x80000000000==1<<43 so
devices limited to DMA mask smaller than the amount of system RAM can
still use more than just 2GB of memory for DMA.
This is an optimization and not a bug fix for DMA API usage.
With the on-demand allocation of indirect TCE table levels enabled and
2 levels, the first TCE level size is just
1<<ceil((log2(0x7ffffffffff+1)-16)/2)=16384 TCEs or 2 system pages.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v5:
* ditched iommu_init_table_res and pass start..end to iommu_init_table
directly
* fixed WARN_ON in iommu_table_reserve_pages (was opposite)
v4:
* fixed take/release ownership handlers
* fixed reserved region for tables with it_offset!=0 (this is not going
to be exploited here but still this is a correct behavior)
v3:
* fixed tce levels calculation
v2:
* adjusted level number to the max order
---
arch/powerpc/include/asm/iommu.h | 7 ++-
arch/powerpc/kernel/iommu.c | 74 ++++++++++++++++-------
arch/powerpc/platforms/cell/iommu.c | 2 +-
arch/powerpc/platforms/pasemi/iommu.c | 2 +-
arch/powerpc/platforms/powernv/pci-ioda.c | 42 ++++++++++---
arch/powerpc/platforms/pseries/iommu.c | 8 +--
arch/powerpc/platforms/pseries/vio.c | 2 +-
arch/powerpc/sysdev/dart_iommu.c | 2 +-
8 files changed, 100 insertions(+), 39 deletions(-)
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 18d342b815e4..d7bf1f104c15 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -111,6 +111,8 @@ struct iommu_table {
struct iommu_table_ops *it_ops;
struct kref it_kref;
int it_nid;
+ unsigned long it_reserved_start; /* Start of not-DMA-able (MMIO) area */
+ unsigned long it_reserved_end;
};
#define IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry) \
@@ -149,8 +151,9 @@ extern int iommu_tce_table_put(struct iommu_table *tbl);
/* Initializes an iommu_table based in values set in the passed-in
* structure
*/
-extern struct iommu_table *iommu_init_table(struct iommu_table * tbl,
- int nid);
+extern struct iommu_table *iommu_init_table(struct iommu_table *tbl,
+ int nid, unsigned long res_start, unsigned long res_end);
+
#define IOMMU_TABLE_GROUP_MAX_TABLES 2
struct iommu_table_group;
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 0a67ce9f827e..e7a2b160d4c6 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -633,11 +633,54 @@ static void iommu_table_clear(struct iommu_table *tbl)
#endif
}
+static void iommu_table_reserve_pages(struct iommu_table *tbl,
+ unsigned long res_start, unsigned long res_end)
+{
+ int i;
+
+ WARN_ON_ONCE(res_end < res_start);
+ /*
+ * Reserve page 0 so it will not be used for any mappings.
+ * This avoids buggy drivers that consider page 0 to be invalid
+ * to crash the machine or even lose data.
+ */
+ if (tbl->it_offset == 0)
+ set_bit(0, tbl->it_map);
+
+ tbl->it_reserved_start = res_start;
+ tbl->it_reserved_end = res_end;
+
+ /* Check if res_start..res_end isn't empty and overlaps the table */
+ if (res_start && res_end &&
+ (tbl->it_offset + tbl->it_size < res_start ||
+ res_end < tbl->it_offset))
+ return;
+
+ for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
+ set_bit(i - tbl->it_offset, tbl->it_map);
+}
+
+static void iommu_table_release_pages(struct iommu_table *tbl)
+{
+ int i;
+
+ /*
+ * In case we have reserved the first bit, we should not emit
+ * the warning below.
+ */
+ if (tbl->it_offset == 0)
+ clear_bit(0, tbl->it_map);
+
+ for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
+ clear_bit(i - tbl->it_offset, tbl->it_map);
+}
+
/*
* Build a iommu_table structure. This contains a bit map which
* is used to manage allocation of the tce space.
*/
-struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
+struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid,
+ unsigned long res_start, unsigned long res_end)
{
unsigned long sz;
static int welcomed = 0;
@@ -656,13 +699,7 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
tbl->it_map = page_address(page);
memset(tbl->it_map, 0, sz);
- /*
- * Reserve page 0 so it will not be used for any mappings.
- * This avoids buggy drivers that consider page 0 to be invalid
- * to crash the machine or even lose data.
- */
- if (tbl->it_offset == 0)
- set_bit(0, tbl->it_map);
+ iommu_table_reserve_pages(tbl, res_start, res_end);
/* We only split the IOMMU table if we have 1GB or more of space */
if ((tbl->it_size << tbl->it_page_shift) >= (1UL * 1024 * 1024 * 1024))
@@ -714,12 +751,7 @@ static void iommu_table_free(struct kref *kref)
return;
}
- /*
- * In case we have reserved the first bit, we should not emit
- * the warning below.
- */
- if (tbl->it_offset == 0)
- clear_bit(0, tbl->it_map);
+ iommu_table_release_pages(tbl);
/* verify that table contains no entries */
if (!bitmap_empty(tbl->it_map, tbl->it_size))
@@ -1024,15 +1056,14 @@ int iommu_take_ownership(struct iommu_table *tbl)
for (i = 0; i < tbl->nr_pools; i++)
spin_lock(&tbl->pools[i].lock);
- if (tbl->it_offset == 0)
- clear_bit(0, tbl->it_map);
+ iommu_table_release_pages(tbl);
if (!bitmap_empty(tbl->it_map, tbl->it_size)) {
pr_err("iommu_tce: it_map is not empty");
ret = -EBUSY;
- /* Restore bit#0 set by iommu_init_table() */
- if (tbl->it_offset == 0)
- set_bit(0, tbl->it_map);
+ /* Undo iommu_table_release_pages, i.e. restore bit#0, etc */
+ iommu_table_reserve_pages(tbl, tbl->it_reserved_start,
+ tbl->it_reserved_end);
} else {
memset(tbl->it_map, 0xff, sz);
}
@@ -1055,9 +1086,8 @@ void iommu_release_ownership(struct iommu_table *tbl)
memset(tbl->it_map, 0, sz);
- /* Restore bit#0 set by iommu_init_table() */
- if (tbl->it_offset == 0)
- set_bit(0, tbl->it_map);
+ iommu_table_reserve_pages(tbl, tbl->it_reserved_start,
+ tbl->it_reserved_end);
for (i = 0; i < tbl->nr_pools; i++)
spin_unlock(&tbl->pools[i].lock);
diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 16dfee29aa41..ca9ffc1c8685 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -486,7 +486,7 @@ cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np,
window->table.it_size = size >> window->table.it_page_shift;
window->table.it_ops = &cell_iommu_ops;
- iommu_init_table(&window->table, iommu->nid);
+ iommu_init_table(&window->table, iommu->nid, 0, 0);
pr_debug("\tioid %d\n", window->ioid);
pr_debug("\tblocksize %ld\n", window->table.it_blocksize);
diff --git a/arch/powerpc/platforms/pasemi/iommu.c b/arch/powerpc/platforms/pasemi/iommu.c
index 77fee09104f8..b500a6e47e6b 100644
--- a/arch/powerpc/platforms/pasemi/iommu.c
+++ b/arch/powerpc/platforms/pasemi/iommu.c
@@ -146,7 +146,7 @@ static void iommu_table_iobmap_setup(void)
*/
iommu_table_iobmap.it_blocksize = 4;
iommu_table_iobmap.it_ops = &iommu_table_iobmap_ops;
- iommu_init_table(&iommu_table_iobmap, 0);
+ iommu_init_table(&iommu_table_iobmap, 0, 0, 0);
pr_debug(" <- %s\n", __func__);
}
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index d8080558d020..ec48ea25a674 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -2303,7 +2303,7 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb,
tbl->it_ops = &pnv_ioda1_iommu_ops;
pe->table_group.tce32_start = tbl->it_offset << tbl->it_page_shift;
pe->table_group.tce32_size = tbl->it_size << tbl->it_page_shift;
- iommu_init_table(tbl, phb->hose->node);
+ iommu_init_table(tbl, phb->hose->node, 0, 0);
if (pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL))
pnv_ioda_setup_bus_dma(pe, pe->pbus);
@@ -2420,6 +2420,7 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe)
{
struct iommu_table *tbl = NULL;
long rc;
+ unsigned long res_start, res_end;
/*
* crashkernel= specifies the kdump kernel's maximum memory at
@@ -2433,19 +2434,46 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe)
* DMA window can be larger than available memory, which will
* cause errors later.
*/
- const u64 window_size = min((u64)pe->table_group.tce32_size, max_memory);
+ const u64 maxblock = 1UL << (PAGE_SHIFT + MAX_ORDER - 1);
- rc = pnv_pci_ioda2_create_table(&pe->table_group, 0,
- IOMMU_PAGE_SHIFT_4K,
- window_size,
- POWERNV_IOMMU_DEFAULT_LEVELS, false, &tbl);
+ /*
+ * We create the default window as big as we can. The constraint is
+ * the max order of allocation possible. The TCE table is likely to
+ * end up being multilevel and with on-demand allocation in place,
+ * the initial use is not going to be huge as the default window aims
+ * to support crippled devices (i.e. not fully 64bit DMAble) only.
+ */
+ /* iommu_table::it_map uses 1 bit per IOMMU page, hence 8 */
+ const u64 window_size = min((maxblock * 8) << PAGE_SHIFT, max_memory);
+ /* Each TCE level cannot exceed maxblock so go multilevel if needed */
+ unsigned long tces_order = ilog2(window_size >> PAGE_SHIFT);
+ unsigned long tcelevel_order = ilog2(maxblock >> 3);
+ unsigned int levels = tces_order / tcelevel_order;
+
+ if (tces_order % tcelevel_order)
+ levels += 1;
+ /*
+ * We try to stick to default levels (which is >1 at the moment) in
+ * order to save memory by relying on on-demain TCE level allocation.
+ */
+ levels = max_t(unsigned int, levels, POWERNV_IOMMU_DEFAULT_LEVELS);
+
+ rc = pnv_pci_ioda2_create_table(&pe->table_group, 0, PAGE_SHIFT,
+ window_size, levels, false, &tbl);
if (rc) {
pe_err(pe, "Failed to create 32-bit TCE table, err %ld",
rc);
return rc;
}
- iommu_init_table(tbl, pe->phb->hose->node);
+ /* We use top part of 32bit space for MMIO so exclude it from DMA */
+ res_start = 0;
+ res_end = 0;
+ if (window_size > pe->phb->ioda.m32_pci_base) {
+ res_start = pe->phb->ioda.m32_pci_base >> tbl->it_page_shift;
+ res_end = min(window_size, SZ_4G) >> tbl->it_page_shift;
+ }
+ iommu_init_table(tbl, pe->phb->hose->node, res_start, res_end);
rc = pnv_pci_ioda2_set_window(&pe->table_group, 0, tbl);
if (rc) {
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 889dc2e44b89..42fb03253334 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -609,7 +609,7 @@ static void pci_dma_bus_setup_pSeries(struct pci_bus *bus)
iommu_table_setparms(pci->phb, dn, tbl);
tbl->it_ops = &iommu_table_pseries_ops;
- iommu_init_table(tbl, pci->phb->node);
+ iommu_init_table(tbl, pci->phb->node, 0, 0);
/* Divide the rest (1.75GB) among the children */
pci->phb->dma_window_size = 0x80000000ul;
@@ -690,7 +690,7 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
iommu_table_setparms_lpar(ppci->phb, pdn, tbl,
ppci->table_group, dma_window);
tbl->it_ops = &iommu_table_lpar_multi_ops;
- iommu_init_table(tbl, ppci->phb->node);
+ iommu_init_table(tbl, ppci->phb->node, 0, 0);
iommu_register_group(ppci->table_group,
pci_domain_nr(bus), 0);
pr_debug(" created table: %p\n", ppci->table_group);
@@ -719,7 +719,7 @@ static void pci_dma_dev_setup_pSeries(struct pci_dev *dev)
tbl = PCI_DN(dn)->table_group->tables[0];
iommu_table_setparms(phb, dn, tbl);
tbl->it_ops = &iommu_table_pseries_ops;
- iommu_init_table(tbl, phb->node);
+ iommu_init_table(tbl, phb->node, 0, 0);
set_iommu_table_base(&dev->dev, tbl);
return;
}
@@ -1169,7 +1169,7 @@ static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
iommu_table_setparms_lpar(pci->phb, pdn, tbl,
pci->table_group, dma_window);
tbl->it_ops = &iommu_table_lpar_multi_ops;
- iommu_init_table(tbl, pci->phb->node);
+ iommu_init_table(tbl, pci->phb->node, 0, 0);
iommu_register_group(pci->table_group,
pci_domain_nr(pci->phb->bus), 0);
pr_debug(" created table: %p\n", pci->table_group);
diff --git a/arch/powerpc/platforms/pseries/vio.c b/arch/powerpc/platforms/pseries/vio.c
index 6601b9d404dc..115934f83935 100644
--- a/arch/powerpc/platforms/pseries/vio.c
+++ b/arch/powerpc/platforms/pseries/vio.c
@@ -1191,7 +1191,7 @@ static struct iommu_table *vio_build_iommu_table(struct vio_dev *dev)
else
tbl->it_ops = &iommu_table_pseries_ops;
- return iommu_init_table(tbl, -1);
+ return iommu_init_table(tbl, -1, 0, 0);
}
/**
diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 21a1fae0714e..6b4a34b36d98 100644
--- a/arch/powerpc/sysdev/dart_iommu.c
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -344,7 +344,7 @@ static void iommu_table_dart_setup(void)
iommu_table_dart.it_index = 0;
iommu_table_dart.it_blocksize = 1;
iommu_table_dart.it_ops = &iommu_dart_ops;
- iommu_init_table(&iommu_table_dart, -1);
+ iommu_init_table(&iommu_table_dart, -1, 0, 0);
/* Reserve the last page of the DART to avoid possible prefetch
* past the DART mapped area
--
2.17.1
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