[PATCH v4 00/10] IOMMU memory observability

[PATCH v4 00/10] IOMMU memory observability

[Pasha Tatashin]

----------------------------------------------------------------------
Changelog
----------------------------------------------------------------------
v4:
- Synced with v6.8-rc3 
- Updated commit log for "iommu: account IOMMU allocated memory" as
  suggested by Michal Koutný
- Added more Acked-bys David Rientjes and Thierry Reding
- Added Tested-by Bagas Sanjaya.

v3:
- Sync with v6.7-rc7
- Addressed comments from David Rientjes: s/pages/page/, added
  unlikely() into the branches, expanded comment for
  iommu_free_pages_list().
- Added Acked-bys: David Rientjes

v2:
- Added Reviewed-by Janne Grunau
- Sync with 6.7.0-rc3
- Separated form the series patches:
vhost-vdpa: account iommu allocations
https://lore.kernel.org/all/20231130200447.2319543-1-pasha.tatashin@soleen.com
vfio: account iommu allocations
https://lore.kernel.org/all/20231130200900.2320829-1-pasha.tatashin@soleen.com
as suggested by Jason Gunthorpe
- Fixed SPARC build issue detected by kernel test robot
- Drop the following patches as they do account iommu page tables:
iommu/dma: use page allocation function provided by iommu-pages.h
iommu/fsl: use page allocation function provided by iommu-pages.h
iommu/iommufd: use page allocation function provided by iommu-pages.h
as suggested by Robin Murphy. These patches are not related to IOMMU
page tables. We might need to do a separate work to support DMA
observability.
- Remove support iommu/io-pgtable-arm-v7s as the 2nd level pages are
under a page size, thanks Robin Murphy for pointing this out.

----------------------------------------------------------------------
Description
----------------------------------------------------------------------
IOMMU subsystem may contain state that is in gigabytes. Majority of that
state is iommu page tables. Yet, there is currently, no way to observe
how much memory is actually used by the iommu subsystem.

This patch series solves this problem by adding both observability to
all pages that are allocated by IOMMU, and also accountability, so
admins can limit the amount if via cgroups.

The system-wide observability is using /proc/meminfo:
SecPageTables:    438176 kB

Contains IOMMU and KVM memory.

Per-node observability:
/sys/devices/system/node/nodeN/meminfo
Node N SecPageTables:    422204 kB

Contains IOMMU and KVM memory in the given NUMA node.

Per-node IOMMU only observability:
/sys/devices/system/node/nodeN/vmstat
nr_iommu_pages 105555

Contains number of pages IOMMU allocated in the given node.

Accountability: using sec_pagetables cgroup-v2 memory.stat entry.

With the change, iova_stress[1] stops as limit is reached:

$ ./iova_stress
iova space:     0T      free memory:   497G
iova space:     1T      free memory:   495G
iova space:     2T      free memory:   493G
iova space:     3T      free memory:   491G

stops as limit is reached.

This series encorporates suggestions that came from the discussion
at LPC [2].
----------------------------------------------------------------------
[1] https://github.com/soleen/iova_stress
[2] https://lpc.events/event/17/contributions/1466
----------------------------------------------------------------------
Previous versions
v1: https://lore.kernel.org/all/20231128204938.1453583-1-pasha.tatashin@soleen.com
v2: https://lore.kernel.org/linux-mm/20231130201504.2322355-1-pasha.tatashin@soleen.com
v3: https://lore.kernel.org/all/20231226200205.562565-1-pasha.tatashin@soleen.com
----------------------------------------------------------------------

Pasha Tatashin (10):
  iommu/vt-d: add wrapper functions for page allocations
  iommu/amd: use page allocation function provided by iommu-pages.h
  iommu/io-pgtable-arm: use page allocation function provided by
    iommu-pages.h
  iommu/io-pgtable-dart: use page allocation function provided by
    iommu-pages.h
  iommu/exynos: use page allocation function provided by iommu-pages.h
  iommu/rockchip: use page allocation function provided by iommu-pages.h
  iommu/sun50i: use page allocation function provided by iommu-pages.h
  iommu/tegra-smmu: use page allocation function provided by
    iommu-pages.h
  iommu: observability of the IOMMU allocations
  iommu: account IOMMU allocated memory

 Documentation/admin-guide/cgroup-v2.rst |   2 +-
 Documentation/filesystems/proc.rst      |   4 +-
 drivers/iommu/amd/amd_iommu.h           |   8 -
 drivers/iommu/amd/init.c                |  91 +++++----
 drivers/iommu/amd/io_pgtable.c          |  13 +-
 drivers/iommu/amd/io_pgtable_v2.c       |  20 +-
 drivers/iommu/amd/iommu.c               |  13 +-
 drivers/iommu/exynos-iommu.c            |  14 +-
 drivers/iommu/intel/dmar.c              |  10 +-
 drivers/iommu/intel/iommu.c             |  47 ++---
 drivers/iommu/intel/iommu.h             |   2 -
 drivers/iommu/intel/irq_remapping.c     |  10 +-
 drivers/iommu/intel/pasid.c             |  12 +-
 drivers/iommu/intel/svm.c               |   7 +-
 drivers/iommu/io-pgtable-arm.c          |  15 +-
 drivers/iommu/io-pgtable-dart.c         |  37 ++--
 drivers/iommu/iommu-pages.h             | 236 ++++++++++++++++++++++++
 drivers/iommu/rockchip-iommu.c          |  14 +-
 drivers/iommu/sun50i-iommu.c            |   7 +-
 drivers/iommu/tegra-smmu.c              |  18 +-
 include/linux/mmzone.h                  |   5 +-
 mm/vmstat.c                             |   3 +
 22 files changed, 397 insertions(+), 191 deletions(-)
 create mode 100644 drivers/iommu/iommu-pages.h

-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 01/10] iommu/vt-d: add wrapper functions for page allocations

[Pasha Tatashin]

In order to improve observability and accountability of IOMMU layer, we
must account the number of pages that are allocated by functions that
are calling directly into buddy allocator.

This is achieved by first wrapping the allocation related functions into a
separate inline functions in new file:

drivers/iommu/iommu-pages.h

Convert all page allocation calls under iommu/intel to use these new
functions.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 drivers/iommu/intel/dmar.c          |  10 +-
 drivers/iommu/intel/iommu.c         |  47 +++----
 drivers/iommu/intel/iommu.h         |   2 -
 drivers/iommu/intel/irq_remapping.c |  10 +-
 drivers/iommu/intel/pasid.c         |  12 +-
 drivers/iommu/intel/svm.c           |   7 +-
 drivers/iommu/iommu-pages.h         | 204 ++++++++++++++++++++++++++++
 7 files changed, 241 insertions(+), 51 deletions(-)
 create mode 100644 drivers/iommu/iommu-pages.h

diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index 23cb80d62a9a..f72b1e4334b1 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -32,6 +32,7 @@
 
 #include "iommu.h"
 #include "../irq_remapping.h"
+#include "../iommu-pages.h"
 #include "perf.h"
 #include "trace.h"
 #include "perfmon.h"
@@ -1185,7 +1186,7 @@ static void free_iommu(struct intel_iommu *iommu)
 	}
 
 	if (iommu->qi) {
-		free_page((unsigned long)iommu->qi->desc);
+		iommu_free_page(iommu->qi->desc);
 		kfree(iommu->qi->desc_status);
 		kfree(iommu->qi);
 	}
@@ -1732,6 +1733,7 @@ int dmar_enable_qi(struct intel_iommu *iommu)
 {
 	struct q_inval *qi;
 	struct page *desc_page;
+	int order;
 
 	if (!ecap_qis(iommu->ecap))
 		return -ENOENT;
@@ -1752,8 +1754,8 @@ int dmar_enable_qi(struct intel_iommu *iommu)
 	 * Need two pages to accommodate 256 descriptors of 256 bits each
 	 * if the remapping hardware supports scalable mode translation.
 	 */
-	desc_page = alloc_pages_node(iommu->node, GFP_ATOMIC | __GFP_ZERO,
-				     !!ecap_smts(iommu->ecap));
+	order = ecap_smts(iommu->ecap) ? 1 : 0;
+	desc_page = __iommu_alloc_pages_node(iommu->node, GFP_ATOMIC, order);
 	if (!desc_page) {
 		kfree(qi);
 		iommu->qi = NULL;
@@ -1764,7 +1766,7 @@ int dmar_enable_qi(struct intel_iommu *iommu)
 
 	qi->desc_status = kcalloc(QI_LENGTH, sizeof(int), GFP_ATOMIC);
 	if (!qi->desc_status) {
-		free_page((unsigned long) qi->desc);
+		iommu_free_page(qi->desc);
 		kfree(qi);
 		iommu->qi = NULL;
 		return -ENOMEM;
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 6fb5f6fceea1..a9cfb41a6a94 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -28,6 +28,7 @@
 #include "../dma-iommu.h"
 #include "../irq_remapping.h"
 #include "../iommu-sva.h"
+#include "../iommu-pages.h"
 #include "pasid.h"
 #include "cap_audit.h"
 #include "perfmon.h"
@@ -224,22 +225,6 @@ static int __init intel_iommu_setup(char *str)
 }
 __setup("intel_iommu=", intel_iommu_setup);
 
-void *alloc_pgtable_page(int node, gfp_t gfp)
-{
-	struct page *page;
-	void *vaddr = NULL;
-
-	page = alloc_pages_node(node, gfp | __GFP_ZERO, 0);
-	if (page)
-		vaddr = page_address(page);
-	return vaddr;
-}
-
-void free_pgtable_page(void *vaddr)
-{
-	free_page((unsigned long)vaddr);
-}
-
 static int domain_type_is_si(struct dmar_domain *domain)
 {
 	return domain->domain.type == IOMMU_DOMAIN_IDENTITY;
@@ -473,7 +458,7 @@ struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus,
 		if (!alloc)
 			return NULL;
 
-		context = alloc_pgtable_page(iommu->node, GFP_ATOMIC);
+		context = iommu_alloc_page_node(iommu->node, GFP_ATOMIC);
 		if (!context)
 			return NULL;
 
@@ -647,17 +632,17 @@ static void free_context_table(struct intel_iommu *iommu)
 	for (i = 0; i < ROOT_ENTRY_NR; i++) {
 		context = iommu_context_addr(iommu, i, 0, 0);
 		if (context)
-			free_pgtable_page(context);
+			iommu_free_page(context);
 
 		if (!sm_supported(iommu))
 			continue;
 
 		context = iommu_context_addr(iommu, i, 0x80, 0);
 		if (context)
-			free_pgtable_page(context);
+			iommu_free_page(context);
 	}
 
-	free_pgtable_page(iommu->root_entry);
+	iommu_free_page(iommu->root_entry);
 	iommu->root_entry = NULL;
 }
 
@@ -795,7 +780,7 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
 		if (!dma_pte_present(pte)) {
 			uint64_t pteval;
 
-			tmp_page = alloc_pgtable_page(domain->nid, gfp);
+			tmp_page = iommu_alloc_page_node(domain->nid, gfp);
 
 			if (!tmp_page)
 				return NULL;
@@ -807,7 +792,7 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
 
 			if (cmpxchg64(&pte->val, 0ULL, pteval))
 				/* Someone else set it while we were thinking; use theirs. */
-				free_pgtable_page(tmp_page);
+				iommu_free_page(tmp_page);
 			else
 				domain_flush_cache(domain, pte, sizeof(*pte));
 		}
@@ -920,7 +905,7 @@ static void dma_pte_free_level(struct dmar_domain *domain, int level,
 		      last_pfn < level_pfn + level_size(level) - 1)) {
 			dma_clear_pte(pte);
 			domain_flush_cache(domain, pte, sizeof(*pte));
-			free_pgtable_page(level_pte);
+			iommu_free_page(level_pte);
 		}
 next:
 		pfn += level_size(level);
@@ -944,7 +929,7 @@ static void dma_pte_free_pagetable(struct dmar_domain *domain,
 
 	/* free pgd */
 	if (start_pfn == 0 && last_pfn == DOMAIN_MAX_PFN(domain->gaw)) {
-		free_pgtable_page(domain->pgd);
+		iommu_free_page(domain->pgd);
 		domain->pgd = NULL;
 	}
 }
@@ -1046,7 +1031,7 @@ static int iommu_alloc_root_entry(struct intel_iommu *iommu)
 {
 	struct root_entry *root;
 
-	root = alloc_pgtable_page(iommu->node, GFP_ATOMIC);
+	root = iommu_alloc_page_node(iommu->node, GFP_ATOMIC);
 	if (!root) {
 		pr_err("Allocating root entry for %s failed\n",
 			iommu->name);
@@ -1718,7 +1703,7 @@ static void domain_exit(struct dmar_domain *domain)
 		LIST_HEAD(freelist);
 
 		domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw), &freelist);
-		put_pages_list(&freelist);
+		iommu_free_pages_list(&freelist);
 	}
 
 	if (WARN_ON(!list_empty(&domain->devices)))
@@ -2452,7 +2437,7 @@ static int copy_context_table(struct intel_iommu *iommu,
 			if (!old_ce)
 				goto out;
 
-			new_ce = alloc_pgtable_page(iommu->node, GFP_KERNEL);
+			new_ce = iommu_alloc_page_node(iommu->node, GFP_KERNEL);
 			if (!new_ce)
 				goto out_unmap;
 
@@ -3385,7 +3370,7 @@ static int intel_iommu_memory_notifier(struct notifier_block *nb,
 					start_vpfn, mhp->nr_pages,
 					list_empty(&freelist), 0);
 			rcu_read_unlock();
-			put_pages_list(&freelist);
+			iommu_free_pages_list(&freelist);
 		}
 		break;
 	}
@@ -3816,7 +3801,7 @@ static int md_domain_init(struct dmar_domain *domain, int guest_width)
 	domain->max_addr = 0;
 
 	/* always allocate the top pgd */
-	domain->pgd = alloc_pgtable_page(domain->nid, GFP_ATOMIC);
+	domain->pgd = iommu_alloc_page_node(domain->nid, GFP_ATOMIC);
 	if (!domain->pgd)
 		return -ENOMEM;
 	domain_flush_cache(domain, domain->pgd, PAGE_SIZE);
@@ -3960,7 +3945,7 @@ int prepare_domain_attach_device(struct iommu_domain *domain,
 		pte = dmar_domain->pgd;
 		if (dma_pte_present(pte)) {
 			dmar_domain->pgd = phys_to_virt(dma_pte_addr(pte));
-			free_pgtable_page(pte);
+			iommu_free_page(pte);
 		}
 		dmar_domain->agaw--;
 	}
@@ -4107,7 +4092,7 @@ static void intel_iommu_tlb_sync(struct iommu_domain *domain,
 				      start_pfn, nrpages,
 				      list_empty(&gather->freelist), 0);
 
-	put_pages_list(&gather->freelist);
+	iommu_free_pages_list(&gather->freelist);
 }
 
 static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index d02f916d8e59..9fe04cea29c4 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1069,8 +1069,6 @@ void domain_update_iommu_cap(struct dmar_domain *domain);
 
 int dmar_ir_support(void);
 
-void *alloc_pgtable_page(int node, gfp_t gfp);
-void free_pgtable_page(void *vaddr);
 void iommu_flush_write_buffer(struct intel_iommu *iommu);
 struct iommu_domain *intel_nested_domain_alloc(struct iommu_domain *parent,
 					       const struct iommu_user_data *user_data);
diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c
index 566297bc87dd..4af73e87275a 100644
--- a/drivers/iommu/intel/irq_remapping.c
+++ b/drivers/iommu/intel/irq_remapping.c
@@ -22,6 +22,7 @@
 
 #include "iommu.h"
 #include "../irq_remapping.h"
+#include "../iommu-pages.h"
 #include "cap_audit.h"
 
 enum irq_mode {
@@ -536,8 +537,8 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 	if (!ir_table)
 		return -ENOMEM;
 
-	pages = alloc_pages_node(iommu->node, GFP_KERNEL | __GFP_ZERO,
-				 INTR_REMAP_PAGE_ORDER);
+	pages = __iommu_alloc_pages_node(iommu->node, GFP_KERNEL,
+					 INTR_REMAP_PAGE_ORDER);
 	if (!pages) {
 		pr_err("IR%d: failed to allocate pages of order %d\n",
 		       iommu->seq_id, INTR_REMAP_PAGE_ORDER);
@@ -622,7 +623,7 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 out_free_bitmap:
 	bitmap_free(bitmap);
 out_free_pages:
-	__free_pages(pages, INTR_REMAP_PAGE_ORDER);
+	__iommu_free_pages(pages, INTR_REMAP_PAGE_ORDER);
 out_free_table:
 	kfree(ir_table);
 
@@ -643,8 +644,7 @@ static void intel_teardown_irq_remapping(struct intel_iommu *iommu)
 			irq_domain_free_fwnode(fn);
 			iommu->ir_domain = NULL;
 		}
-		free_pages((unsigned long)iommu->ir_table->base,
-			   INTR_REMAP_PAGE_ORDER);
+		iommu_free_pages(iommu->ir_table->base, INTR_REMAP_PAGE_ORDER);
 		bitmap_free(iommu->ir_table->bitmap);
 		kfree(iommu->ir_table);
 		iommu->ir_table = NULL;
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 3239cefa4c33..b6ecff24bafa 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -20,6 +20,7 @@
 
 #include "iommu.h"
 #include "pasid.h"
+#include "../iommu-pages.h"
 
 /*
  * Intel IOMMU system wide PASID name space:
@@ -59,8 +60,7 @@ int intel_pasid_alloc_table(struct device *dev)
 
 	size = max_pasid >> (PASID_PDE_SHIFT - 3);
 	order = size ? get_order(size) : 0;
-	pages = alloc_pages_node(info->iommu->node,
-				 GFP_KERNEL | __GFP_ZERO, order);
+	pages = __iommu_alloc_pages_node(info->iommu->node, GFP_KERNEL, order);
 	if (!pages) {
 		kfree(pasid_table);
 		return -ENOMEM;
@@ -97,10 +97,10 @@ void intel_pasid_free_table(struct device *dev)
 	max_pde = pasid_table->max_pasid >> PASID_PDE_SHIFT;
 	for (i = 0; i < max_pde; i++) {
 		table = get_pasid_table_from_pde(&dir[i]);
-		free_pgtable_page(table);
+		iommu_free_page(table);
 	}
 
-	free_pages((unsigned long)pasid_table->table, pasid_table->order);
+	iommu_free_pages(pasid_table->table, pasid_table->order);
 	kfree(pasid_table);
 }
 
@@ -146,7 +146,7 @@ static struct pasid_entry *intel_pasid_get_entry(struct device *dev, u32 pasid)
 retry:
 	entries = get_pasid_table_from_pde(&dir[dir_index]);
 	if (!entries) {
-		entries = alloc_pgtable_page(info->iommu->node, GFP_ATOMIC);
+		entries = iommu_alloc_page_node(info->iommu->node, GFP_ATOMIC);
 		if (!entries)
 			return NULL;
 
@@ -158,7 +158,7 @@ static struct pasid_entry *intel_pasid_get_entry(struct device *dev, u32 pasid)
 		 */
 		if (cmpxchg64(&dir[dir_index].val, 0ULL,
 			      (u64)virt_to_phys(entries) | PASID_PTE_PRESENT)) {
-			free_pgtable_page(entries);
+			iommu_free_page(entries);
 			goto retry;
 		}
 		if (!ecap_coherent(info->iommu->ecap)) {
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 40edd282903f..ed3993657283 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -23,6 +23,7 @@
 #include "pasid.h"
 #include "perf.h"
 #include "../iommu-sva.h"
+#include "../iommu-pages.h"
 #include "trace.h"
 
 static irqreturn_t prq_event_thread(int irq, void *d);
@@ -67,7 +68,7 @@ int intel_svm_enable_prq(struct intel_iommu *iommu)
 	struct page *pages;
 	int irq, ret;
 
-	pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, PRQ_ORDER);
+	pages = __iommu_alloc_pages(GFP_KERNEL, PRQ_ORDER);
 	if (!pages) {
 		pr_warn("IOMMU: %s: Failed to allocate page request queue\n",
 			iommu->name);
@@ -118,7 +119,7 @@ int intel_svm_enable_prq(struct intel_iommu *iommu)
 	dmar_free_hwirq(irq);
 	iommu->pr_irq = 0;
 free_prq:
-	free_pages((unsigned long)iommu->prq, PRQ_ORDER);
+	iommu_free_pages(iommu->prq, PRQ_ORDER);
 	iommu->prq = NULL;
 
 	return ret;
@@ -141,7 +142,7 @@ int intel_svm_finish_prq(struct intel_iommu *iommu)
 		iommu->iopf_queue = NULL;
 	}
 
-	free_pages((unsigned long)iommu->prq, PRQ_ORDER);
+	iommu_free_pages(iommu->prq, PRQ_ORDER);
 	iommu->prq = NULL;
 
 	return 0;
diff --git a/drivers/iommu/iommu-pages.h b/drivers/iommu/iommu-pages.h
new file mode 100644
index 000000000000..c412d0aaa399
--- /dev/null
+++ b/drivers/iommu/iommu-pages.h
@@ -0,0 +1,204 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2024, Google LLC.
+ * Pasha Tatashin <pasha.tatashin@soleen.com>
+ */
+
+#ifndef __IOMMU_PAGES_H
+#define __IOMMU_PAGES_H
+
+#include <linux/vmstat.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+
+/*
+ * All page allocation that are performed in the IOMMU subsystem must use one of
+ * the functions below.  This is necessary for the proper accounting as IOMMU
+ * state can be rather large, i.e. multiple gigabytes in size.
+ */
+
+/**
+ * __iommu_alloc_pages_node - allocate a zeroed page of a given order from
+ * specific NUMA node.
+ * @nid: memory NUMA node id
+ * @gfp: buddy allocator flags
+ * @order: page order
+ *
+ * returns the head struct page of the allocated page.
+ */
+static inline struct page *__iommu_alloc_pages_node(int nid, gfp_t gfp,
+						    int order)
+{
+	struct page *page;
+
+	page = alloc_pages_node(nid, gfp | __GFP_ZERO, order);
+	if (unlikely(!page))
+		return NULL;
+
+	return page;
+}
+
+/**
+ * __iommu_alloc_pages - allocate a zeroed page of a given order.
+ * @gfp: buddy allocator flags
+ * @order: page order
+ *
+ * returns the head struct page of the allocated page.
+ */
+static inline struct page *__iommu_alloc_pages(gfp_t gfp, int order)
+{
+	struct page *page;
+
+	page = alloc_pages(gfp | __GFP_ZERO, order);
+	if (unlikely(!page))
+		return NULL;
+
+	return page;
+}
+
+/**
+ * __iommu_alloc_page_node - allocate a zeroed page at specific NUMA node.
+ * @nid: memory NUMA node id
+ * @gfp: buddy allocator flags
+ *
+ * returns the struct page of the allocated page.
+ */
+static inline struct page *__iommu_alloc_page_node(int nid, gfp_t gfp)
+{
+	return __iommu_alloc_pages_node(nid, gfp, 0);
+}
+
+/**
+ * __iommu_alloc_page - allocate a zeroed page
+ * @gfp: buddy allocator flags
+ *
+ * returns the struct page of the allocated page.
+ */
+static inline struct page *__iommu_alloc_page(gfp_t gfp)
+{
+	return __iommu_alloc_pages(gfp, 0);
+}
+
+/**
+ * __iommu_free_pages - free page of a given order
+ * @page: head struct page of the page
+ * @order: page order
+ */
+static inline void __iommu_free_pages(struct page *page, int order)
+{
+	if (!page)
+		return;
+
+	__free_pages(page, order);
+}
+
+/**
+ * __iommu_free_page - free page
+ * @page: struct page of the page
+ */
+static inline void __iommu_free_page(struct page *page)
+{
+	__iommu_free_pages(page, 0);
+}
+
+/**
+ * iommu_alloc_pages_node - allocate a zeroed page of a given order from
+ * specific NUMA node.
+ * @nid: memory NUMA node id
+ * @gfp: buddy allocator flags
+ * @order: page order
+ *
+ * returns the virtual address of the allocated page
+ */
+static inline void *iommu_alloc_pages_node(int nid, gfp_t gfp, int order)
+{
+	struct page *page = __iommu_alloc_pages_node(nid, gfp, order);
+
+	if (unlikely(!page))
+		return NULL;
+
+	return page_address(page);
+}
+
+/**
+ * iommu_alloc_pages - allocate a zeroed page of a given order
+ * @gfp: buddy allocator flags
+ * @order: page order
+ *
+ * returns the virtual address of the allocated page
+ */
+static inline void *iommu_alloc_pages(gfp_t gfp, int order)
+{
+	struct page *page = __iommu_alloc_pages(gfp, order);
+
+	if (unlikely(!page))
+		return NULL;
+
+	return page_address(page);
+}
+
+/**
+ * iommu_alloc_page_node - allocate a zeroed page at specific NUMA node.
+ * @nid: memory NUMA node id
+ * @gfp: buddy allocator flags
+ *
+ * returns the virtual address of the allocated page
+ */
+static inline void *iommu_alloc_page_node(int nid, gfp_t gfp)
+{
+	return iommu_alloc_pages_node(nid, gfp, 0);
+}
+
+/**
+ * iommu_alloc_page - allocate a zeroed page
+ * @gfp: buddy allocator flags
+ *
+ * returns the virtual address of the allocated page
+ */
+static inline void *iommu_alloc_page(gfp_t gfp)
+{
+	return iommu_alloc_pages(gfp, 0);
+}
+
+/**
+ * iommu_free_pages - free page of a given order
+ * @virt: virtual address of the page to be freed.
+ * @order: page order
+ */
+static inline void iommu_free_pages(void *virt, int order)
+{
+	if (!virt)
+		return;
+
+	__iommu_free_pages(virt_to_page(virt), order);
+}
+
+/**
+ * iommu_free_page - free page
+ * @virt: virtual address of the page to be freed.
+ */
+static inline void iommu_free_page(void *virt)
+{
+	iommu_free_pages(virt, 0);
+}
+
+/**
+ * iommu_free_pages_list - free a list of pages.
+ * @page: the head of the lru list to be freed.
+ *
+ * There are no locking requirement for these pages, as they are going to be
+ * put on a free list as soon as refcount reaches 0. Pages are put on this LRU
+ * list once they are removed from the IOMMU page tables. However, they can
+ * still be access through debugfs.
+ */
+static inline void iommu_free_pages_list(struct list_head *page)
+{
+	while (!list_empty(page)) {
+		struct page *p = list_entry(page->prev, struct page, lru);
+
+		list_del(&p->lru);
+		put_page(p);
+	}
+}
+
+#endif	/* __IOMMU_PAGES_H */
-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 02/10] iommu/amd: use page allocation function provided by iommu-pages.h

[Pasha Tatashin]

Convert iommu/amd/* files to use the new page allocation functions
provided in iommu-pages.h.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 drivers/iommu/amd/amd_iommu.h     |  8 ---
 drivers/iommu/amd/init.c          | 91 ++++++++++++++-----------------
 drivers/iommu/amd/io_pgtable.c    | 13 +++--
 drivers/iommu/amd/io_pgtable_v2.c | 20 +++----
 drivers/iommu/amd/iommu.c         | 13 +++--
 5 files changed, 64 insertions(+), 81 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 8b3601f285fd..9270c820a2ab 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -142,14 +142,6 @@ static inline int get_pci_sbdf_id(struct pci_dev *pdev)
 	return PCI_SEG_DEVID_TO_SBDF(seg, devid);
 }
 
-static inline void *alloc_pgtable_page(int nid, gfp_t gfp)
-{
-	struct page *page;
-
-	page = alloc_pages_node(nid, gfp | __GFP_ZERO, 0);
-	return page ? page_address(page) : NULL;
-}
-
 bool translation_pre_enabled(struct amd_iommu *iommu);
 bool amd_iommu_is_attach_deferred(struct device *dev);
 int __init add_special_device(u8 type, u8 id, u32 *devid, bool cmd_line);
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index c83bd0c2a1c9..239ddf46426f 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -35,6 +35,7 @@
 
 #include "amd_iommu.h"
 #include "../irq_remapping.h"
+#include "../iommu-pages.h"
 
 /*
  * definitions for the ACPI scanning code
@@ -648,8 +649,8 @@ static int __init find_last_devid_acpi(struct acpi_table_header *table, u16 pci_
 /* Allocate per PCI segment device table */
 static inline int __init alloc_dev_table(struct amd_iommu_pci_seg *pci_seg)
 {
-	pci_seg->dev_table = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO | GFP_DMA32,
-						      get_order(pci_seg->dev_table_size));
+	pci_seg->dev_table = iommu_alloc_pages(GFP_KERNEL | GFP_DMA32,
+					       get_order(pci_seg->dev_table_size));
 	if (!pci_seg->dev_table)
 		return -ENOMEM;
 
@@ -658,17 +659,16 @@ static inline int __init alloc_dev_table(struct amd_iommu_pci_seg *pci_seg)
 
 static inline void free_dev_table(struct amd_iommu_pci_seg *pci_seg)
 {
-	free_pages((unsigned long)pci_seg->dev_table,
-		    get_order(pci_seg->dev_table_size));
+	iommu_free_pages(pci_seg->dev_table,
+			 get_order(pci_seg->dev_table_size));
 	pci_seg->dev_table = NULL;
 }
 
 /* Allocate per PCI segment IOMMU rlookup table. */
 static inline int __init alloc_rlookup_table(struct amd_iommu_pci_seg *pci_seg)
 {
-	pci_seg->rlookup_table = (void *)__get_free_pages(
-						GFP_KERNEL | __GFP_ZERO,
-						get_order(pci_seg->rlookup_table_size));
+	pci_seg->rlookup_table = iommu_alloc_pages(GFP_KERNEL,
+						   get_order(pci_seg->rlookup_table_size));
 	if (pci_seg->rlookup_table == NULL)
 		return -ENOMEM;
 
@@ -677,16 +677,15 @@ static inline int __init alloc_rlookup_table(struct amd_iommu_pci_seg *pci_seg)
 
 static inline void free_rlookup_table(struct amd_iommu_pci_seg *pci_seg)
 {
-	free_pages((unsigned long)pci_seg->rlookup_table,
-		   get_order(pci_seg->rlookup_table_size));
+	iommu_free_pages(pci_seg->rlookup_table,
+			 get_order(pci_seg->rlookup_table_size));
 	pci_seg->rlookup_table = NULL;
 }
 
 static inline int __init alloc_irq_lookup_table(struct amd_iommu_pci_seg *pci_seg)
 {
-	pci_seg->irq_lookup_table = (void *)__get_free_pages(
-					     GFP_KERNEL | __GFP_ZERO,
-					     get_order(pci_seg->rlookup_table_size));
+	pci_seg->irq_lookup_table = iommu_alloc_pages(GFP_KERNEL,
+						      get_order(pci_seg->rlookup_table_size));
 	kmemleak_alloc(pci_seg->irq_lookup_table,
 		       pci_seg->rlookup_table_size, 1, GFP_KERNEL);
 	if (pci_seg->irq_lookup_table == NULL)
@@ -698,8 +697,8 @@ static inline int __init alloc_irq_lookup_table(struct amd_iommu_pci_seg *pci_se
 static inline void free_irq_lookup_table(struct amd_iommu_pci_seg *pci_seg)
 {
 	kmemleak_free(pci_seg->irq_lookup_table);
-	free_pages((unsigned long)pci_seg->irq_lookup_table,
-		   get_order(pci_seg->rlookup_table_size));
+	iommu_free_pages(pci_seg->irq_lookup_table,
+			 get_order(pci_seg->rlookup_table_size));
 	pci_seg->irq_lookup_table = NULL;
 }
 
@@ -707,8 +706,8 @@ static int __init alloc_alias_table(struct amd_iommu_pci_seg *pci_seg)
 {
 	int i;
 
-	pci_seg->alias_table = (void *)__get_free_pages(GFP_KERNEL,
-					get_order(pci_seg->alias_table_size));
+	pci_seg->alias_table = iommu_alloc_pages(GFP_KERNEL,
+						 get_order(pci_seg->alias_table_size));
 	if (!pci_seg->alias_table)
 		return -ENOMEM;
 
@@ -723,8 +722,8 @@ static int __init alloc_alias_table(struct amd_iommu_pci_seg *pci_seg)
 
 static void __init free_alias_table(struct amd_iommu_pci_seg *pci_seg)
 {
-	free_pages((unsigned long)pci_seg->alias_table,
-		   get_order(pci_seg->alias_table_size));
+	iommu_free_pages(pci_seg->alias_table,
+			 get_order(pci_seg->alias_table_size));
 	pci_seg->alias_table = NULL;
 }
 
@@ -735,8 +734,8 @@ static void __init free_alias_table(struct amd_iommu_pci_seg *pci_seg)
  */
 static int __init alloc_command_buffer(struct amd_iommu *iommu)
 {
-	iommu->cmd_buf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-						  get_order(CMD_BUFFER_SIZE));
+	iommu->cmd_buf = iommu_alloc_pages(GFP_KERNEL,
+					   get_order(CMD_BUFFER_SIZE));
 
 	return iommu->cmd_buf ? 0 : -ENOMEM;
 }
@@ -844,19 +843,19 @@ static void iommu_disable_command_buffer(struct amd_iommu *iommu)
 
 static void __init free_command_buffer(struct amd_iommu *iommu)
 {
-	free_pages((unsigned long)iommu->cmd_buf, get_order(CMD_BUFFER_SIZE));
+	iommu_free_pages(iommu->cmd_buf, get_order(CMD_BUFFER_SIZE));
 }
 
 static void *__init iommu_alloc_4k_pages(struct amd_iommu *iommu,
 					 gfp_t gfp, size_t size)
 {
 	int order = get_order(size);
-	void *buf = (void *)__get_free_pages(gfp, order);
+	void *buf = iommu_alloc_pages(gfp, order);
 
 	if (buf &&
 	    check_feature(FEATURE_SNP) &&
 	    set_memory_4k((unsigned long)buf, (1 << order))) {
-		free_pages((unsigned long)buf, order);
+		iommu_free_pages(buf, order);
 		buf = NULL;
 	}
 
@@ -866,7 +865,7 @@ static void *__init iommu_alloc_4k_pages(struct amd_iommu *iommu,
 /* allocates the memory where the IOMMU will log its events to */
 static int __init alloc_event_buffer(struct amd_iommu *iommu)
 {
-	iommu->evt_buf = iommu_alloc_4k_pages(iommu, GFP_KERNEL | __GFP_ZERO,
+	iommu->evt_buf = iommu_alloc_4k_pages(iommu, GFP_KERNEL,
 					      EVT_BUFFER_SIZE);
 
 	return iommu->evt_buf ? 0 : -ENOMEM;
@@ -900,14 +899,13 @@ static void iommu_disable_event_buffer(struct amd_iommu *iommu)
 
 static void __init free_event_buffer(struct amd_iommu *iommu)
 {
-	free_pages((unsigned long)iommu->evt_buf, get_order(EVT_BUFFER_SIZE));
+	iommu_free_pages(iommu->evt_buf, get_order(EVT_BUFFER_SIZE));
 }
 
 /* allocates the memory where the IOMMU will log its events to */
 static int __init alloc_ppr_log(struct amd_iommu *iommu)
 {
-	iommu->ppr_log = iommu_alloc_4k_pages(iommu, GFP_KERNEL | __GFP_ZERO,
-					      PPR_LOG_SIZE);
+	iommu->ppr_log = iommu_alloc_4k_pages(iommu, GFP_KERNEL, PPR_LOG_SIZE);
 
 	return iommu->ppr_log ? 0 : -ENOMEM;
 }
@@ -936,14 +934,14 @@ static void iommu_enable_ppr_log(struct amd_iommu *iommu)
 
 static void __init free_ppr_log(struct amd_iommu *iommu)
 {
-	free_pages((unsigned long)iommu->ppr_log, get_order(PPR_LOG_SIZE));
+	iommu_free_pages(iommu->ppr_log, get_order(PPR_LOG_SIZE));
 }
 
 static void free_ga_log(struct amd_iommu *iommu)
 {
 #ifdef CONFIG_IRQ_REMAP
-	free_pages((unsigned long)iommu->ga_log, get_order(GA_LOG_SIZE));
-	free_pages((unsigned long)iommu->ga_log_tail, get_order(8));
+	iommu_free_pages(iommu->ga_log, get_order(GA_LOG_SIZE));
+	iommu_free_pages(iommu->ga_log_tail, get_order(8));
 #endif
 }
 
@@ -988,13 +986,11 @@ static int iommu_init_ga_log(struct amd_iommu *iommu)
 	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
 		return 0;
 
-	iommu->ga_log = (u8 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-					get_order(GA_LOG_SIZE));
+	iommu->ga_log = iommu_alloc_pages(GFP_KERNEL, get_order(GA_LOG_SIZE));
 	if (!iommu->ga_log)
 		goto err_out;
 
-	iommu->ga_log_tail = (u8 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-					get_order(8));
+	iommu->ga_log_tail = iommu_alloc_pages(GFP_KERNEL, get_order(8));
 	if (!iommu->ga_log_tail)
 		goto err_out;
 
@@ -1007,7 +1003,7 @@ static int iommu_init_ga_log(struct amd_iommu *iommu)
 
 static int __init alloc_cwwb_sem(struct amd_iommu *iommu)
 {
-	iommu->cmd_sem = iommu_alloc_4k_pages(iommu, GFP_KERNEL | __GFP_ZERO, 1);
+	iommu->cmd_sem = iommu_alloc_4k_pages(iommu, GFP_KERNEL, 1);
 
 	return iommu->cmd_sem ? 0 : -ENOMEM;
 }
@@ -1015,7 +1011,7 @@ static int __init alloc_cwwb_sem(struct amd_iommu *iommu)
 static void __init free_cwwb_sem(struct amd_iommu *iommu)
 {
 	if (iommu->cmd_sem)
-		free_page((unsigned long)iommu->cmd_sem);
+		iommu_free_page((void *)iommu->cmd_sem);
 }
 
 static void iommu_enable_xt(struct amd_iommu *iommu)
@@ -1080,7 +1076,6 @@ static bool __copy_device_table(struct amd_iommu *iommu)
 	u32 lo, hi, devid, old_devtb_size;
 	phys_addr_t old_devtb_phys;
 	u16 dom_id, dte_v, irq_v;
-	gfp_t gfp_flag;
 	u64 tmp;
 
 	/* Each IOMMU use separate device table with the same size */
@@ -1114,9 +1109,8 @@ static bool __copy_device_table(struct amd_iommu *iommu)
 	if (!old_devtb)
 		return false;
 
-	gfp_flag = GFP_KERNEL | __GFP_ZERO | GFP_DMA32;
-	pci_seg->old_dev_tbl_cpy = (void *)__get_free_pages(gfp_flag,
-						    get_order(pci_seg->dev_table_size));
+	pci_seg->old_dev_tbl_cpy = iommu_alloc_pages(GFP_KERNEL | GFP_DMA32,
+						     get_order(pci_seg->dev_table_size));
 	if (pci_seg->old_dev_tbl_cpy == NULL) {
 		pr_err("Failed to allocate memory for copying old device table!\n");
 		memunmap(old_devtb);
@@ -2800,8 +2794,8 @@ static void early_enable_iommus(void)
 
 		for_each_pci_segment(pci_seg) {
 			if (pci_seg->old_dev_tbl_cpy != NULL) {
-				free_pages((unsigned long)pci_seg->old_dev_tbl_cpy,
-						get_order(pci_seg->dev_table_size));
+				iommu_free_pages(pci_seg->old_dev_tbl_cpy,
+						 get_order(pci_seg->dev_table_size));
 				pci_seg->old_dev_tbl_cpy = NULL;
 			}
 		}
@@ -2814,8 +2808,8 @@ static void early_enable_iommus(void)
 		pr_info("Copied DEV table from previous kernel.\n");
 
 		for_each_pci_segment(pci_seg) {
-			free_pages((unsigned long)pci_seg->dev_table,
-				   get_order(pci_seg->dev_table_size));
+			iommu_free_pages(pci_seg->dev_table,
+					 get_order(pci_seg->dev_table_size));
 			pci_seg->dev_table = pci_seg->old_dev_tbl_cpy;
 		}
 
@@ -3018,8 +3012,8 @@ static bool __init check_ioapic_information(void)
 
 static void __init free_dma_resources(void)
 {
-	free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
-		   get_order(MAX_DOMAIN_ID/8));
+	iommu_free_pages(amd_iommu_pd_alloc_bitmap,
+			 get_order(MAX_DOMAIN_ID / 8));
 	amd_iommu_pd_alloc_bitmap = NULL;
 
 	free_unity_maps();
@@ -3091,9 +3085,8 @@ static int __init early_amd_iommu_init(void)
 	/* Device table - directly used by all IOMMUs */
 	ret = -ENOMEM;
 
-	amd_iommu_pd_alloc_bitmap = (void *)__get_free_pages(
-					    GFP_KERNEL | __GFP_ZERO,
-					    get_order(MAX_DOMAIN_ID/8));
+	amd_iommu_pd_alloc_bitmap = iommu_alloc_pages(GFP_KERNEL,
+						      get_order(MAX_DOMAIN_ID / 8));
 	if (amd_iommu_pd_alloc_bitmap == NULL)
 		goto out;
 
diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
index 2a0d1e97e52f..7676b0f019d0 100644
--- a/drivers/iommu/amd/io_pgtable.c
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -22,6 +22,7 @@
 
 #include "amd_iommu_types.h"
 #include "amd_iommu.h"
+#include "../iommu-pages.h"
 
 static void v1_tlb_flush_all(void *cookie)
 {
@@ -156,7 +157,7 @@ static bool increase_address_space(struct protection_domain *domain,
 	bool ret = true;
 	u64 *pte;
 
-	pte = alloc_pgtable_page(domain->nid, gfp);
+	pte = iommu_alloc_page_node(domain->nid, gfp);
 	if (!pte)
 		return false;
 
@@ -187,7 +188,7 @@ static bool increase_address_space(struct protection_domain *domain,
 
 out:
 	spin_unlock_irqrestore(&domain->lock, flags);
-	free_page((unsigned long)pte);
+	iommu_free_page(pte);
 
 	return ret;
 }
@@ -250,7 +251,7 @@ static u64 *alloc_pte(struct protection_domain *domain,
 
 		if (!IOMMU_PTE_PRESENT(__pte) ||
 		    pte_level == PAGE_MODE_NONE) {
-			page = alloc_pgtable_page(domain->nid, gfp);
+			page = iommu_alloc_page_node(domain->nid, gfp);
 
 			if (!page)
 				return NULL;
@@ -259,7 +260,7 @@ static u64 *alloc_pte(struct protection_domain *domain,
 
 			/* pte could have been changed somewhere. */
 			if (!try_cmpxchg64(pte, &__pte, __npte))
-				free_page((unsigned long)page);
+				iommu_free_page(page);
 			else if (IOMMU_PTE_PRESENT(__pte))
 				*updated = true;
 
@@ -431,7 +432,7 @@ static int iommu_v1_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
 	}
 
 	/* Everything flushed out, free pages now */
-	put_pages_list(&freelist);
+	iommu_free_pages_list(&freelist);
 
 	return ret;
 }
@@ -580,7 +581,7 @@ static void v1_free_pgtable(struct io_pgtable *iop)
 	/* Make changes visible to IOMMUs */
 	amd_iommu_domain_update(dom);
 
-	put_pages_list(&freelist);
+	iommu_free_pages_list(&freelist);
 }
 
 static struct io_pgtable *v1_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
diff --git a/drivers/iommu/amd/io_pgtable_v2.c b/drivers/iommu/amd/io_pgtable_v2.c
index 6d69ba60744f..477371b1ed54 100644
--- a/drivers/iommu/amd/io_pgtable_v2.c
+++ b/drivers/iommu/amd/io_pgtable_v2.c
@@ -18,6 +18,7 @@
 
 #include "amd_iommu_types.h"
 #include "amd_iommu.h"
+#include "../iommu-pages.h"
 
 #define IOMMU_PAGE_PRESENT	BIT_ULL(0)	/* Is present */
 #define IOMMU_PAGE_RW		BIT_ULL(1)	/* Writeable */
@@ -99,11 +100,6 @@ static inline int page_size_to_level(u64 pg_size)
 	return PAGE_MODE_1_LEVEL;
 }
 
-static inline void free_pgtable_page(u64 *pt)
-{
-	free_page((unsigned long)pt);
-}
-
 static void free_pgtable(u64 *pt, int level)
 {
 	u64 *p;
@@ -125,10 +121,10 @@ static void free_pgtable(u64 *pt, int level)
 		if (level > 2)
 			free_pgtable(p, level - 1);
 		else
-			free_pgtable_page(p);
+			iommu_free_page(p);
 	}
 
-	free_pgtable_page(pt);
+	iommu_free_page(pt);
 }
 
 /* Allocate page table */
@@ -156,14 +152,14 @@ static u64 *v2_alloc_pte(int nid, u64 *pgd, unsigned long iova,
 		}
 
 		if (!IOMMU_PTE_PRESENT(__pte)) {
-			page = alloc_pgtable_page(nid, gfp);
+			page = iommu_alloc_page_node(nid, gfp);
 			if (!page)
 				return NULL;
 
 			__npte = set_pgtable_attr(page);
 			/* pte could have been changed somewhere. */
 			if (cmpxchg64(pte, __pte, __npte) != __pte)
-				free_pgtable_page(page);
+				iommu_free_page(page);
 			else if (IOMMU_PTE_PRESENT(__pte))
 				*updated = true;
 
@@ -185,7 +181,7 @@ static u64 *v2_alloc_pte(int nid, u64 *pgd, unsigned long iova,
 		if (pg_size == IOMMU_PAGE_SIZE_1G)
 			free_pgtable(__pte, end_level - 1);
 		else if (pg_size == IOMMU_PAGE_SIZE_2M)
-			free_pgtable_page(__pte);
+			iommu_free_page(__pte);
 	}
 
 	return pte;
@@ -374,7 +370,7 @@ static struct io_pgtable *v2_alloc_pgtable(struct io_pgtable_cfg *cfg, void *coo
 	int ret;
 	int ias = IOMMU_IN_ADDR_BIT_SIZE;
 
-	pgtable->pgd = alloc_pgtable_page(pdom->nid, GFP_ATOMIC);
+	pgtable->pgd = iommu_alloc_page_node(pdom->nid, GFP_ATOMIC);
 	if (!pgtable->pgd)
 		return NULL;
 
@@ -397,7 +393,7 @@ static struct io_pgtable *v2_alloc_pgtable(struct io_pgtable_cfg *cfg, void *coo
 	return &pgtable->iop;
 
 err_free_pgd:
-	free_pgtable_page(pgtable->pgd);
+	iommu_free_page(pgtable->pgd);
 
 	return NULL;
 }
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 4283dd8191f0..0c7bd09ab617 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -42,6 +42,7 @@
 #include "amd_iommu.h"
 #include "../dma-iommu.h"
 #include "../irq_remapping.h"
+#include "../iommu-pages.h"
 
 #define CMD_SET_TYPE(cmd, t) ((cmd)->data[1] |= ((t) << 28))
 
@@ -1637,7 +1638,7 @@ static void free_gcr3_tbl_level1(u64 *tbl)
 
 		ptr = iommu_phys_to_virt(tbl[i] & PAGE_MASK);
 
-		free_page((unsigned long)ptr);
+		iommu_free_page(ptr);
 	}
 }
 
@@ -1665,7 +1666,7 @@ static void free_gcr3_table(struct protection_domain *domain)
 	else
 		BUG_ON(domain->glx != 0);
 
-	free_page((unsigned long)domain->gcr3_tbl);
+	iommu_free_page(domain->gcr3_tbl);
 }
 
 /*
@@ -1692,7 +1693,7 @@ static int setup_gcr3_table(struct protection_domain *domain, int pasids)
 	if (levels > amd_iommu_max_glx_val)
 		return -EINVAL;
 
-	domain->gcr3_tbl = alloc_pgtable_page(domain->nid, GFP_ATOMIC);
+	domain->gcr3_tbl = iommu_alloc_page_node(domain->nid, GFP_ATOMIC);
 	if (domain->gcr3_tbl == NULL)
 		return -ENOMEM;
 
@@ -2074,7 +2075,7 @@ static void protection_domain_free(struct protection_domain *domain)
 		free_gcr3_table(domain);
 
 	if (domain->iop.root)
-		free_page((unsigned long)domain->iop.root);
+		iommu_free_page(domain->iop.root);
 
 	if (domain->id)
 		domain_id_free(domain->id);
@@ -2089,7 +2090,7 @@ static int protection_domain_init_v1(struct protection_domain *domain, int mode)
 	BUG_ON(mode < PAGE_MODE_NONE || mode > PAGE_MODE_6_LEVEL);
 
 	if (mode != PAGE_MODE_NONE) {
-		pt_root = (void *)get_zeroed_page(GFP_KERNEL);
+		pt_root = iommu_alloc_page(GFP_KERNEL);
 		if (!pt_root)
 			return -ENOMEM;
 	}
@@ -2762,7 +2763,7 @@ static u64 *__get_gcr3_pte(u64 *root, int level, u32 pasid, bool alloc)
 			if (!alloc)
 				return NULL;
 
-			root = (void *)get_zeroed_page(GFP_ATOMIC);
+			root = iommu_alloc_page(GFP_ATOMIC);
 			if (root == NULL)
 				return NULL;
 
-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 03/10] iommu/io-pgtable-arm: use page allocation function provided by iommu-pages.h

[Pasha Tatashin]

Convert iommu/io-pgtable-arm.c to use the new page allocation functions
provided in iommu-pages.h.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 drivers/iommu/io-pgtable-arm.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index f7828a7aad41..3d23b924cec1 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -21,6 +21,7 @@
 #include <asm/barrier.h>
 
 #include "io-pgtable-arm.h"
+#include "iommu-pages.h"
 
 #define ARM_LPAE_MAX_ADDR_BITS		52
 #define ARM_LPAE_S2_MAX_CONCAT_PAGES	16
@@ -198,14 +199,10 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,
 
 	VM_BUG_ON((gfp & __GFP_HIGHMEM));
 
-	if (cfg->alloc) {
+	if (cfg->alloc)
 		pages = cfg->alloc(cookie, size, gfp);
-	} else {
-		struct page *p;
-
-		p = alloc_pages_node(dev_to_node(dev), gfp | __GFP_ZERO, order);
-		pages = p ? page_address(p) : NULL;
-	}
+	else
+		pages = iommu_alloc_pages_node(dev_to_node(dev), gfp, order);
 
 	if (!pages)
 		return NULL;
@@ -233,7 +230,7 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,
 	if (cfg->free)
 		cfg->free(cookie, pages, size);
 	else
-		free_pages((unsigned long)pages, order);
+		iommu_free_pages(pages, order);
 
 	return NULL;
 }
@@ -249,7 +246,7 @@ static void __arm_lpae_free_pages(void *pages, size_t size,
 	if (cfg->free)
 		cfg->free(cookie, pages, size);
 	else
-		free_pages((unsigned long)pages, get_order(size));
+		iommu_free_pages(pages, get_order(size));
 }
 
 static void __arm_lpae_sync_pte(arm_lpae_iopte *ptep, int num_entries,
-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 04/10] iommu/io-pgtable-dart: use page allocation function provided by iommu-pages.h

[Pasha Tatashin]

Convert iommu/io-pgtable-dart.c to use the new page allocation functions
provided in iommu-pages.h., and remove unnecessary struct io_pgtable_cfg
argument from __dart_alloc_pages().

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Janne Grunau <j@jannau.net>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 drivers/iommu/io-pgtable-dart.c | 37 +++++++++++++--------------------
 1 file changed, 14 insertions(+), 23 deletions(-)

diff --git a/drivers/iommu/io-pgtable-dart.c b/drivers/iommu/io-pgtable-dart.c
index 74b1ef2b96be..ad28031e1e93 100644
--- a/drivers/iommu/io-pgtable-dart.c
+++ b/drivers/iommu/io-pgtable-dart.c
@@ -23,6 +23,7 @@
 #include <linux/types.h>
 
 #include <asm/barrier.h>
+#include "iommu-pages.h"
 
 #define DART1_MAX_ADDR_BITS	36
 
@@ -106,18 +107,12 @@ static phys_addr_t iopte_to_paddr(dart_iopte pte,
 	return paddr;
 }
 
-static void *__dart_alloc_pages(size_t size, gfp_t gfp,
-				    struct io_pgtable_cfg *cfg)
+static void *__dart_alloc_pages(size_t size, gfp_t gfp)
 {
 	int order = get_order(size);
-	struct page *p;
 
 	VM_BUG_ON((gfp & __GFP_HIGHMEM));
-	p = alloc_pages(gfp | __GFP_ZERO, order);
-	if (!p)
-		return NULL;
-
-	return page_address(p);
+	return iommu_alloc_pages(gfp, order);
 }
 
 static int dart_init_pte(struct dart_io_pgtable *data,
@@ -262,13 +257,13 @@ static int dart_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
 
 	/* no L2 table present */
 	if (!pte) {
-		cptep = __dart_alloc_pages(tblsz, gfp, cfg);
+		cptep = __dart_alloc_pages(tblsz, gfp);
 		if (!cptep)
 			return -ENOMEM;
 
 		pte = dart_install_table(cptep, ptep, 0, data);
 		if (pte)
-			free_pages((unsigned long)cptep, get_order(tblsz));
+			iommu_free_pages(cptep, get_order(tblsz));
 
 		/* L2 table is present (now) */
 		pte = READ_ONCE(*ptep);
@@ -419,8 +414,7 @@ apple_dart_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
 	cfg->apple_dart_cfg.n_ttbrs = 1 << data->tbl_bits;
 
 	for (i = 0; i < cfg->apple_dart_cfg.n_ttbrs; ++i) {
-		data->pgd[i] = __dart_alloc_pages(DART_GRANULE(data), GFP_KERNEL,
-					   cfg);
+		data->pgd[i] = __dart_alloc_pages(DART_GRANULE(data), GFP_KERNEL);
 		if (!data->pgd[i])
 			goto out_free_data;
 		cfg->apple_dart_cfg.ttbr[i] = virt_to_phys(data->pgd[i]);
@@ -429,9 +423,10 @@ apple_dart_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
 	return &data->iop;
 
 out_free_data:
-	while (--i >= 0)
-		free_pages((unsigned long)data->pgd[i],
-			   get_order(DART_GRANULE(data)));
+	while (--i >= 0) {
+		iommu_free_pages(data->pgd[i],
+				 get_order(DART_GRANULE(data)));
+	}
 	kfree(data);
 	return NULL;
 }
@@ -439,6 +434,7 @@ apple_dart_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
 static void apple_dart_free_pgtable(struct io_pgtable *iop)
 {
 	struct dart_io_pgtable *data = io_pgtable_to_data(iop);
+	int order = get_order(DART_GRANULE(data));
 	dart_iopte *ptep, *end;
 	int i;
 
@@ -449,15 +445,10 @@ static void apple_dart_free_pgtable(struct io_pgtable *iop)
 		while (ptep != end) {
 			dart_iopte pte = *ptep++;
 
-			if (pte) {
-				unsigned long page =
-					(unsigned long)iopte_deref(pte, data);
-
-				free_pages(page, get_order(DART_GRANULE(data)));
-			}
+			if (pte)
+				iommu_free_pages(iopte_deref(pte, data), order);
 		}
-		free_pages((unsigned long)data->pgd[i],
-			   get_order(DART_GRANULE(data)));
+		iommu_free_pages(data->pgd[i], order);
 	}
 
 	kfree(data);
-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 05/10] iommu/exynos: use page allocation function provided by iommu-pages.h

[Pasha Tatashin]

Convert iommu/exynos-iommu.c to use the new page allocation functions
provided in iommu-pages.h.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 drivers/iommu/exynos-iommu.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 2c6e9094f1e9..3eab0ae65a4f 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -22,6 +22,8 @@
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 
+#include "iommu-pages.h"
+
 typedef u32 sysmmu_iova_t;
 typedef u32 sysmmu_pte_t;
 static struct iommu_domain exynos_identity_domain;
@@ -900,11 +902,11 @@ static struct iommu_domain *exynos_iommu_domain_alloc_paging(struct device *dev)
 	if (!domain)
 		return NULL;
 
-	domain->pgtable = (sysmmu_pte_t *)__get_free_pages(GFP_KERNEL, 2);
+	domain->pgtable = iommu_alloc_pages(GFP_KERNEL, 2);
 	if (!domain->pgtable)
 		goto err_pgtable;
 
-	domain->lv2entcnt = (short *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
+	domain->lv2entcnt = iommu_alloc_pages(GFP_KERNEL, 1);
 	if (!domain->lv2entcnt)
 		goto err_counter;
 
@@ -930,9 +932,9 @@ static struct iommu_domain *exynos_iommu_domain_alloc_paging(struct device *dev)
 	return &domain->domain;
 
 err_lv2ent:
-	free_pages((unsigned long)domain->lv2entcnt, 1);
+	iommu_free_pages(domain->lv2entcnt, 1);
 err_counter:
-	free_pages((unsigned long)domain->pgtable, 2);
+	iommu_free_pages(domain->pgtable, 2);
 err_pgtable:
 	kfree(domain);
 	return NULL;
@@ -973,8 +975,8 @@ static void exynos_iommu_domain_free(struct iommu_domain *iommu_domain)
 					phys_to_virt(base));
 		}
 
-	free_pages((unsigned long)domain->pgtable, 2);
-	free_pages((unsigned long)domain->lv2entcnt, 1);
+	iommu_free_pages(domain->pgtable, 2);
+	iommu_free_pages(domain->lv2entcnt, 1);
 	kfree(domain);
 }
 
-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 06/10] iommu/rockchip: use page allocation function provided by iommu-pages.h

[Pasha Tatashin]

Convert iommu/rockchip-iommu.c to use the new page allocation functions
provided in iommu-pages.h.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 drivers/iommu/rockchip-iommu.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 2685861c0a12..e04f22d481d0 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -26,6 +26,8 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
+#include "iommu-pages.h"
+
 /** MMU register offsets */
 #define RK_MMU_DTE_ADDR		0x00	/* Directory table address */
 #define RK_MMU_STATUS		0x04
@@ -727,14 +729,14 @@ static u32 *rk_dte_get_page_table(struct rk_iommu_domain *rk_domain,
 	if (rk_dte_is_pt_valid(dte))
 		goto done;
 
-	page_table = (u32 *)get_zeroed_page(GFP_ATOMIC | rk_ops->gfp_flags);
+	page_table = iommu_alloc_page(GFP_ATOMIC | rk_ops->gfp_flags);
 	if (!page_table)
 		return ERR_PTR(-ENOMEM);
 
 	pt_dma = dma_map_single(dma_dev, page_table, SPAGE_SIZE, DMA_TO_DEVICE);
 	if (dma_mapping_error(dma_dev, pt_dma)) {
 		dev_err(dma_dev, "DMA mapping error while allocating page table\n");
-		free_page((unsigned long)page_table);
+		iommu_free_page(page_table);
 		return ERR_PTR(-ENOMEM);
 	}
 
@@ -1061,7 +1063,7 @@ static struct iommu_domain *rk_iommu_domain_alloc_paging(struct device *dev)
 	 * Each level1 (dt) and level2 (pt) table has 1024 4-byte entries.
 	 * Allocate one 4 KiB page for each table.
 	 */
-	rk_domain->dt = (u32 *)get_zeroed_page(GFP_KERNEL | rk_ops->gfp_flags);
+	rk_domain->dt = iommu_alloc_page(GFP_KERNEL | rk_ops->gfp_flags);
 	if (!rk_domain->dt)
 		goto err_free_domain;
 
@@ -1083,7 +1085,7 @@ static struct iommu_domain *rk_iommu_domain_alloc_paging(struct device *dev)
 	return &rk_domain->domain;
 
 err_free_dt:
-	free_page((unsigned long)rk_domain->dt);
+	iommu_free_page(rk_domain->dt);
 err_free_domain:
 	kfree(rk_domain);
 
@@ -1104,13 +1106,13 @@ static void rk_iommu_domain_free(struct iommu_domain *domain)
 			u32 *page_table = phys_to_virt(pt_phys);
 			dma_unmap_single(dma_dev, pt_phys,
 					 SPAGE_SIZE, DMA_TO_DEVICE);
-			free_page((unsigned long)page_table);
+			iommu_free_page(page_table);
 		}
 	}
 
 	dma_unmap_single(dma_dev, rk_domain->dt_dma,
 			 SPAGE_SIZE, DMA_TO_DEVICE);
-	free_page((unsigned long)rk_domain->dt);
+	iommu_free_page(rk_domain->dt);
 
 	kfree(rk_domain);
 }
-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 07/10] iommu/sun50i: use page allocation function provided by iommu-pages.h

[Pasha Tatashin]

Convert iommu/sun50i-iommu.c to use the new page allocation functions
provided in iommu-pages.h.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 drivers/iommu/sun50i-iommu.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
index 41484a5a399b..172ddb717eb5 100644
--- a/drivers/iommu/sun50i-iommu.c
+++ b/drivers/iommu/sun50i-iommu.c
@@ -26,6 +26,8 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
+#include "iommu-pages.h"
+
 #define IOMMU_RESET_REG			0x010
 #define IOMMU_RESET_RELEASE_ALL			0xffffffff
 #define IOMMU_ENABLE_REG		0x020
@@ -679,8 +681,7 @@ sun50i_iommu_domain_alloc_paging(struct device *dev)
 	if (!sun50i_domain)
 		return NULL;
 
-	sun50i_domain->dt = (u32 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-						    get_order(DT_SIZE));
+	sun50i_domain->dt = iommu_alloc_pages(GFP_KERNEL, get_order(DT_SIZE));
 	if (!sun50i_domain->dt)
 		goto err_free_domain;
 
@@ -702,7 +703,7 @@ static void sun50i_iommu_domain_free(struct iommu_domain *domain)
 {
 	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
 
-	free_pages((unsigned long)sun50i_domain->dt, get_order(DT_SIZE));
+	iommu_free_pages(sun50i_domain->dt, get_order(DT_SIZE));
 	sun50i_domain->dt = NULL;
 
 	kfree(sun50i_domain);
-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 08/10] iommu/tegra-smmu: use page allocation function provided by iommu-pages.h

[Pasha Tatashin]

Convert iommu/tegra-smmu.c to use the new page allocation functions
provided in iommu-pages.h.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 drivers/iommu/tegra-smmu.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 310871728ab4..5e0730dc1b0e 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -19,6 +19,8 @@
 #include <soc/tegra/ahb.h>
 #include <soc/tegra/mc.h>
 
+#include "iommu-pages.h"
+
 struct tegra_smmu_group {
 	struct list_head list;
 	struct tegra_smmu *smmu;
@@ -282,7 +284,7 @@ static struct iommu_domain *tegra_smmu_domain_alloc_paging(struct device *dev)
 
 	as->attr = SMMU_PD_READABLE | SMMU_PD_WRITABLE | SMMU_PD_NONSECURE;
 
-	as->pd = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
+	as->pd = __iommu_alloc_page(GFP_KERNEL | __GFP_DMA);
 	if (!as->pd) {
 		kfree(as);
 		return NULL;
@@ -290,7 +292,7 @@ static struct iommu_domain *tegra_smmu_domain_alloc_paging(struct device *dev)
 
 	as->count = kcalloc(SMMU_NUM_PDE, sizeof(u32), GFP_KERNEL);
 	if (!as->count) {
-		__free_page(as->pd);
+		__iommu_free_page(as->pd);
 		kfree(as);
 		return NULL;
 	}
@@ -298,7 +300,7 @@ static struct iommu_domain *tegra_smmu_domain_alloc_paging(struct device *dev)
 	as->pts = kcalloc(SMMU_NUM_PDE, sizeof(*as->pts), GFP_KERNEL);
 	if (!as->pts) {
 		kfree(as->count);
-		__free_page(as->pd);
+		__iommu_free_page(as->pd);
 		kfree(as);
 		return NULL;
 	}
@@ -599,14 +601,14 @@ static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
 		dma = dma_map_page(smmu->dev, page, 0, SMMU_SIZE_PT,
 				   DMA_TO_DEVICE);
 		if (dma_mapping_error(smmu->dev, dma)) {
-			__free_page(page);
+			__iommu_free_page(page);
 			return NULL;
 		}
 
 		if (!smmu_dma_addr_valid(smmu, dma)) {
 			dma_unmap_page(smmu->dev, dma, SMMU_SIZE_PT,
 				       DMA_TO_DEVICE);
-			__free_page(page);
+			__iommu_free_page(page);
 			return NULL;
 		}
 
@@ -649,7 +651,7 @@ static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
 		tegra_smmu_set_pde(as, iova, 0);
 
 		dma_unmap_page(smmu->dev, pte_dma, SMMU_SIZE_PT, DMA_TO_DEVICE);
-		__free_page(page);
+		__iommu_free_page(page);
 		as->pts[pde] = NULL;
 	}
 }
@@ -688,7 +690,7 @@ static struct page *as_get_pde_page(struct tegra_smmu_as *as,
 	if (gfpflags_allow_blocking(gfp))
 		spin_unlock_irqrestore(&as->lock, *flags);
 
-	page = alloc_page(gfp | __GFP_DMA | __GFP_ZERO);
+	page = __iommu_alloc_page(gfp | __GFP_DMA);
 
 	if (gfpflags_allow_blocking(gfp))
 		spin_lock_irqsave(&as->lock, *flags);
@@ -700,7 +702,7 @@ static struct page *as_get_pde_page(struct tegra_smmu_as *as,
 	 */
 	if (as->pts[pde]) {
 		if (page)
-			__free_page(page);
+			__iommu_free_page(page);
 
 		page = as->pts[pde];
 	}
-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 09/10] iommu: observability of the IOMMU allocations

[Pasha Tatashin]

Add NR_IOMMU_PAGES into node_stat_item that counts number of pages
that are allocated by the IOMMU subsystem.

The allocations can be view per-node via:
/sys/devices/system/node/nodeN/vmstat.

For example:

$ grep iommu /sys/devices/system/node/node*/vmstat
/sys/devices/system/node/node0/vmstat:nr_iommu_pages 106025
/sys/devices/system/node/node1/vmstat:nr_iommu_pages 3464

The value is in page-count, therefore, in the above example
the iommu allocations amount to ~428M.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 drivers/iommu/iommu-pages.h | 30 ++++++++++++++++++++++++++++++
 include/linux/mmzone.h      |  3 +++
 mm/vmstat.c                 |  3 +++
 3 files changed, 36 insertions(+)

diff --git a/drivers/iommu/iommu-pages.h b/drivers/iommu/iommu-pages.h
index c412d0aaa399..7336f976b641 100644
--- a/drivers/iommu/iommu-pages.h
+++ b/drivers/iommu/iommu-pages.h
@@ -17,6 +17,30 @@
  * state can be rather large, i.e. multiple gigabytes in size.
  */
 
+/**
+ * __iommu_alloc_account - account for newly allocated page.
+ * @page: head struct page of the page.
+ * @order: order of the page
+ */
+static inline void __iommu_alloc_account(struct page *page, int order)
+{
+	const long pgcnt = 1l << order;
+
+	mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, pgcnt);
+}
+
+/**
+ * __iommu_free_account - account a page that is about to be freed.
+ * @page: head struct page of the page.
+ * @order: order of the page
+ */
+static inline void __iommu_free_account(struct page *page, int order)
+{
+	const long pgcnt = 1l << order;
+
+	mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, -pgcnt);
+}
+
 /**
  * __iommu_alloc_pages_node - allocate a zeroed page of a given order from
  * specific NUMA node.
@@ -35,6 +59,8 @@ static inline struct page *__iommu_alloc_pages_node(int nid, gfp_t gfp,
 	if (unlikely(!page))
 		return NULL;
 
+	__iommu_alloc_account(page, order);
+
 	return page;
 }
 
@@ -53,6 +79,8 @@ static inline struct page *__iommu_alloc_pages(gfp_t gfp, int order)
 	if (unlikely(!page))
 		return NULL;
 
+	__iommu_alloc_account(page, order);
+
 	return page;
 }
 
@@ -89,6 +117,7 @@ static inline void __iommu_free_pages(struct page *page, int order)
 	if (!page)
 		return;
 
+	__iommu_free_account(page, order);
 	__free_pages(page, order);
 }
 
@@ -197,6 +226,7 @@ static inline void iommu_free_pages_list(struct list_head *page)
 		struct page *p = list_entry(page->prev, struct page, lru);
 
 		list_del(&p->lru);
+		__iommu_free_account(p, 0);
 		put_page(p);
 	}
 }
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index a497f189d988..bb6bc504915a 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -203,6 +203,9 @@ enum node_stat_item {
 #endif
 	NR_PAGETABLE,		/* used for pagetables */
 	NR_SECONDARY_PAGETABLE, /* secondary pagetables, e.g. KVM pagetables */
+#ifdef CONFIG_IOMMU_SUPPORT
+	NR_IOMMU_PAGES,		/* # of pages allocated by IOMMU */
+#endif
 #ifdef CONFIG_SWAP
 	NR_SWAPCACHE,
 #endif
diff --git a/mm/vmstat.c b/mm/vmstat.c
index db79935e4a54..8507c497218b 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1242,6 +1242,9 @@ const char * const vmstat_text[] = {
 #endif
 	"nr_page_table_pages",
 	"nr_sec_page_table_pages",
+#ifdef CONFIG_IOMMU_SUPPORT
+	"nr_iommu_pages",
+#endif
 #ifdef CONFIG_SWAP
 	"nr_swapcached",
 #endif
-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v4 10/10] iommu: account IOMMU allocated memory

[Pasha Tatashin]

In order to be able to limit the amount of memory that is allocated
by IOMMU subsystem, the memory must be accounted.

Account IOMMU as part of the secondary pagetables as it was discussed
at LPC.

The value of SecPageTables now contains mmeory allocation by IOMMU
and KVM.

There is a difference between GFP_ACCOUNT and what NR_IOMMU_PAGES shows.
GFP_ACCOUNT is set only where it makes sense to charge to user
processes, i.e. IOMMU Page Tables, but there more IOMMU shared data
that should not really be charged to a specific process.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 Documentation/admin-guide/cgroup-v2.rst | 2 +-
 Documentation/filesystems/proc.rst      | 4 ++--
 drivers/iommu/iommu-pages.h             | 2 ++
 include/linux/mmzone.h                  | 2 +-
 4 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 17e6e9565156..15f80fea8df7 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1432,7 +1432,7 @@ PAGE_SIZE multiple when read back.
 	  sec_pagetables
 		Amount of memory allocated for secondary page tables,
 		this currently includes KVM mmu allocations on x86
-		and arm64.
+		and arm64 and IOMMU page tables.
 
 	  percpu (npn)
 		Amount of memory used for storing per-cpu kernel
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 104c6d047d9b..604b2dccdc5a 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -1110,8 +1110,8 @@ KernelStack
 PageTables
               Memory consumed by userspace page tables
 SecPageTables
-              Memory consumed by secondary page tables, this currently
-              currently includes KVM mmu allocations on x86 and arm64.
+              Memory consumed by secondary page tables, this currently includes
+              KVM mmu and IOMMU allocations on x86 and arm64.
 NFS_Unstable
               Always zero. Previous counted pages which had been written to
               the server, but has not been committed to stable storage.
diff --git a/drivers/iommu/iommu-pages.h b/drivers/iommu/iommu-pages.h
index 7336f976b641..e3eb93857a73 100644
--- a/drivers/iommu/iommu-pages.h
+++ b/drivers/iommu/iommu-pages.h
@@ -27,6 +27,7 @@ static inline void __iommu_alloc_account(struct page *page, int order)
 	const long pgcnt = 1l << order;
 
 	mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, pgcnt);
+	mod_lruvec_page_state(page, NR_SECONDARY_PAGETABLE, pgcnt);
 }
 
 /**
@@ -39,6 +40,7 @@ static inline void __iommu_free_account(struct page *page, int order)
 	const long pgcnt = 1l << order;
 
 	mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, -pgcnt);
+	mod_lruvec_page_state(page, NR_SECONDARY_PAGETABLE, -pgcnt);
 }
 
 /**
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index bb6bc504915a..a18edcf12d53 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -202,7 +202,7 @@ enum node_stat_item {
 	NR_KERNEL_SCS_KB,	/* measured in KiB */
 #endif
 	NR_PAGETABLE,		/* used for pagetables */
-	NR_SECONDARY_PAGETABLE, /* secondary pagetables, e.g. KVM pagetables */
+	NR_SECONDARY_PAGETABLE, /* secondary pagetables, KVM & IOMMU */
 #ifdef CONFIG_IOMMU_SUPPORT
 	NR_IOMMU_PAGES,		/* # of pages allocated by IOMMU */
 #endif
-- 
2.43.0.594.gd9cf4e227d-goog

Re: [PATCH v4 00/10] IOMMU memory observability

[Joerg Roedel]

Hi Pasha,

On Wed, Feb 07, 2024 at 05:40:52PM +0000, Pasha Tatashin wrote:
> v4:
> - Synced with v6.8-rc3 
> - Updated commit log for "iommu: account IOMMU allocated memory" as
>   suggested by Michal Koutný
> - Added more Acked-bys David Rientjes and Thierry Reding
> - Added Tested-by Bagas Sanjaya.

Thanks for these changes! To merge them I need more reviews and/or acks
from the actual iommu driver maintainers.

Thanks,

	Joerg

Re: [PATCH v4 07/10] iommu/sun50i: use page allocation function provided by iommu-pages.h

[Jernej Škrabec]

Dne sreda, 07. februar 2024 ob 18:40:59 CET je Pasha Tatashin napisal(a):
> Convert iommu/sun50i-iommu.c to use the new page allocation functions
> provided in iommu-pages.h.
> 
> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
> Acked-by: David Rientjes <rientjes@google.com>
> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>

Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

Re: [PATCH v4 09/10] iommu: observability of the IOMMU allocations

[Robin Murphy]

On 2024-02-07 5:41 pm, Pasha Tatashin wrote:
> Add NR_IOMMU_PAGES into node_stat_item that counts number of pages
> that are allocated by the IOMMU subsystem.
> 
> The allocations can be view per-node via:
> /sys/devices/system/node/nodeN/vmstat.
> 
> For example:
> 
> $ grep iommu /sys/devices/system/node/node*/vmstat
> /sys/devices/system/node/node0/vmstat:nr_iommu_pages 106025
> /sys/devices/system/node/node1/vmstat:nr_iommu_pages 3464
> 
> The value is in page-count, therefore, in the above example
> the iommu allocations amount to ~428M.
> 
> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
> Acked-by: David Rientjes <rientjes@google.com>
> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
> ---
>   drivers/iommu/iommu-pages.h | 30 ++++++++++++++++++++++++++++++
>   include/linux/mmzone.h      |  3 +++
>   mm/vmstat.c                 |  3 +++
>   3 files changed, 36 insertions(+)
> 
> diff --git a/drivers/iommu/iommu-pages.h b/drivers/iommu/iommu-pages.h
> index c412d0aaa399..7336f976b641 100644
> --- a/drivers/iommu/iommu-pages.h
> +++ b/drivers/iommu/iommu-pages.h
> @@ -17,6 +17,30 @@
>    * state can be rather large, i.e. multiple gigabytes in size.
>    */
>   
> +/**
> + * __iommu_alloc_account - account for newly allocated page.
> + * @page: head struct page of the page.
> + * @order: order of the page
> + */
> +static inline void __iommu_alloc_account(struct page *page, int order)
> +{
> +	const long pgcnt = 1l << order;
> +
> +	mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, pgcnt);
> +}
> +
> +/**
> + * __iommu_free_account - account a page that is about to be freed.
> + * @page: head struct page of the page.
> + * @order: order of the page
> + */
> +static inline void __iommu_free_account(struct page *page, int order)
> +{
> +	const long pgcnt = 1l << order;
> +
> +	mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, -pgcnt);
> +}
> +
>   /**
>    * __iommu_alloc_pages_node - allocate a zeroed page of a given order from
>    * specific NUMA node.
> @@ -35,6 +59,8 @@ static inline struct page *__iommu_alloc_pages_node(int nid, gfp_t gfp,
>   	if (unlikely(!page))
>   		return NULL;
>   
> +	__iommu_alloc_account(page, order);
> +
>   	return page;
>   }
>   
> @@ -53,6 +79,8 @@ static inline struct page *__iommu_alloc_pages(gfp_t gfp, int order)
>   	if (unlikely(!page))
>   		return NULL;
>   
> +	__iommu_alloc_account(page, order);
> +
>   	return page;
>   }
>   
> @@ -89,6 +117,7 @@ static inline void __iommu_free_pages(struct page *page, int order)
>   	if (!page)
>   		return;
>   
> +	__iommu_free_account(page, order);
>   	__free_pages(page, order);
>   }
>   
> @@ -197,6 +226,7 @@ static inline void iommu_free_pages_list(struct list_head *page)
>   		struct page *p = list_entry(page->prev, struct page, lru);
>   
>   		list_del(&p->lru);
> +		__iommu_free_account(p, 0);

I'm keen to revive my patches to hook up freelist support in 
io-pgtable-arm, which would then mean a chance of higher-order GFP_COMP 
allocations coming back though this path - do you have any pointers for 
what I'd have to do here to make it work properly?

Thanks,
Robin.

>   		put_page(p);
>   	}
>   }
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index a497f189d988..bb6bc504915a 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -203,6 +203,9 @@ enum node_stat_item {
>   #endif
>   	NR_PAGETABLE,		/* used for pagetables */
>   	NR_SECONDARY_PAGETABLE, /* secondary pagetables, e.g. KVM pagetables */
> +#ifdef CONFIG_IOMMU_SUPPORT
> +	NR_IOMMU_PAGES,		/* # of pages allocated by IOMMU */
> +#endif
>   #ifdef CONFIG_SWAP
>   	NR_SWAPCACHE,
>   #endif
> diff --git a/mm/vmstat.c b/mm/vmstat.c
> index db79935e4a54..8507c497218b 100644
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -1242,6 +1242,9 @@ const char * const vmstat_text[] = {
>   #endif
>   	"nr_page_table_pages",
>   	"nr_sec_page_table_pages",
> +#ifdef CONFIG_IOMMU_SUPPORT
> +	"nr_iommu_pages",
> +#endif
>   #ifdef CONFIG_SWAP
>   	"nr_swapcached",
>   #endif

Re: [PATCH v4 05/10] iommu/exynos: use page allocation function provided by iommu-pages.h

[Marek Szyprowski]

On 07.02.2024 18:40, Pasha Tatashin wrote:
> Convert iommu/exynos-iommu.c to use the new page allocation functions
> provided in iommu-pages.h.
>
> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
> Acked-by: David Rientjes <rientjes@google.com>
> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>   drivers/iommu/exynos-iommu.c | 14 ++++++++------
>   1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index 2c6e9094f1e9..3eab0ae65a4f 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -22,6 +22,8 @@
>   #include <linux/pm_runtime.h>
>   #include <linux/slab.h>
>   
> +#include "iommu-pages.h"
> +
>   typedef u32 sysmmu_iova_t;
>   typedef u32 sysmmu_pte_t;
>   static struct iommu_domain exynos_identity_domain;
> @@ -900,11 +902,11 @@ static struct iommu_domain *exynos_iommu_domain_alloc_paging(struct device *dev)
>   	if (!domain)
>   		return NULL;
>   
> -	domain->pgtable = (sysmmu_pte_t *)__get_free_pages(GFP_KERNEL, 2);
> +	domain->pgtable = iommu_alloc_pages(GFP_KERNEL, 2);
>   	if (!domain->pgtable)
>   		goto err_pgtable;
>   
> -	domain->lv2entcnt = (short *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
> +	domain->lv2entcnt = iommu_alloc_pages(GFP_KERNEL, 1);
>   	if (!domain->lv2entcnt)
>   		goto err_counter;
>   
> @@ -930,9 +932,9 @@ static struct iommu_domain *exynos_iommu_domain_alloc_paging(struct device *dev)
>   	return &domain->domain;
>   
>   err_lv2ent:
> -	free_pages((unsigned long)domain->lv2entcnt, 1);
> +	iommu_free_pages(domain->lv2entcnt, 1);
>   err_counter:
> -	free_pages((unsigned long)domain->pgtable, 2);
> +	iommu_free_pages(domain->pgtable, 2);
>   err_pgtable:
>   	kfree(domain);
>   	return NULL;
> @@ -973,8 +975,8 @@ static void exynos_iommu_domain_free(struct iommu_domain *iommu_domain)
>   					phys_to_virt(base));
>   		}
>   
> -	free_pages((unsigned long)domain->pgtable, 2);
> -	free_pages((unsigned long)domain->lv2entcnt, 1);
> +	iommu_free_pages(domain->pgtable, 2);
> +	iommu_free_pages(domain->lv2entcnt, 1);
>   	kfree(domain);
>   }
>   

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Re: [PATCH v4 01/10] iommu/vt-d: add wrapper functions for page allocations

[Robin Murphy]

On 2024-02-07 5:40 pm, Pasha Tatashin wrote:
[...]> diff --git a/drivers/iommu/iommu-pages.h 
b/drivers/iommu/iommu-pages.h
> new file mode 100644
> index 000000000000..c412d0aaa399
> --- /dev/null
> +++ b/drivers/iommu/iommu-pages.h
> @@ -0,0 +1,204 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2024, Google LLC.
> + * Pasha Tatashin <pasha.tatashin@soleen.com>
> + */
> +
> +#ifndef __IOMMU_PAGES_H
> +#define __IOMMU_PAGES_H
> +
> +#include <linux/vmstat.h>
> +#include <linux/gfp.h>
> +#include <linux/mm.h>
> +
> +/*
> + * All page allocation that are performed in the IOMMU subsystem must use one of

"All page allocations" is too broad; As before, this is only about 
pagetable allocations, or I guess for the full nuance, allocations of 
pagetables and other per-iommu_domain configuration structures which are 
reasonable to report as "pagetables" to userspace.

> + * the functions below.  This is necessary for the proper accounting as IOMMU
> + * state can be rather large, i.e. multiple gigabytes in size.
> + */
> +
> +/**
> + * __iommu_alloc_pages_node - allocate a zeroed page of a given order from
> + * specific NUMA node.
> + * @nid: memory NUMA node id
> + * @gfp: buddy allocator flags
> + * @order: page order
> + *
> + * returns the head struct page of the allocated page.
> + */
> +static inline struct page *__iommu_alloc_pages_node(int nid, gfp_t gfp,
> +						    int order)
> +{
> +	struct page *page;
> +
> +	page = alloc_pages_node(nid, gfp | __GFP_ZERO, order);
> +	if (unlikely(!page))
> +		return NULL;
> +
> +	return page;
> +}

All 3 invocations of this only use the returned struct page to trivially 
derive page_address(), so we really don't need it; just clean up these 
callsites a bit more.

> +
> +/**
> + * __iommu_alloc_pages - allocate a zeroed page of a given order.
> + * @gfp: buddy allocator flags
> + * @order: page order
> + *
> + * returns the head struct page of the allocated page.
> + */
> +static inline struct page *__iommu_alloc_pages(gfp_t gfp, int order)
> +{
> +	struct page *page;
> +
> +	page = alloc_pages(gfp | __GFP_ZERO, order);
> +	if (unlikely(!page))
> +		return NULL;
> +
> +	return page;
> +}

Same for the single invocation of this one.

> +
> +/**
> + * __iommu_alloc_page_node - allocate a zeroed page at specific NUMA node.
> + * @nid: memory NUMA node id
> + * @gfp: buddy allocator flags
> + *
> + * returns the struct page of the allocated page.
> + */
> +static inline struct page *__iommu_alloc_page_node(int nid, gfp_t gfp)
> +{
> +	return __iommu_alloc_pages_node(nid, gfp, 0);
> +}

There are no users of this at all.

> +
> +/**
> + * __iommu_alloc_page - allocate a zeroed page
> + * @gfp: buddy allocator flags
> + *
> + * returns the struct page of the allocated page.
> + */
> +static inline struct page *__iommu_alloc_page(gfp_t gfp)
> +{
> +	return __iommu_alloc_pages(gfp, 0);
> +}
> +
> +/**
> + * __iommu_free_pages - free page of a given order
> + * @page: head struct page of the page
> + * @order: page order
> + */
> +static inline void __iommu_free_pages(struct page *page, int order)
> +{
> +	if (!page)
> +		return;
> +
> +	__free_pages(page, order);
> +}
> +
> +/**
> + * __iommu_free_page - free page
> + * @page: struct page of the page
> + */
> +static inline void __iommu_free_page(struct page *page)
> +{
> +	__iommu_free_pages(page, 0);
> +}

Beyond one more trivial Intel cleanup for __iommu_alloc_pages(), these 3 
are then only used by tegra-smmu, so honestly I'd be inclined to just 
open-code there page_address()/virt_to_page() conversions as appropriate 
there (once again I think the whole thing could in fact be refactored to 
not use struct pages at all because all it's ever ultimately doing with 
them is page_address(), but that would be a bigger job so definitely 
out-of-scope for this series).

> +
> +/**
> + * iommu_alloc_pages_node - allocate a zeroed page of a given order from
> + * specific NUMA node.
> + * @nid: memory NUMA node id
> + * @gfp: buddy allocator flags
> + * @order: page order
> + *
> + * returns the virtual address of the allocated page
> + */
> +static inline void *iommu_alloc_pages_node(int nid, gfp_t gfp, int order)
> +{
> +	struct page *page = __iommu_alloc_pages_node(nid, gfp, order);
> +
> +	if (unlikely(!page))
> +		return NULL;

As a general point I'd prefer to fold these checks into the accounting 
function itself rather than repeat them all over.

> +
> +	return page_address(page);
> +}
> +
> +/**
> + * iommu_alloc_pages - allocate a zeroed page of a given order
> + * @gfp: buddy allocator flags
> + * @order: page order
> + *
> + * returns the virtual address of the allocated page
> + */
> +static inline void *iommu_alloc_pages(gfp_t gfp, int order)
> +{
> +	struct page *page = __iommu_alloc_pages(gfp, order);
> +
> +	if (unlikely(!page))
> +		return NULL;
> +
> +	return page_address(page);
> +}
> +
> +/**
> + * iommu_alloc_page_node - allocate a zeroed page at specific NUMA node.
> + * @nid: memory NUMA node id
> + * @gfp: buddy allocator flags
> + *
> + * returns the virtual address of the allocated page
> + */
> +static inline void *iommu_alloc_page_node(int nid, gfp_t gfp)
> +{
> +	return iommu_alloc_pages_node(nid, gfp, 0);
> +}

TBH I'm not entirely convinced that saving 4 characters per invocation 
times 11 invocations makes this wrapper worthwhile :/

> +
> +/**
> + * iommu_alloc_page - allocate a zeroed page
> + * @gfp: buddy allocator flags
> + *
> + * returns the virtual address of the allocated page
> + */
> +static inline void *iommu_alloc_page(gfp_t gfp)
> +{
> +	return iommu_alloc_pages(gfp, 0);
> +}
> +
> +/**
> + * iommu_free_pages - free page of a given order
> + * @virt: virtual address of the page to be freed.
> + * @order: page order
> + */
> +static inline void iommu_free_pages(void *virt, int order)
> +{
> +	if (!virt)
> +		return;
> +
> +	__iommu_free_pages(virt_to_page(virt), order);
> +}
> +
> +/**
> + * iommu_free_page - free page
> + * @virt: virtual address of the page to be freed.
> + */
> +static inline void iommu_free_page(void *virt)
> +{
> +	iommu_free_pages(virt, 0);
> +}
> +
> +/**
> + * iommu_free_pages_list - free a list of pages.
> + * @page: the head of the lru list to be freed.
> + *
> + * There are no locking requirement for these pages, as they are going to be
> + * put on a free list as soon as refcount reaches 0. Pages are put on this LRU
> + * list once they are removed from the IOMMU page tables. However, they can
> + * still be access through debugfs.
> + */
> +static inline void iommu_free_pages_list(struct list_head *page)

Nit: I'd be inclined to call this iommu_put_pages_list for consistency.

> +{
> +	while (!list_empty(page)) {
> +		struct page *p = list_entry(page->prev, struct page, lru);
> +
> +		list_del(&p->lru);
> +		put_page(p);
> +	}
> +}

I realise now you've also missed the common freelist freeing sites in 
iommu-dma.

Thanks,
Robin.

> +
> +#endif	/* __IOMMU_PAGES_H */

Re: [PATCH v4 05/10] iommu/exynos: use page allocation function provided by iommu-pages.h

[Pasha Tatashin]

On Fri, Feb 9, 2024 at 6:26 AM Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
>
> On 07.02.2024 18:40, Pasha Tatashin wrote:
> > Convert iommu/exynos-iommu.c to use the new page allocation functions
> > provided in iommu-pages.h.
> >
> > Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
> > Acked-by: David Rientjes <rientjes@google.com>
> > Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>

Thank you,
Pasha

Re: [PATCH v4 07/10] iommu/sun50i: use page allocation function provided by iommu-pages.h

[Pasha Tatashin]

On Fri, Feb 9, 2024 at 5:55 AM Jernej Škrabec <jernej.skrabec@gmail.com> wrote:
>
> Dne sreda, 07. februar 2024 ob 18:40:59 CET je Pasha Tatashin napisal(a):
> > Convert iommu/sun50i-iommu.c to use the new page allocation functions
> > provided in iommu-pages.h.
> >
> > Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
> > Acked-by: David Rientjes <rientjes@google.com>
> > Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
>
> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Thank you,
Pasha

Re: [PATCH v4 01/10] iommu/vt-d: add wrapper functions for page allocations

[Pasha Tatashin]

Hi Robin,

Thank you for reviewing this.

> > +#ifndef __IOMMU_PAGES_H
> > +#define __IOMMU_PAGES_H
> > +
> > +#include <linux/vmstat.h>
> > +#include <linux/gfp.h>
> > +#include <linux/mm.h>
> > +
> > +/*
> > + * All page allocation that are performed in the IOMMU subsystem must use one of
>
> "All page allocations" is too broad; As before, this is only about
> pagetable allocations, or I guess for the full nuance, allocations of
> pagetables and other per-iommu_domain configuration structures which are
> reasonable to report as "pagetables" to userspace.

I will update the comment.


>
> > + * the functions below.  This is necessary for the proper accounting as IOMMU
> > + * state can be rather large, i.e. multiple gigabytes in size.
> > + */
> > +
> > +/**
> > + * __iommu_alloc_pages_node - allocate a zeroed page of a given order from
> > + * specific NUMA node.
> > + * @nid: memory NUMA node id
> > + * @gfp: buddy allocator flags
> > + * @order: page order
> > + *
> > + * returns the head struct page of the allocated page.
> > + */
> > +static inline struct page *__iommu_alloc_pages_node(int nid, gfp_t gfp,
> > +                                                 int order)
> > +{
> > +     struct page *page;
> > +
> > +     page = alloc_pages_node(nid, gfp | __GFP_ZERO, order);
> > +     if (unlikely(!page))
> > +             return NULL;
> > +
> > +     return page;
> > +}
>
> All 3 invocations of this only use the returned struct page to trivially
> derive page_address(), so we really don't need it; just clean up these
> callsites a bit more.

I will remove this function, and update all invocations to use
iommu_alloc_pages_node() directly.


> > + * __iommu_alloc_pages - allocate a zeroed page of a given order.
> > + * @gfp: buddy allocator flags
> > + * @order: page order
> > + *
> > + * returns the head struct page of the allocated page.
> > + */
> > +static inline struct page *__iommu_alloc_pages(gfp_t gfp, int order)
> > +{
> > +     struct page *page;
> > +
> > +     page = alloc_pages(gfp | __GFP_ZERO, order);
> > +     if (unlikely(!page))
> > +             return NULL;
> > +
> > +     return page;
> > +}
>
> Same for the single invocation of this one.

I kept this function, but removed __iommu_alloc_page() that depends on
it. This is because tegra-smmu needs a "struct page" allocator.

>
> > +
> > +/**
> > + * __iommu_alloc_page_node - allocate a zeroed page at specific NUMA node.
> > + * @nid: memory NUMA node id
> > + * @gfp: buddy allocator flags
> > + *
> > + * returns the struct page of the allocated page.
> > + */
> > +static inline struct page *__iommu_alloc_page_node(int nid, gfp_t gfp)
> > +{
> > +     return __iommu_alloc_pages_node(nid, gfp, 0);
> > +}
>
> There are no users of this at all.

Yes, I added it just for completeness, I will remove it.


> > + * __iommu_alloc_page - allocate a zeroed page
> > + * @gfp: buddy allocator flags
> > + *
> > + * returns the struct page of the allocated page.
> > + */
> > +static inline struct page *__iommu_alloc_page(gfp_t gfp)
> > +{
> > +     return __iommu_alloc_pages(gfp, 0);
> > +}
> > +
> > +/**
> > + * __iommu_free_pages - free page of a given order
> > + * @page: head struct page of the page
> > + * @order: page order
> > + */
> > +static inline void __iommu_free_pages(struct page *page, int order)
> > +{
> > +     if (!page)
> > +             return;
> > +
> > +     __free_pages(page, order);
> > +}
> > +
> > +/**
> > + * __iommu_free_page - free page
> > + * @page: struct page of the page
> > + */
> > +static inline void __iommu_free_page(struct page *page)
> > +{
> > +     __iommu_free_pages(page, 0);
> > +}
>
> Beyond one more trivial Intel cleanup for __iommu_alloc_pages(), these 3
> are then only used by tegra-smmu, so honestly I'd be inclined to just
> open-code there page_address()/virt_to_page() conversions as appropriate
> there (once again I think the whole thing could in fact be refactored to
> not use struct pages at all because all it's ever ultimately doing with
> them is page_address(), but that would be a bigger job so definitely
> out-of-scope for this series).

I removed __iommu_free_page(), but kept __iommu_free_pages() variant.

>
> > +
> > +/**
> > + * iommu_alloc_pages_node - allocate a zeroed page of a given order from
> > + * specific NUMA node.
> > + * @nid: memory NUMA node id
> > + * @gfp: buddy allocator flags
> > + * @order: page order
> > + *
> > + * returns the virtual address of the allocated page
> > + */
> > +static inline void *iommu_alloc_pages_node(int nid, gfp_t gfp, int order)
> > +{
> > +     struct page *page = __iommu_alloc_pages_node(nid, gfp, order);
> > +
> > +     if (unlikely(!page))
> > +             return NULL;
>
> As a general point I'd prefer to fold these checks into the accounting
> function itself rather than repeat them all over.

For the free functions this saves a few cycles by not repeating this
check again inside __free_pages(), to keep things symmetrical it makes
sense to keep __iomu_free_account and __iomu_alloc_account the same.
With the other clean-up there are not that many of these checks left.

> > + */
> > +static inline void *iommu_alloc_page_node(int nid, gfp_t gfp)
> > +{
> > +     return iommu_alloc_pages_node(nid, gfp, 0);
> > +}
>
> TBH I'm not entirely convinced that saving 4 characters per invocation
> times 11 invocations makes this wrapper worthwhile :/

Let's keep them. After the clean-up that you suggested, there are
fewer functions left in this file, but I think that it is cleaner to
keep these remaining, as it is beneficial to easily distinguish when
exactly one page is allocated vs when multiple are allocated via code
search.


> > + *
> > + * There are no locking requirement for these pages, as they are going to be
> > + * put on a free list as soon as refcount reaches 0. Pages are put on this LRU
> > + * list once they are removed from the IOMMU page tables. However, they can
> > + * still be access through debugfs.
> > + */
> > +static inline void iommu_free_pages_list(struct list_head *page)
>
> Nit: I'd be inclined to call this iommu_put_pages_list for consistency.

I will rename it to iommu_put_pages_list(), indeed a better name.

>
> > +{
> > +     while (!list_empty(page)) {
> > +             struct page *p = list_entry(page->prev, struct page, lru);
> > +
> > +             list_del(&p->lru);
> > +             put_page(p);
> > +     }
> > +}
>
> I realise now you've also missed the common freelist freeing sites in
> iommu-dma.

Ah yes, thank you for catching that. I will fix it.

Pasha

Re: [PATCH v4 01/10] iommu/vt-d: add wrapper functions for page allocations

[Robin Murphy]

On 10/02/2024 2:21 am, Pasha Tatashin wrote:
[...]
>>> +/**
>>> + * iommu_alloc_pages_node - allocate a zeroed page of a given order from
>>> + * specific NUMA node.
>>> + * @nid: memory NUMA node id
>>> + * @gfp: buddy allocator flags
>>> + * @order: page order
>>> + *
>>> + * returns the virtual address of the allocated page
>>> + */
>>> +static inline void *iommu_alloc_pages_node(int nid, gfp_t gfp, int order)
>>> +{
>>> +     struct page *page = __iommu_alloc_pages_node(nid, gfp, order);
>>> +
>>> +     if (unlikely(!page))
>>> +             return NULL;
>>
>> As a general point I'd prefer to fold these checks into the accounting
>> function itself rather than repeat them all over.
> 
> For the free functions this saves a few cycles by not repeating this
> check again inside __free_pages(), to keep things symmetrical it makes
> sense to keep __iomu_free_account and __iomu_alloc_account the same.
> With the other clean-up there are not that many of these checks left.

__free_pages() doesn't accept NULL, so __iommu_free_pages() shouldn't 
need a check; free_pages() does, but correspondingly iommu_free_pages() 
needs its own check up-front to avoid virt_to_page(NULL); either way it 
means there are no callers of iommu_free_account() who should be passing 
NULL.

The VA-returning allocators of course need to avoid page_address(NULL), 
so I clearly made this comment in the wrong place to begin with, oops. 
In the end I guess that will leave __iommu_alloc_pages() as the only 
caller of iommu_alloc_account() who doesn't already need to handle their 
own NULL. OK, I'm convinced, apologies for having to bounce it off you 
to work it through :)

>>> + */
>>> +static inline void *iommu_alloc_page_node(int nid, gfp_t gfp)
>>> +{
>>> +     return iommu_alloc_pages_node(nid, gfp, 0);
>>> +}
>>
>> TBH I'm not entirely convinced that saving 4 characters per invocation
>> times 11 invocations makes this wrapper worthwhile :/
> 
> Let's keep them. After the clean-up that you suggested, there are
> fewer functions left in this file, but I think that it is cleaner to
> keep these remaining, as it is beneficial to easily distinguish when
> exactly one page is allocated vs when multiple are allocated via code
> search.

But is it, really? It's not at all obvious to me *why* it would be 
significantly interesting to distinguish fixed order-0 allocations from 
higher-order or variable-order (which may still be 0) ones. After all, 
there's no regular alloc_page_node() wrapper, yet plenty more callers of 
alloc_pages_node(..., 0) :/

Thanks,
Robin.

Re: [PATCH v4 01/10] iommu/vt-d: add wrapper functions for page allocations

[Pasha Tatashin]

> >>> + */
> >>> +static inline void *iommu_alloc_page_node(int nid, gfp_t gfp)
> >>> +{
> >>> +     return iommu_alloc_pages_node(nid, gfp, 0);
> >>> +}
> >>
> >> TBH I'm not entirely convinced that saving 4 characters per invocation
> >> times 11 invocations makes this wrapper worthwhile :/
> >
> > Let's keep them. After the clean-up that you suggested, there are
> > fewer functions left in this file, but I think that it is cleaner to
> > keep these remaining, as it is beneficial to easily distinguish when
> > exactly one page is allocated vs when multiple are allocated via code
> > search.
>
> But is it, really? It's not at all obvious to me *why* it would be
> significantly interesting to distinguish fixed order-0 allocations from
> higher-order or variable-order (which may still be 0) ones. After all,
> there's no regular alloc_page_node() wrapper, yet plenty more callers of
> alloc_pages_node(..., 0) :/

The pages that are allocated with order > 0 cannot be freed using
iommu_put_pages_list(), without messing up refcounts in the tail
pages. I think having a dedicated function that guarantees order = 0
pages allocation makes it easier for the reviewer to follow the code,
and ensures that only these pages are put on the freelist.

Even in the existing code, the order=0 allocation is wrapped in the
*alloc_pgtable_page() function.

Pasha


>
> Thanks,
> Robin.