From: "Isaac J. Manjarres" <isaacm@codeaurora.org>
To: iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, freedreno@lists.freedesktop.org,
dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org
Cc: "Isaac J. Manjarres" <isaacm@codeaurora.org>,
will@kernel.org, joro@8bytes.org, pdaly@codeaurora.org,
pratikp@codeaurora.org, kernel-team@android.com,
robin.murphy@arm.com
Subject: [PATCH v2 2/7] iommu/io-pgtable: Add refcounting for io-pgtable format modules
Date: Mon, 21 Dec 2020 16:44:31 -0800 [thread overview]
Message-ID: <1608597876-32367-3-git-send-email-isaacm@codeaurora.org> (raw)
In-Reply-To: <1608597876-32367-1-git-send-email-isaacm@codeaurora.org>
In preparation for modularizing io-pgtable formats, add support
for reference counting the io-pgtable format modules to ensure
that the modules are not unloaded while they are in use.
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
---
drivers/iommu/io-pgtable-arm-v7s.c | 1 +
drivers/iommu/io-pgtable-arm.c | 5 +++++
drivers/iommu/io-pgtable.c | 12 ++++++++++--
include/linux/io-pgtable.h | 2 ++
4 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 89aad2f..a5cb755a 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -840,6 +840,7 @@ static struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = {
.fmt = ARM_V7S,
.alloc = arm_v7s_alloc_pgtable,
.free = arm_v7s_free_pgtable,
+ .owner = THIS_MODULE,
};
#ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index ff0ea2f..e8b1e34 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -1049,26 +1049,31 @@ static struct io_pgtable_init_fns io_pgtable_arm_lpae_init_fns[] = {
.fmt = ARM_32_LPAE_S1,
.alloc = arm_32_lpae_alloc_pgtable_s1,
.free = arm_lpae_free_pgtable,
+ .owner = THIS_MODULE,
},
{
.fmt = ARM_32_LPAE_S2,
.alloc = arm_32_lpae_alloc_pgtable_s2,
.free = arm_lpae_free_pgtable,
+ .owner = THIS_MODULE,
},
{
.fmt = ARM_64_LPAE_S1,
.alloc = arm_64_lpae_alloc_pgtable_s1,
.free = arm_lpae_free_pgtable,
+ .owner = THIS_MODULE,
},
{
.fmt = ARM_64_LPAE_S2,
.alloc = arm_64_lpae_alloc_pgtable_s2,
.free = arm_lpae_free_pgtable,
+ .owner = THIS_MODULE,
},
{
.fmt = ARM_MALI_LPAE,
.alloc = arm_mali_lpae_alloc_pgtable,
.free = arm_lpae_free_pgtable,
+ .owner = THIS_MODULE,
},
};
diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c
index 2c6eb2e..cc83542 100644
--- a/drivers/iommu/io-pgtable.c
+++ b/drivers/iommu/io-pgtable.c
@@ -10,6 +10,7 @@
#include <linux/bug.h>
#include <linux/io-pgtable.h>
#include <linux/kernel.h>
+#include <linux/module.h>
#include <linux/rwlock.h>
#include <linux/slab.h>
#include <linux/types.h>
@@ -52,9 +53,14 @@ struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
if (!fns)
return NULL;
+ if (!try_module_get(fns->owner))
+ return NULL;
+
iop = fns->alloc(cfg, cookie);
- if (!iop)
+ if (!iop) {
+ module_put(fns->owner);
return NULL;
+ }
iop->fmt = fmt;
iop->cookie = cookie;
@@ -79,8 +85,10 @@ void free_io_pgtable_ops(struct io_pgtable_ops *ops)
iop = io_pgtable_ops_to_pgtable(ops);
io_pgtable_tlb_flush_all(iop);
fns = io_pgtable_get_init_fns(iop->fmt);
- if (fns)
+ if (fns) {
fns->free(iop);
+ module_put(fns->owner);
+ }
}
EXPORT_SYMBOL_GPL(free_io_pgtable_ops);
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index 45b367ce..a03b262 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -169,11 +169,13 @@ struct io_pgtable_ops {
* @fmt: The page table format.
* @alloc: Allocate a set of page tables described by cfg.
* @free: Free the page tables associated with iop.
+ * @owner: Driver module providing these ops.
*/
struct io_pgtable_init_fns {
enum io_pgtable_fmt fmt;
struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
void (*free)(struct io_pgtable *iop);
+ struct module *owner;
};
/**
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2020-12-22 0:46 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-22 0:44 [RFC PATCH v2 0/7] iommu: Permit modular builds of io-pgtable drivers Isaac J. Manjarres
2020-12-22 0:44 ` [PATCH v2 1/7] iommu/io-pgtable: Introduce dynamic io-pgtable fmt registration Isaac J. Manjarres
2020-12-22 19:27 ` Robin Murphy
2020-12-22 19:54 ` isaacm
2020-12-23 13:44 ` Robin Murphy
2020-12-23 15:14 ` isaacm
2020-12-23 15:38 ` Georgi Djakov
2020-12-23 19:17 ` kernel test robot
2020-12-22 0:44 ` Isaac J. Manjarres [this message]
2020-12-22 0:44 ` [PATCH v2 3/7] iommu/arm-smmu: Add dependency on io-pgtable format modules Isaac J. Manjarres
2020-12-22 19:27 ` Robin Murphy
2020-12-22 19:49 ` isaacm
2020-12-23 13:05 ` Robin Murphy
2020-12-23 15:10 ` isaacm
2020-12-22 0:44 ` [PATCH v2 4/7] iommu/arm-smmu-v3: Add dependency on io-pgtable-arm format module Isaac J. Manjarres
2020-12-22 0:44 ` [PATCH v2 5/7] drm/msm: " Isaac J. Manjarres
2021-01-18 21:16 ` Rob Clark
2021-01-18 21:39 ` Will Deacon
2021-01-19 17:19 ` Rob Clark
2020-12-22 0:44 ` [PATCH v2 6/7] drm/panfrost: " Isaac J. Manjarres
2020-12-22 0:44 ` [PATCH v2 7/7] iommu/io-pgtable-arm: Allow building modular io-pgtable fmts Isaac J. Manjarres
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