Re: [PATCH 1/3] iommu/io-pgtable-arm: Prepare for modularization

[Robin Murphy]

On 2020-12-18 08:38, Isaac J. Manjarres wrote:
The io-pgtable-arm and io-pgtable-arm-v7s source files will
be compiled as separate modules, along with the io-pgtable
source. Export the symbols for the io-pgtable init function
structures for the io-pgtable module to use.

In my current build tree, the io-pgtable glue itself is a whopping 379 
bytes of code and data - is there really any benefit to all the 
additional overhead of making that modular? Given the number of 
different users (including AMD now), I think at this point we should 
start considering this as part of the IOMMU core, and just tweak the 
interface such that formats can register their own init_fns dynamically 
instead of the static array that's always horrible.

Robin.

Signed-off-by: Isaac J. Manjarres <isa...@codeaurora.org>
---
  drivers/iommu/io-pgtable-arm-v7s.c | 4 ++++
  drivers/iommu/io-pgtable-arm.c     | 8 ++++++++
  2 files changed, 12 insertions(+)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c 
b/drivers/iommu/io-pgtable-arm-v7s.c
index 1d92ac9..f062c1c 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -28,6 +28,7 @@
  #include <linux/iommu.h>
  #include <linux/kernel.h>
  #include <linux/kmemleak.h>
+#include <linux/module.h>
  #include <linux/sizes.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>
@@ -839,6 +840,7 @@ struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = {
        .alloc  = arm_v7s_alloc_pgtable,
        .free   = arm_v7s_free_pgtable,
  };
+EXPORT_SYMBOL_GPL(io_pgtable_arm_v7s_init_fns);
  
  #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST
  
@@ -984,3 +986,5 @@ static int __init arm_v7s_do_selftests(void)
  }
  subsys_initcall(arm_v7s_do_selftests);
  #endif
+
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 87def58..2623d57 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -13,6 +13,7 @@
  #include <linux/bitops.h>
  #include <linux/io-pgtable.h>
  #include <linux/kernel.h>
+#include <linux/module.h>
  #include <linux/sizes.h>
  #include <linux/slab.h>
  #include <linux/types.h>
@@ -1047,26 +1048,31 @@ struct io_pgtable_init_fns 
io_pgtable_arm_64_lpae_s1_init_fns = {
        .alloc  = arm_64_lpae_alloc_pgtable_s1,
        .free   = arm_lpae_free_pgtable,
  };
+EXPORT_SYMBOL_GPL(io_pgtable_arm_64_lpae_s1_init_fns);
  
  struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = {
        .alloc  = arm_64_lpae_alloc_pgtable_s2,
        .free   = arm_lpae_free_pgtable,
  };
+EXPORT_SYMBOL_GPL(io_pgtable_arm_64_lpae_s2_init_fns);
  
  struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns = {
        .alloc  = arm_32_lpae_alloc_pgtable_s1,
        .free   = arm_lpae_free_pgtable,
  };
+EXPORT_SYMBOL_GPL(io_pgtable_arm_32_lpae_s1_init_fns);
  
  struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = {
        .alloc  = arm_32_lpae_alloc_pgtable_s2,
        .free   = arm_lpae_free_pgtable,
  };
+EXPORT_SYMBOL_GPL(io_pgtable_arm_32_lpae_s2_init_fns);
  
  struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns = {
        .alloc  = arm_mali_lpae_alloc_pgtable,
        .free   = arm_lpae_free_pgtable,
  };
+EXPORT_SYMBOL_GPL(io_pgtable_arm_mali_lpae_init_fns);
  
  #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE_SELFTEST
  
@@ -1252,3 +1258,5 @@ static int __init arm_lpae_do_selftests(void)
  }
  subsys_initcall(arm_lpae_do_selftests);
  #endif
+
+MODULE_LICENSE("GPL v2");