percpu: more flexibility for @dyn_size of pcpu_setup_first_chunk()

Impact: cleanup, more flexibility for first chunk init

Non-negative @dyn_size used to be allowed iff @unit_size wasn't auto.
This restriction stemmed from implementation detail and made things a
bit less intuitive.  This patch allows @dyn_size to be specified
regardless of @unit_size and swaps the positions of @dyn_size and
@unit_size so that the parameter order makes more sense (static,
reserved and dyn sizes followed by enclosing unit_size).

While at it, add @unit_size >= PCPU_MIN_UNIT_SIZE sanity check.

Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 6 insertions, 7 deletions

diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index efa615f2bf43..e41c51f6ada1 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -233,8 +233,8 @@ proceed:
                 "%zu bytes\n", vm.addr, static_size);
 
         ret = pcpu_setup_first_chunk(pcpur_get_page, static_size,
-                                     PERCPU_FIRST_CHUNK_RESERVE,
-                                     PMD_SIZE, dyn_size, vm.addr, NULL);
+                                     PERCPU_FIRST_CHUNK_RESERVE, dyn_size,
+                                     PMD_SIZE, vm.addr, NULL);
         goto out_free_ar;
 
 enomem:
@@ -315,9 +315,8 @@ static ssize_t __init setup_pcpu_embed(size_t static_size)
                 pcpue_size >> PAGE_SHIFT, pcpue_ptr, static_size);
 
         return pcpu_setup_first_chunk(pcpue_get_page, static_size,
-                                      PERCPU_FIRST_CHUNK_RESERVE,
-                                      pcpue_unit_size, dyn_size,
-                                      pcpue_ptr, NULL);
+                                      PERCPU_FIRST_CHUNK_RESERVE, dyn_size,
+                                      pcpue_unit_size, pcpue_ptr, NULL);
 }
 
 /*
@@ -375,8 +374,8 @@ static ssize_t __init setup_pcpu_4k(size_t static_size)
                 pcpu4k_nr_static_pages, static_size);
 
         ret = pcpu_setup_first_chunk(pcpu4k_get_page, static_size,
-                                     PERCPU_FIRST_CHUNK_RESERVE, -1, -1, NULL,
-                                     pcpu4k_populate_pte);
+                                     PERCPU_FIRST_CHUNK_RESERVE, -1,
+                                     -1, NULL, pcpu4k_populate_pte);
         goto out_free_ar;
 
 enomem: