isci: pad stp and smp request sizes

Ross says:
 "The memory allocation for these requests doesn’t take into account the
  additional memory needed when the code in
  scic_sds_s[mst]p_request_assign_buffers() shifts the struct
  scu_task_context so that it is cache line aligned:

  In an example from my machine, total buffer that I’ve given to SCIC goes
  from 0x410024566f84 to 0x410024567308.  From this same example, this
  call shifts my task_context_buffer from 0x410024567208 to
  0x410024567240.

  This means that the task_context_buffer that used to range from
  0x410024567208 to 0x410024567308 instead now goes from 0x410024567240 to
  0x410024567340.

  When the memset() call at the end of scic_task_request_construct()
  clears out this task_context_buffer, it does so from 0x410024567240 to
  0x410024567340, effectively killing whatever buffer follows this
  allocation in memory."

djbw:
Use the kernel's PTR_ALIGN instead of
scic_sds_request_align_task_context_buffer() and SMP_CACHE_BYTES instead of
the local CACHE_LINE_SIZE definition.

TODO: These allocations really want to be better defined in a union rather
than opaque buffers carved up by macros.

Reported-by: Ross Zwisler <ross.zwisler@intel.com>
Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

4 files changed, 24 insertions, 51 deletions

diff --git a/drivers/scsi/isci/core/scic_sds_request.c b/drivers/scsi/isci/core/scic_sds_request.c
index 7b9ce1e878a7..00bebb9c0692 100644
--- a/drivers/scsi/isci/core/scic_sds_request.c
+++ b/drivers/scsi/isci/core/scic_sds_request.c
@@ -222,7 +222,7 @@ static u32 scic_sds_ssp_request_get_object_size(void)
         return sizeof(struct scic_sds_request)
                + scic_ssp_io_request_get_object_size()
                + sizeof(struct scu_task_context)
-               + CACHE_LINE_SIZE
+               + SMP_CACHE_BYTES
                + sizeof(struct scu_sgl_element_pair) * SCU_MAX_SGL_ELEMENT_PAIRS;
 }
 
@@ -395,13 +395,15 @@ static void scic_sds_ssp_io_request_assign_buffers(
         this_request->sgl_element_pair_buffer =
                 scic_sds_ssp_request_get_sgl_element_buffer(this_request);
         this_request->sgl_element_pair_buffer =
-                scic_sds_request_align_sgl_element_buffer(this_request->sgl_element_pair_buffer);
+                PTR_ALIGN(this_request->sgl_element_pair_buffer,
+                          sizeof(struct scu_sgl_element_pair));
 
         if (this_request->was_tag_assigned_by_user == false) {
                 this_request->task_context_buffer =
                         scic_sds_ssp_request_get_task_context_buffer(this_request);
                 this_request->task_context_buffer =
-                        scic_sds_request_align_task_context_buffer(this_request->task_context_buffer);
+                        PTR_ALIGN(this_request->task_context_buffer,
+                                  SMP_CACHE_BYTES);
         }
 }
 
@@ -638,7 +640,7 @@ static void scic_sds_ssp_task_request_assign_buffers(
                 this_request->task_context_buffer =
                         scic_sds_ssp_task_request_get_task_context_buffer(this_request);
                 this_request->task_context_buffer =
-                        scic_sds_request_align_task_context_buffer(this_request->task_context_buffer);
+                        PTR_ALIGN(this_request->task_context_buffer, SMP_CACHE_BYTES);
         }
 }
 
diff --git a/drivers/scsi/isci/core/scic_sds_request.h b/drivers/scsi/isci/core/scic_sds_request.h
index 19b6feef373e..06b53c3b0aa0 100644
--- a/drivers/scsi/isci/core/scic_sds_request.h
+++ b/drivers/scsi/isci/core/scic_sds_request.h
@@ -313,28 +313,6 @@ extern const struct scic_sds_io_request_state_handler scic_sds_smp_request_start
 #define scic_sds_request_get_task_context(request) \
         ((request)->task_context_buffer)
 
-#define CACHE_LINE_SIZE (64)
-#define scic_sds_request_align_task_context_buffer(address) \
-        ((struct scu_task_context *)(\
-                 (((unsigned long)(address)) + (CACHE_LINE_SIZE - 1)) \
-                 & ~(CACHE_LINE_SIZE - 1) \
-                 ))
-
-/**
- * scic_sds_request_align_sgl_element_buffer() -
- *
- * This macro will align the memory address so that it is correct for the SCU
- * hardware to DMA the SGL element pairs.
- */
-#define scic_sds_request_align_sgl_element_buffer(address) \
-        ((struct scu_sgl_element_pair *)(\
-                 ((char *)(address)) \
-                 + (\
-                         ((~(unsigned long)(address)) + 1) \
-                         & (sizeof(struct scu_sgl_element_pair) - 1)    \
-                         ) \
-                 ))
-
 /**
  * scic_sds_request_set_status() -
  *
diff --git a/drivers/scsi/isci/core/scic_sds_smp_request.c b/drivers/scsi/isci/core/scic_sds_smp_request.c
index 85c890630d60..962bd3994f10 100644
--- a/drivers/scsi/isci/core/scic_sds_smp_request.c
+++ b/drivers/scsi/isci/core/scic_sds_smp_request.c
@@ -80,7 +80,8 @@ u32 scic_sds_smp_request_get_object_size(void)
         return sizeof(struct scic_sds_request)
                + sizeof(struct smp_request)
                + sizeof(struct smp_response)
-               + sizeof(struct scu_task_context);
+               + sizeof(struct scu_task_context)
+               + SMP_CACHE_BYTES;
 }
 
 /**
@@ -137,7 +138,7 @@ void scic_sds_smp_request_assign_buffers(
                 this_request->task_context_buffer =
                         scic_sds_smp_request_get_task_context_buffer(this_request);
                 this_request->task_context_buffer =
-                        scic_sds_request_align_task_context_buffer(this_request->task_context_buffer);
+                        PTR_ALIGN(this_request->task_context_buffer, SMP_CACHE_BYTES);
         }
 
 }
diff --git a/drivers/scsi/isci/core/scic_sds_stp_request.c b/drivers/scsi/isci/core/scic_sds_stp_request.c
index 0f17a28dd196..8da309f81ac2 100644
--- a/drivers/scsi/isci/core/scic_sds_stp_request.c
+++ b/drivers/scsi/isci/core/scic_sds_stp_request.c
@@ -131,33 +131,25 @@ u32 scic_sds_stp_request_get_object_size(void)
                + sizeof(struct sata_fis_reg_h2d)
                + sizeof(struct sata_fis_reg_d2h)
                + sizeof(struct scu_task_context)
+               + SMP_CACHE_BYTES
                + sizeof(struct scu_sgl_element_pair) * SCU_MAX_SGL_ELEMENT_PAIRS;
 }
 
-/**
- *
- *
- *
- */
-void scic_sds_stp_request_assign_buffers(
-        struct scic_sds_request *request)
+void scic_sds_stp_request_assign_buffers(struct scic_sds_request *sci_req)
 {
-        struct scic_sds_stp_request *this_request = (struct scic_sds_stp_request *)request;
-
-        this_request->parent.command_buffer =
-                scic_sds_stp_request_get_h2d_reg_buffer(this_request);
-        this_request->parent.response_buffer =
-                scic_sds_stp_request_get_response_buffer(this_request);
-        this_request->parent.sgl_element_pair_buffer =
-                scic_sds_stp_request_get_sgl_element_buffer(this_request);
-        this_request->parent.sgl_element_pair_buffer =
-                scic_sds_request_align_sgl_element_buffer(this_request->parent.sgl_element_pair_buffer);
-
-        if (this_request->parent.was_tag_assigned_by_user == false) {
-                this_request->parent.task_context_buffer =
-                        scic_sds_stp_request_get_task_context_buffer(this_request);
-                this_request->parent.task_context_buffer =
-                        scic_sds_request_align_task_context_buffer(this_request->parent.task_context_buffer);
+        struct scic_sds_stp_request *stp_req = container_of(sci_req, typeof(*stp_req), parent);
+
+        sci_req->command_buffer = scic_sds_stp_request_get_h2d_reg_buffer(stp_req);
+        sci_req->response_buffer = scic_sds_stp_request_get_response_buffer(stp_req);
+        sci_req->sgl_element_pair_buffer = scic_sds_stp_request_get_sgl_element_buffer(stp_req);
+        sci_req->sgl_element_pair_buffer = PTR_ALIGN(sci_req->sgl_element_pair_buffer,
+                                                     sizeof(struct scu_sgl_element_pair));
+
+        if (sci_req->was_tag_assigned_by_user == false) {
+                sci_req->task_context_buffer =
+                        scic_sds_stp_request_get_task_context_buffer(stp_req);
+                sci_req->task_context_buffer = PTR_ALIGN(sci_req->task_context_buffer,
+                                                         SMP_CACHE_BYTES);
         }
 }