[PATCH v2 09/37] drm/i915/lmem: support kernel mapping

Matthew Auld
2019-06-27T20:56:47Z

From: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>

We can create LMEM objects, but we also need to support mapping them
into kernel space for internal use.

Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_pages.c | 18 ++++-
drivers/gpu/drm/i915/intel_region_lmem.c | 24 ++++++
drivers/gpu/drm/i915/intel_region_lmem.h | 6 ++
.../drm/i915/selftests/intel_memory_region.c | 77 +++++++++++++++++++
4 files changed, 121 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index b36ad269f4ea..15eaaedffc46 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -176,7 +176,9 @@ __i915_gem_object_unset_pages(struct drm_i915_gem_object *obj)
void *ptr;

ptr = page_mask_bits(obj->mm.mapping);
- if (is_vmalloc_addr(ptr))
+ if (i915_gem_object_is_lmem(obj))
+ io_mapping_unmap(ptr);
+ else if (is_vmalloc_addr(ptr))
vunmap(ptr);
else
kunmap(kmap_to_page(ptr));
@@ -235,7 +237,7 @@ int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
}

/* The 'mapping' part of i915_gem_object_pin_map() below */
-static void *i915_gem_object_map(const struct drm_i915_gem_object *obj,
+static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
enum i915_map_type type)
{
unsigned long n_pages = obj->base.size >> PAGE_SHIFT;
@@ -248,6 +250,11 @@ static void *i915_gem_object_map(const struct drm_i915_gem_object *obj,
pgprot_t pgprot;
void *addr;

+ if (i915_gem_object_is_lmem(obj)) {
+ /* XXX: we are ignoring the type here -- this is simply wc */
+ return i915_gem_object_lmem_io_map(obj, 0, obj->base.size);
+ }
+
/* A single page can always be kmapped */
if (n_pages == 1 && type == I915_MAP_WB)
return kmap(sg_page(sgt->sgl));
@@ -293,7 +300,8 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj,
void *ptr;
int err;

- if (unlikely(!i915_gem_object_has_struct_page(obj)))
+ if (unlikely(!i915_gem_object_has_struct_page(obj) &&
+ !i915_gem_object_is_lmem(obj)))
return ERR_PTR(-ENXIO);

err = mutex_lock_interruptible(&obj->mm.lock);
@@ -325,7 +333,9 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj,
goto err_unpin;
}

- if (is_vmalloc_addr(ptr))
+ if (i915_gem_object_is_lmem(obj))
+ io_mapping_unmap(ptr);
+ else if (is_vmalloc_addr(ptr))
vunmap(ptr);
else
kunmap(kmap_to_page(ptr));
diff --git a/drivers/gpu/drm/i915/intel_region_lmem.c b/drivers/gpu/drm/i915/intel_region_lmem.c
index 15655cc5013f..701bcac3479e 100644
--- a/drivers/gpu/drm/i915/intel_region_lmem.c
+++ b/drivers/gpu/drm/i915/intel_region_lmem.c
@@ -73,6 +73,30 @@ static const struct intel_memory_region_ops region_lmem_ops = {
.create_object = lmem_create_object,
};

+/* XXX: Time to vfunc your life up? */
+void __iomem *i915_gem_object_lmem_io_map_page(struct drm_i915_gem_object *obj,
+ unsigned long n)
+{
+ resource_size_t offset;
+
+ offset = i915_gem_object_get_dma_address(obj, n);
+
+ return io_mapping_map_atomic_wc(&obj->memory_region->iomap, offset);
+}
+
+void __iomem *i915_gem_object_lmem_io_map(struct drm_i915_gem_object *obj,
+ unsigned long n,
+ unsigned long size)
+{
+ resource_size_t offset;
+
+ GEM_BUG_ON(!(obj->flags & I915_BO_ALLOC_CONTIGUOUS));
+
+ offset = i915_gem_object_get_dma_address(obj, n);
+
+ return io_mapping_map_wc(&obj->memory_region->iomap, offset, size);
+}
+
bool i915_gem_object_is_lmem(struct drm_i915_gem_object *obj)
{
struct intel_memory_region *region = obj->memory_region;
diff --git a/drivers/gpu/drm/i915/intel_region_lmem.h b/drivers/gpu/drm/i915/intel_region_lmem.h
index 0f0a6249d5b9..20084f7b4bff 100644
--- a/drivers/gpu/drm/i915/intel_region_lmem.h
+++ b/drivers/gpu/drm/i915/intel_region_lmem.h
@@ -6,6 +6,12 @@
#ifndef __INTEL_REGION_LMEM_H
#define __INTEL_REGION_LMEM_H

+
+void __iomem *i915_gem_object_lmem_io_map(struct drm_i915_gem_object *obj,
+ unsigned long n, unsigned long size);
+void __iomem *i915_gem_object_lmem_io_map_page(struct drm_i915_gem_object *obj,
+ unsigned long n);
+
bool i915_gem_object_is_lmem(struct drm_i915_gem_object *obj);

struct drm_i915_gem_object *
diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
index 3ac320b28ef1..85d118c10d15 100644
--- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
@@ -9,8 +9,11 @@

#include "mock_gem_device.h"
#include "gem/selftests/mock_context.h"
+#include "selftests/igt_flush_test.h"
#include "mock_drm.h"

+#include "gem/i915_gem_object_blt.h"
+
static void close_objects(struct list_head *objects)
{
struct drm_i915_gem_object *obj, *on;
@@ -365,6 +368,79 @@ static int igt_lmem_create(void *arg)
return err;
}

+static int igt_lmem_write_cpu(void *arg)
+{
+ struct drm_i915_private *i915 = arg;
+ struct intel_context *ce = i915->engine[BCS0]->kernel_context;
+ struct drm_i915_gem_object *obj;
+ struct rnd_state prng;
+ u32 *vaddr;
+ u32 dword;
+ u32 val;
+ u32 sz;
+ int err;
+
+ if (!HAS_ENGINE(i915, BCS0))
+ return 0;
+
+ sz = round_up(prandom_u32_state(&prng) % SZ_32M, PAGE_SIZE);
+
+ obj = i915_gem_object_create_lmem(i915, sz, I915_BO_ALLOC_CONTIGUOUS);
+ if (IS_ERR(obj))
+ return PTR_ERR(obj);
+
+ vaddr = i915_gem_object_pin_map(obj, I915_MAP_WC);
+ if (IS_ERR(vaddr)) {
+ pr_err("Failed to iomap lmembar; err=%d\n", (int)PTR_ERR(vaddr));
+ err = PTR_ERR(vaddr);
+ goto out_put;
+ }
+
+ val = prandom_u32_state(&prng);
+
+ /* Write from gpu and then read from cpu */
+ err = i915_gem_object_fill_blt(obj, ce, val);
+ if (err)
+ goto out_unpin;
+
+ i915_gem_object_lock(obj);
+ err = i915_gem_object_set_to_wc_domain(obj, true);
+ i915_gem_object_unlock(obj);
+ if (err)
+ goto out_unpin;
+
+ for (dword = 0; dword < sz / sizeof(u32); ++dword) {
+ if (vaddr[dword] != val) {
+ pr_err("vaddr[%u]=%u, val=%u\n", dword, vaddr[dword],
+ val);
+ err = -EINVAL;
+ break;
+ }
+ }
+
+ /* Write from the cpu and read again from the cpu */
+ memset32(vaddr, val ^ 0xdeadbeaf, sz / sizeof(u32));
+
+ for (dword = 0; dword < sz / sizeof(u32); ++dword) {
+ if (vaddr[dword] != (val ^ 0xdeadbeaf)) {
+ pr_err("vaddr[%u]=%u, val=%u\n", dword, vaddr[dword],
+ val ^ 0xdeadbeaf);
+ err = -EINVAL;
+ break;
+ }
+ }
+
+out_unpin:
+ i915_gem_object_unpin_map(obj);
+out_put:
+ i915_gem_object_put(obj);
+
+ if (igt_flush_test(i915, I915_WAIT_LOCKED))
+ err = -EIO;
+
+ return err;
+}
+
int intel_memory_region_mock_selftests(void)
{
static const struct i915_subtest tests[] = {
@@ -406,6 +482,7 @@ int intel_memory_region_live_selftests(struct drm_i915_private *i915)
{
static const struct i915_subtest tests[] = {
SUBTEST(igt_lmem_create),
+ SUBTEST(igt_lmem_write_cpu),
};
int err;

--
2.20.1