[PATCH v12 18/29] HMM: add new HMM page table flag (valid device memory).

["Jérôme Glisse" <jglisse@redhat.com>]

For memory migrated to device we need a new type of memory entry.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Sherry Cheung <SCheung@nvidia.com>
Signed-off-by: Subhash Gutti <sgutti@nvidia.com>
Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Jatin Kumar <jakumar@nvidia.com>
---
 include/linux/hmm_pt.h | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/include/linux/hmm_pt.h b/include/linux/hmm_pt.h
index 8a59a75..b017aa7 100644
--- a/include/linux/hmm_pt.h
+++ b/include/linux/hmm_pt.h
@@ -74,10 +74,11 @@ static inline unsigned long hmm_pde_pfn(dma_addr_t pde)
  * In the first case the device driver must ignore any pfn entry as they might
  * show as transient state while HMM is mapping the page.
  */
-#define HMM_PTE_VALID_DMA_BIT	0
-#define HMM_PTE_VALID_PFN_BIT	1
-#define HMM_PTE_WRITE_BIT	2
-#define HMM_PTE_DIRTY_BIT	3
+#define HMM_PTE_VALID_DEV_BIT	0
+#define HMM_PTE_VALID_DMA_BIT	1
+#define HMM_PTE_VALID_PFN_BIT	2
+#define HMM_PTE_WRITE_BIT	3
+#define HMM_PTE_DIRTY_BIT	4
 /*
  * Reserve some bits for device driver private flags. Note that thus can only
  * be manipulated using the hmm_pte_*_bit() sets of helpers.
@@ -85,7 +86,7 @@ static inline unsigned long hmm_pde_pfn(dma_addr_t pde)
  * WARNING ONLY SET/CLEAR THOSE FLAG ON PTE ENTRY THAT HAVE THE VALID BIT SET
  * AS OTHERWISE ANY BIT SET BY THE DRIVER WILL BE OVERWRITTEN BY HMM.
  */
-#define HMM_PTE_HW_SHIFT	4
+#define HMM_PTE_HW_SHIFT	8
 
 #define HMM_PTE_PFN_MASK	(~((dma_addr_t)((1 << PAGE_SHIFT) - 1)))
 #define HMM_PTE_DMA_MASK	(~((dma_addr_t)((1 << PAGE_SHIFT) - 1)))
@@ -166,6 +167,7 @@ static inline bool hmm_pte_test_and_set_bit(dma_addr_t *ptep,
 	HMM_PTE_TEST_AND_CLEAR_BIT(name, bit)\
 	HMM_PTE_TEST_AND_SET_BIT(name, bit)
 
+HMM_PTE_BIT_HELPER(valid_dev, HMM_PTE_VALID_DEV_BIT)
 HMM_PTE_BIT_HELPER(valid_dma, HMM_PTE_VALID_DMA_BIT)
 HMM_PTE_BIT_HELPER(valid_pfn, HMM_PTE_VALID_PFN_BIT)
 HMM_PTE_BIT_HELPER(dirty, HMM_PTE_DIRTY_BIT)
@@ -176,11 +178,23 @@ static inline dma_addr_t hmm_pte_from_pfn(dma_addr_t pfn)
 	return (pfn << PAGE_SHIFT) | (1 << HMM_PTE_VALID_PFN_BIT);
 }
 
+static inline dma_addr_t hmm_pte_from_dev_addr(dma_addr_t dma_addr)
+{
+	return (dma_addr & HMM_PTE_DMA_MASK) | (1 << HMM_PTE_VALID_DEV_BIT);
+}
+
 static inline dma_addr_t hmm_pte_from_dma_addr(dma_addr_t dma_addr)
 {
 	return (dma_addr & HMM_PTE_DMA_MASK) | (1 << HMM_PTE_VALID_DMA_BIT);
 }
 
+static inline dma_addr_t hmm_pte_dev_addr(dma_addr_t pte)
+{
+	/* FIXME Use max dma addr instead of 0 ? */
+	return hmm_pte_test_valid_dev(&pte) ? (pte & HMM_PTE_DMA_MASK) :
+					      (dma_addr_t)-1UL;
+}
+
 static inline dma_addr_t hmm_pte_dma_addr(dma_addr_t pte)
 {
 	/* FIXME Use max dma addr instead of 0 ? */
-- 
2.4.3