[PATCH 17/36] HMM: add new HMM page table flag (valid device memory).

From: j . glisse
Date: Thu May 21 2015 - 15:34:25 EST


From: JÃrÃme Glisse <jglisse@xxxxxxxxxx>

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

Signed-off-by: JÃrÃme Glisse <jglisse@xxxxxxxxxx>
Signed-off-by: Sherry Cheung <SCheung@xxxxxxxxxx>
Signed-off-by: Subhash Gutti <sgutti@xxxxxxxxxx>
Signed-off-by: Mark Hairgrove <mhairgrove@xxxxxxxxxx>
Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
Signed-off-by: Jatin Kumar <jakumar@xxxxxxxxxx>
---
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 78a9073..26cfe5e 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 ? */
--
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/