Re: [PATCH v4 2/8] MIPS: Octeon: Enable LMTDMA/LMTST operations.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 11/30/2017 01:36 PM, James Hogan wrote:
On Tue, Nov 28, 2017 at 04:55:34PM -0800, David Daney wrote:
From: Carlos Munoz <cmunoz@xxxxxxxxxx>

LMTDMA/LMTST operations move data between cores and I/O devices:

* LMTST operations can send an address and a variable length
   (up to 128 bytes) of data to an I/O device.
* LMTDMA operations can send an address and a variable length
   (up to 128) of data to the I/O device and then return a
   variable length (up to 128 bytes) response from the IOI device.

Should that be "I/O"?

Yes, I will fix the changelog.




Signed-off-by: Carlos Munoz <cmunoz@xxxxxxxxxx>
Signed-off-by: Steven J. Hill <Steven.Hill@xxxxxxxxxx>
Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
---
  arch/mips/cavium-octeon/setup.c       |  6 ++++++
  arch/mips/include/asm/octeon/octeon.h | 12 ++++++++++--
  2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
index a8034d0dcade..99e6a68bc652 100644
--- a/arch/mips/cavium-octeon/setup.c
+++ b/arch/mips/cavium-octeon/setup.c
@@ -609,6 +609,12 @@ void octeon_user_io_init(void)
  #else
  	cvmmemctl.s.cvmsegenak = 0;
  #endif
+	if (OCTEON_IS_OCTEON3()) {
+		/* Enable LMTDMA */
+		cvmmemctl.s.lmtena = 1;
+		/* Scratch line to use for LMT operation */
+		cvmmemctl.s.lmtline = 2;

Out of curiosity, is there significance to the value 2 and associated
virtual address 0xffffffffffff8100, or is it pretty arbitrary?

Yes, there is significance.

CPU local memory starts at 0xffffffffffff8000, each line is 0x80 bytes. so the 2nd line starts at 0xffffffffffff8100



+	}
  	/* R/W If set, CVMSEG is available for loads/stores in
  	 * supervisor mode. */
  	cvmmemctl.s.cvmsegenas = 0;
diff --git a/arch/mips/include/asm/octeon/octeon.h b/arch/mips/include/asm/octeon/octeon.h
index c99c4b6a79f4..92a17d67c1fa 100644
--- a/arch/mips/include/asm/octeon/octeon.h
+++ b/arch/mips/include/asm/octeon/octeon.h
@@ -179,7 +179,15 @@ union octeon_cvmemctl {
  		/* RO 1 = BIST fail, 0 = BIST pass */
  		__BITFIELD_FIELD(uint64_t wbfbist:1,
  		/* Reserved */
-		__BITFIELD_FIELD(uint64_t reserved:17,
+		__BITFIELD_FIELD(uint64_t reserved_52_57:6,
+		/* When set, LMTDMA/LMTST operations are permitted */
+		__BITFIELD_FIELD(uint64_t lmtena:1,
+		/* Selects the CVMSEG LM cacheline used by LMTDMA
+		 * LMTST and wide atomic store operations.
+		 */
+		__BITFIELD_FIELD(uint64_t lmtline:6,
+		/* Reserved */
+		__BITFIELD_FIELD(uint64_t reserved_41_44:4,
  		/* OCTEON II - TLB replacement policy: 0 = bitmask LRU; 1 = NLU.
  		 * This field selects between the TLB replacement policies:
  		 * bitmask LRU or NLU. Bitmask LRU maintains a mask of
@@ -275,7 +283,7 @@ union octeon_cvmemctl {
  		/* R/W Size of local memory in cache blocks, 54 (6912
  		 * bytes) is max legal value. */
  		__BITFIELD_FIELD(uint64_t lmemsz:6,
-		;)))))))))))))))))))))))))))))))))
+		;))))))))))))))))))))))))))))))))))))
  	} s;
  };

Regardless, the patch looks good to me.

Reviewed-by: James Hogan <jhogan@xxxxxxxxxx>

Cheers
James


_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel



[Index of Archives]     [Linux Driver Backports]     [DMA Engine]     [Linux GPIO]     [Linux SPI]     [Video for Linux]     [Linux USB Devel]     [Linux Coverity]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux