[PATCH 0/2] sh_eth: remove SH_ETH_OFFSET_INVALID abuses

[PATCH 0/2] sh_eth: remove SH_ETH_OFFSET_INVALID abuses

[Sergei Shtylyov]

Hello!

Here's a set of 2 patches against DaveM's 'net-next.git' repo. They get rid of
the abuse of SH_ETH_OFFSET_INVALID for the register existence checks, so that
only its necessary uses would remain...

[1/2] sh_eth: add sh_eth_cpu_data::no_xdfar flag
[2/2] sh_eth: kill useless check in __sh_eth_get_regs()

MBR, Sergei

[PATCH net-next 1/2] sh_eth: add sh_eth_cpu_data::no_xdfar flag

[Sergei Shtylyov]

The commit 6ded286555c2 ("sh_eth: Fix RX recovery on R-Car in case of RX
ring underrun") added a check for an bad RDFAR offset in sh_eth_rx(), so
that the code could work on the R-Car Ether controllers which don't have
this register (and TDFAR), then the commit 3365711df02 ("sh_eth: WARN on
access to a register not implemented in a particular chip") replaced
offset 0 with 0xffff. Adding/checking the 'no_xdfar' bit field in the
'struct sh_eth_cpu_data' instead results in less object code...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
 drivers/net/ethernet/renesas/sh_eth.c |    5 +++--
 drivers/net/ethernet/renesas/sh_eth.h |    1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

Index: net-next/drivers/net/ethernet/renesas/sh_eth.c
===================================================================
--- net-next.orig/drivers/net/ethernet/renesas/sh_eth.c
+++ net-next/drivers/net/ethernet/renesas/sh_eth.c
@@ -702,6 +702,7 @@ static struct sh_eth_cpu_data rcar_gen1_
 	.mpr		= 1,
 	.tpauser	= 1,
 	.hw_swap	= 1,
+	.no_xdfar	= 1,
 };
 
 /* R-Car Gen2 and RZ/G1 */
@@ -735,6 +736,7 @@ static struct sh_eth_cpu_data rcar_gen2_
 	.mpr		= 1,
 	.tpauser	= 1,
 	.hw_swap	= 1,
+	.no_xdfar	= 1,
 	.rmiimode	= 1,
 	.magic		= 1,
 };
@@ -1615,8 +1617,7 @@ static int sh_eth_rx(struct net_device *
 	/* If we don't need to check status, don't. -KDU */
 	if (!(sh_eth_read(ndev, EDRRR) & EDRRR_R)) {
 		/* fix the values for the next receiving if RDE is set */
-		if (intr_status & EESR_RDE &&
-		    mdp->reg_offset[RDFAR] != SH_ETH_OFFSET_INVALID) {
+		if (intr_status & EESR_RDE && !mdp->cd->no_xdfar) {
 			u32 count = (sh_eth_read(ndev, RDFAR) -
 				     sh_eth_read(ndev, RDLAR)) >> 4;
 
Index: net-next/drivers/net/ethernet/renesas/sh_eth.h
===================================================================
--- net-next.orig/drivers/net/ethernet/renesas/sh_eth.h
+++ net-next/drivers/net/ethernet/renesas/sh_eth.h
@@ -508,6 +508,7 @@ struct sh_eth_cpu_data {
 	unsigned rpadir:1;	/* E-DMAC have RPADIR */
 	unsigned no_trimd:1;	/* E-DMAC DO NOT have TRIMD */
 	unsigned no_ade:1;	/* E-DMAC DO NOT have ADE bit in EESR */
+	unsigned no_xdfar:1;	/* E-DMAC DOES NOT have RDFAR/TDFAR */
 	unsigned xdfar_rw:1;	/* E-DMAC has writeable RDFAR/TDFAR */
 	unsigned hw_checksum:1;	/* E-DMAC has CSMR */
 	unsigned select_mii:1;	/* EtherC have RMII_MII (MII select register) */

[PATCH net-next 2/2] sh_eth: kill useless check in __sh_eth_get_regs()

[Sergei Shtylyov]

Iff TSU registers exist on a given [G]Ether controller, they always include
the CAM entry table registers (TSU_ADR{H|L}<n>), thus the check for invalid
TSU_ADRH0 offset in __sh_eth_get_regs() is useless...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
 drivers/net/ethernet/renesas/sh_eth.c |   23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

Index: net-next/drivers/net/ethernet/renesas/sh_eth.c
===================================================================
--- net-next.orig/drivers/net/ethernet/renesas/sh_eth.c
+++ net-next/drivers/net/ethernet/renesas/sh_eth.c
@@ -2153,22 +2153,17 @@ static size_t __sh_eth_get_regs(struct n
 		add_tsu_reg(TSU_POST2);
 		add_tsu_reg(TSU_POST3);
 		add_tsu_reg(TSU_POST4);
-		if (mdp->reg_offset[TSU_ADRH0] != SH_ETH_OFFSET_INVALID) {
-			/* This is the start of a table, not just a single
-			 * register.
-			 */
-			if (buf) {
-				unsigned int i;
+		/* This is the start of a table, not just a single register. */
+		if (buf) {
+			unsigned int i;
 
-				mark_reg_valid(TSU_ADRH0);
-				for (i = 0; i < SH_ETH_TSU_CAM_ENTRIES * 2; i++)
-					*buf++ = ioread32(
-						mdp->tsu_addr +
-						mdp->reg_offset[TSU_ADRH0] +
-						i * 4);
-			}
-			len += SH_ETH_TSU_CAM_ENTRIES * 2;
+			mark_reg_valid(TSU_ADRH0);
+			for (i = 0; i < SH_ETH_TSU_CAM_ENTRIES * 2; i++)
+				*buf++ = ioread32(mdp->tsu_addr +
+						  mdp->reg_offset[TSU_ADRH0] +
+						  i * 4);
 		}
+		len += SH_ETH_TSU_CAM_ENTRIES * 2;
 	}
 
 #undef mark_reg_valid

Re: [PATCH net-next 1/2] sh_eth: add sh_eth_cpu_data::no_xdfar flag

[Sergei Shtylyov]

On 04/01/2018 12:22 AM, Sergei Shtylyov wrote:

> The commit 6ded286555c2 ("sh_eth: Fix RX recovery on R-Car in case of RX
> ring underrun") added a check for an bad RDFAR offset in sh_eth_rx(), so
> that the code could work on the R-Car Ether controllers which don't have
> this register (and TDFAR), then the commit 3365711df02 ("sh_eth: WARN on

   Oops, only 11 digits! Should have been 3365711df024. :-)

> access to a register not implemented in a particular chip") replaced
> offset 0 with 0xffff. Adding/checking the 'no_xdfar' bit field in the
> 'struct sh_eth_cpu_data' instead results in less object code...
> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

[...]

MBR, Sergei

Re: [PATCH 0/2] sh_eth: remove SH_ETH_OFFSET_INVALID abuses

[David Miller]

From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Date: Sun, 1 Apr 2018 00:15:04 +0300

> Hello!
> 
> Here's a set of 2 patches against DaveM's 'net-next.git' repo. They get rid of
> the abuse of SH_ETH_OFFSET_INVALID for the register existence checks, so that
> only its necessary uses would remain...
> 
> [1/2] sh_eth: add sh_eth_cpu_data::no_xdfar flag
> [2/2] sh_eth: kill useless check in __sh_eth_get_regs()

Series applied, thank you.