From: Frank Li <Frank.li@oss.nxp.com>
To: Julian Braha <julianbraha@gmail.com>
Cc: maddy@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com,
chleroy@kernel.org, Frank.Li@kernel.org, andrew+netdev@lunn.ch,
davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com, kernel-janitors@vger.kernel.org,
linusw@kernel.org, kees@kernel.org, colin.i.king@gmail.com,
rosenp@gmail.com, joao@joaoff.com, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org
Subject: Re: [PATCH v2] powerpc: remove dead 440SP code
Date: Tue, 1 Sep 2026 10:28:47 -0500 [thread overview]
Message-ID: <apbvL6_WqojjOeRA@SMW015318> (raw)
In-Reply-To: <20260901150645.1199097-1-julianbraha@gmail.com>
On Tue, Sep 01, 2026 at 04:06:45PM +0100, Julian Braha wrote:
> The 440SP config option can never be enabled, making all references to it
> dead code.
>
> The only board using CONFIG_440SP was IBM LUAN, which was commented out by
> commit f65573314e4e ("[POWERPC] Re-organize Kconfig code for 4xx in
> arch/powerpc") then removed by commit ff5f483f3091 ("powerpc: 4xx: remove
> commented out Kconfig entries").
>
> Let's remove support for 440SP, since nobody can be using it anyway.
>
> This dead code was found by kconfirm, a static analysis tool for Kconfig.
>
> Signed-off-by: Julian Braha <julianbraha@gmail.com>
> ---
> Changes since v1:
> - cleaned up preprocessor condition
> - added historic details to description
>
> Link to v1:
> https://lore.kernel.org/all/20260816125615.985387-1-julianbraha@gmail.com/
> ---
> arch/powerpc/boot/cuboot-katmai.c | 2 +-
> arch/powerpc/include/asm/async_tx.h | 2 +-
> arch/powerpc/include/asm/dcr-regs.h | 10 +++++-----
> arch/powerpc/kernel/cpu_specs_44x.h | 12 ------------
> arch/powerpc/platforms/44x/Kconfig | 3 ---
> drivers/dma/Kconfig | 2 +-
> drivers/dma/ppc4xx/adma.c | 9 ---------
> drivers/dma/ppc4xx/adma.h | 2 +-
> drivers/dma/ppc4xx/dma.h | 9 ---------
Please split for difference subsystem.
Frank
> drivers/net/ethernet/ibm/emac/mal.h | 2 +-
> 10 files changed, 10 insertions(+), 43 deletions(-)
>
> diff --git a/arch/powerpc/boot/cuboot-katmai.c b/arch/powerpc/boot/cuboot-katmai.c
> index 034a748fde24..fcd71e76309f 100644
> --- a/arch/powerpc/boot/cuboot-katmai.c
> +++ b/arch/powerpc/boot/cuboot-katmai.c
> @@ -31,7 +31,7 @@ static void katmai_fixups(void)
> {
> unsigned long sysclk = 33333000;
>
> - /* 440SP Clock logic is all but identical to 440GX
> + /* 440SPe Clock logic is all but identical to 440GX
> * so we just use that code for now at least
> */
> ibm440spe_fixup_clocks(sysclk, 6 * 1843200, 0);
> diff --git a/arch/powerpc/include/asm/async_tx.h b/arch/powerpc/include/asm/async_tx.h
> index a14758426dd5..1ff5b2ca3ed1 100644
> --- a/arch/powerpc/include/asm/async_tx.h
> +++ b/arch/powerpc/include/asm/async_tx.h
> @@ -7,7 +7,7 @@
> #ifndef _ASM_POWERPC_ASYNC_TX_H_
> #define _ASM_POWERPC_ASYNC_TX_H_
>
> -#if defined(CONFIG_440SPe) || defined(CONFIG_440SP)
> +#if defined(CONFIG_440SPe)
> extern struct dma_chan *
> ppc440spe_async_tx_find_best_channel(enum dma_transaction_type cap,
> struct page **dst_lst, int dst_cnt, struct page **src_lst,
> diff --git a/arch/powerpc/include/asm/dcr-regs.h b/arch/powerpc/include/asm/dcr-regs.h
> index 5c1a4973f46a..e39a55e527da 100644
> --- a/arch/powerpc/include/asm/dcr-regs.h
> +++ b/arch/powerpc/include/asm/dcr-regs.h
> @@ -25,11 +25,11 @@
> * of the driver main register set
> */
>
> -/* CPRs (440GX and 440SP/440SPe) */
> +/* CPRs (440GX and 440SPe) */
> #define DCRN_CPR0_CONFIG_ADDR 0xc
> #define DCRN_CPR0_CONFIG_DATA 0xd
>
> -/* SDRs (440GX and 440SP/440SPe) */
> +/* SDRs (440GX and 440SPe) */
> #define DCRN_SDR0_CONFIG_ADDR 0xe
> #define DCRN_SDR0_CONFIG_DATA 0xf
>
> @@ -159,18 +159,18 @@
> #define L2C_SNP_ESR 0x00000800
>
> /*
> - * DCR register offsets for 440SP/440SPe I2O/DMA controller.
> + * DCR register offsets for 440SPe I2O/DMA controller.
> * The base address is configured in the device tree.
> */
> #define DCRN_I2O0_IBAL 0x006
> #define DCRN_I2O0_IBAH 0x007
> #define I2O_REG_ENABLE 0x00000001 /* Enable I2O/DMA access */
>
> -/* 440SP/440SPe Software Reset DCR */
> +/* 440SPe Software Reset DCR */
> #define DCRN_SDR0_SRST 0x0200
> #define DCRN_SDR0_SRST_I2ODMA (0x80000000 >> 15) /* Reset I2O/DMA */
>
> -/* 440SP/440SPe Memory Queue DCR offsets */
> +/* 440SPe Memory Queue DCR offsets */
> #define DCRN_MQ0_XORBA 0x04
> #define DCRN_MQ0_CF2H 0x06
> #define DCRN_MQ0_CFBHL 0x0f
> diff --git a/arch/powerpc/kernel/cpu_specs_44x.h b/arch/powerpc/kernel/cpu_specs_44x.h
> index 69c4cdc0cdee..41ed2c16d8cc 100644
> --- a/arch/powerpc/kernel/cpu_specs_44x.h
> +++ b/arch/powerpc/kernel/cpu_specs_44x.h
> @@ -172,18 +172,6 @@ static struct cpu_spec cpu_specs[] __initdata = {
> .machine_check = machine_check_440A,
> .platform = "ppc440",
> },
> - { /* 440SP Rev. A */
> - .pvr_mask = 0xfff00fff,
> - .pvr_value = 0x53200891,
> - .cpu_name = "440SP Rev. A",
> - .cpu_features = CPU_FTRS_44X,
> - .cpu_user_features = COMMON_USER_BOOKE,
> - .mmu_features = MMU_FTR_TYPE_44x,
> - .icache_bsize = 32,
> - .dcache_bsize = 32,
> - .machine_check = machine_check_4xx,
> - .platform = "ppc440",
> - },
> { /* 440SPe Rev. A */
> .pvr_mask = 0xfff00fff,
> .pvr_value = 0x53400890,
> diff --git a/arch/powerpc/platforms/44x/Kconfig b/arch/powerpc/platforms/44x/Kconfig
> index 150813cea945..b481ef2b0f4c 100644
> --- a/arch/powerpc/platforms/44x/Kconfig
> +++ b/arch/powerpc/platforms/44x/Kconfig
> @@ -260,9 +260,6 @@ config 440GX
> select IBM_EMAC_ZMII if IBM_EMAC #test only
> select IBM_EMAC_TAH if IBM_EMAC #test only
>
> -config 440SP
> - bool
> -
> config 440SPe
> bool
> select IBM_EMAC_EMAC4 if IBM_EMAC
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index ae6a682c9f76..f0f61b4932f5 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -77,7 +77,7 @@ config AMBA_PL08X
>
> config AMCC_PPC440SPE_ADMA
> tristate "AMCC PPC440SPe ADMA support"
> - depends on 440SPe || 440SP
> + depends on 440SPe
> select DMA_ENGINE
> select DMA_ENGINE_RAID
> select ARCH_HAS_ASYNC_TX_FIND_CHANNEL
> diff --git a/drivers/dma/ppc4xx/adma.c b/drivers/dma/ppc4xx/adma.c
> index 279a431ccae3..ecbf4c84a318 100644
> --- a/drivers/dma/ppc4xx/adma.c
> +++ b/drivers/dma/ppc4xx/adma.c
> @@ -4349,14 +4349,9 @@ static ssize_t poly_show(struct device_driver *dev, char *buf)
> ssize_t size = 0;
> u32 reg;
>
> -#ifdef CONFIG_440SP
> - /* 440SP has fixed polynomial */
> - reg = 0x4d;
> -#else
> reg = dcr_read(ppc440spe_mq_dcr_host, DCRN_MQ0_CFBHL);
> reg >>= MQ0_CFBHL_POLY;
> reg &= 0xFF;
> -#endif
>
> size = sysfs_emit(buf, "PPC440SP(e) RAID-6 driver "
> "uses 0x1%02x polynomial.\n", reg);
> @@ -4368,10 +4363,6 @@ static ssize_t poly_store(struct device_driver *dev, const char *buf,
> {
> unsigned long reg, val;
> int err;
> -#ifdef CONFIG_440SP
> - /* 440SP uses default 0x14D polynomial only */
> - return -EINVAL;
> -#endif
>
> if (!count || count > 6)
> return -EINVAL;
> diff --git a/drivers/dma/ppc4xx/adma.h b/drivers/dma/ppc4xx/adma.h
> index f8a5d7c1fb40..0ec35382d274 100644
> --- a/drivers/dma/ppc4xx/adma.h
> +++ b/drivers/dma/ppc4xx/adma.h
> @@ -19,7 +19,7 @@
> #define tx_to_ppc440spe_adma_slot(tx) \
> container_of(tx, struct ppc440spe_adma_desc_slot, async_tx)
>
> -/* Default polynomial (for 440SP is only available) */
> +/* Default polynomial */
> #define PPC440SPE_DEFAULT_POLY 0x4d
>
> #define PPC440SPE_ADMA_ENGINES_NUM (XOR_ENGINES_NUM + DMA_ENGINES_NUM)
> diff --git a/drivers/dma/ppc4xx/dma.h b/drivers/dma/ppc4xx/dma.h
> index b5725481bfa6..17cbb2d1ee1c 100644
> --- a/drivers/dma/ppc4xx/dma.h
> +++ b/drivers/dma/ppc4xx/dma.h
> @@ -70,20 +70,11 @@
>
> #define DMA_CUED_XOR_BASE (0x10000000)
> #define DMA_CUED_XOR_HB (0x00000008)
> -
> -#ifdef CONFIG_440SP
> -#define DMA_CUED_MULT1_OFF 0
> -#define DMA_CUED_MULT2_OFF 8
> -#define DMA_CUED_MULT3_OFF 16
> -#define DMA_CUED_REGION_OFF 24
> -#define DMA_CUED_XOR_WIN_MSK (0xFC000000)
> -#else
> #define DMA_CUED_MULT1_OFF 2
> #define DMA_CUED_MULT2_OFF 10
> #define DMA_CUED_MULT3_OFF 18
> #define DMA_CUED_REGION_OFF 26
> #define DMA_CUED_XOR_WIN_MSK (0xF0000000)
> -#endif
>
> #define DMA_CUED_REGION_MSK 0x3
> #define DMA_RXOR123 0x0
> diff --git a/drivers/net/ethernet/ibm/emac/mal.h b/drivers/net/ethernet/ibm/emac/mal.h
> index e0ddc41186a2..6cdd40bca2cd 100644
> --- a/drivers/net/ethernet/ibm/emac/mal.h
> +++ b/drivers/net/ethernet/ibm/emac/mal.h
> @@ -26,7 +26,7 @@
> * We call MAL 1 the version in 405GP, 405GPR, 405EP, 440EP, 440GR and
> * NP405H.
> *
> - * We call MAL 2 the version in 440GP, 440GX, 440SP, 440SPE and Axon
> + * We call MAL 2 the version in 440GP, 440GX, 440SPE and Axon
> *
> * The driver expects a "version" property in the emac node containing
> * a number 1 or 2. New device-trees for EMAC capable platforms are thus
> --
> 2.55.0
>
next prev parent reply other threads:[~2026-09-01 15:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-01 15:06 Julian Braha
2026-09-01 15:28 ` Frank Li [this message]
2026-09-01 15:33 ` Julian Braha
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