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From:   "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To:     Christophe Leroy <christophe.leroy@c-s.fr>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>, npiggin@gmail.com,
        hch@infradead.org
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 3/4] powerpc: Add support for GENERIC_EARLY_IOREMAP
In-Reply-To: <412c7eaa6a373d8f82a3c3ee01e6a65a1a6589de.1568295907.git.christophe.leroy@c-s.fr>
References: <cover.1568295907.git.christophe.leroy@c-s.fr> <412c7eaa6a373d8f82a3c3ee01e6a65a1a6589de.1568295907.git.christophe.leroy@c-s.fr>
Date:   Thu, 12 Sep 2019 21:07:32 +0530
Message-ID: <87ftl1seyr.fsf@linux.ibm.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Christophe Leroy <christophe.leroy@c-s.fr> writes:

> Add support for GENERIC_EARLY_IOREMAP.
>
> Let's define 16 slots of 256Kbytes each for early ioremap.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
>  arch/powerpc/Kconfig              |  1 +
>  arch/powerpc/include/asm/Kbuild   |  1 +
>  arch/powerpc/include/asm/fixmap.h | 12 ++++++++++++
>  arch/powerpc/kernel/setup_32.c    |  3 +++
>  arch/powerpc/kernel/setup_64.c    |  3 +++
>  5 files changed, 20 insertions(+)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 6a7c797fa9d2..8fe252962518 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -161,6 +161,7 @@ config PPC
>  	select GENERIC_CMOS_UPDATE
>  	select GENERIC_CPU_AUTOPROBE
>  	select GENERIC_CPU_VULNERABILITIES	if PPC_BARRIER_NOSPEC
> +	select GENERIC_EARLY_IOREMAP
>  	select GENERIC_IRQ_SHOW
>  	select GENERIC_IRQ_SHOW_LEVEL
>  	select GENERIC_PCI_IOMAP		if PCI
> diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
> index 9a1d2fc6ceb7..30829120659c 100644
> --- a/arch/powerpc/include/asm/Kbuild
> +++ b/arch/powerpc/include/asm/Kbuild
> @@ -12,3 +12,4 @@ generic-y += preempt.h
>  generic-y += vtime.h
>  generic-y += msi.h
>  generic-y += simd.h
> +generic-y += early_ioremap.h
> diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
> index 722289a1d000..d5c4d357bd33 100644
> --- a/arch/powerpc/include/asm/fixmap.h
> +++ b/arch/powerpc/include/asm/fixmap.h
> @@ -15,6 +15,7 @@
>  #define _ASM_FIXMAP_H
>  
>  #ifndef __ASSEMBLY__
> +#include <linux/sizes.h>
>  #include <asm/page.h>
>  #include <asm/pgtable.h>
>  #ifdef CONFIG_HIGHMEM
> @@ -64,6 +65,14 @@ enum fixed_addresses {
>  		       FIX_IMMR_SIZE,
>  #endif
>  	/* FIX_PCIE_MCFG, */
> +	__end_of_permanent_fixed_addresses,
> +
> +#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
> +#define FIX_BTMAPS_SLOTS	16
> +#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
> +
> +	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
> +	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
>  	__end_of_fixed_addresses
>  };
>  
> @@ -71,6 +80,7 @@ enum fixed_addresses {
>  #define FIXADDR_START		(FIXADDR_TOP - __FIXADDR_SIZE)
>  
>  #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
> +#define FIXMAP_PAGE_IO	PAGE_KERNEL_NCG
>  
>  #include <asm-generic/fixmap.h>
>  
> @@ -85,5 +95,7 @@ static inline void __set_fixmap(enum fixed_addresses idx,
>  	map_kernel_page(__fix_to_virt(idx), phys, flags);
>  }
>  
> +#define __early_set_fixmap	__set_fixmap
> +
>  #endif /* !__ASSEMBLY__ */
>  #endif
> diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
> index a7541edf0cdb..dcffe927f5b9 100644
> --- a/arch/powerpc/kernel/setup_32.c
> +++ b/arch/powerpc/kernel/setup_32.c
> @@ -44,6 +44,7 @@
>  #include <asm/asm-prototypes.h>
>  #include <asm/kdump.h>
>  #include <asm/feature-fixups.h>
> +#include <asm/early_ioremap.h>
>  
>  #include "setup.h"
>  
> @@ -80,6 +81,8 @@ notrace void __init machine_init(u64 dt_ptr)
>  	/* Configure static keys first, now that we're relocated. */
>  	setup_feature_keys();
>  
> +	early_ioremap_setup();
> +
>  	/* Enable early debugging if any specified (see udbg.h) */
>  	udbg_early_init();
>  
> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
> index 44b4c432a273..b85f6a1cc3a1 100644
> --- a/arch/powerpc/kernel/setup_64.c
> +++ b/arch/powerpc/kernel/setup_64.c
> @@ -65,6 +65,7 @@
>  #include <asm/hw_irq.h>
>  #include <asm/feature-fixups.h>
>  #include <asm/kup.h>
> +#include <asm/early_ioremap.h>
>  
>  #include "setup.h"
>  
> @@ -338,6 +339,8 @@ void __init early_setup(unsigned long dt_ptr)
>  	apply_feature_fixups();
>  	setup_feature_keys();
>  
> +	early_ioremap_setup();
> +
>  	/* Initialize the hash table or TLB handling */
>  	early_init_mmu();
>  

Can we remove early_ioremap_range() after this?

-aneesh