Subject: Re: [PATCH V2 55/68] powerpc/mm: VMALLOC abstraction

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Thu, 28 Apr 2016 11:39:10 +0530

vmalloc range differs between hash and radix config. Hence make
VMALLOC_START and related constants a variable which get
runtime initialized depending on hash or radix.

> Signed-off-by: Aneesh Kumar K.V <[email-masked]>
> ---
>  arch/powerpc/include/asm/book3s/64/hash.h    | 14 +++++++-------
>  arch/powerpc/include/asm/book3s/64/pgtable.h | 15 ++++++++++++---
>  arch/powerpc/include/asm/book3s/64/radix.h   | 21 +++++++++++++++++++++
>  arch/powerpc/kernel/pci_64.c                 |  3 ++-
>  arch/powerpc/mm/hash_utils_64.c              |  8 ++++++++
>  arch/powerpc/mm/pgtable-radix.c              |  7 +++++++
>  arch/powerpc/mm/pgtable_64.c                 | 13 +++++++++++--
>  arch/powerpc/mm/slb_low.S                    |  2 +-
>  8 files changed, 69 insertions(+), 14 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
> index 43bd7d15f41e..9da410ea7e1a 100644
> --- a/arch/powerpc/include/asm/book3s/64/hash.h
> +++ b/arch/powerpc/include/asm/book3s/64/hash.h
> @@ -45,17 +45,17 @@
>  /*
>   * Define the address range of the kernel non-linear virtual area
>   */
> -#define KERN_VIRT_START ASM_CONST(0xD000000000000000)
> -#define KERN_VIRT_SIZE	ASM_CONST(0x0000100000000000)
> +#define H_KERN_VIRT_START ASM_CONST(0xD000000000000000)
> +#define H_KERN_VIRT_SIZE	ASM_CONST(0x0000100000000000)
>
>  /*
>   * The vmalloc space starts at the beginning of that region, and
>   * occupies half of it on hash CPUs and a quarter of it on Book3E
>   * (we keep a quarter for the virtual memmap)
>   */
> -#define VMALLOC_START	KERN_VIRT_START
> -#define VMALLOC_SIZE	(KERN_VIRT_SIZE >> 1)
> -#define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
> +#define H_VMALLOC_START	H_KERN_VIRT_START
> +#define H_VMALLOC_SIZE	(H_KERN_VIRT_SIZE >> 1)
> +#define H_VMALLOC_END	(H_VMALLOC_START + H_VMALLOC_SIZE)
>
>  /*
>   * Region IDs
> @@ -64,7 +64,7 @@
>  #define REGION_MASK		(0xfUL << REGION_SHIFT)
>  #define REGION_ID(ea)		(((unsigned long)(ea)) >> REGION_SHIFT)
>
> -#define VMALLOC_REGION_ID	(REGION_ID(VMALLOC_START))
> +#define VMALLOC_REGION_ID	(REGION_ID(H_VMALLOC_START))
>  #define KERNEL_REGION_ID	(REGION_ID(PAGE_OFFSET))
>  #define VMEMMAP_REGION_ID	(0xfUL)	/* Server only */
>  #define USER_REGION_ID		(0UL)
> @@ -73,7 +73,7 @@
>   * Defines the address of the vmemap area, in its own region on
>   * hash table CPUs.
>   */
> -#define VMEMMAP_BASE		(VMEMMAP_REGION_ID << REGION_SHIFT)
> +#define H_VMEMMAP_BASE		(VMEMMAP_REGION_ID << REGION_SHIFT)
>
>  #ifdef CONFIG_PPC_MM_SLICES
>  #define HAVE_ARCH_UNMAPPED_AREA
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index b8ee70458bae..87519ad1c5dc 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -208,6 +208,18 @@ extern unsigned long __pgd_val_bits;
>  #define PUD_MASKED_BITS		0xc0000000000000ffUL
>  /* Bits to mask out from a PGD to get to the PUD page */
>  #define PGD_MASKED_BITS		0xc0000000000000ffUL
> +
> +extern unsigned long __vmalloc_start;
> +extern unsigned long __vmalloc_end;
> +#define VMALLOC_START	__vmalloc_start
> +#define VMALLOC_END	__vmalloc_end
> +
> +extern unsigned long __kernel_virt_start;
> +extern unsigned long __kernel_virt_size;
> +#define KERN_VIRT_START __kernel_virt_start
> +#define KERN_VIRT_SIZE  __kernel_virt_size
> +extern struct page *vmemmap;
> +extern unsigned long ioremap_bot;
>  #endif /* __ASSEMBLY__ */
>
>  #include <asm/book3s/64/hash.h>
> @@ -220,7 +232,6 @@ extern unsigned long __pgd_val_bits;
>  #endif
>
>  #include <asm/barrier.h>
> -
>  /*
>   * The second half of the kernel virtual space is used for IO mappings,
>   * it's itself carved into the PIO region (ISA and PHB IO space) and
> @@ -239,8 +250,6 @@ extern unsigned long __pgd_val_bits;
>  #define IOREMAP_BASE	(PHB_IO_END)
>  #define IOREMAP_END	(KERN_VIRT_START + KERN_VIRT_SIZE)
>
> -#define vmemmap			((struct page *)VMEMMAP_BASE)
> -
>  /* Advertise special mapping type for AGP */
>  #define HAVE_PAGE_AGP
>
> diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
> index 040c4a56d07b..d0449c0f2166 100644
> --- a/arch/powerpc/include/asm/book3s/64/radix.h
> +++ b/arch/powerpc/include/asm/book3s/64/radix.h
> @@ -30,6 +30,27 @@
>  #define R_PGTABLE_EADDR_SIZE (R_PTE_INDEX_SIZE + R_PMD_INDEX_SIZE +	\
>  			      R_PUD_INDEX_SIZE + R_PGD_INDEX_SIZE + PAGE_SHIFT)
>  #define R_PGTABLE_RANGE (ASM_CONST(1) << R_PGTABLE_EADDR_SIZE)
> +/*
> + * We support 52 bit address space, Use top bit for kernel
> + * virtual mapping. Also make sure kernel fit in the top
> + * quadrant.
> + */
> +#define R_KERN_VIRT_START ASM_CONST(0xc008000000000000)
> +#define R_KERN_VIRT_SIZE  ASM_CONST(0x0008000000000000)
> +
> +/*
> + * The vmalloc space starts at the beginning of that region, and
> + * occupies a quarter of it on radix config.
> + * (we keep a quarter for the virtual memmap)
> + */
> +#define R_VMALLOC_START	R_KERN_VIRT_START
> +#define R_VMALLOC_SIZE	(R_KERN_VIRT_SIZE >> 2)
> +#define R_VMALLOC_END	(R_VMALLOC_START + R_VMALLOC_SIZE)
> +/*
> + * Defines the address of the vmemap area, in its own region on
> + * hash table CPUs.
> + */
> +#define R_VMEMMAP_BASE		(R_VMALLOC_END)
>
>  #ifndef __ASSEMBLY__
>  #define R_PTE_TABLE_SIZE	(sizeof(pte_t) << R_PTE_INDEX_SIZE)
> diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
> index 41503d7d53a1..3759df52bd67 100644
> --- a/arch/powerpc/kernel/pci_64.c
> +++ b/arch/powerpc/kernel/pci_64.c
> @@ -38,7 +38,7 @@
>   * ISA drivers use hard coded offsets.  If no ISA bus exists nothing
>   * is mapped on the first 64K of IO space
>   */
> -unsigned long pci_io_base = ISA_IO_BASE;
> +unsigned long pci_io_base;
>  EXPORT_SYMBOL(pci_io_base);
>
>  static int __init pcibios_init(void)
> @@ -47,6 +47,7 @@ static int __init pcibios_init(void)
>
>  	printk(KERN_INFO "PCI: Probing PCI hardware\n");
>
> +	pci_io_base = ISA_IO_BASE;
>  	/* For now, override phys_mem_access_prot. If we need it,g
>  	 * later, we may move that initialization to each ppc_md
>  	 */
> diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
> index aef691b75784..599c4684e158 100644
> --- a/arch/powerpc/mm/hash_utils_64.c
> +++ b/arch/powerpc/mm/hash_utils_64.c
> @@ -885,6 +885,14 @@ void __init hlearly_init_mmu(void)
>  	__pmd_val_bits = 0;
>  	__pud_val_bits = 0;
>  	__pgd_val_bits = 0;
> +
> +	__kernel_virt_start = H_KERN_VIRT_START;
> +	__kernel_virt_size = H_KERN_VIRT_SIZE;
> +	__vmalloc_start = H_VMALLOC_START;
> +	__vmalloc_end = H_VMALLOC_END;
> +	vmemmap = (struct page *)H_VMEMMAP_BASE;
> +	ioremap_bot = IOREMAP_BASE;
> +
>  	/* Initialize the MMU Hash table and create the linear mapping
>  	 * of memory. Has to be done before SLB initialization as this is
>  	 * currently where the page size encoding is obtained.
> diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
> index 5a0400fb5d71..508453c0eac4 100644
> --- a/arch/powerpc/mm/pgtable-radix.c
> +++ b/arch/powerpc/mm/pgtable-radix.c
> @@ -322,6 +322,13 @@ void __init rearly_init_mmu(void)
>  	__pud_val_bits = R_PUD_VAL_BITS;
>  	__pgd_val_bits = R_PGD_VAL_BITS;
>
> +	__kernel_virt_start = R_KERN_VIRT_START;
> +	__kernel_virt_size = R_KERN_VIRT_SIZE;
> +	__vmalloc_start = R_VMALLOC_START;
> +	__vmalloc_end = R_VMALLOC_END;
> +	vmemmap = (struct page *)R_VMEMMAP_BASE;
> +	ioremap_bot = IOREMAP_BASE;
> +
>  	radix_init_page_sizes();
>  	if (!firmware_has_feature(FW_FEATURE_LPAR))
>  		radix_init_partition_table();
> diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
> index a58259793198..88b6cfc0a3e3 100644
> --- a/arch/powerpc/mm/pgtable_64.c
> +++ b/arch/powerpc/mm/pgtable_64.c
> @@ -97,9 +97,18 @@ unsigned long __pud_val_bits;
>  EXPORT_SYMBOL(__pud_val_bits);
>  unsigned long __pgd_val_bits;
>  EXPORT_SYMBOL(__pgd_val_bits);
> -
> +unsigned long __kernel_virt_start;
> +EXPORT_SYMBOL(__kernel_virt_start);
> +unsigned long __kernel_virt_size;
> +EXPORT_SYMBOL(__kernel_virt_size);
> +unsigned long __vmalloc_start;
> +EXPORT_SYMBOL(__vmalloc_start);
> +unsigned long __vmalloc_end;
> +EXPORT_SYMBOL(__vmalloc_end);
> +struct page *vmemmap;
> +EXPORT_SYMBOL(vmemmap);
>  #endif
> -unsigned long ioremap_bot = IOREMAP_BASE;
> +unsigned long ioremap_bot;
>
>  /**
>   * __ioremap_at - Low level function to establish the page tables
> diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
> index aade18f3f21f..5d840b249fd4 100644
> --- a/arch/powerpc/mm/slb_low.S
> +++ b/arch/powerpc/mm/slb_low.S
> @@ -91,7 +91,7 @@ slb_miss_kernel_load_vmemmap:
>  	 * can be demoted from 64K -> 4K dynamically on some machines
>  	 */
>  	clrldi	r11,r10,48
> -	cmpldi	r11,(VMALLOC_SIZE >> 28) - 1
> +	cmpldi	r11,(H_VMALLOC_SIZE >> 28) - 1
>  	bgt	5f
>  	lhz	r11,PACAVMALLOCSLLP(r13)
>  	b	6f
> -- 
> 2.5.0