From fded332bf40349788c83399751fd3764fddc4b51 Mon Sep 17 00:00:00 2001 From: Michael Schmitz Date: Mon, 31 Mar 2014 21:06:05 +1300 Subject: [PATCH] m68k/atari - stram: alloc ST-RAM pool even if kernel not in ST-RAM With the kernel loaded to FastRAM (TT-RAM), none of the ST-RAM address range is mapped by init_mem, and ST-RAM is not accessible through the normal allocation pathways as a result. Implement ST-RAM pool allocation to be based on physical addresses always (it already was when the kernel was loaded in ST-RAM). Return kernel virtual addresses as per normal. The current test for the kernel residing in ST-RAM always returns true. Use the bootinfo memory chunk order instead - with the kernel in FastRAM, ST-RAM (phys. 0x0) is not the first chunk. In case the kernel is running from FastRAM, delay mapping of ST-RAM pool until after mem_init. Provide helper functions for those users of ST-RAM that need to be aware of the backing physical addresses. Kudos to Geert for his hints on getting this started. Signed-off-by: Michael Schmitz Signed-off-by: Geert Uytterhoeven --- arch/m68k/atari/stram.c | 71 ++++++++++++++++++++++------- arch/m68k/include/asm/atari_stram.h | 2 + 2 files changed, 56 insertions(+), 17 deletions(-) diff --git a/arch/m68k/atari/stram.c b/arch/m68k/atari/stram.c index 0810c8d56e59..5f8cb5a234d9 100644 --- a/arch/m68k/atari/stram.c +++ b/arch/m68k/atari/stram.c @@ -47,6 +47,7 @@ static struct resource stram_pool = { static unsigned long pool_size = 1024*1024; +static unsigned long stram_virt_offset; static int __init atari_stram_setup(char *arg) { @@ -67,14 +68,12 @@ early_param("stram_pool", atari_stram_setup); void __init atari_stram_init(void) { int i; - void *stram_start; /* * determine whether kernel code resides in ST-RAM * (then ST-RAM is the first memory block at virtual 0x0) */ - stram_start = phys_to_virt(0); - kernel_in_stram = (stram_start == 0); + kernel_in_stram = (m68k_memory[0].addr == 0); for (i = 0; i < m68k_num_memory; ++i) { if (m68k_memory[i].addr == 0) { @@ -89,24 +88,62 @@ void __init atari_stram_init(void) /* * This function is called from setup_arch() to reserve the pages needed for - * ST-RAM management. + * ST-RAM management, if the kernel resides in ST-RAM. */ void __init atari_stram_reserve_pages(void *start_mem) { - /* - * always reserve first page of ST-RAM, the first 2 KiB are - * supervisor-only! - */ - if (!kernel_in_stram) - reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT); + if (kernel_in_stram) { + pr_debug("atari_stram pool: kernel in ST-RAM, using alloc_bootmem!\n"); + stram_pool.start = (resource_size_t)alloc_bootmem_low_pages(pool_size); + stram_pool.end = stram_pool.start + pool_size - 1; + request_resource(&iomem_resource, &stram_pool); + stram_virt_offset = 0; + pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n", + pool_size, &stram_pool); + pr_debug("atari_stram pool: stram_virt_offset = %lx\n", + stram_virt_offset); + } +} - stram_pool.start = (resource_size_t)alloc_bootmem_low_pages(pool_size); - stram_pool.end = stram_pool.start + pool_size - 1; - request_resource(&iomem_resource, &stram_pool); - pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n", - pool_size, &stram_pool); +/* + * This function is called as arch initcall to reserve the pages needed for + * ST-RAM management, if the kernel does not reside in ST-RAM. + */ +int __init atari_stram_map_pages(void) +{ + if (!kernel_in_stram) { + /* + * Skip page 0, as the fhe first 2 KiB are supervisor-only! + */ + pr_debug("atari_stram pool: kernel not in ST-RAM, using ioremap!\n"); + stram_pool.start = PAGE_SIZE; + stram_pool.end = stram_pool.start + pool_size - 1; + request_resource(&iomem_resource, &stram_pool); + stram_virt_offset = (unsigned long) ioremap(stram_pool.start, + resource_size(&stram_pool)) - stram_pool.start; + pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n", + pool_size, &stram_pool); + pr_debug("atari_stram pool: stram_virt_offset = %lx\n", + stram_virt_offset); + } + return 0; +} +arch_initcall(atari_stram_map_pages); + + +void *atari_stram_to_virt(unsigned long phys) +{ + return (void *)(phys + stram_virt_offset); +} +EXPORT_SYMBOL(atari_stram_to_virt); + + +unsigned long atari_stram_to_phys(void *virt) +{ + return (unsigned long)(virt - stram_virt_offset); } +EXPORT_SYMBOL(atari_stram_to_phys); void *atari_stram_alloc(unsigned long size, const char *owner) @@ -134,14 +171,14 @@ void *atari_stram_alloc(unsigned long size, const char *owner) } pr_debug("atari_stram_alloc: returning %pR\n", res); - return (void *)res->start; + return atari_stram_to_virt(res->start); } EXPORT_SYMBOL(atari_stram_alloc); void atari_stram_free(void *addr) { - unsigned long start = (unsigned long)addr; + unsigned long start = atari_stram_to_phys(addr); struct resource *res; unsigned long size; diff --git a/arch/m68k/include/asm/atari_stram.h b/arch/m68k/include/asm/atari_stram.h index 62e27598af91..4e771c22d6a9 100644 --- a/arch/m68k/include/asm/atari_stram.h +++ b/arch/m68k/include/asm/atari_stram.h @@ -8,6 +8,8 @@ /* public interface */ void *atari_stram_alloc(unsigned long size, const char *owner); void atari_stram_free(void *); +void *atari_stram_to_virt(unsigned long phys); +unsigned long atari_stram_to_phys(void *); /* functions called internally by other parts of the kernel */ void atari_stram_init(void); -- 2.20.1