From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp07.in.ibm.com (e28smtp07.in.ibm.com [125.16.236.7]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id BAAC51A005D for ; Mon, 7 Mar 2016 20:56:35 +1100 (AEDT) Received: from localhost by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 7 Mar 2016 15:26:27 +0530 Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay02.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u279u2wQ37683296 for ; Mon, 7 Mar 2016 15:26:03 +0530 Received: from d28av01.in.ibm.com (localhost [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u27FPEKo015841 for ; Mon, 7 Mar 2016 20:55:15 +0530 From: Anshuman Khandual To: linuxppc-dev@lists.ozlabs.org Cc: aneesh.kumar@linux.vnet.ibm.com, mpe@ellerman.id.au Subject: [PATCH V2] powerpc/mm: Add validation for platform reserved memory ranges Date: Mon, 7 Mar 2016 15:25:59 +0530 Message-Id: <1457344559-2505-1-git-send-email-khandual@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , For partition running on PHYP, there can be a adjunct partition which shares the virtual address range with the operating system. Virtual address ranges which can be used by the adjunct partition are communicated with virtual device node of the device tree with a property known as "ibm,reserved-virtual-addresses". This patch introduces a new function named 'validate_reserved_va_range' which is called during initialization to validate that these reserved virtual address ranges do not overlap with the address ranges used by the kernel for all supported memory contexts. This helps prevent the possibility of getting return codes similar to H_RESOURCE for H_PROTECT hcalls for conflicting HPTE entries. Signed-off-by: Anshuman Khandual --- - Tested on both POWER8 LE and BE platforms Changes in V2: - Added braces to the definition of LINUX_VA_BITS - Adjusted tabs as spaces for the definition of PARTIAL_LINUX_VA_MASK arch/powerpc/mm/hash_utils_64.c | 77 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index ba59d59..b47f667 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -1564,3 +1564,80 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base, /* Finally limit subsequent allocations */ memblock_set_current_limit(ppc64_rma_size); } + +/* + * PAPR says that each reserved virtual address range record + * contains three be32 elements which is of toal 12 bytes. + * First two be32 elements contain the abbreviated virtual + * address (high order 32 bits and low order 32 bits that + * generate the abbreviated virtual address of 64 bits which + * need to be concatenated with 24 bits of 0 at the end) and + * the third be32 element contains the size of the reserved + * virtual address range as number of consecutive 4K pages. + */ +struct reserved_va_record { + __be32 high_addr; + __be32 low_addr; + __be32 nr_pages_4K; +}; + +/* + * Linux uses 65 bits (CONTEXT_BITS + ESID_BITS + SID_SHIFT) + * of virtual address. As reserved virtual address comes in + * as an abbreviated form (64 bits) from the device tree, we + * will use a partial address bit mask (65 >> 24) to match it + * for simplicity. + */ +#define RVA_LESS_BITS 24 +#define LINUX_VA_BITS (CONTEXT_BITS + ESID_BITS + SID_SHIFT) +#define PARTIAL_LINUX_VA_MASK ((1ULL << (LINUX_VA_BITS - RVA_LESS_BITS)) - 1) + +static int __init validate_reserved_va_range(void) +{ + struct reserved_va_record rva; + struct device_node *np; + int records, ret, i; + __be64 vaddr; + + np = of_find_node_by_name(NULL, "vdevice"); + if (!np) + return -ENODEV; + + records = of_property_count_elems_of_size(np, + "ibm,reserved-virtual-addresses", + sizeof(struct reserved_va_record)); + if (records < 0) + return records; + + for (i = 0; i < records; i++) { + ret = of_property_read_u32_index(np, + "ibm,reserved-virtual-addresses", + 3 * i, &rva.high_addr); + if (ret) + return ret; + + ret = of_property_read_u32_index(np, + "ibm,reserved-virtual-addresses", + 3 * i + 1, &rva.low_addr); + if (ret) + return ret; + + ret = of_property_read_u32_index(np, + "ibm,reserved-virtual-addresses", + 3 * i + 2, &rva.nr_pages_4K); + if (ret) + return ret; + + vaddr = rva.high_addr; + vaddr = (vaddr << 32) | rva.low_addr; + if (vaddr & cpu_to_be64(~PARTIAL_LINUX_VA_MASK)) + continue; + + pr_err("RVA [0x%llx000000 (0x%x in bytes)] overlapped\n", + vaddr, rva.nr_pages_4K * 4096); + BUG(); + } + of_node_put(np); + return 0; +} +__initcall(validate_reserved_va_range); -- 2.1.0