From mboxrd@z Thu Jan 1 00:00:00 1970 From: Terry Loftin Date: Wed, 11 Oct 2006 22:40:51 +0000 Subject: [PATCH] kexec-tools: ia64: icache flush should align to 32-bytes Message-Id: <452D72F3.50107@hp.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Hi, I've run into problems testing kexec/kdump on a Montecito revision C processor. In purgatory, __dummy_efi_function is copied onto the end of the command line boot parameter (command_line + command_line_len) and this address is used to replace the EFI call to set_virtual_address_map(). The copied range is then icache flushed. The destination address is aligned to 16-bytes (in kexec-elf-ia64.c), but the fc.i instruction flushes a 32-byte range "associated" with that address. When my command line length is 16-byte aligned but not 32-byte aligned, this results in the first 16-bytes of __dummy_efi_function getting flushed (and the 16 bytes prior to that), but the second half of the function (the part with the br.ret) does not get flushed. kdump then hangs in purgatory. By adding a few spaces to my command line, it becomes both 16 and 32-byte aligned, and kdump works. This patch makes icache_flush_range() align the start address to 32-bytes and account for the difference. The patch is against Horms kexec-tools-testing tree. As a side note, you could also fix this by just adding 32 to the length passed to flush_icache_range() but that hides the dependent behavior. Thanks, -T --- kexec-tools-testing/purgatory/arch/ia64/purgatory-ia64.c 2006-10-06 13:40:50.000000000 -0600 +++ kexec-tools-testing-new/purgatory/arch/ia64/purgatory-ia64.c 2006-10-11 16:05:06.000000000 -0600 @@ -222,7 +222,9 @@ void flush_icache_range(char *start, unsigned long len) { - unsigned long i; + unsigned long i,addr; + addr = (unsigned long)start & ~31UL; + len += (unsigned long)start - addr; for (i = 0;i < len; i += 32) asm volatile("fc.i %0"::"r"(start + i):"memory"); asm volatile (";;sync.i;;":::"memory");