Re: [PATCH RFC V2 2/2] arm64: Pass RAM boundary and enable-dcache flag to purgatory

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

On 01/12/2016 02:12 PM, Pratyush Anand wrote:
> When "enable-dcache" is passed to the kexec() command line, kexec-tools
> passes this information to purgatory, which in turn enables cache during
> sha-256 verification.
>
> RAM boundary which includes all the sections is needed for creating
> identity page mapping and to enable d-cache for those areas. Therefore
> these informations are passed to purgatory as well.
>
> Signed-off-by: Pratyush Anand <panand@redhat.com>
> ---
>   kexec/arch/arm64/include/arch/options.h |  6 +++++-
>   kexec/arch/arm64/include/types.h        | 16 ++++++++++++++++
>   kexec/arch/arm64/kexec-arm64.c          | 24 +++++++++++++++++++++++-
>   purgatory/arch/arm64/entry.S            | 15 +++++++++++++++
>   purgatory/arch/arm64/purgatory-arm64.c  | 10 +++++++++-
>   5 files changed, 68 insertions(+), 3 deletions(-)
>   create mode 100644 kexec/arch/arm64/include/types.h
>
> diff --git a/kexec/arch/arm64/include/arch/options.h b/kexec/arch/arm64/include/arch/options.h
> index fbe17de595a9..3d84bb12ee37 100644
> --- a/kexec/arch/arm64/include/arch/options.h
> +++ b/kexec/arch/arm64/include/arch/options.h
> @@ -8,7 +8,8 @@
>   #define OPT_PORT		((OPT_MAX)+4)
>   #define OPT_REUSE_CMDLINE	((OPT_MAX)+5)
>   #define OPT_PORT_LSR		((OPT_MAX)+6)
> -#define OPT_ARCH_MAX		((OPT_MAX)+7)
> +#define OPT_ENABLE_DCACHE	((OPT_MAX)+7)
> +#define OPT_ARCH_MAX		((OPT_MAX)+8)
>
>   #define KEXEC_ARCH_OPTIONS \
>   	KEXEC_OPTIONS \
> @@ -20,6 +21,7 @@
>   	{ "port",         1, NULL, OPT_PORT }, \
>   	{ "port-lsr",     1, NULL, OPT_PORT_LSR }, \
>   	{ "ramdisk",      1, NULL, OPT_INITRD }, \
> +	{ "enable-dcache", 0, NULL, OPT_ENABLE_DCACHE }, \

in alphabetical order, please.

>   	{ "reuse-cmdline", 0, NULL, OPT_REUSE_CMDLINE }, \
>
>   #define KEXEC_ARCH_OPT_STR KEXEC_OPT_STR /* Only accept long arch options. */
> @@ -33,6 +35,7 @@ static const char arm64_opts_usage[] __attribute__ ((unused)) =
>   "     --initrd=FILE         Use FILE as the kernel initial ramdisk.\n"
>   "     --port=ADDRESS        Purgatory output to port ADDRESS.\n"
>   "     --port-lsr=ADDR,VAL   Purgatory output port line status address and TX Empty Bit Field.\n"
> +"     --enable-dcache       Enable D-Cache in Purgatory for faster SHA verification.\n"

ditto :)

-Takahiro AKASHI

>   "     --ramdisk=FILE        Use FILE as the kernel initial ramdisk.\n"
>   "     --reuse-cmdline       Use command line arg of primary kernel.\n";
>
> @@ -44,6 +47,7 @@ struct arm64_opts {
>   	uint64_t port;
>   	uint64_t port_lsr;
>   	uint32_t port_lsr_val;
> +	uint32_t enable_dcache;
>   };
>
>   extern struct arm64_opts arm64_opts;
> diff --git a/kexec/arch/arm64/include/types.h b/kexec/arch/arm64/include/types.h
> new file mode 100644
> index 000000000000..08f833a6d585
> --- /dev/null
> +++ b/kexec/arch/arm64/include/types.h
> @@ -0,0 +1,16 @@
> +#ifndef _TYPES_H_
> +#define _TYPES_H_
> +
> +#define min(x,y) ({ \
> +	typeof(x) _x = (x);	\
> +	typeof(y) _y = (y);	\
> +	(void) (&_x == &_y);	\
> +	_x < _y ? _x : _y; })
> +
> +#define max(x,y) ({ \
> +	typeof(x) _x = (x);	\
> +	typeof(y) _y = (y);	\
> +	(void) (&_x == &_y);	\
> +	_x > _y ? _x : _y; })
> +
> +#endif /* _TYPES_H_ */
> diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c
> index be9170af06e8..9b78b481f4a0 100644
> --- a/kexec/arch/arm64/kexec-arm64.c
> +++ b/kexec/arch/arm64/kexec-arm64.c
> @@ -29,6 +29,7 @@
>   #include "fs2dt.h"
>   #include "kexec-syscall.h"
>   #include "arch/options.h"
> +#include "types.h"
>
>   /* Global varables the core kexec routines expect. */
>
> @@ -103,6 +104,9 @@ int arch_process_options(int argc, char **argv)
>   			arm64_opts.port_lsr_val = strtoul(strtok(NULL, ","),
>   							NULL, 0);
>   			break;
> +		case OPT_ENABLE_DCACHE:
> +			arm64_opts.enable_dcache = 1;
> +			break;
>   		case OPT_PAGE_OFFSET:
>   			arm64_opts.page_offset = strtoull(optarg, NULL, 0);
>   			break;
> @@ -591,12 +595,15 @@ static uint64_t read_sink(const char *command_line)
>   int arm64_load_other_segments(struct kexec_info *info,
>   	uint64_t kernel_entry, char *option)
>   {
> -	int result;
> +	int result, i;
>   	uint64_t dtb_base;
> +	unsigned long arm64_ram_start = -1;
> +	unsigned long arm64_ram_end = 0;
>   	unsigned long hole_min, hole_max;
>   	uint64_t purgatory_sink;
>   	uint64_t purgatory_sink_lsr;
>   	uint32_t purgatory_sink_lsr_val;
> +	uint32_t purgatory_enable_dcache;
>   	struct mem_ehdr ehdr;
>   	char *initrd_buf = NULL;
>   	struct dtb dtb_1 = {.name = "dtb_1"};
> @@ -621,6 +628,7 @@ int arm64_load_other_segments(struct kexec_info *info,
>
>   	purgatory_sink_lsr = arm64_opts.port_lsr;
>   	purgatory_sink_lsr_val = arm64_opts.port_lsr_val;
> +	purgatory_enable_dcache = arm64_opts.enable_dcache;
>
>   	if (arm64_opts.dtb) {
>   		dtb_2.buf = slurp_file(arm64_opts.dtb, &dtb_2.size);
> @@ -724,11 +732,25 @@ int arm64_load_other_segments(struct kexec_info *info,
>   	elf_rel_set_symbol(&info->rhdr, "arm64_sink_lsr_val",
>   		&purgatory_sink_lsr_val, sizeof(purgatory_sink_lsr_val));
>
> +	elf_rel_set_symbol(&info->rhdr, "arm64_enable_dcache",
> +		&purgatory_enable_dcache, sizeof(purgatory_enable_dcache));
> +
>   	elf_rel_set_symbol(&info->rhdr, "arm64_kernel_entry", &kernel_entry,
>   		sizeof(kernel_entry));
>
>   	elf_rel_set_symbol(&info->rhdr, "arm64_dtb_addr", &dtb_base,
>   		sizeof(dtb_base));
> +	for (i = 0; i < info->nr_segments; i++) {
> +		arm64_ram_start = min(arm64_ram_start,
> +				(unsigned long)info->segment[i].mem);
> +		arm64_ram_end = max(arm64_ram_end,
> +				((unsigned long)info->segment[i].mem +
> +				 info->segment[i].memsz));
> +	}
> +	elf_rel_set_symbol(&info->rhdr, "arm64_ram_start",
> +			&arm64_ram_start, sizeof(arm64_ram_start));
> +	elf_rel_set_symbol(&info->rhdr, "arm64_ram_end",
> +			&arm64_ram_end, sizeof(arm64_ram_end));
>
>   	return 0;
>   }
> diff --git a/purgatory/arch/arm64/entry.S b/purgatory/arch/arm64/entry.S
> index be184e9a7469..d5563459d078 100644
> --- a/purgatory/arch/arm64/entry.S
> +++ b/purgatory/arch/arm64/entry.S
> @@ -63,7 +63,22 @@ arm64_kexec_lite:
>   	.quad	0
>   size arm64_kexec_lite
>
> +.globl arm64_ram_start
> +arm64_ram_start:
> +	.quad	0
> +size arm64_ram_start
> +
> +.globl arm64_ram_end
> +arm64_ram_end:
> +	.quad	0
> +size arm64_ram_end
> +
>   .globl arm64_sink_lsr_val
>   arm64_sink_lsr_val:
>   	.long	0
>   size arm64_sink_lsr_val
> +
> +.globl arm64_enable_dcache
> +arm64_enable_dcache:
> +	.long	0
> +size arm64_enable_dcache
> diff --git a/purgatory/arch/arm64/purgatory-arm64.c b/purgatory/arch/arm64/purgatory-arm64.c
> index bca802e0504d..70c01aee46e0 100644
> --- a/purgatory/arch/arm64/purgatory-arm64.c
> +++ b/purgatory/arch/arm64/purgatory-arm64.c
> @@ -4,14 +4,18 @@
>
>   #include <stdint.h>
>   #include <purgatory.h>
> +#include "cache.h"
>
>   /* Symbols set by kexec. */
>
>   extern uint32_t *arm64_sink;
>   extern uint32_t *arm64_sink_lsr;
>   extern uint32_t arm64_sink_lsr_val;
> +extern uint32_t arm64_enable_dcache;
>   extern void (*arm64_kernel_entry)(uint64_t, uint64_t, uint64_t, uint64_t);
>   extern uint64_t arm64_dtb_addr;
> +extern uint64_t arm64_ram_start;
> +extern uint64_t arm64_ram_end;
>
>   static void wait_for_xmit_complete(void)
>   {
> @@ -44,6 +48,8 @@ void putchar(int ch)
>
>   void post_verification_setup_arch(void)
>   {
> +	if (arm64_enable_dcache)
> +		disable_dcache(arm64_ram_start, arm64_ram_end);
>   	arm64_kernel_entry(arm64_dtb_addr, 0, 0, 0);
>   }
>
> @@ -51,5 +57,7 @@ void setup_arch(void)
>   {
>   	printf("purgatory: entry=%lx\n", (unsigned long)arm64_kernel_entry);
>   	printf("purgatory: dtb=%lx\n", arm64_dtb_addr);
> -}
>
> +	if (arm64_enable_dcache)
> +		enable_dcache(arm64_ram_start, arm64_ram_end, (uint64_t)arm64_sink);
> +}
>

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