Re: [Qemu-devel] [RESEND PATCH 14/23] hw/acpi/aml-build: Add ToUUID macro

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 20 May 2015 19:02:12 +0800
Shannon Zhao <zhaoshenglong@huawei.com> wrote:

> 
> 
> On 2015/5/20 18:57, Igor Mammedov wrote:
> > On Wed, 20 May 2015 12:19:55 +0800
> > Shannon Zhao <zhaoshenglong@huawei.com> wrote:
> > 
> >> From: Shannon Zhao <shannon.zhao@linaro.org>
> >>
> >> Add ToUUID macro, this is useful for generating PCIe ACPI table.
> >>
> >> Signed-off-by: Shannon Zhao <zhaoshenglong@huawei.com>
> >> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> >> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
> > Please remove my RB in cases when changes in patch are not trivial.
> > 
> 
> Ok, forgot this.
> 
> >> ---
> >>  hw/acpi/aml-build.c         | 112 ++++++++++++++++++++++++++++++++++++++++++++
> >>  include/hw/acpi/aml-build.h |   1 +
> >>  2 files changed, 113 insertions(+)
> >>
> >> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> >> index 7fcc44e..bdcbad2 100644
> >> --- a/hw/acpi/aml-build.c
> >> +++ b/hw/acpi/aml-build.c
> >> @@ -28,6 +28,8 @@
> >>  #include "qemu/bswap.h"
> >>  #include "qemu/bitops.h"
> >>  #include "hw/acpi/bios-linker-loader.h"
> >> +#include "qapi/error.h"
> >> +#include "qemu-common.h"
> >>  
> >>  static GArray *build_alloc_array(void)
> >>  {
> >> @@ -955,6 +957,116 @@ Aml *aml_qword_memory(AmlDecode dec, AmlMinFixed min_fixed,
> >>                               addr_trans, len, flags);
> >>  }
> >>  
> >> +static void String2Byte(const char *str, uint8_t *byte_list)
> >> +{
> >> +    unsigned long long val;
> >> +    char *end;
> >> +    const char *start = str;
> >> +    int i, j = 0;
> >> +    Error *err = NULL;
> >> +
> >> +    if (strlen(str) != 36) {
> >> +        error_setg(&err, "Length of UUID string is not 36");
> >> +        goto error;
> >> +    }
> >> +
> >> +    val = strtoull(start, &end, 16);
> >> +    if ((end - start) != 8) {
> >> +        error_setg(&err, "Length of first part of UUID string is not 8");
> >> +        goto error;
> >> +    }
> >> +    for (i = 3; i >= 0; i--) {
> >> +        byte_list[j] = extract32(val, (8 * i), 8);
> >> +        j++;
> >> +    }
> >> +    start = end + 1;
> >> +
> >> +    val = strtoull(start, &end, 16);
> >> +    if ((end - start) != 4) {
> >> +        error_setg(&err, "Length of second part of UUID string is not 4");
> >> +        goto error;
> >> +    }
> >> +    for (i = 1; i >= 0; i--) {
> >> +        byte_list[j] = extract32(val, (8 * i), 8);
> >> +        j++;
> >> +    }
> >> +    start = end + 1;
> >> +
> >> +    val = strtoull(start, &end, 16);
> >> +    if ((end - start) != 4) {
> >> +        error_setg(&err, "Length of third part of UUID string is not 4");
> >> +        goto error;
> >> +    }
> >> +    for (i = 1; i >= 0; i--) {
> >> +        byte_list[j] = extract32(val, (8 * i), 8);
> >> +        j++;
> >> +    }
> >> +    start = end + 1;
> >> +
> >> +    val = strtoull(start, &end, 16);
> >> +    if ((end - start) != 4) {
> >> +        error_setg(&err, "Length of fourth part of UUID string is not 4");
> >> +        goto error;
> >> +    }
> >> +    for (i = 1; i >= 0; i--) {
> >> +        byte_list[j] = extract32(val, (8 * i), 8);
> >> +        j++;
> >> +    }
> >> +    start = end + 1;
> >> +
> >> +    val = strtoull(start, &end, 16);
> >> +    if ((end - start) != 12) {
> >> +        error_setg(&err, "Length of fifth part of UUID string is not 12");
> >> +        goto error;
> >> +    }
> >> +    for (i = 5; i >= 0; i--) {
> >> +        byte_list[j] = extract64(val, (8 * i), 8);
> >> +        j++;
> >> +    }
> >> +
> >> +    return;
> >> +
> >> +error:
> >> +    error_report_err(err);
> >> +    exit(1);
> >> +}
> > To me this looks just crazy,
> > I find the previous patch much easier to read/understand
> > 
> > maybe previous patch +separated asserts as was suggested
> > an earlier.
> > 
> 
> Michael suggests add a pre-parse function to parse the string to bytes
> list.
As you see result is more complex than original approach,
without clear benefits.

> 
> On 2015/5/19 16:37, Michael S. Tsirkin wrote:>>> Why doesn't that
> something else give us a pre-parse structure then?
> >>> > >
> >> >
> >> > a pre-parse structure?
> > Yes - have caller validate and parse the string, on failure report
> > it to user cleanly, on success give us a byte array
> > avoiding need to call Hex2Byte.
> >
> 
> 
> > 
> >> +
> >> +/*
> >> + * ACPI 3.0: 17.5.124 ToUUID (Convert String to UUID Macro)
> >> + * e.g. UUID: aabbccdd-eeff-gghh-iijj-kkllmmnnoopp
> >> + * call aml_touuid("aabbccdd-eeff-gghh-iijj-kkllmmnnoopp");
> >> + */
> >> +Aml *aml_touuid(const char *uuid)
> >> +{
> >> +    Aml *var = aml_bundle(0x11 /* BufferOp */, AML_BUFFER);
> >> +    uint8_t byte_list[16];
> >> +
> >> +    String2Byte(uuid, byte_list);
> >> +
> >> +    build_append_byte(var->buf, byte_list[3]); /* dd - at offset 00 */
> >> +    build_append_byte(var->buf, byte_list[2]); /* cc - at offset 01 */
> >> +    build_append_byte(var->buf, byte_list[1]); /* bb - at offset 02 */
> >> +    build_append_byte(var->buf, byte_list[0]); /* aa - at offset 03 */
> >> +
> >> +    build_append_byte(var->buf, byte_list[5]); /* ff - at offset 04 */
> >> +    build_append_byte(var->buf, byte_list[4]); /* ee - at offset 05 */
> >> +
> >> +    build_append_byte(var->buf, byte_list[7]); /* hh - at offset 06 */
> >> +    build_append_byte(var->buf, byte_list[6]); /* gg - at offset 07 */
> >> +
> >> +    build_append_byte(var->buf, byte_list[8]); /* ii - at offset 08 */
> >> +    build_append_byte(var->buf, byte_list[9]); /* jj - at offset 09 */
> >> +
> >> +    build_append_byte(var->buf, byte_list[10]); /* kk - at offset 10 */
> >> +    build_append_byte(var->buf, byte_list[11]); /* ll - at offset 11 */
> >> +    build_append_byte(var->buf, byte_list[12]); /* mm - at offset 12 */
> >> +    build_append_byte(var->buf, byte_list[13]); /* nn - at offset 13 */
> >> +    build_append_byte(var->buf, byte_list[14]); /* oo - at offset 14 */
> >> +    build_append_byte(var->buf, byte_list[15]); /* pp - at offset 15 */
> >> +
> >> +    return var;
> >> +}
> >> +
> >>  void
> >>  build_header(GArray *linker, GArray *table_data,
> >>               AcpiTableHeader *h, const char *sig, int len, uint8_t rev)
> >> diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> >> index fac70ea..a873b46 100644
> >> --- a/include/hw/acpi/aml-build.h
> >> +++ b/include/hw/acpi/aml-build.h
> >> @@ -257,6 +257,7 @@ Aml *aml_buffer(int buffer_size, uint8_t *byte_list);
> >>  Aml *aml_resource_template(void);
> >>  Aml *aml_field(const char *name, AmlAccessType type, AmlUpdateRule rule);
> >>  Aml *aml_varpackage(uint32_t num_elements);
> >> +Aml *aml_touuid(const char *uuid);
> >>  
> >>  void
> >>  build_header(GArray *linker, GArray *table_data,
> > 
> > 
> > .
> > 
>