| Message ID | 20200510203409.203520-11-sjg@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | dm: Add programmatic generation of ACPI tables (part B) | expand |
Hi Simon, -----"Simon Glass" <sjg at chromium.org> schrieb: ----- > Betreff: [PATCH v2 13/35] acpigen: Support writing a length > > It is convenient to write a length value for preceding a block of data. > Of course the length is not known or is hard to calculate a priori. So add > a way to mark the start on a stack, so the length can be updated when > known. > > Signed-off-by: Simon Glass <sjg at chromium.org> > --- > > Changes in v2: None > Changes in v1: None > > include/acpi/acpigen.h | 3 ++ > include/dm/acpi.h | 7 +++++ > lib/acpi/acpigen.c | 33 ++++++++++++++++++++++ > test/dm/acpigen.c | 64 ++++++++++++++++++++++++++++++++++++++++-- > 4 files changed, 105 insertions(+), 2 deletions(-) > > diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h > index 7365cce738..31366f5e34 100644 > --- a/include/acpi/acpigen.h > +++ b/include/acpi/acpigen.h > @@ -65,4 +65,7 @@ void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size); > */ > void acpigen_emit_string(struct acpi_ctx *ctx, const char *str); > > +void acpigen_write_len_f(struct acpi_ctx *ctx); > +void acpigen_pop_len(struct acpi_ctx *ctx); > + > #endif > diff --git a/include/dm/acpi.h b/include/dm/acpi.h > index 7563a4c60a..2bd03eaa0a 100644 > --- a/include/dm/acpi.h > +++ b/include/dm/acpi.h > @@ -22,6 +22,9 @@ > /* Length of an ACPI name string including nul terminator */ > #define ACPI_NAME_MAX (ACPI_NAME_LEN + 1) > > +/* Number of nested objects supported */ > +#define ACPIGEN_LENSTACK_SIZE 10 > + > #if !defined(__ACPI__) > > /** > @@ -34,12 +37,16 @@ > * adding a new table. The RSDP holds pointers to the RSDT and XSDT. > * @rsdt: Pointer to the Root System Description Table > * @xsdt: Pointer to the Extended System Description Table > + * @len_stack: Stack of 'length' words to fix up later > + * @ltop: Points to current top of stack (0 = empty) > */ > struct acpi_ctx { > void *current; > struct acpi_rsdp *rsdp; > struct acpi_rsdt *rsdt; > struct acpi_xsdt *xsdt; > + char *len_stack[ACPIGEN_LENSTACK_SIZE]; > + int ltop; > }; > > /** > diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c > index 1223f0d1c4..bd1fa24fb6 100644 > --- a/lib/acpi/acpigen.c > +++ b/lib/acpi/acpigen.c > @@ -10,6 +10,7 @@ > > #include <common.h> > #include <dm.h> > +#include <log.h> > #include <acpi/acpigen.h> > #include <dm/acpi.h> > > @@ -37,6 +38,38 @@ void acpigen_emit_dword(struct acpi_ctx *ctx, uint data) > acpigen_emit_byte(ctx, (data >> 24) & 0xff); > } > > +/* > + * Maximum length for an ACPI object generated by this code, > + * > + * If you need to change this, change acpigen_write_len_f(ctx) and > + * acpigen_pop_len(ctx) > + */ > +#define ACPIGEN_MAXLEN 0xfffff > + > +void acpigen_write_len_f(struct acpi_ctx *ctx) > +{ > + assert(ctx->ltop < (ACPIGEN_LENSTACK_SIZE - 1)); > + ctx->len_stack[ctx->ltop++] = ctx->current; > + acpigen_emit_byte(ctx, 0); > + acpigen_emit_byte(ctx, 0); > + acpigen_emit_byte(ctx, 0); > +} > + > +void acpigen_pop_len(struct acpi_ctx *ctx) > +{ > + int len; > + char *p; > + > + assert(ctx->ltop > 0); > + p = ctx->len_stack[--ctx->ltop]; > + len = ctx->current - (void *)p; > + assert(len <= ACPIGEN_MAXLEN); > + /* generate store length for 0xfffff max */ > + p[0] = (0x80 | (len & 0xf)); Nit: Without context this code is hard to understand. I would propose adding a comment pointing to "ACPI 6.3 20.2.4 Package Length Encoding" and using a define for 0x80 (something like ACPI_PKG_LEN_3_BYTES ...). > + p[1] = (len >> 4 & 0xff); > + p[2] = (len >> 12 & 0xff); > +} > + > void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size) > { > int i; > diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c > index 3d580a23a5..f9c15b7503 100644 > --- a/test/dm/acpigen.c > +++ b/test/dm/acpigen.c > @@ -22,7 +22,7 @@ > #define TEST_STRING "frogmore" > #define TEST_STREAM2 "\xfa\xde" > > -static int alloc_context(struct acpi_ctx **ctxp) > +static int alloc_context_size(struct acpi_ctx **ctxp, int size) > { > struct acpi_ctx *ctx; > > @@ -30,7 +30,8 @@ static int alloc_context(struct acpi_ctx **ctxp) > ctx = malloc(sizeof(*ctx)); > if (!ctx) > return -ENOMEM; > - ctx->current = malloc(150); > + ctx->current = malloc(size); > + ctx->ltop = 0; > if (!ctx->current) > return -ENOMEM; > *ctxp = ctx; > @@ -38,6 +39,11 @@ static int alloc_context(struct acpi_ctx **ctxp) > return 0; > } > > +static int alloc_context(struct acpi_ctx **ctxp) > +{ > + return alloc_context_size(ctxp, 150); > +} > + > static void free_context(struct acpi_ctx **ctxp) > { > free(*ctxp); > @@ -334,3 +340,57 @@ static int dm_test_acpi_spi(struct unit_test_state *uts) > return 0; > } > DM_TEST(dm_test_acpi_spi, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT); > + > +/** > + * get_length() - decode a three-byte length field > + * > + * @ptr: Length encoded as per ACPI > + * @return decoded length, or -EINVAL on error > + */ > +static int get_length(u8 *ptr) > +{ > + if (!(*ptr & 0x80)) > + return -EINVAL; > + > + return (*ptr & 0xf) | ptr[1] << 4 | ptr[2] << 12; > +} > + > +/* Test emitting a length */ > +static int dm_test_acpi_len(struct unit_test_state *uts) > +{ > + const int size = 0xc0000; > + struct acpi_ctx *ctx; > + u8 *ptr; > + int i; > + > + ut_assertok(alloc_context_size(&ctx, size)); > + > + ptr = acpigen_get_current(ctx); > + > + /* Write a byte and a 3-byte length */ > + acpigen_write_len_f(ctx); > + acpigen_emit_byte(ctx, 0x23); > + acpigen_pop_len(ctx); > + ut_asserteq(1 + 3, get_length(ptr)); > + > + /* Write 200 bytes so we need two length bytes */ > + ptr = ctx->current; > + acpigen_write_len_f(ctx); > + for (i = 0; i < 200; i++) > + acpigen_emit_byte(ctx, 0x23); > + acpigen_pop_len(ctx); > + ut_asserteq(200 + 3, get_length(ptr)); > + > + /* Write 40KB so we need three length bytes */ > + ptr = ctx->current; > + acpigen_write_len_f(ctx); > + for (i = 0; i < 40000; i++) > + acpigen_emit_byte(ctx, 0x23); > + acpigen_pop_len(ctx); > + ut_asserteq(40000 + 3, get_length(ptr)); > + > + free_context(&ctx); > + > + return 0; > +} > +DM_TEST(dm_test_acpi_len, 0); > -- > 2.26.2.645.ge9eca65c58-goog > Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h index 7365cce738..31366f5e34 100644 --- a/include/acpi/acpigen.h +++ b/include/acpi/acpigen.h @@ -65,4 +65,7 @@ void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size); */ void acpigen_emit_string(struct acpi_ctx *ctx, const char *str); +void acpigen_write_len_f(struct acpi_ctx *ctx); +void acpigen_pop_len(struct acpi_ctx *ctx); + #endif diff --git a/include/dm/acpi.h b/include/dm/acpi.h index 7563a4c60a..2bd03eaa0a 100644 --- a/include/dm/acpi.h +++ b/include/dm/acpi.h @@ -22,6 +22,9 @@ /* Length of an ACPI name string including nul terminator */ #define ACPI_NAME_MAX (ACPI_NAME_LEN + 1) +/* Number of nested objects supported */ +#define ACPIGEN_LENSTACK_SIZE 10 + #if !defined(__ACPI__) /** @@ -34,12 +37,16 @@ * adding a new table. The RSDP holds pointers to the RSDT and XSDT. * @rsdt: Pointer to the Root System Description Table * @xsdt: Pointer to the Extended System Description Table + * @len_stack: Stack of 'length' words to fix up later + * @ltop: Points to current top of stack (0 = empty) */ struct acpi_ctx { void *current; struct acpi_rsdp *rsdp; struct acpi_rsdt *rsdt; struct acpi_xsdt *xsdt; + char *len_stack[ACPIGEN_LENSTACK_SIZE]; + int ltop; }; /** diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c index 1223f0d1c4..bd1fa24fb6 100644 --- a/lib/acpi/acpigen.c +++ b/lib/acpi/acpigen.c @@ -10,6 +10,7 @@ #include <common.h> #include <dm.h> +#include <log.h> #include <acpi/acpigen.h> #include <dm/acpi.h> @@ -37,6 +38,38 @@ void acpigen_emit_dword(struct acpi_ctx *ctx, uint data) acpigen_emit_byte(ctx, (data >> 24) & 0xff); } +/* + * Maximum length for an ACPI object generated by this code, + * + * If you need to change this, change acpigen_write_len_f(ctx) and + * acpigen_pop_len(ctx) + */ +#define ACPIGEN_MAXLEN 0xfffff + +void acpigen_write_len_f(struct acpi_ctx *ctx) +{ + assert(ctx->ltop < (ACPIGEN_LENSTACK_SIZE - 1)); + ctx->len_stack[ctx->ltop++] = ctx->current; + acpigen_emit_byte(ctx, 0); + acpigen_emit_byte(ctx, 0); + acpigen_emit_byte(ctx, 0); +} + +void acpigen_pop_len(struct acpi_ctx *ctx) +{ + int len; + char *p; + + assert(ctx->ltop > 0); + p = ctx->len_stack[--ctx->ltop]; + len = ctx->current - (void *)p; + assert(len <= ACPIGEN_MAXLEN); + /* generate store length for 0xfffff max */ + p[0] = (0x80 | (len & 0xf)); + p[1] = (len >> 4 & 0xff); + p[2] = (len >> 12 & 0xff); +} + void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size) { int i; diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c index 3d580a23a5..f9c15b7503 100644 --- a/test/dm/acpigen.c +++ b/test/dm/acpigen.c @@ -22,7 +22,7 @@ #define TEST_STRING "frogmore" #define TEST_STREAM2 "\xfa\xde" -static int alloc_context(struct acpi_ctx **ctxp) +static int alloc_context_size(struct acpi_ctx **ctxp, int size) { struct acpi_ctx *ctx; @@ -30,7 +30,8 @@ static int alloc_context(struct acpi_ctx **ctxp) ctx = malloc(sizeof(*ctx)); if (!ctx) return -ENOMEM; - ctx->current = malloc(150); + ctx->current = malloc(size); + ctx->ltop = 0; if (!ctx->current) return -ENOMEM; *ctxp = ctx; @@ -38,6 +39,11 @@ static int alloc_context(struct acpi_ctx **ctxp) return 0; } +static int alloc_context(struct acpi_ctx **ctxp) +{ + return alloc_context_size(ctxp, 150); +} + static void free_context(struct acpi_ctx **ctxp) { free(*ctxp); @@ -334,3 +340,57 @@ static int dm_test_acpi_spi(struct unit_test_state *uts) return 0; } DM_TEST(dm_test_acpi_spi, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT); + +/** + * get_length() - decode a three-byte length field + * + * @ptr: Length encoded as per ACPI + * @return decoded length, or -EINVAL on error + */ +static int get_length(u8 *ptr) +{ + if (!(*ptr & 0x80)) + return -EINVAL; + + return (*ptr & 0xf) | ptr[1] << 4 | ptr[2] << 12; +} + +/* Test emitting a length */ +static int dm_test_acpi_len(struct unit_test_state *uts) +{ + const int size = 0xc0000; + struct acpi_ctx *ctx; + u8 *ptr; + int i; + + ut_assertok(alloc_context_size(&ctx, size)); + + ptr = acpigen_get_current(ctx); + + /* Write a byte and a 3-byte length */ + acpigen_write_len_f(ctx); + acpigen_emit_byte(ctx, 0x23); + acpigen_pop_len(ctx); + ut_asserteq(1 + 3, get_length(ptr)); + + /* Write 200 bytes so we need two length bytes */ + ptr = ctx->current; + acpigen_write_len_f(ctx); + for (i = 0; i < 200; i++) + acpigen_emit_byte(ctx, 0x23); + acpigen_pop_len(ctx); + ut_asserteq(200 + 3, get_length(ptr)); + + /* Write 40KB so we need three length bytes */ + ptr = ctx->current; + acpigen_write_len_f(ctx); + for (i = 0; i < 40000; i++) + acpigen_emit_byte(ctx, 0x23); + acpigen_pop_len(ctx); + ut_asserteq(40000 + 3, get_length(ptr)); + + free_context(&ctx); + + return 0; +} +DM_TEST(dm_test_acpi_len, 0);
It is convenient to write a length value for preceding a block of data. Of course the length is not known or is hard to calculate a priori. So add a way to mark the start on a stack, so the length can be updated when known. Signed-off-by: Simon Glass <sjg at chromium.org> --- Changes in v2: None Changes in v1: None include/acpi/acpigen.h | 3 ++ include/dm/acpi.h | 7 +++++ lib/acpi/acpigen.c | 33 ++++++++++++++++++++++ test/dm/acpigen.c | 64 ++++++++++++++++++++++++++++++++++++++++-- 4 files changed, 105 insertions(+), 2 deletions(-)