On Monday, December 11, 2017 4:50:58 PM CET Prarit Bhargava wrote: > Other architectures can use SPCR to setup an early console or console > but the current code is ARM64 specific. > > Change the name of parse_spcr() to acpi_parse_spcr(). Add a weak > function acpi_arch_setup_console() that can be used for arch-specific > setup. Move flags into ACPI code. Update the Documention on the use of > the SPCR. > > [v2]: Don't return an error in the baud_rate check of acpi_parse_spcr(). > Keep ACPI_SPCR_TABLE selected for ARM64. Fix 8-bit port access width > mmio value. Move baud rate check earlier. > > Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx> This mostly affects ARM64, so ACKs from that side are requisite for it. > Cc: linux-doc@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: linux-pm@xxxxxxxxxxxxxxx > Cc: linux-acpi@xxxxxxxxxxxxxxx > Cc: linux-serial@xxxxxxxxxxxxxxx > Cc: Bhupesh Sharma <bhsharma@xxxxxxxxxx> > Cc: Lv Zheng <lv.zheng@xxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> > Cc: x86@xxxxxxxxxx > Cc: Jonathan Corbet <corbet@xxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Will Deacon <will.deacon@xxxxxxx> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> > Cc: Timur Tabi <timur@xxxxxxxxxxxxxx> > --- > Documentation/admin-guide/kernel-parameters.txt | 6 +- > arch/arm64/kernel/acpi.c | 128 ++++++++++++++++- > drivers/acpi/Kconfig | 7 +- > drivers/acpi/spcr.c | 175 ++++++------------------ > drivers/tty/serial/earlycon.c | 15 +- > include/linux/acpi.h | 11 +- > include/linux/serial_core.h | 2 - > 7 files changed, 184 insertions(+), 160 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 6571fbfdb2a1..0d173289c67e 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -914,9 +914,9 @@ > > earlycon= [KNL] Output early console device and options. > > - When used with no options, the early console is > - determined by the stdout-path property in device > - tree's chosen node. > + [ARM64] The early console is determined by the > + stdout-path property in device tree's chosen node, > + or determined by the ACPI SPCR table. > > cdns,<addr>[,options] > Start an early, polled-mode console on a Cadence > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > index b3162715ed78..b3e33bbdf3b7 100644 > --- a/arch/arm64/kernel/acpi.c > +++ b/arch/arm64/kernel/acpi.c > @@ -25,7 +25,6 @@ > #include <linux/memblock.h> > #include <linux/of_fdt.h> > #include <linux/smp.h> > -#include <linux/serial_core.h> > > #include <asm/cputype.h> > #include <asm/cpu_ops.h> > @@ -177,6 +176,128 @@ static int __init acpi_fadt_sanity_check(void) > return ret; > } > > +/* > + * Erratum 44 for QDF2432v1 and QDF2400v1 SoCs describes the BUSY bit as > + * occasionally getting stuck as 1. To avoid the potential for a hang, check > + * TXFE == 0 instead of BUSY == 1. This may not be suitable for all UART > + * implementations, so only do so if an affected platform is detected in > + * acpi_parse_spcr(). > + */ > +bool qdf2400_e44_present; > +EXPORT_SYMBOL(qdf2400_e44_present); > + > +/* > + * Some Qualcomm Datacenter Technologies SoCs have a defective UART BUSY bit. > + * Detect them by examining the OEM fields in the SPCR header, similar to PCI > + * quirk detection in pci_mcfg.c. > + */ > +static bool qdf2400_erratum_44_present(struct acpi_table_header *h) > +{ > + if (memcmp(h->oem_id, "QCOM ", ACPI_OEM_ID_SIZE)) > + return false; > + > + if (!memcmp(h->oem_table_id, "QDF2432 ", ACPI_OEM_TABLE_ID_SIZE)) > + return true; > + > + if (!memcmp(h->oem_table_id, "QDF2400 ", ACPI_OEM_TABLE_ID_SIZE) && > + h->oem_revision == 1) > + return true; > + > + return false; > +} > + > +/* > + * APM X-Gene v1 and v2 UART hardware is an 16550 like device but has its > + * register aligned to 32-bit. In addition, the BIOS also encoded the > + * access width to be 8 bits. This function detects this errata condition. > + */ > +static bool xgene_8250_erratum_present(struct acpi_table_spcr *tb) > +{ > + bool xgene_8250 = false; > + > + if (tb->interface_type != ACPI_DBG2_16550_COMPATIBLE) > + return false; > + > + if (memcmp(tb->header.oem_id, "APMC0D", ACPI_OEM_ID_SIZE) && > + memcmp(tb->header.oem_id, "HPE ", ACPI_OEM_ID_SIZE)) > + return false; > + > + if (!memcmp(tb->header.oem_table_id, "XGENESPC", > + ACPI_OEM_TABLE_ID_SIZE) && tb->header.oem_revision == 0) > + xgene_8250 = true; > + > + if (!memcmp(tb->header.oem_table_id, "ProLiant", > + ACPI_OEM_TABLE_ID_SIZE) && tb->header.oem_revision == 1) > + xgene_8250 = true; > + > + return xgene_8250; > +} > + > +int acpi_arch_setup_console(struct acpi_table_spcr *table, > + char *opts, char *uart, char *iotype, > + int baud_rate, bool earlycon) > +{ > + if (table->header.revision < 2) { > + pr_err("wrong table version\n"); > + return -ENOENT; > + } > + > + switch (table->interface_type) { > + case ACPI_DBG2_ARM_SBSA_32BIT: > + snprintf(iotype, ACPI_SPCR_BUF_SIZE, "mmio32"); > + /* fall through */ > + case ACPI_DBG2_ARM_PL011: > + case ACPI_DBG2_ARM_SBSA_GENERIC: > + case ACPI_DBG2_BCM2835: > + snprintf(uart, ACPI_SPCR_BUF_SIZE, "pl011"); > + break; > + default: > + if (strlen(uart) == 0) > + return -ENOENT; > + } > + > + /* > + * If the E44 erratum is required, then we need to tell the pl011 > + * driver to implement the work-around. > + * > + * The global variable is used by the probe function when it > + * creates the UARTs, whether or not they're used as a console. > + * > + * If the user specifies "traditional" earlycon, the qdf2400_e44 > + * console name matches the EARLYCON_DECLARE() statement, and > + * SPCR is not used. Parameter "earlycon" is false. > + * > + * If the user specifies "SPCR" earlycon, then we need to update > + * the console name so that it also says "qdf2400_e44". Parameter > + * "earlycon" is true. > + * > + * For consistency, if we change the console name, then we do it > + * for everyone, not just earlycon. > + */ > + if (qdf2400_erratum_44_present(&table->header)) { > + qdf2400_e44_present = true; > + if (earlycon) > + snprintf(uart, ACPI_SPCR_BUF_SIZE, "qdf2400_e44"); > + } > + > + if (xgene_8250_erratum_present(table)) { > + snprintf(iotype, ACPI_SPCR_BUF_SIZE, "mmio32"); > + > + /* for xgene v1 and v2 we don't know the clock rate of the > + * UART so don't attempt to change to the baud rate state > + * in the table because driver cannot calculate the dividers > + */ > + snprintf(opts, ACPI_SPCR_OPTS_SIZE, "%s,%s,0x%llx", uart, > + iotype, table->serial_port.address); > + } else { > + snprintf(opts, ACPI_SPCR_OPTS_SIZE, "%s,%s,0x%llx,%d", uart, > + iotype, table->serial_port.address, baud_rate); > + } > + > + return 0; > +} > +EXPORT_SYMBOL(acpi_arch_setup_console); > + > /* > * acpi_boot_table_init() called from setup_arch(), always. > * 1. find RSDP and get its address, and then find XSDT > @@ -230,10 +351,11 @@ void __init acpi_boot_table_init(void) > > done: > if (acpi_disabled) { > - if (earlycon_init_is_deferred) > + if (console_acpi_spcr_enable) > early_init_dt_scan_chosen_stdout(); > } else { > - parse_spcr(earlycon_init_is_deferred); > + /* Always enable the ACPI SPCR console */ > + acpi_parse_spcr(console_acpi_spcr_enable); > if (IS_ENABLED(CONFIG_ACPI_BGRT)) > acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt); > } > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index 46505396869e..9ae98eeada76 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -79,7 +79,12 @@ config ACPI_DEBUGGER_USER > endif > > config ACPI_SPCR_TABLE > - bool > + bool "ACPI Serial Port Console Redirection Support" > + default y if ARM64 > + help > + Enable support for Serial Port Console Redirection (SPCR) Table. > + This table provides information about the configuration of the > + earlycon console. > > config ACPI_LPIT > bool > diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c > index 324b35bfe781..f4bb8110e404 100644 > --- a/drivers/acpi/spcr.c > +++ b/drivers/acpi/spcr.c > @@ -16,65 +16,18 @@ > #include <linux/kernel.h> > #include <linux/serial_core.h> > > -/* > - * Erratum 44 for QDF2432v1 and QDF2400v1 SoCs describes the BUSY bit as > - * occasionally getting stuck as 1. To avoid the potential for a hang, check > - * TXFE == 0 instead of BUSY == 1. This may not be suitable for all UART > - * implementations, so only do so if an affected platform is detected in > - * parse_spcr(). > - */ > -bool qdf2400_e44_present; > -EXPORT_SYMBOL(qdf2400_e44_present); > - > -/* > - * Some Qualcomm Datacenter Technologies SoCs have a defective UART BUSY bit. > - * Detect them by examining the OEM fields in the SPCR header, similiar to PCI > - * quirk detection in pci_mcfg.c. > - */ > -static bool qdf2400_erratum_44_present(struct acpi_table_header *h) > -{ > - if (memcmp(h->oem_id, "QCOM ", ACPI_OEM_ID_SIZE)) > - return false; > - > - if (!memcmp(h->oem_table_id, "QDF2432 ", ACPI_OEM_TABLE_ID_SIZE)) > - return true; > - > - if (!memcmp(h->oem_table_id, "QDF2400 ", ACPI_OEM_TABLE_ID_SIZE) && > - h->oem_revision == 1) > - return true; > - > - return false; > -} > - > -/* > - * APM X-Gene v1 and v2 UART hardware is an 16550 like device but has its > - * register aligned to 32-bit. In addition, the BIOS also encoded the > - * access width to be 8 bits. This function detects this errata condition. > - */ > -static bool xgene_8250_erratum_present(struct acpi_table_spcr *tb) > +int __weak acpi_arch_setup_console(struct acpi_table_spcr *table, > + char *opts, char *uart, char *iotype, > + int baud_rate, bool earlycon) > { > - bool xgene_8250 = false; > - > - if (tb->interface_type != ACPI_DBG2_16550_COMPATIBLE) > - return false; > - > - if (memcmp(tb->header.oem_id, "APMC0D", ACPI_OEM_ID_SIZE) && > - memcmp(tb->header.oem_id, "HPE ", ACPI_OEM_ID_SIZE)) > - return false; > - > - if (!memcmp(tb->header.oem_table_id, "XGENESPC", > - ACPI_OEM_TABLE_ID_SIZE) && tb->header.oem_revision == 0) > - xgene_8250 = true; > - > - if (!memcmp(tb->header.oem_table_id, "ProLiant", > - ACPI_OEM_TABLE_ID_SIZE) && tb->header.oem_revision == 1) > - xgene_8250 = true; > - > - return xgene_8250; > + snprintf(opts, ACPI_SPCR_OPTS_SIZE, "%s,%s,0x%llx,%d", uart, iotype, > + table->serial_port.address, baud_rate); > + return 0; > } > > +bool console_acpi_spcr_enable __initdata; > /** > - * parse_spcr() - parse ACPI SPCR table and add preferred console > + * acpi_parse_spcr() - parse ACPI SPCR table and add preferred console > * > * @earlycon: set up earlycon for the console specified by the table > * > @@ -86,13 +39,13 @@ static bool xgene_8250_erratum_present(struct acpi_table_spcr *tb) > * from arch initialization code as soon as the DT/ACPI decision is made. > * > */ > -int __init parse_spcr(bool earlycon) > +int __init acpi_parse_spcr(bool earlycon) > { > - static char opts[64]; > + static char opts[ACPI_SPCR_OPTS_SIZE]; > + static char uart[ACPI_SPCR_BUF_SIZE]; > + static char iotype[ACPI_SPCR_BUF_SIZE]; > struct acpi_table_spcr *table; > acpi_status status; > - char *uart; > - char *iotype; > int baud_rate; > int err; > > @@ -105,48 +58,6 @@ int __init parse_spcr(bool earlycon) > if (ACPI_FAILURE(status)) > return -ENOENT; > > - if (table->header.revision < 2) { > - err = -ENOENT; > - pr_err("wrong table version\n"); > - goto done; > - } > - > - if (table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { > - switch (ACPI_ACCESS_BIT_WIDTH(( > - table->serial_port.access_width))) { > - default: > - pr_err("Unexpected SPCR Access Width. Defaulting to byte size\n"); > - case 8: > - iotype = "mmio"; > - break; > - case 16: > - iotype = "mmio16"; > - break; > - case 32: > - iotype = "mmio32"; > - break; > - } > - } else > - iotype = "io"; > - > - switch (table->interface_type) { > - case ACPI_DBG2_ARM_SBSA_32BIT: > - iotype = "mmio32"; > - /* fall through */ > - case ACPI_DBG2_ARM_PL011: > - case ACPI_DBG2_ARM_SBSA_GENERIC: > - case ACPI_DBG2_BCM2835: > - uart = "pl011"; > - break; > - case ACPI_DBG2_16550_COMPATIBLE: > - case ACPI_DBG2_16550_SUBSET: > - uart = "uart"; > - break; > - default: > - err = -ENOENT; > - goto done; > - } > - > switch (table->baud_rate) { > case 3: > baud_rate = 9600; > @@ -165,43 +76,36 @@ int __init parse_spcr(bool earlycon) > goto done; > } > > - /* > - * If the E44 erratum is required, then we need to tell the pl011 > - * driver to implement the work-around. > - * > - * The global variable is used by the probe function when it > - * creates the UARTs, whether or not they're used as a console. > - * > - * If the user specifies "traditional" earlycon, the qdf2400_e44 > - * console name matches the EARLYCON_DECLARE() statement, and > - * SPCR is not used. Parameter "earlycon" is false. > - * > - * If the user specifies "SPCR" earlycon, then we need to update > - * the console name so that it also says "qdf2400_e44". Parameter > - * "earlycon" is true. > - * > - * For consistency, if we change the console name, then we do it > - * for everyone, not just earlycon. > - */ > - if (qdf2400_erratum_44_present(&table->header)) { > - qdf2400_e44_present = true; > - if (earlycon) > - uart = "qdf2400_e44"; > + switch (table->interface_type) { > + case ACPI_DBG2_16550_COMPATIBLE: > + case ACPI_DBG2_16550_SUBSET: > + snprintf(uart, ACPI_SPCR_BUF_SIZE, "uart"); > + break; > + default: > + break; > } > > - if (xgene_8250_erratum_present(table)) { > - iotype = "mmio32"; > + if (table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { > + u8 width = ACPI_ACCESS_BIT_WIDTH(( > + table->serial_port.access_width)); > + switch (width) { > + default: > + pr_err("Unexpected SPCR Access Width. Defaulting to byte size\n"); > + case 8: > + snprintf(iotype, ACPI_SPCR_BUF_SIZE, "mmio"); > + break; > + case 16: > + case 32: > + snprintf(iotype, ACPI_SPCR_BUF_SIZE, "mmio%d", width); > + break; > + } > + } else > + snprintf(iotype, ACPI_SPCR_BUF_SIZE, "io"); > > - /* for xgene v1 and v2 we don't know the clock rate of the > - * UART so don't attempt to change to the baud rate state > - * in the table because driver cannot calculate the dividers > - */ > - snprintf(opts, sizeof(opts), "%s,%s,0x%llx", uart, iotype, > - table->serial_port.address); > - } else { > - snprintf(opts, sizeof(opts), "%s,%s,0x%llx,%d", uart, iotype, > - table->serial_port.address, baud_rate); > - } > + err = acpi_arch_setup_console(table, opts, uart, iotype, baud_rate, > + earlycon); > + if (err) > + goto done; > > pr_info("console: %s\n", opts); > > @@ -209,7 +113,6 @@ int __init parse_spcr(bool earlycon) > setup_earlycon(opts); > > err = add_preferred_console(uart, 0, opts + strlen(uart) + 1); > - > done: > acpi_put_table((struct acpi_table_header *)table); > return err; > diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c > index 4c8b80f1c688..b22afb62c7a3 100644 > --- a/drivers/tty/serial/earlycon.c > +++ b/drivers/tty/serial/earlycon.c > @@ -196,26 +196,15 @@ int __init setup_earlycon(char *buf) > return -ENOENT; > } > > -/* > - * When CONFIG_ACPI_SPCR_TABLE is defined, "earlycon" without parameters in > - * command line does not start DT earlycon immediately, instead it defers > - * starting it until DT/ACPI decision is made. At that time if ACPI is enabled > - * call parse_spcr(), else call early_init_dt_scan_chosen_stdout() > - */ > -bool earlycon_init_is_deferred __initdata; > - > /* early_param wrapper for setup_earlycon() */ > static int __init param_setup_earlycon(char *buf) > { > int err; > > - /* > - * Just 'earlycon' is a valid param for devicetree earlycons; > - * don't generate a warning from parse_early_params() in that case > - */ > + /* Just 'earlycon' is a valid param for devicetree and ACPI SPCR. */ > if (!buf || !buf[0]) { > if (IS_ENABLED(CONFIG_ACPI_SPCR_TABLE)) { > - earlycon_init_is_deferred = true; > + console_acpi_spcr_enable = true; > return 0; > } else if (!buf) { > return early_init_dt_scan_chosen_stdout(); > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index dc1ebfeeb5ec..875d7327d91c 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -1241,10 +1241,17 @@ static inline bool acpi_has_watchdog(void) { return false; } > #endif > > #ifdef CONFIG_ACPI_SPCR_TABLE > +#define ACPI_SPCR_OPTS_SIZE 64 > +#define ACPI_SPCR_BUF_SIZE 32 > extern bool qdf2400_e44_present; > -int parse_spcr(bool earlycon); > +extern bool console_acpi_spcr_enable __initdata; > +extern int acpi_arch_setup_console(struct acpi_table_spcr *table, > + char *opts, char *uart, char *iotype, > + int baud_rate, bool earlycon); > +int acpi_parse_spcr(bool earlycon); > #else > -static inline int parse_spcr(bool earlycon) { return 0; } > +static const bool console_acpi_spcr_enable; > +static inline int acpi_parse_spcr(bool earlycon) { return 0; } > #endif > > #if IS_ENABLED(CONFIG_ACPI_GENERIC_GSI) > diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h > index 37b044e78333..abfffb4b1c37 100644 > --- a/include/linux/serial_core.h > +++ b/include/linux/serial_core.h > @@ -376,10 +376,8 @@ extern int of_setup_earlycon(const struct earlycon_id *match, > const char *options); > > #ifdef CONFIG_SERIAL_EARLYCON > -extern bool earlycon_init_is_deferred __initdata; > int setup_earlycon(char *buf); > #else > -static const bool earlycon_init_is_deferred; > static inline int setup_earlycon(char *buf) { return 0; } > #endif > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html