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Message-ID: <20200123013238.19059-2-caoj.fnst@cn.fujitsu.com>
Date: Thu, 23 Jan 2020 09:32:37 +0800
From: Cao jin <caoj.fnst@...fujitsu.com>
To: <x86@...nel.org>, <linux-pm@...r.kernel.org>,
<linux-kernel@...r.kernel.org>
CC: <rjw@...ysocki.net>, <len.brown@...el.com>, <pavel@....cz>,
<tglx@...utronix.de>, <mingo@...hat.com>, <hpa@...or.com>
Subject: [RFC PATCH 1/2] x86/acpi: Improve code readablity of early madt processing
Current processing logic is confusing.
Return value of early_acpi_parse_madt_lapic_addr_ovr() indicates error(< 0),
parsed entry number(>= 0). So, it makes no sense to initialize acpi_lapic &
smp_found_config seeing no override entry, instead, initialize them seeing
MADT.
Put register_lapic_address() into override entry processing doesn't make
sense either.
Improved all the related comments too.
Signed-off-by: Cao jin <caoj.fnst@...fujitsu.com>
---
arch/x86/kernel/acpi/boot.c | 28 ++++++++++------------------
1 file changed, 10 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 04205ce127a1..2131035bba98 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1003,11 +1003,7 @@ static int __init acpi_parse_fadt(struct acpi_table_header *table)
}
#ifdef CONFIG_X86_LOCAL_APIC
-/*
- * Parse LAPIC entries in MADT
- * returns 0 on success, < 0 on error
- */
-
+/* Returns >= 0 on success, indicates parsed entry number; < 0 on error. */
static int __init early_acpi_parse_madt_lapic_addr_ovr(void)
{
int count;
@@ -1025,11 +1021,8 @@ static int __init early_acpi_parse_madt_lapic_addr_ovr(void)
if (count < 0) {
printk(KERN_ERR PREFIX
"Error parsing LAPIC address override entry\n");
- return count;
}
- register_lapic_address(acpi_lapic_addr);
-
return count;
}
@@ -1234,19 +1227,16 @@ static inline int acpi_parse_madt_ioapic_entries(void)
static void __init early_acpi_process_madt(void)
{
#ifdef CONFIG_X86_LOCAL_APIC
- int error;
+ int ret;
if (!acpi_table_parse(ACPI_SIG_MADT, acpi_parse_madt)) {
+ /* Found MADT */
+ acpi_lapic = 1;
+ smp_found_config = 1;
- /*
- * Parse MADT LAPIC entries
- */
- error = early_acpi_parse_madt_lapic_addr_ovr();
- if (!error) {
- acpi_lapic = 1;
- smp_found_config = 1;
- }
- if (error == -EINVAL) {
+ /* See if override entry exists. */
+ ret = early_acpi_parse_madt_lapic_addr_ovr();
+ if (ret == -EINVAL) {
/*
* Dell Precision Workstation 410, 610 come here.
*/
@@ -1254,6 +1244,8 @@ static void __init early_acpi_process_madt(void)
"Invalid BIOS MADT, disabling ACPI\n");
disable_acpi();
}
+
+ register_lapic_address(acpi_lapic_addr);
}
#endif
}
--
2.21.0
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