diff mbox series

[v2,3/4] riscv: cpu: fixes to display proper CPU features

Message ID 1590512951-1045-4-git-send-email-sagar.kadam@sifive.com
State Superseded
Delegated to: Andes
Headers show
Series update clock handler and proper cpu features | expand

Commit Message

Sagar Kadam May 26, 2020, 5:09 p.m. UTC
The cmd "cpu detail" fetches uninitialized cpu feature information
and thus displays wrong / inconsitent details as below. FU540-C000 doesn't
have any microcode, yet the cmd display's it.
=> cpu detail
  0: cpu@0      rv64imac
        ID = 0, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
        Microcode version 0x0
        Device ID 0x0
  1: cpu@1      rv64imafdc
        ID = 1, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
        Microcode version 0x0
        Device ID 0x0
  2: cpu@2      rv64imafdc
        ID = 2, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
        Microcode version 0x0
        Device ID 0x0
  3: cpu@3      rv64imafdc
        ID = 3, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
        Microcode version 0x0
        Device ID 0x0
  4: cpu@4      rv64imafdc
        ID = 4, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
        Microcode version 0x0
        Device ID 0x0

The L1 cache or MMU entry seen above is also displayed inconsistently.
So initialize features to zero before fetching from device tree.
Additionally the conditional check to read "mmu-type" from device tree
is not rightly handled due to which the cpu feature doesn't include
CPU_FEAT_MMU even if it's corresponding entry is present in device tree.

We now see correct features as:

=> cpu detail
  0: cpu@0      rv64imac
        ID = 0, freq = 999.100 MHz
  1: cpu@1      rv64imafdc
        ID = 1, freq = 999.100 MHz: MMU
  2: cpu@2      rv64imafdc
        ID = 2, freq = 999.100 MHz: MMU
  3: cpu@3      rv64imafdc
        ID = 3, freq = 999.100 MHz: MMU
  4: cpu@4      rv64imafdc
        ID = 4, freq = 999.100 MHz: MMU

Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
---
 drivers/cpu/riscv_cpu.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Pragnesh Patel May 27, 2020, 2:15 p.m. UTC | #1
>-----Original Message-----
>From: Sagar Kadam <sagar.kadam@sifive.com>
>Sent: 26 May 2020 22:39
>To: u-boot@lists.denx.de; rick@andestech.com; lukma@denx.de
>Cc: jagan@amarulasolutions.com; bmeng.cn@gmail.com; Pragnesh Patel
><pragnesh.patel@sifive.com>; seanga2@gmail.com; Sagar Kadam
><sagar.kadam@sifive.com>
>Subject: [PATCH v2 3/4] riscv: cpu: fixes to display proper CPU features
>
>The cmd "cpu detail" fetches uninitialized cpu feature information and thus
>displays wrong / inconsitent details as below. FU540-C000 doesn't have any
>microcode, yet the cmd display's it.
>=> cpu detail
>  0: cpu@0      rv64imac
>        ID = 0, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
>        Microcode version 0x0
>        Device ID 0x0
>  1: cpu@1      rv64imafdc
>        ID = 1, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
>        Microcode version 0x0
>        Device ID 0x0
>  2: cpu@2      rv64imafdc
>        ID = 2, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
>        Microcode version 0x0
>        Device ID 0x0
>  3: cpu@3      rv64imafdc
>        ID = 3, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
>        Microcode version 0x0
>        Device ID 0x0
>  4: cpu@4      rv64imafdc
>        ID = 4, freq = 999.100 MHz: L1 cache, MMU, Microcode, Device ID
>        Microcode version 0x0
>        Device ID 0x0
>
>The L1 cache or MMU entry seen above is also displayed inconsistently.
>So initialize features to zero before fetching from device tree.
>Additionally the conditional check to read "mmu-type" from device tree is not
>rightly handled due to which the cpu feature doesn't include
>CPU_FEAT_MMU even if it's corresponding entry is present in device tree.
>
>We now see correct features as:
>
>=> cpu detail
>  0: cpu@0      rv64imac
>        ID = 0, freq = 999.100 MHz
>  1: cpu@1      rv64imafdc
>        ID = 1, freq = 999.100 MHz: MMU
>  2: cpu@2      rv64imafdc
>        ID = 2, freq = 999.100 MHz: MMU
>  3: cpu@3      rv64imafdc
>        ID = 3, freq = 999.100 MHz: MMU
>  4: cpu@4      rv64imafdc
>        ID = 4, freq = 999.100 MHz: MMU
>
>Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
>---
> drivers/cpu/riscv_cpu.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)

Reviewed-by: Pragnesh Patel <pragnesh.patel@sifive.com>

>
>diff --git a/drivers/cpu/riscv_cpu.c b/drivers/cpu/riscv_cpu.c index
>76b0489..8c4b5e7 100644
>--- a/drivers/cpu/riscv_cpu.c
>+++ b/drivers/cpu/riscv_cpu.c
>@@ -38,6 +38,8 @@ static int riscv_cpu_get_info(struct udevice *dev, struct
>cpu_info *info)
>
> 	/* Zero out the frequency, in case sizeof(ulong) != sizeof(u32) */
> 	info->cpu_freq = 0;
>+	/* Initialise cpu features before updating from device tree */
>+	info->features = 0;
>
> 	/* First try getting the frequency from the assigned clock */
> 	ret = clk_get_by_index(dev, 0, &clk);
>@@ -52,7 +54,7 @@ static int riscv_cpu_get_info(struct udevice *dev, struct
>cpu_info *info)
> 		dev_read_u32(dev, "clock-frequency", (u32 *)&info-
>>cpu_freq);
>
> 	mmu = dev_read_string(dev, "mmu-type");
>-	if (!mmu)
>+	if (mmu)
> 		info->features |= BIT(CPU_FEAT_MMU);
>
> 	return 0;
>--
>2.7.4
diff mbox series

Patch

diff --git a/drivers/cpu/riscv_cpu.c b/drivers/cpu/riscv_cpu.c
index 76b0489..8c4b5e7 100644
--- a/drivers/cpu/riscv_cpu.c
+++ b/drivers/cpu/riscv_cpu.c
@@ -38,6 +38,8 @@  static int riscv_cpu_get_info(struct udevice *dev, struct cpu_info *info)
 
 	/* Zero out the frequency, in case sizeof(ulong) != sizeof(u32) */
 	info->cpu_freq = 0;
+	/* Initialise cpu features before updating from device tree */
+	info->features = 0;
 
 	/* First try getting the frequency from the assigned clock */
 	ret = clk_get_by_index(dev, 0, &clk);
@@ -52,7 +54,7 @@  static int riscv_cpu_get_info(struct udevice *dev, struct cpu_info *info)
 		dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq);
 
 	mmu = dev_read_string(dev, "mmu-type");
-	if (!mmu)
+	if (mmu)
 		info->features |= BIT(CPU_FEAT_MMU);
 
 	return 0;