-----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