From 51500d37700904a0ee1ef775a585d871b36f7060 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Thu, 4 Jul 2019 14:12:21 +0200 Subject: [PATCH] Revert "hw/block/pflash_cfi02: Reduce I/O accesses to 16-bit" MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This reverts commit 3ae0343db69c379beb5750b4ed70794bbed51b85. Stephen Checkoway noticed commit 3ae0343db69 is incorrect. This commit state all parallel flashes are limited to 16-bit accesses, however the x32 configuration exists in some models, such the Cypress S29CL032J, which CFI Device Geometry Definition announces: CFI ADDR DATA 0x28,0x29 = 0x0003 (x32-only asynchronous interface) Guests should not be affected by the previous change, because QEMU does not announce itself as x32 capable: /* Flash device interface (8 & 16 bits) */ pfl->cfi_table[0x28] = 0x02; pfl->cfi_table[0x29] = 0x00; Commit 3ae0343db69 does not restrict the bus to 16-bit accesses, but restrict the implementation as 16-bit access max, so a guest 32-bit access will result in 2x 16-bit calls. Now, we have 2 boards that register the flash device in 32-bit access: - PPC: taihu_405ep The CFI id matches the S29AL008J that is a 1MB in x16, while the code QEMU forces it to be 2MB, and checking Linux it expects a 4MB flash. - ARM: Digic4 While the comment says "Samsung K8P3215UQB 64M Bit (4Mx16)", this flash is 32Mb (2MB). Also note the CFI id does not match the comment. To avoid unexpected side effect, we revert commit 3ae0343db69, and will clean the board code later. Reported-by: Stephen Checkoway Reviewed-by: Markus Armbruster Signed-off-by: Philippe Mathieu-Daudé --- hw/block/pflash_cfi02.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/hw/block/pflash_cfi02.c b/hw/block/pflash_cfi02.c index 5392290c72..83084b9d72 100644 --- a/hw/block/pflash_cfi02.c +++ b/hw/block/pflash_cfi02.c @@ -317,6 +317,8 @@ static uint64_t pflash_read(void *opaque, hwaddr offset, unsigned int width) boff = offset & 0xFF; if (pfl->width == 2) { boff = boff >> 1; + } else if (pfl->width == 4) { + boff = boff >> 2; } switch (pfl->cmd) { default: @@ -447,6 +449,8 @@ static void pflash_write(void *opaque, hwaddr offset, uint64_t value, boff = offset; if (pfl->width == 2) { boff = boff >> 1; + } else if (pfl->width == 4) { + boff = boff >> 2; } /* Only the least-significant 11 bits are used in most cases. */ boff &= 0x7FF; @@ -706,7 +710,6 @@ static void pflash_write(void *opaque, hwaddr offset, uint64_t value, static const MemoryRegionOps pflash_cfi02_ops = { .read = pflash_read, .write = pflash_write, - .impl.max_access_size = 2, .valid.min_access_size = 1, .valid.max_access_size = 4, .endianness = DEVICE_NATIVE_ENDIAN, -- 2.11.4.GIT